Leslie S. Prichep, Ph.D.

Measuring brain electrical activity to track recovery from sport-related concussion
Barr, William B; Prichep, Leslie S; Chabot, Robert; Powell, Matthew R; McCrea, Michael
2012 ;26(1):58-66, Brain injury
PRIMARY OBJECTIVE: To follow recovery from concussion in a sample of athletes using an electroencephalographic (EEG) index of quantitative brain activity developed previously on an independent Emergency Department (ED) sample of head-injured subjects with traumatic brain injury. METHODS AND PROCEDURES: EEG recordings from five frontal electrode sites were obtained on 59 injured athletes and 31 controls at the time of injury and at 8 and 45 days afterward. All subjects also completed standardized clinical assessment of post-concussion symptoms, postural stability and cognitive functioning at injury and 8 and 45 days post-injury. RESULTS: Abnormalities in clinical assessment measures were observed in injured subjects only at time of injury. Statistical analysis of brain electrical activity measures with the ED-based algorithm revealed significant differences between injured athletes vs controls at the time of injury and at day 8. Measures from the two groups did not differ on day 45. CONCLUSIONS: This study demonstrated that an algorithm of brain electrical activity developed on an independent sample of ED subjects with head injury is sensitive to the effects of sport-related concussion. Using this algorithm, abnormal features of brain electrical activity were detected in athletes with concussion at the time of injury and persisted beyond the point of recovery on clinical measures
— id: 149954, year: 2012, vol: 26, page: 58, stat: Journal Article,

Source imaging of QEEG as a method to detect awareness in a person in vegetative state
John, E Roy; Halper, James P; Lowe, R Sandlin; Merkin, Henry; Defina, Philip; Prichep, Leslie S
2011 ;25(4):426-432, Brain injury
BACKGROUND: Assessment of awareness in patients with severe brain injury remains subjective, although patients with even limited awareness (e.g. minimal conscious state, MCS) have different prognoses and treatment than those in vegetative state (VS). Recently, task appropriate differential regional activation in VS has been reported using fMRI during mental imagery. PRIMARY OBJECTIVE: Demonstration of conscious awareness in reproducible differential EEG source localization images in a VS patient reflecting requested mental imagery was performed. METHODS: A VS patient (with re-test) and a normal control were requested to imagine singing and to mentally perform serial subtraction, while EEG was recorded. QEEG source localization was performed to identify regions of brain activation in response to tasks. RESULTS: Replicable distinctive activation of brain areas appropriate for each task was seen in the VS patient and control. Frequency spectra shifted to beta, with significant source activation in regions including the bilateral anterior cingulate, insula, left caudate and dorsolateral pre-frontal cortex to singing and the putamen, insula, left pre-frontal cortex and right temporal gyrus to subtraction by 7's. CONCLUSIONS: Results from this single case suggests the potential utility of QEEG source localization images to detect awareness in patients clinically diagnosed as being in VS. This indicates the possibility that EEG may serve as an important adjunct to the assessment of awareness in patients with disorders of consciousness in the clinical setting
— id: 130296, year: 2011, vol: 25, page: 426, stat: Journal Article,

Can quantitative brain electrical activity aid in the triage of mild traumatic brain-injured patients
O'Neil B.J.; Prichep L.S.; Naunheim R.; Chabot R.
2011 ;58(4 SUPPL 1):S208-S208, Annals of emergency medicine
Study Objectives: The incidence ofUS Emergency department (ED) visits for traumaticbraininjury(TBI) exceeds 1,000,000 cases/year, with thevastmajorityofthese for mild injury (mTBI). Using existing CT scan decision rules, such as the New Orleans Criteria(NOC), results inapproximately70% negativeCTscanrate. Thepresentstudy investigates the use of quantified brain electrical activity to assess its possible role in the initial triage of ED mTBI patients as compared to decision rules such as NOC. Methods: 119 patients who reported to the ED with mTBI and who received CT scans were studied. Using a hand-held EEG acquisition device, data was collected from frontal leads, and the NOC were recorded. The EEG was processed off-line to generate a single index (TBI-Index, biomarker). A previously validated index value found to be sensitive for significant brain dysfunction in mTBI patients was utilized. This TBI-Index value was compared to the NOC for the ability to predict positive CT findings. Results: This sample had a mean age of 48.32 (range 18-92 years) and contained 38 patients with positive CT scans (CT+) and 81 with negative CT scans (CT-). Both the brain electrical activity TBI-Index and the NOC had sensitivities >90%. However, the specificity of the TBI-Index was more than twice as high as that of NOC. Other performance measures (PPV, NPV, pLR, nLR and odds ratio) were also superior using the TBI-Index. When the TBI index and NOC are used in combination the sensitivity to positive CT goes to 97%. Conclusions: In patients presenting to the ED with mTBI, the TBI-Index used in this study had a high NPV, odds ratio and sensitivity for positive CT findings, and A specificity which outperformed the NOC. Combining the index with NOC resulted in a sensitivity of 97.0% (only 1 false negative). This study suggests a potential clinical utility in aiding in the initial triage of mTBI patients
— id: 138728, year: 2011, vol: 58, page: S208, stat: Journal Article,

Assessing interactions in the brain with exact low-resolution electromagnetic tomography
Pascual-Marqui, Roberto D; Lehmann, Dietrich; Koukkou, Martha; Kochi, Kieko; Anderer, Peter; Saletu, Bernd; Tanaka, Hideaki; Hirata, Koichi; John, E Roy; Prichep, Leslie; Biscay-Lirio, Rolando; Kinoshita, Toshihiko
2011 Oct 13;369(1952):3768-3784, Philosophical transactions. Series A, Mathematical, physical, & engineering sciences (Royal Society)
Scalp electric potentials (electroencephalogram; EEG) are contingent to the impressed current density unleashed by cortical pyramidal neurons undergoing post-synaptic processes. EEG neuroimaging consists of estimating the cortical current density from scalp recordings. We report a solution to this inverse problem that attains exact localization: exact low-resolution brain electromagnetic tomography (eLORETA). This non-invasive method yields high time-resolution intracranial signals that can be used for assessing functional dynamic connectivity in the brain, quantified by coherence and phase synchronization. However, these measures are non-physiologically high because of volume conduction and low spatial resolution. We present a new method to solve this problem by decomposing them into instantaneous and lagged components, with the lagged part having almost pure physiological origin
— id: 138005, year: 2011, vol: 369, page: 3768, stat: Journal Article,

Evaluation of the Pain Matrix Using EEG Source Localization: A Feasibility Study
Prichep LS; John ER; Howard B; Merkin H; Hiesiger EM
2011 Aug;12(8):1241-18 L, Pain medicine
Objectives. An extensive neuroimaging literature on chronic pain demonstrates increased cerebral blood flow and metabolism consistent with increased neuronal activity in the structures comprising the 'Pain Matrix'; furthermore, some of these regions have been shown to encode pain intensity. It is the objective of this study to demonstrate the feasibility of using quantitative electroencephalography (EEG) source localization to reflect and to quantify activity in the Pain Matrix. Methods. Eyes closed resting EEG was recorded from 19 standardized scalp locations, in a pilot sample of five patients with chronic neuropathic pain, before and after pain reduction. Quantitative electro encephalography (QEEG) source localization was computed estimating the mathematically most probable source generators of EEG surface potentials in each state. Sources identified in this way have been demonstrated to coregister with those identified by neuroimaging methods. Results. QEEG sources demonstrated frequency specific increased neuronal activity in the baseline high pain state in structures including the thalamus, somatosensory cortex, anterior and posterior insula, medial and lateral prefrontal cortex and cingulate. Significant reduction of activation in these regions was seen when pain was reduced (>/=50% on subjective ratings). Conclusion. The areas that were activated in the high pain state localized to the same regions reported by other neuroimaging methods and with frequency specificity. The frequency and regionally specific activation may indicate distinctive patterns of pathophysiology underlying the pain matrix. Although in a small number of patients, this work suggests that QEEG may be a useful tool in the exploration and quantification of the pain matrix in a clinical setting
— id: 135642, year: 2011, vol: 12, page: 1241, stat: Journal Article,

Group independent component analysis of resting state EEG in large normative samples
Congedo, Marco; John, Roy E; De Ridder, Dirk; Prichep, Leslie
2010 Nov;78(2):89-99, International journal of psychophysiology
EEG (Electroencephalography) resting state was studied by means of group blind source separation (gBSS), employing a test-retest strategy in two large-sample normative databases (N=57 and N=84). Using a BSS method in the complex Fourier domain and a model-driven distributed inverse solution we closely replicate both the spatial distribution and spectral pattern of seven source components. Norms were then constructed for their spectral power so as to allow testing patients against the norms. As compared to existing normative databases based on scalp spectral measures, the resulting tool defines a smaller number of features with very little inter-correlation. Furthermore, these features are physiologically meaningful as they relate the activity of several brain regions, forming a total of seven patterns, each with a peculiar spatial distribution and spectral profile. This new tool, that we name normative independent component analysis (NICA), may serve as an adjunct to diagnosis and assessment of abnormal brain functioning and aid in research on normal resting state networks
— id: 139131, year: 2010, vol: 78, page: 89, stat: Journal Article,

On the "dependence" of "independent" group EEG sources; an EEG study on two large databases
Congedo, Marco; John, Roy E; De Ridder, Dirk; Prichep, Leslie; Isenhart, Robert
2010 Jun;23(2):134-138, Brain topography
The aim of this work is to study the coherence profile (dependence) of robust eyes-closed resting EEG sources isolated by group blind source separation (gBSS). We employ a test-retest strategy using two large sample normative databases (N = 57 and 84). Using a BSS method in the complex Fourier domain, we show that we can rigourously study the out-of-phase dependence of the extracted components, albeit they are extracted so as to be in-phase independent (by BSS definition). Our focus on lagged communication between components effectively yields dependence measures unbiased by volume conduction effects, which is a major concern about the validity of any dependence measures issued by EEG measurements. We are able to show the organization of the extracted components in two networks. Within each network components oscillate coherently with multiple-frequency dynamics, whereas between networks they exchange information at non-random multiple time-lag rates
— id: 139133, year: 2010, vol: 23, page: 134, stat: Journal Article,

Acute effects and recovery after sport-related concussion: a neurocognitive and quantitative brain electrical activity study
McCrea, Michael; Prichep, Leslie; Powell, Matthew R; Chabot, Robert; Barr, William B
2010 Jul-Aug;25(4):283-292, Journal of head trauma rehabilitation
OBJECTIVE: To investigate the clinical utility and sensitivity of a portable, automatic, frontal quantitative electroencephalographic (QEEG) acquisition device currently in development in detecting abnormal brain electrical activity after sport-related concussion. DESIGN: This was a prospective, non-randomized study of 396 high school and college football players, including cohorts of 28 athletes with concussion and 28 matched controls. All subjects underwent preseason baseline testing on measures of postconcussive symptoms, postural stability, and cognitive functioning, as well as QEEG. Clinical testing and QEEG were repeated on day of injury and days 8 and 45 postinjury for the concussion and control groups. MAIN OUTCOMES AND RESULTS: The injured group reported more significant postconcussive symptoms during the first 3 days postinjury, which resolved by days 5 and 8. Injured subjects also performed poorer than controls on neurocognitive testing on the day of injury, but no differences were evident on day 8 or day 45. QEEG studies revealed significant abnormalities in electrical brain activity in the injured group on day of injury and day 8 postinjury, but not on day 45. CONCLUSIONS: Results from the current study on clinical recovery after sport-related concussion are consistent with early reports indicating a typical course of full recovery in symptoms and cognitive dysfunction within the first week of injury. QEEG results, however, suggest that the duration of physiological recovery after concussion may extend longer than observed clinical recovery. Further study is required to replicate and extend these findings in a larger clinical sample, and further demonstrate the utility of QEEG as a marker of recovery after sport-related concussion
— id: 139132, year: 2010, vol: 25, page: 283, stat: Journal Article,

Localizing epileptogenic regions in partial epilepsy using three-dimensional statistical parametric maps of background EEG source spectra
Alper, Kenneth; Raghavan, Manoj; Isenhart, Robert; Howard, Bryant; Doyle, Werner; John, Roy; Prichep, Leslie
2008 Feb 1;39(3):1257-1265, Neuroimage
This preliminary study sought to localize epileptogenic regions in patients with partial epilepsy by analysis of interictal EEG activity utilizing variable resolution electromagnetic tomography (VARETA), a three-dimensional quantitative electroencephalographic (QEEG) frequency-domain distributed source modeling technique. The very narrow band (VNB) spectra spanned the frequency range 0.39 Hz to 19.1 Hz, in 0.39 Hz steps. These VNB spectra were compared to normative data and transformed to provide Z-scores for every scalp derivation, and the spatial distributions of the probable EEG generators of the most abnormal values were displayed on slices from a probabilistic MRI atlas. Each voxel was color-coded to represent the significance of the deviation relative to age appropriate normative values. We compared the resulting three-dimensional images to the localization of epileptogenic regions based on invasive intracranial EEG recordings of seizure onsets. The VARETA image indicated abnormal interictal spectral power values in regions of seizure onset identified by invasive monitoring, mainly in delta and theta range (1.5 to 8.0 Hz). The VARETA localization of the most abnormal voxel was congruent with the epileptogenic regions identified by intracranial recordings with regard to hemisphere in all 6 cases, and with regard to lobe in 5 cases. In contrast, abnormal findings with routine EEG agreed with invasive monitoring with regard to hemisphere in 3 cases and with regard to lobe in 2 cases. These results suggest that analysis of background interictal EEG utilizing distributed source models should be investigated further in clinical epilepsy
— id: 76455, year: 2008, vol: 39, page: 1257, stat: Journal Article,

Automated multivariate features of brain electrical activity predicts severity of head injury in the emergency department
Naunheim, R; English, J; Treaster, M; Prichep, L
2008 JUL ;25(7):879-879, Journal of neurotrauma
— id: 86846, year: 2008, vol: 25, page: 879, stat: Journal Article,

Cocaine cue versus cocaine dosing in humans: evidence for distinct neurophysiological response profiles
Reid, Malcolm S; Flammino, Frank; Howard, Bryant; Nilsen, Diana; Prichep, Leslie S
2008 Nov;91(1):155-164, Pharmacology biochemistry & behavior
Subjective, physiological and electroencephalographic (EEG) profiles were studied in cocaine dependent study participants in response to cocaine cue exposure or a dose of smoked cocaine. Both stimuli increased subjective ratings of cocaine high and craving, enhanced negative affect, and boosted plasma ACTH and skin conductance levels. However, cocaine dose produced a greater increase in high and a more prolonged increase in plasma ACTH, while cocaine cue produced a decline in skin temperature. Both stimuli produced increases in absolute theta, alpha and beta EEG power over the prefrontal cortex. However, interhemispheric EEG coherence over the prefrontal cortex decreased during cocaine cue exposure but increased following cocaine dose. Moreover, correlation analysis of subjective, physiological and EEG responding to cocaine cue and dose revealed distinct profiles. Delta and theta activity were associated with negative affect during cocaine cue exposure, but were associated with cocaine craving and reward following cocaine dosing. In both conditions, alpha activity was marker for anxiousness but not high. These data demonstrate similar subjective, physiological responding in clinical laboratory states of cocaine craving and reward. However, differences in EEG response profiles, and their relationship to function, indicate distinct neurophysiological mediators of cocaine craving and reward within the prefrontal cortex
— id: 92848, year: 2008, vol: 91, page: 155, stat: Journal Article,

The pre-mild cognitive impairment, subjective cognitive impairment stage of Alzheimer's disease
Reisberg, Barry; Prichep, Leslie; Mosconi, Lisa; John, E Roy; Glodzik-Sobanska, Lidia; Boksay, Istvan; Monteiro, Isabel; Torossian, Carol; Vedvyas, Alok; Ashraf, Nauman; Jamil, Imran A; de Leon, Mony J
2008 Jan;4(1 Suppl 1):S98-S108, Alzheimer's & Dementia
BACKGROUND: Subjective cognitive impairment (SCI) has been a common, but poorly understood condition, frequently occurring in older persons. METHODS: The past and the emerging literature on SCI and synonymously named conditions is reviewed. RESULTS: Findings include: (1) There is support from at least one longitudinal study for a long-standing concept of SCI as a pre-mild cognitive impairment (MCI) condition lasting approximately 15years. (2) There are complex relationships between SCI and depression and anxiety. (3) Differences in SCI subjects from age-matched non-SCI persons are being published in terms of cognitive tests, hippocampal gray matter density, hippocampal volumes, cerebral metabolism, and urinary cortisol levels. Psychometric and dementia test score differences between SCI and MCI subjects have long been evident. (4) Predictive electrophysiologic features of subsequent decline in SCI subjects are being published. CONCLUSIONS: Studies of therapeutic agents in SCI treatment and resultant Alzheimer's disease prevention appear to be feasible. These trials are also necessary from a public health perspective
— id: 81577, year: 2008, vol: 4, page: S98, stat: Journal Article,

Toward a better understanding of the pathophysiology of OCD SSRI responders: QEEG source localization
Bolwig, T G; Hansen, E S; Hansen, A; Merkin, H; Prichep, L S
2007 Mar;115(3):237-242, Acta psychiatrica Scandinavica
OBJECTIVE: To demonstrate the utility of three-dimensional source localization of the scalp-recorded electroencephalogram (EEG) for the identification of the most probable underlying brain dysfunction in patients with obsessive-compulsive disorder (OCD). METHOD: Eyes-closed resting EEG data was recorded from the scalp locations of the International 10/20 System. Variable resolution electromagnetic tomography (VARETA) was applied to artifact-free EEG data. This mathematical algorithm estimates the source generators of EEG recorded from the scalp. RESULTS: An excess in the alpha range was found with sources in the corpus striatum, in the orbito-frontal and temporo-frontal regions in untreated OCD patients. This abnormality was seen to decrease following successful treatment with paroxetine. CONCLUSION: The VARETA findings of an activation/deactivation pattern in cortical and subcortical structures in paroxetine-responsive patients are in good accordance with data obtained in previously published positron emission tomography studies related to current hypotheses of a thalamo-striatal-frontal feedback loop being relevant for understanding the pathophysiology of OCD
— id: 92849, year: 2007, vol: 115, page: 237, stat: Journal Article,

Electrophysiological subtypes of psychotic states
John, E R; Prichep, L S; Winterer, G; Herrmann, W M; diMichele, F; Halper, J; Bolwig, T G; Cancro, R
2007 Jul;116(1):17-35, Acta psychiatrica Scandinavica
OBJECTIVE: This research sought neurobiological features common to psychotic states displayed by patients with different clinical diagnoses. METHOD: Cluster analysis with quantitative electroencephalographic (QEEG) variables was used to subtype drug-naive, non-medicated, and medicated schizophrenic, depressed and alcoholic patients with psychotic symptoms, from the USA and Germany. QEEG source localization brain images were computed for each cluster. RESULTS: Psychotic patients with schizophrenia, depression and alcoholism, and drug- naive schizophrenic patients, were distributed among six clusters. QEEG images revealed one set of brain regions differentially upregulated in each cluster and another group of structures downregulated in the same way in every cluster. CONCLUSION: Subtypes previously found among 94 schizophrenic patients were replicated in a sample of 390 non-schizophrenic as well as schizophrenic psychotics, and displayed common neurobiological abnormalities. Collaborative longitudinal studies using these economical methods might improve differential understanding and treatment of patients based upon these features rather than clinical symptoms
— id: 73413, year: 2007, vol: 116, page: 17, stat: Journal Article,

Application and comparison of classification algorithms for recognition of Alzheimer's disease in electrical brain activity (EEG)
Lehmann, Christoph; Koenig, Thomas; Jelic, Vesna; Prichep, Leslie; John, Roy E; Wahlund, Lars-Olof; Dodge, Yadolah; Dierks, Thomas
2007 Apr 15;161(2):342-350, Journal of neuroscience methods
The early detection of subjects with probable Alzheimer's disease (AD) is crucial for effective appliance of treatment strategies. Here we explored the ability of a multitude of linear and non-linear classification algorithms to discriminate between the electroencephalograms (EEGs) of patients with varying degree of AD and their age-matched control subjects. Absolute and relative spectral power, distribution of spectral power, and measures of spatial synchronization were calculated from recordings of resting eyes-closed continuous EEGs of 45 healthy controls, 116 patients with mild AD and 81 patients with moderate AD, recruited in two different centers (Stockholm, New York). The applied classification algorithms were: principal component linear discriminant analysis (PC LDA), partial least squares LDA (PLS LDA), principal component logistic regression (PC LR), partial least squares logistic regression (PLS LR), bagging, random forest, support vector machines (SVM) and feed-forward neural network. Based on 10-fold cross-validation runs it could be demonstrated that even tough modern computer-intensive classification algorithms such as random forests, SVM and neural networks show a slight superiority, more classical classification algorithms performed nearly equally well. Using random forests classification a considerable sensitivity of up to 85% and a specificity of 78%, respectively for the test of even only mild AD patients has been reached, whereas for the comparison of moderate AD vs. controls, using SVM and neural networks, values of 89% and 88% for sensitivity and specificity were achieved. Such a remarkable performance proves the value of these classification algorithms for clinical diagnostics
— id: 139134, year: 2007, vol: 161, page: 342, stat: Journal Article,

Quantitative EEG and electromagnetic brain imaging in aging and in the evolution of dementia
Prichep, Leslie S
2007 Feb;1097:156-167, Annals of the New York Academy of Sciences
Electroencephalographic (EEG) changes with normal aging have long been reported. Departures from age-expected changes have been observed in mild cognitive impairment and dementia, the magnitude of which correlates with the degree of cognitive impairment. Such abnormalities include increased delta and theta activity, decreased mean frequency, and changes in coherence. Similar findings have been reported using magnetoencephalography (MEG) at rest and during performance of mental tasks. Electrophysiological features have also been shown to be predictive of future decline in mild cognitive impairment (MCI) and Alzheimer's disease (AD). We have recently reported results from initial quantitative electroencephalography (QEEG) evaluations of normal elderly subjects (with only subjective reports of memory loss), predicting future cognitive decline or conversion to dementia, with high prediction accuracy (approximately 95%). In this report, source localization algorithms were used to identify the mathematically most probable underlying generators of abnormal features of the scalp-recorded EEG from these patients with differential outcomes. Using this QEEG method, abnormalities in brain regions identified in studies of AD using MEG, MRI, and positron emission tomography (PET) imaging were found in the premorbid recordings of those subjects who go on to decline or convert to dementia
— id: 71871, year: 2007, vol: 1097, page: 156, stat: Journal Article,

Quantitative EEG and electromagnetic brain imaging in aging and in the evolution of dementia
Prichep, Leslie S
Imaging and the aging brain Malden, MA, US: Blackwell Publishing, 2007,
(from the chapter) Electroencephalographic (EEC) changes with normal aging have long been reported. Departures from age-expected changes have been observed in mild cognitive impairment and dementia, the magnitude of which correlates with the degree of cognitive impairment. Such abnormalities include increased delta and theta activity, decreased mean frequency, and changes in coherence. Similar findings have been reported using magnetoencephalography (MEG) at rest and during performance of mental tasks. Electrophysiological features have also been shown to be predictive of future decline in mild cognitive impairment (MCI) and Alzheimer's disease (AD). We have recently reported results from initial quantitative electroencephalography (QEEG) evaluations of normal elderly subjects (with only subjective reports of memory loss), predicting future cognitive decline or conversion to dementia, with high prediction accuracy (approximately 95%). In this report, source localization algorithms were used to identify the mathematically most probable underlying generators of abnormal features of the scalp-recorded EEG from these patients with differential outcomes. Using this QEEG method, abnormalities in brain regions identified in studies of AD using MEG, MRI, and positron emission tomography (PET) imaging were found in the premorbid recordings of those subjects who go on to decline or convert to dementia.
— id: 4481, year: 2007, vol: , page: 156, stat: Chapter,

Correlation of PET and qEEG in normal subjects
Alper, Kenneth R; John, E Roy; Brodie, Jonathan; Gunther, Wilfred; Daruwala, Raoul; Prichep, Leslie S
2006 Apr 30;146(3):271-282, Psychiatry research
Positron emission tomography (PET) and quantitative electroencephalography (qEEG) were obtained in 15 normal male subjects with eyes closed at rest. Correlations between qEEG variables and regional metabolism were examined as an approach to investigating the metabolic and neuroanatomical basis of the generation of the EEG. Analogous to the neurometric approach to qEEG, a normative 2-fluoro-deoxyglucose voxel data base was developed for the PET image. The PET image was transformed to an idealized cylindrical set of coordinates to allow registration with the Talairach stereotactic atlas. PET regions of interest for the thalamus, the left and right temporal lobes, the medial frontal cortex and the dorsolateral prefrontal cortex were defined using Talairach coordinates and correlated to the QEEG. Salient findings included a negative correlation of thalamic metabolism to alpha power and a positive correlation of medial frontal cortical metabolism to delta EEG power. The significance of these findings is discussed with reference to the existing literature on the physiology of the generation of the EEG
— id: 67000, year: 2006, vol: 146, page: 271, stat: Journal Article,

Optimal denoising of brainstem Auditory Evoked Response (BAER) for automatic peak identification and brainstem assessment
Jacquin, Arnaud; Causevic, Elvir; John, E Roy; Prichep, Leslie S
2006 ;1:1723-1726, Conference Proceedings (IEEE Engineering in Medicine & Biology Society)
Brainstem auditory evoked responses (BAER) are transient signals embedded in the EEG recorded from scalp electrodes, when a subject is presented with a series of acoustic clicks. These signals typically have a signal-to-noise ratio (SNR) well below -10 dB. The extraction of BAER signals from the EEG for the purpose of automatically computing features of interest from the BAER waveform(s) is described in this paper. These features are: 1) Presence of an actual BAER response (at least peak I), 2) Presence of peak V, 3) Inter-peak latency I-V. We propose to combine a signal-adaptive denoising technique based on complex wavelets with a signal quality metric referred to as the FSP variance ratio for quantitative evaluation of signal quality in order to optimally denoise BAER signals and perform reliable waveform analysis
— id: 92786, year: 2006, vol: 1, page: 1723, stat: Journal Article,

The relevance of QEEG to the evaluation of behavioral disorders and pharmacological interventions
John, E Roy; Prichep, Leslie S
2006 Apr;37(2):135-143, Clinical EEG & neuroscience
It has become apparent that the electrical signals recorded from the scalp of healthy individuals under standardized conditions are predictable, and that patients with a wide variety of brain disorders display activity with unusual features. It also early became apparent that centrally active medications produced striking changes in this activity. The application of computerized signal analysis to EEG recordings collected using standardized procedures has made it possible to obtain quantitative descriptions of brain electrical activity (QEEG) in normal individuals and patients with disorders of brain function or structure, as well as quantitative description of the ways in which centrally active medications alter this activity (Pharmaco-EEG or 'PEEG'). With the emergence of three-dimensional EEG source localization techniques, it has recently become possible to visualize the mathematically most probable generators of QEEG abnormalities within the brain as well as the neuroanatomical regions where abnormal activity is most altered by efficacious medication. As QEEG and PEEG have evolved, a vast body of facts has been accumulated, describing changes in the EEG or event-related potentials (ERPs). observed in a variety of brain disorders or after administration of a variety of medications. With some notable exceptions, these studies have tended to be phenomenological rather than analytic. There has not been a systematic attempt to integrate these phenomena in order to build better understanding of how the abnormal behaviors of a particular psychiatric patient might be related to the specific pattern of the deviant electrical activity, nor just how pharmacological reduction of that deviant activity may have resulted in more normal behavior. This article is an endeavor to provide a more specific theoretical framework for understanding the relationships between the neuroanatomy and neurochemistry of the homeostatic system underlying the regulation of the QEEG, and the mechanisms revealed by Pharmaco-EEG that aid in correcting these illnesses
— id: 64660, year: 2006, vol: 37, page: 135, stat: Journal Article,

QEEG subtyping and source localization reveal the need for polypharmacy
John, ER; Prichep, LS; Cancro, R
2006 NOV 23 ;54(1):33-33, Neuropsychobiology
— id: 69292, year: 2006, vol: 54, page: 33, stat: Journal Article,

Electroencephalographic mapping during routine clinical practice: cortical arousal during tracheal intubation?
Kox, Wolfgang J; von Heymann, Christian; Heinze, Judith; Prichep, Leslie S; John, E Roy; Rundshagen, Ingrid
2006 Mar;102(3):825-831, Anesthesia & analgesia
We used quantitative analysis of the electroencephalogram (EEG) in 42 patients to assess the effect of tracheal intubation after induction of anesthesia with etomidate and sufentanil using standard clinical practice. The EEG was recorded from eight bipolar electrode derivations and Z-transformed relative to age expected normative data for relative power in the delta, theta, alpha, and beta frequency bands. Tracheal intubation resulted in classical cortical arousal, as indicated by acceleration of the EEG frequencies. Significant effects were seen in all frequency bands, most pronounced in the alpha frequency band, with the largest increase bilaterally in the fronto-temporal regions (F-values: Delta - 9.592, P < 0.001; theta - 1.691, P < 0.001; alpha - 18.439, P < 0.001; beta - 4.504, P < 0.001). Changes in alpha and delta power during induction of anesthesia were correlated with the dose of etomidate (P < 0.05). Changes in alpha after tracheal intubation were correlated at the parietooccipital brain regions to the dose of sufentanil (P < 0.05). Individual titration of the dose of etomidate and sufentanil, as during routine clinical practice, is not sufficient to block the strong noxious stimulation of tracheal intubation and results in cortical arousal. The clinical impact of this cortical wake-up phenomenon is undetermined
— id: 68147, year: 2006, vol: 102, page: 825, stat: Journal Article,

Guideline for the use of qEEG results
Luthringer, R; Drinkenburg, W; Boeijinga, P; Prichep, L; Soufflet, L
2006 NOV 23 ;54(1):25-26, Neuropsychobiology
— id: 69290, year: 2006, vol: 54, page: 25, stat: Journal Article,

Prediction of longitudinal cognitive decline in normal elderly with subjective complaints using electrophysiological imaging
Prichep, L S; John, E R; Ferris, S H; Rausch, L; Fang, Z; Cancro, R; Torossian, C; Reisberg, B
2006 Mar;27(3):471-481, Neurobiology of aging
An extensive literature reports changes in quantitative electroencephalogram (QEEG) with aging and a relationship between magnitude of changes and degree of clinical deterioration in progressive dementia. Longitudinal studies have demonstrated QEEG differences between mild cognitively impaired (MCI) elderly who go on to decline and those who do not. This study focuses on normal elderly with subjective cognitive complaints to assess the utility of QEEG in predicting future decline within 7 years. Forty-four normal elderly received extensive clinical, neurocognitive and QEEG examinations at baseline. All study subjects (N = 44) had only subjective complaints but no objective evidence of cognitive deficit (evaluated using the Global Deterioration Scale [GDS] score, GDS stage = 2) at baseline and were re-evaluated during 7-9 year follow-up. Baseline QEEGs of Decliners differed significantly (p < 0.0001, by MANOVA) from Non-Decliners, characterized by increases in theta power, slowing of mean frequency, and changes in covariance among regions, especially on the right hemisphere. Using logistic regression, an R2 of 0.93 (p < 0.001) was obtained between baseline QEEG features and probability of future decline, with an overall predictive accuracy of 90%. These data indicate high sensitivity and specificity for baseline QEEG as a differential predictor of future cognitive state in normal, subjectively impaired elderly
— id: 63733, year: 2006, vol: 27, page: 471, stat: Journal Article,

QEEG source localization of epileptiform foci
Prichep, LS; Alper, K
2006 NOV 23 ;54(1):28-29, Neuropsychobiology
— id: 69291, year: 2006, vol: 54, page: 28, stat: Journal Article,

QEEG as an adjunct to diagnosis and a monitoring tool for psychiatric dysfunction - The evolution of dementia in the elderly
Prichep, LS; John, ER
2006 NOV 23 ;54(1):35-36, Neuropsychobiology
— id: 69293, year: 2006, vol: 54, page: 35, stat: Journal Article,

Topographic imaging of quantitative EEG in response to smoked cocaine self-administration in humans
Reid, Malcolm S; Flammino, Frank; Howard, Bryant; Nilsen, Diana; Prichep, Leslie S
2006 Apr;31(4):872-884, Neuropsychopharmacology
Quantitative electroencephalographic (qEEG) profiles were studied in cocaine-dependent patients in response to an acute, single-blind, self-administered dose of smoked cocaine base (50 mg) vs placebo. qEEG data were averaged using neurometric analytical methods and the spectral power of each primary bandwidth was computed and topographically imaged. Additional measures included cocaine-induced high, craving, and related subjective ratings, heart rate, blood pressure, and plasma cortisol and homovanillic acid levels. In all, 13 crack cocaine-dependent subjects were tested. Cocaine produced a rapid increase in subjective ratings of cocaine high and good drug effect, and a more persistent increase in cocaine craving and nervousness. Cocaine also produced a rapid rise in heart rate and a prolonged increase in plasma cortisol. Placebo, administered in the context of cocaine cues and dosing expectations, had no cocaine-like subjective or physiological effects. Cocaine produced a rapid increase in absolute theta, alpha, and beta power over the prefrontal cortex (FP1, FP2), lasting up to 25 min after dosing. The increase in theta power was correlated with good drug effect, and the increase in alpha power was correlated with nervousness. Cocaine also produced a similar increase in delta coherence over the prefrontal cortex, which was positively correlated with plasma cortisol, and negatively correlated with nervousness. Placebo resulted in an increase in alpha power over the prefrontal cortex. These data demonstrate the involvement of prefrontal cortex in the qEEG response to acute cocaine. Evidence indicates slow wave qEEG, delta and theta activity, involvement in the rewarding properties of cocaine
— id: 64194, year: 2006, vol: 31, page: 872, stat: Journal Article,

Addiction and the human brain
Schloat, Anson L; Cochran, Peter; Dewey, Steven; Prichep, Leslie S.; White, Aaron; Hefferan, Elizabeth K.; Hauser, Wanda
Mt. Kisco NY : Human Relations Media, 2006,
— id: 1112, year: 2006, vol: , page: , stat: ,

The neurophysiology of attention-deficit/hyperactivity disorder
di Michele, Flavia; Prichep, Leslie; John, E Roy; Chabot, Robert J
2005 Oct;58(1):81-93, International journal of psychophysiology
Recent reviews of the neurobiology of Attention-Deficit/Hyperactivity Disorder (AD/HD) have concluded that there is no single pathophysiological profile underlying this disorder. Certainly, dysfunctions in the frontal/subcortical pathways that control attention and motor behavior are implicated. However, no diagnostic criteria or behavioral/neuroimaging techniques allow a clear discrimination among subtypes within this disorder, especially when problems with learning are also considered. Two major Quantitative EEG (QEEG) subtypes have been found to characterize AD/HD. Here we review the major findings in the neurophysiology of AD/HD, focusing on QEEG, and briefly present our previous findings using a source localization technique called Variable Resolution Electromagnetic Tomography (VARETA). These two techniques represent a possible objective method to identify specific patterns corresponding to EEG-defined subtypes of AD/HD. We then propose a model representing the distribution of the neural generators in these two major AD/HD subtypes, localized within basal ganglia and right anterior cortical regions, and hippocampal, para-hippocampal and temporal cortical regions, respectively. A comprehensive review of neurochemical, genetic, neuroimaging, pharmacological and neuropsychological evidence in support of this model is then presented. These results indicate the value of the neurophysiological model of AD/HD and support the involvement of different neuroanatomical systems, particularly the dopaminergic pathways
— id: 61249, year: 2005, vol: 58, page: 81, stat: Journal Article,

Thalamocortical connection and anesthesia - Reply
John, ER; Prichep, LS
2005 OCT ;103(4):906-907, Anesthesiology
— id: 58691, year: 2005, vol: 103, page: 906, stat: Journal Article,

Decreased EEG synchronization in Alzheimer's disease and mild cognitive impairment
Koenig, T; Prichep, L; Dierks, T; Hubl, D; Wahlund, L O; John, E R; Jelic, V
2005 Feb;26(2):165-171, Neurobiology of aging
The hypothesis of a functional disconnection of neuro-cognitive networks in patients with mild cognitive impairment (MCI) and Alzheimer Dementia was investigated using baseline resting EEG data. EEG databases from New York (264 subjects) and Stockholm (155 subjects), including healthy controls and patients with varying degrees of cognitive decline or Alzheimer Dementia were analyzed using Global Field Synchronization (GFS), a novel measure of global EEG synchronization. GFS reflects the global amount of phase-locked activity at a given frequency by a single number; it is independent of the recording reference and of implicit source models. Patients showed decreased GFS values in Alpha, Beta, and Gamma frequency bands, and increased GFS values in the Delta band, confirming the hypothesized disconnection syndrome. The results are discussed within the framework of current knowledge about the functional significance of the affected frequency bands
— id: 68594, year: 2005, vol: 26, page: 165, stat: Journal Article,

[Topographic electroencephalography: endotracheal intubation during anaesthesia with propofol/fentanyl]
Rundshagen, I; Schroder, T; Heinze, J; Prichep, L; John, E R; Kox, W J
2005 Nov;40(11):633-639, Anesthesiologie, Intensivmedizin, Notfallmedizin, Schmerztherapie. AINS
OBJECTIVE: We used quantitative analysis of the electroencephalogram (EEG) during routine clinical practice to assess the effect of tracheal intubation following induction of anesthesia with propofol and fentanyl. METHODS: The topographic EEG was recorded from eight bipolar electrode derivations in 25 patients. Z-scores relative to age expected normative data were computed for relative power in the delta, theta, alpha and beta frequency bands. Multivariate statistics (Hotellings' t-sqare) were used to evaluate changes in regional brain electrical activity. RESULTS: Tracheal intubation induced an increase in alpha and beta frequencies, while delta power was reduced (F-values: Delta: 7.68, p = 0.011; Alpha 31.93; p < 0.001; Beta 12.85, p = 0.001). The most pronounced regional effect was seen for the alpha frequency band with the largest increase in both fronto-temporal regions (F-value 33.89, p < 0.001). During clinical practice the patients received propofol 2.7 (+/- 1.2; minimum: 0.5, maximum 6.9) mg kg (- 1) and fentanyl 2 (+/- 1; minimum 1, maximum 4) microg kg (- 1). Vital parameters did not change during intubation. CONCLUSION: Individual titration of the dose of propofol and fentanyl as done during routine clinical practice is not sufficient to block the strong noxious stimulation of intubation. Tracheal intubation resulted in 'classical' cortical arousal. It remains open whether this cortical wake-up phenomenon has a clinical impact
— id: 68593, year: 2005, vol: 40, page: 633, stat: Journal Article,

Quantitative electroenchephalographic mapping studies on cue-induced alcohol craving
Reid, MS; Starosta, A; Flammino, F; Howard, B; Prichep, LS
2004 MAY ;28(5):21A-21A, Alcoholism: clinical & experimental research
— id: 98204, year: 2004, vol: 28, page: 21A, stat: Journal Article,

Changes in cortical electrical activity during induction of anaesthesia with thiopental/fentanyl and tracheal intubation: a quantitative electroencephalographic analysis
Rundshagen, I; Schroder, T; Prichep, L S; John, E R; Kox, W J
2004 Jan;92(1):33-38, British journal of anaesthesia
BACKGROUND: There are regional differences in the effects of anaesthetics agents and perioperative stimuli on the EEG. We studied the topography of the EEG during induction of anaesthesia and intubation in patients receiving thiopental and fentanyl to document regional electrical brain activity. METHODS: EEG was recorded in 25 patients in the awake state, after pre-medication, during induction, at loss of consciousness and after intubation. Eight bipolar recordings were made and the relative power of the frequency bands delta, theta, alpha, and beta were used (after z-score transformation for age) to measure changes in regional EEG activity. RESULTS: Noxious stimulation during tracheal intubation partially reversed the slowing of the EEG caused by anaesthesia. During induction of anaesthesia alpha activity was most reduced in temporal and occipital regions. The most prominent EEG changes after intubation were an increase in alpha and a decrease in delta power (P<0.001). The largest changes were in the frontal and temporal leads for alpha and in the frontal and central leads for delta. Heart rate and arterial pressure remained constant during intubation. CONCLUSIONS: Changes in alpha and delta power were identified as the most sensitive EEG measures of regional changes in electrical brain activity during anaesthesia and noxious stimulation
— id: 68151, year: 2004, vol: 92, page: 33, stat: Journal Article,

Positive and negative affect and physiological arousal in alcohol cue reactivity: alcoholics versus non-alcoholics
Reid, MS; Careri, J; O'Leary, S; Starosta, A; Prichep, L; Franck, J; Wennberg, P
2003 MAR ;57(2):105-106, Nordic journal of psychiatry
— id: 36596, year: 2003, vol: 57, page: 105, stat: Journal Article,

Subtyping of psychiatric disorders: implications for drug development
Cancro, Robert; E Roy, John; Chabot, Robert; Prichep, Leslie
2002 Dec;4(4):329-335, Dialogues in Clinical Neuroscience
Psychiatric diagnosis suffers from being based on phenomenology and not on pathophysiology. Data are presented showing that psychiatric patients reveal consistent quantitative electroencephalographic abnormalities, such that they can be separated from normals and from each other. Clustering these pathophysiological groupings reveals an underlying variability, which permits useful subtyping. Data are presented relating subtyping to pharmacological treatment
— id: 140532, year: 2002, vol: 4, page: 329, stat: Journal Article,

Patient State Index: titration of delivery and recovery from propofol, alfentanil, and nitrous oxide anesthesia
Drover, David R; Lemmens, Harry J; Pierce, Eric T; Plourde, Gilles; Loyd, Gary; Ornstein, Eugene; Prichep, Leslie S; Chabot, Robert J; Gugino, Laverne
2002 Jul;97(1):82-89, Anesthesiology
BACKGROUND: The Patient State Index (PSI) uses derived quantitative electroencephalogram features in a multivariate algorithm that varies as a function of hypnotic state. Data are recorded from two anterior, one midline central, and one midline posterior scalp locations. PSI has been demonstrated to have a significant relation to level of hypnosis during intravenous propofol, inhalation, and nitrous oxide-narcotic anesthesia. This multisite study evaluated the utility of PSI monitoring as an adjunct to standard anesthetic practice for guiding the delivery of propofol and alfentanil to accelerate emergence from anesthesia. METHODS: Three hundred six patients were enrolled in this multicenter prospective randomized clinical study. Using continuous monitoring throughout the period of propofol-alfentanil-nitrous oxide anesthesia delivery, PSI guidance was compared with use of standard practice guidelines (both before [historic controls] and after exposure to the PSA 4000 monitor [Physiometrix, Inc., N. Billerica, MA; standard practice controls]). Anesthesia was always administered with the aim of providing hemodynamic stability, with rapid recovery. RESULTS: No significant differences were found for demographic variables or for site. The PSI group received significantly less propofol than the standard practice control group (11.9 microg x kg(-1) x min(-1); P < 0.01) and historic control group (18.2 microg x kg(-1) x min(-1); P < 0.001). Verbal response time, emergence time, extubation time, and eligibility for operating room discharge time were all significantly shorter for the PSI group compared with the historic control (3.3-3.8 min; P < 0.001) and standard practice control (1.4-1.5 min; P < 0.05 or P < 0.01) groups. No significant differences in the number of unwanted somatic events or hemodynamic instability and no incidences of reported awareness were found. CONCLUSIONS: Patient State Index-directed titration of propofol delivery resulted in faster emergence and recovery from propofol-alfentanil-nitrous oxide anesthesia, with modest decrease in the amount of propofol delivered, without increasing the number of unwanted events
— id: 68148, year: 2002, vol: 97, page: 82, stat: Journal Article,

Brain field dynamics in Alzheimer's disease
Koenig, T; Hubl, D; Dierks, T; Jelic, V; Wahlund, LO; John, ER; Prichep, L
2002 Jul-Aug;23(1):1745-, Neurobiology of aging
— id: 32433, year: 2002, vol: 23, page: 1745, stat: Journal Article,

Millisecond by millisecond, year by year: normative EEG microstates and developmental stages
Koenig, Thomas; Prichep, Leslie; Lehmann, Dietrich; Sosa, Pedro Valdes; Braeker, Elisabeth; Kleinlogel, Horst; Isenhart, Robert; John, E Roy
2002 May;16(1):41-48, Neuroimage
Most studies of continuous EEG data have used frequency transformation, which allows the quantification of brain states that vary over seconds. For the analysis of shorter, transient EEG events, it is possible to identify and quantify brain electric microstates as subsecond time epochs with stable field topography. These microstates may correspond to basic building blocks of human information processing. Microstate analysis yields a compact and comprehensive repertoire of short lasting classes of brain topographic maps, which may be considered to reflect global functional states. Each microstate class is described by topography, mean duration, frequency of occurrence and percentage analysis time occupied. This paper presents normative microstate data for resting EEG obtained from a database of 496 subjects between the age of 6 and 80 years. The extracted microstate variables showed a lawful, complex evolution with age. The pattern of changes with age is compatible with the existence of developmental stages as claimed by developmental psychologists. The results are discussed in the framework of state dependent information processing and suggest the existence of biologically predetermined top-down processes that bias brain electric activity to functional states appropriate for age-specific learning and behavior
— id: 68149, year: 2002, vol: 16, page: 41, stat: Journal Article,

Outcome related electrophysiological subtypes of cocaine dependence
Prichep, Leslie S; Alper, Kenneth R; Sverdlov, Lev; Kowalik, Sharon C; John, E R; Merkin, Henry; Tom, Mee Lee; Howard, Bryant; Rosenthal, Mitchell S
2002 Jan;33(1):8-20, Clinical electroencephalography
We previously described the existence of two quantitative EEG (QEEG) subtypes of cocaine dependent males, identified at baseline, displaying differential proneness to relapse. The current study expands the population to include females and enhances the measure set to include both QEEG and somatosensory EP (SEP) features. Fifty-seven cocaine dependent adults (16 F, 41 M) were evaluated 5-14 days after last cocaine use, while in residence at a drug-free therapeutic community. The median length of stay in treatment (continued abstinence) was 25 weeks. Using a small subset of QEEG and SEP baseline features, three subtypes (CLUS) were identified. CLUS 2 (n = 25) and CLUS 3 (n = 23) replicated the published subtypes, while CLUS 1 (n = 9) was previously undescribed. Cluster membership was significantly associated with length of stay in treatment (chi 2 = 13.789, P < 0.001), but not with length of exposure to crack cocaine or to any demographic or clinical features. Seventy-eight percent of CLUS 1 and 65% of CLUS 3 left treatment < or = 25 weeks, whereas 80% of CLUS 2 remained in treatment > 25 weeks. The existence of outcome related subtypes may reflect: [1] differential neurophysiological vulnerability, 'traits,' predisposing individuals to cocaine addiction; or [2] differential neurosensitivity, 'states,' due to the effects of chronic cocaine exposure, and associated differences in treatment outcome. Using Variable Resolution Electrical Tomographic Analysis (VARETA), the mathematically most probable neuroanatomical source of the scalp recorded EEG data was localized. Computation of VARETA on the baseline Cluster profiles suggest significant differences in the underlying pathophysiology of these subtypes
— id: 68150, year: 2002, vol: 33, page: 8, stat: Journal Article,

Catatonia in pervasive developmental disorders
Brasic JR; Barnett JY; Kowalik S; Prichep L; John ER; Nadrich RH; Will MV; Bronson B; Ahmad R; Kurz L; Brathwaite C; Cancro R.
2001 ;16(Suppl 1):S46-S47, Movement disorders
— id: 25540, year: 2001, vol: 16, page: S46, stat: Journal Article,

The clinical role of computerized EEG in the evaluation and treatment of learning and attention disorders in children and adolescents
Chabot RJ; di Michele F; Prichep L; John ER
2001 Spring;13(2):171-186, Journal of neuropsychiatry & clinical neurosciences
Quantitative EEG (QEEG) can play an important role in the evaluation and treatment of children and adolescents with attention deficit and learning disorders. Children with learning disorders are a heterogeneous population with QEEG abnormality in 25% to 45% of reported cases. EEG slowing is the most common abnormal finding, and the nature of the QEEG abnormality may be related to future academic performance. Children with attention disorders are a more homogeneous population, with QEEG abnormalities in up to 80%. In this population, frontal/polar regions are most likely to show deviations from normal development, with the thalamocortical and/or septal-hippocampal pathways most likely to be disturbed. QEEG shows high sensitivity and specificity for distinguishing normal children and children with learning disorders and attention disorders from each other and may provide useful information for determining the likelihood that children with attention problems will respond to treatment with stimulant medication
— id: 26730, year: 2001, vol: 13, page: 171, stat: Journal Article,

Quantitative EEG changes associated with loss and return of consciousness in healthy adult volunteers anaesthetized with propofol or sevoflurane
Gugino, L D; Chabot, R J; Prichep, L S; John, E R; Formanek, V; Aglio, L S
2001 Sep;87(3):421-428, British journal of anaesthesia
Significant changes in topographic quantitative EEG (QEEG) features were documented during induction and emergence from anaesthesia induced by the systematic administration of sevoflurane and propofol in combination with remifentanil. The goal was to identify those changes that were sensitive to alterations in the state of consciousness but independent of anaesthetic protocol. Healthy paid volunteers were anaesthetized and reawakened using propofol/remifentanil and sevoflurane/remifentanil, administered in graded steps while the level of arousal was measured. Alterations in the level of arousal were accompanied by significant QEEG changes, many of which were consistent across anaesthetic protocols. Light sedation was accompanied by decreased posterior alpha and increased frontal/central beta power. Frontal power predominance increased with deeper sedation, involving alpha and, to a lesser extent, delta and theta power. With loss of consciousness, delta and theta power increased further in anterior regions and also spread to posterior regions. These changes reversed with return to consciousness
— id: 68152, year: 2001, vol: 87, page: 421, stat: Journal Article,

Invariant reversible qeeg effects of anesthetics
John ER; Prichep LS; Kox W; Valdes-Sosa P; Bosch-Bayard J; Aubert E; Tom M; diMichele F; Gugino LD
2001 Jun;10(2):165-183, Consciousness & cognition
Continuous recordings of brain electrical activity were obtained from a group of 176 patients throughout surgical procedures using general anesthesia. Artifact-free data from the 19 electrodes of the International 10/20 System were subjected to quantitative analysis of the electroencephalogram (QEEG). Induction was variously accomplished with etomidate, propofol or thiopental. Anesthesia was maintained throughout the procedures by isoflurane, desflurane or sevoflurane (N = 68), total intravenous anesthesia using propofol (N = 49), or nitrous oxide plus narcotics (N = 59). A set of QEEG measures were found which reversibly displayed high heterogeneity of variance between four states as follows: (1) during induction; (2) just after loss of consciousness (LOC); (3) just before return of consciousness (ROC); (4) just after ROC. Homogeneity of variance across all agents within states was found. Topographic statistical probability images were compared between states. At LOC, power increased in all frequency bands in the power spectrum with the exception of a decrease in gamma activity, and there was a marked anteriorization of power. Additionally, a significant change occurred in hemispheric relationships, with prefrontal and frontal regions of each hemisphere becoming more closely coupled, and anterior and posterior regions on each hemisphere, as well as homologous regions between the two hemispheres, uncoupling. All of these changes reversed upon ROC. Variable resolution electromagnetic tomography (VARETA) was performed to localize salient features of power anteriorization in three dimensions. A common set of neuroanatomical regions appeared to be the locus of the most probable generators of the observed EEG changes.
— id: 21179, year: 2001, vol: 10, page: 165, stat: Journal Article,

Localization of deep white matter lymphoma using VARETA: a case study
Prichep LS; John ER; Tom ML
2001 Apr;32(2):62-66, Clinical electroencephalography
Methods have recently been proposed for localization of multiple brain sources of particular EEG frequencies recorded from the scalp, to identify their most probable neuroanatomical generators. This paper reports the accurate localization of a deep white matter lymphoma, using Variable Resolution Electromagnetic Tomography (VARETA). The accuracy of this localization was confirmed by MRI studies. The patient was referred for a quantitative EEG evaluation, two weeks following an automobile accident, with no known loss of consciousness. There was marked excess and asymmetry of frontal slow wave activity, with highly significant hypocoherence. Significant gradient shifts within the left hemisphere were also seen. Visual inspection of the EEG tracings revealed theta paroxysms in left dorsolateral and mesial frontal regions. The MRI revealed a large space-occupying lesion deep within the white matter of the left frontal lobe, with evidence of subependymal spread and significant surrounding vasogenic edema. Localization of the sources of the maximal QEEG abnormalities using VARETA was consistent with the lesion location seen in the MRI images. This case demonstrates that VARETA can achieve highly sensitive and accurate localization of sources of QEEG abnormalities which lie in the deepest brain regions
— id: 26742, year: 2001, vol: 32, page: 62, stat: Journal Article,

Clinical manifestations of progressive catatonia
Brasic JR; Zagzag D; Kowalik S; Prichep L; John ER; Barnett JY; Bronson B; Nadrich RH; Cancro R; Buchsbaum M; Brathwaite C
2000 ;3:13-14, German journal of psychiatry
Background: Individuals with pervasive developmental disorders are vulnerable to the occurrence of catatonia and persistent functional deterioration. Objective: To facilitate the recognition of the clinical diagnosis of pervasive developmental disorder and catatonia, we describe the manifestations of a patient with a pervasive developmental disorder who exhibited progressive catatonia. Method: A young man with a pervasive developmental disorder who developed progressive catatonia at the age of 14 years was videotaped participating in a structured movement assessment battery over 9 sessions between 16 years 8 months and 19 years 9 months of age. Results: Mutism, social withdrawal, blepharospasm, grimacing, and inability to perform the activities of daily living progressively increase during the course of the illness. Conclusion: Pervasive developmental disorder and catatonia can be diagnosed and monitored in outpatient settings by the use of structured assessment protocols
— id: 20745, year: 2000, vol: 3, page: 13, stat: Journal Article,

QEEG subtyping of schizophrenics predicts response to medication
John, ER; Prichep, LS; Cancro, R; Herrmann, W; Winterer, GW; Valdes-Sosa, P
2000 JAN 3 ;41(1):142-142, Schizophrenia research
— id: 54757, year: 2000, vol: 41, page: 142, stat: Journal Article,

Progressive catatonia
Brasic JR; Zagzag D; Kowalik S; Prichep L; John ER; Liang HG; Klutchko B; Cancro R; Sheitman BB; Buchsbaum M; Brathwaite C
1999 Feb;84(1):239-246, Psychological reports
We present the case of a young man with a diagnosis of a childhood-onset pervasive developmental disorder who developed a progressive neurologic deterioration with persistent catatonia and right hemiparesis. On his initial evaluation approximately three years after the onset of mutism, he manifested right hemiparesis and catalepsy. Two years later, although catalepsy had subsided, motor function had deteriorated so that he could not use his hands to feed or dress himself. Oral-facialbuccal dyskinesia manifested by blepharospasm and grimacing were present constantly during waking hours. Quantitative electroencephalography demonstrated markedly decreased amplitude, a finding associated with catatonia. Left sural nerve biopsy indicated large axon cylinder degeneration. Left deltoid biopsy demonstrated perimysial fibrosis and type II fiber predominance. Although magnetic resonance imaging of the head without contrast was normal, positron emission tomography indicated hypometabolism of the right cerebral and the right cerebellar hemispheres. The patient continues to deteriorate despite a course of 25 electroconvulsive treatments. He continues to manifest criteria for catatonia including motoric immobility, mutism, and peculiarities of voluntary movement such as prominent grimacing. We suspect an inherited neurodegenerative disorder. Since catatonia is a treatable condition frequently associated with medical and neurological diseases, examination for the features of catatonia must be included in the assessment of patients with progressive brain degeneration. This report is an attempt to clarify the traits of a serious variant of progressive brain degeneration
— id: 6085, year: 1999, vol: 84, page: 239, stat: Journal Article,

Prediction of treatment outcome in cocaine dependent males using quantitative EEG
Prichep LS; Alper KR; Kowalik SC; Vaysblat LS; Merkin HA; Tom M; John ER; Rosenthal MS
1999 Mar 1;54(1):35-43, Drug & alcohol dependence
This study investigates the existence of outcome related neurophysiological subtypes within a population of abstinent cocaine dependent adults. We have previously reported and replicated the existence of a distinctive quantitative EEG (QEEG) profile in such a population, and demonstrated the persistence of this pattern at one and six month follow-up evaluations. This profile is characterized by significant deficits of absolute and relative delta and theta power, and excess of relative alpha power, as compared with age expected normal values. Abnormalities were greater in anterior than posterior regions, and disturbances in interhemispheric relationships were also observed. In the current study, 35 adult males with DSM-III-R cocaine dependence, were evaluated while residents of a drug-free residential therapeutic community, 5-15 days after last use of crack cocaine. Using multivariate cluster analysis, two neurophysiological subtypes were identified from the baseline QEEGs; Cluster 1 characterized by significant deficits of delta and theta activity, significant excess of alpha activity and more normal amounts of beta activity (alpha CLUS) and Cluster 2 characterized by deficits of delta, more normal amounts of theta and anterior excess of alpha and beta activity beta CLUS). No significant relationships were found between QEEG subtype membership and length of exposure to cocaine, time since last use of cocaine or any demographic characteristics. Further, no significant relationships were found between the commonly reported comorbid clinical features of depression and anxiety and subtype membership. However, a significant relationship was found between QEEG subtype membership and length of stay in treatment, with members of the alpha CLUS retained in treatment significantly longer than members of the beta CLUS
— id: 7429, year: 1999, vol: 54, page: 35, stat: Journal Article,

Quantitative EEG correlates of cue-induced cocaine craving
Reid, Malcolm S; Ciplet, Debra; Tom, Mee Lee; Prichep, Leslie
1999 Oct 23-28;25(1-2):1297-1297, Abstracts (Society for Neuroscience)
— id: 15855, year: 1999, vol: 25, page: 1297, stat: Journal Article,

Correlation of qEEG with PET in schizophrenia
Alper K; Gunther W; Prichep LS; John ER; Brodie J
1998 ;38(1):50-56, Neuropsychobiology
PET relative metabolism was correlated with quantitative EEG in 9 schizophrenic patients. The PET metabolic regions of interest were the frontal lobes, thalamus and basal ganglia, and right and left temporal lobes. Significant positive correlations were seen for the frontal lobes and delta EEG power, and alpha power with subcortical metabolism. The physiologic plausibility of those correlations is discussed with reference to the possible effect of neuroleptic medication
— id: 7481, year: 1998, vol: 38, page: 50, stat: Journal Article,

Persistent QEEG abnormality in crack cocaine users at 6 months of drug abstinence
Alper KR; Prichep LS; Kowalik S; Rosenthal MS; John ER
1998 Jul;19(1):1-9, Neuropsychopharmacology
The major objective of this study was to examine the persistence of abnormal quantitative EEG (qEEG) measures over a six month time interval in subjects in strictly supervised drug free residential treatment for crack cocaine dependence. Seventeen subjects were assessed with qEEG at five to 10 days, one month and six months following their last use of cocaine. No significant changes were noted over time in abnormal qEEG measures, which included deficits of absolute and relative power in the delta band and increased relative alpha power. The persistence of qEEG abnormality in crack cocaine withdrawal suggests a persistent neurobiologic alteration resulting from chronic cocaine exposure. The specificity of the qEEG findings is discussed, and an interpretation is suggested with reference to the hypothesis of neural sensitization in cocaine dependence
— id: 7480, year: 1998, vol: 19, page: 1, stat: Journal Article,

Neurometric QEEG studies of crack cocaine dependence and treatment outcome
Prichep LS; Alper K; Kowalik SC; Rosenthal M
1996 ;15(4):39-53, Journal of addictive diseases
This paper presents an overview of the quantitative electrophysiological (QEEC) research on cocaine dependence conducted at Brain Research Laboratories of New York University Medical Center. These studies have demonstrated that subjects with DSM-III-R cocaine dependence (without dependence on any other substance) evaluated in the withdrawal state, have replicable abnormalities in brain function when evaluated at baseline (approximately 5 to 10 days after last crack cocaine use), which are still seen at one and six month follow-up evaluations. These abnormalities were characterized by significant excess of relative alpha power and deficit of absolute and relative delta and theta power. Abnormalities were greater in anterior than posterior regions, and disturbances in interhemispheric relationships were also observed. In addition, QEEC subtypes were identified within the population of cocaine dependent subjects at baseline, and these subtypes were found to be significantly related to subsequent length of stay in treatment. The relationship between these QEEG findings and the neuropharmacology of cocaine dependence is discussed
— id: 12667, year: 1996, vol: 15, page: 39, stat: Journal Article,

Quantitative electroencephalographic characteristics of crack cocaine dependence
Prichep LS; Alper KR; Kowalik S; Merkin H; Tom M; John ER; Rosenthal MS
1996 Nov 15;40(10):986-993, Biological psychiatry
This study replicates preliminary findings reporting a quantitative electroencephalographic (QEEG) profile of crack cocaine dependence in abstinence. All subjects (n = 52) met criteria for DMS-III-R cocaine dependence (in the form of crack), and were residing in a drug-free therapeutic community. Baseline QEEG evaluations were conducted at intake (5-10 days after last use of crack, and at follow-up (1 month after last reported use). Previous findings of significant excess of relative alpha power and deficit of absolute and relative delta and theta power were replicated in this expanded group. Abnormalities were greater in anterior than posterior regions, and disturbances in interhemispheric relationships were also observed. Further, QEEG showed little change in the interval between the first and second evaluations. This QEEG profile may reflect persistent alterations in neurotransmission as a possible consequence of chronic cocaine exposure
— id: 12472, year: 1996, vol: 40, page: 986, stat: Journal Article,

Quantitative EEG characteristics of children exposed in utero to cocaine
Prichep LS; Kowalik SC; Alper K; de Jesus C
1995 Jul;26(3):166-172, Clinical electroencephalography
Quantitative EEGs (QEEGs) were evaluated in a group of 6 school age children with in utero cocaine exposure. Their QEEGs showed significant deviations from age expected normal values. Further, the QEEG profile of brain dysfunction seen in these children was extremely similar to that previously reported in a large population of crack cocaine dependent adults. These abnormalities were characterized by significant excess of relative power in the alpha frequency band, and deficits of absolute and relative power in the delta and theta bands. Characteristic disturbances in interhemispheric relationships were also present. The similarities between the QEEG profiles of those adults with chronic exposure and children with prenatal exposure suggests that the brain dysfunction reflected in the QEEG is not a result of a transient change in neurotransmission, but a more profound alteration which persists in these children at school age. Further study is required to extend these findings to a larger group of children, and to investigate the potential relationship between these neurophysiological abnormalities and the developmental, behavioral and co-morbid features observed in such children
— id: 6948, year: 1995, vol: 26, page: 166, stat: Journal Article,

Quantitative electrophysiological characteristics and subtyping of schizophrenia
John ER; Prichep LS; Alper KR; Mas FG; Cancro R; Easton P; Sverdlov L
1994 Dec 15;36(12):801-826, Biological psychiatry
Quantitative descriptors of resting electroencephalogram (EEG) (QEEG) and event-related potentials (QERP) to visual and auditory stimuli were obtained from normal subjects and 94 chronic schizophrenic patients on medication, 25 chronic schizophrenics off medication, and 15 schizophrenics with no history of medication. These schizophrenic groups showed a high incidence of neurometric features that were significantly deviant from normative values. Multivariate discriminant analysis using these features successfully separated the schizophrenic patients from normals with high accuracy in independent replication. The data from the medicated group were subjected to cluster analysis. Newly developed algorithms were used for objective selection of the most effective set of variables for clustering and the optimum number of clusters to be sought. Five clusters were obtained, containing roughly equivalent proportions of the sample with markedly different QEEG profiles. The whole sample was then classified into these clusters. Each cluster contained patients both on and off medication, but patients who had never been medicated were classified into only three of these clusters. No significant clinical or demographic differences were found between members of the five clusters; however, clear differences in QERP profiles were seen. These results are described in detail and possible physiological and pharmacological implications are discussed
— id: 6653, year: 1994, vol: 36, page: 801, stat: Journal Article,

Standardized varimax descriptors of event related potentials: evaluation of psychiatric patients
John ER; Prichep LS; Easton P
1994 Mar;55(1):13-40, Psychiatry research
A large normative data base of visual and auditory event related potentials (ERPs) was collected. Factor analysis (PCVA) was used to extract factor wave shapes that accurately reconstructed these normal ERPs with appropriate 'factor scores.' The mean value and standard deviation (SD) of the normative factor score distribution were computed separately for each stimulus, factor, and electrode. This enabled reconstruction of any individual ERP as a combination of these standardized Varimax descriptors, with z-transformation of the required factor scores giving objective statistical assessment of ERP wave shape. Statistical probability factor z-score topographic maps were constructed, color coded in SDs from the normative means. The incidence of significant individual deviations from these normative mean values was at or near chance levels in test groups of normal subjects. For many of these new ERP descriptors, significant deviations from the norms were found for single features in from 20% to as much as 63% of the patients in particular diagnostic categories. Factor z-scores were used to construct multivariate discriminant functions that accurately and replicably separated (1) normal from schizophrenic from demented subjects and (2) schizophrenic from bipolar depressed subjects
— id: 12993, year: 1994, vol: 55, page: 13, stat: Journal Article,

Statistical probability mapping of brain function and structure
John, E. Roy; Zhang, Jian-Zhou; Brodie, Jonathon D; Prichep, Leslie S
Functional neuroimaging: Technical foundations San Diego, CA, US: Academic Press, 1994,
(from the chapter) to make more explicit the anatomical information potentially available from [EEGs and sensory evoked potentials (ERPs)], [researchers] used interpolation algorithms operating on quantitative values assigned to electrode positions on a spatial grid to construct topographic maps / these maps showed cranial distributions of momentary EEG voltages, integrated EEG power in some time interval, or, eventually, computed the power in spectral frequency bands using Fast Fourier Transform (FFT) /// topographic mapping of quantitative EEG (QEEG) measures [voltage and power maps, normative databases, statistical probability maps, advantages of Z-transformation] / statistical classifiers using QEEG [diagnostic discriminant functions, subtype identification by cluster analysis] / statistical probability images (SPI) of PET [positron emission tomography] scans [construction of a normative pixel database, shape and size normalization--pixel Z scores] / validation of normalization procedure / heterogeneity of schizophrenic population
— id: 4771, year: 1994, vol: , page: 137, stat: Chapter,

Quantitative EEG correlates of cognitive deterioration in the elderly [published erratum appears in Neurobiol Aging 1994 May-Jun;15(3):391]
Prichep LS; John ER; Ferris SH; Reisberg B; Almas M; Alper K; Cancro R
1994 Jan-Feb;15(1):85-90, Neurobiology of aging
We report on the quantitative analysis of the EEG (QEEG), using the Neurometric method, in large samples of normal elderly; normal subjectively impaired elderly; patients with mild cognitive impairment; patients presenting with a continuum of primary cognitive deterioration from mild to moderately severe as measured by the Global Deterioration Scale (GDS), compatible with dementia of the Alzheimer's type (DAT). Neurometric QEEG measures were found to be a sensitive index of degree of cognitive impairment, especially reflected in increased absolute and relative power in the theta band, with delta increasing in later stages of deterioration. While these abnormalities were widespread, neither localized or lateralized, MANOVA's for GDS and relative power in theta reached highest significance in a bilateral temporo-parietal arc. A possible relationship between hippocampal dysfunction, cognitive deterioration, and theta abnormalities is discussed in relation to these findings. The results suggest that Neurometric QEEG features are sensitive to the earliest presence of subjective cognitive dysfunction and might be useful in the initial evaluation of patients with suspected dementia, as well as in estimating the degree of cognitive deterioration in DAT patients
— id: 6488, year: 1994, vol: 15, page: 85, stat: Journal Article,

QEEG PREDICTION OF COGNITIVE DETERIORATION IN NORMAL ELDERLY
PRICHEP, LS; JOHN, ER; REISBERG, B; FERRIS, S
1994 NOV ;18(2):140-141, International journal of psychophysiology
— id: 87448, year: 1994, vol: 18, page: 140, stat: Journal Article,

Standardized varimax descriptors of event related potentials: basic considerations
John ER; Easton P; Prichep LS; Friedman J
1993 Winter;6(2):143-162, Brain topography
This paper describes a set of proposed standardized quantitative descriptors of event-related potentials, based upon principal component varimax analysis (PCVA). No claim is made that these mathematical descriptors correspond to discrete neurophysiological processes which generate the ERP. However, adoption and prospective evaluation of such a set of precise, standardized descriptors of the quantitative ERP may eventually result in advances like those which resulted from adoption of equally arbitrary standardized descriptors for QEEG. PCVA was performed on data from normal subjects and from groups of patients with a wide variety of psychiatric disorders ('Abnormals'). This yielded two sets of factor waveshapes, Normal and Abnormal, which were closely similar. Reconstruction of the normal and abnormal ERP data with either set of factors yielded almost identical allocation of variance. These results gave acceptable reassurance that factors derived from normal population could reasonably be used to describe ERP waveshapes from patients. The ERPs at each electrode of the 10/20 System in a 'training group' of normal subjects were then reconstructed. The resulting distributions of factor scores were transformed to achieve Gaussianity. Mean values and standard deviations were obtained for the normative distribution of each factor score, the root mean square deviation, the residual and the absolute ERP power at each electrode. Individual ERPs could then be reconstructed with the normal factors, and the resulting factor scores rescaled to 'probability of abnormal morphology' by Z-transformation. Statistical probability maps could be generated by using a color scale in standard deviation units. These methods were used to evaluate visual and auditory ERPs from an independent normal 'test group' and the patients in the Abnormal sample. High specificity and sensitivity were obtained for many factor Z- scores. Multiple discriminant functions were constructed which separated normal from abnormal patients with high, replicable accuracy. Further development and testing of these descriptors may make them clinically useful
— id: 6415, year: 1993, vol: 6, page: 143, stat: Journal Article,

Treatment resistant depression in a case of minor head injury: an electrophysiological hypothesis
Mas F; Prichep LS; Alper K
1993 Jul;24(3):118-122, Clinical electroencephalography
A relatively small but highly concordant literature suggests that manic depressive psychoses may include familial as well as nonfamilial subtypes. The latter, which appears to be an acquired form, follows brain injury of various etiology, displays EEG abnormalities and tends to respond well to anticonvulsant therapy. In this study we postulate an extension of this dichotomy to a larger spectrum of affective disorder, including milder but 'treatment resistant' forms often associated with a high degree of dysfunction. Central to this hypothesis is information gathered from the longitudinal study of a well defined case in which precise clinical and electrophysiological data have been obtained at critical junctures. This data also leads us to suggest the existence of a latent vulnerability to psychosocial stressors in a subgroup of minor head injured patients. Once triggered, the resulting psychopathological state may be clinically indistinguishable from similar but etiologically distinct conditions. However, they respond poorly, if at all, to the treatments usually effective for mood disorders, often causing puzzlement and frustration among clinicians as well as mounting hopelessness in patients. This organic mood disorder subtype, which can be described as 'neuro-sensitization mood disorder,' may be identified by combining a thorough history, including perinatal events and putative brain injury, with electrophysiological data consisting of quantitative EEG (QEEG) in association with evoked potentials. In cases with positive findings, anticonvulsants such as carbamazepine, clonazepam and valproic acid can be a treatment of choice
— id: 6447, year: 1993, vol: 24, page: 118, stat: Journal Article,

Quantitative electroencephalographic subtyping of obsessive-compulsive disorder
Prichep LS; Mas F; Hollander E; Liebowitz M; John ER; Almas M; DeCaria CM; Levine RH
1993 Apr;50(1):25-32, Psychiatry research
Current neuropsychological, electrophysiological, and other imaging data strongly suggest the existence of a neurobiological basis for obsessive-compulsive disorder (OCD), which was long considered to be exclusively of psychogenic origin. The positive response of some OCD patients to neurosurgery, as well as the efficacy of agents that selectively block serotonin reuptake, lends further support to a biological involvement. However, a survey of the treatment literature reveals that only 45-62% of OCD patients improve with these specific medications. In a pilot study using a quantitative electroencephalographic (QEEG) method known as neurometrics, in which QEEG data from OCD patients were compared statistically with those from an age-appropriate normative population, we previously reported the existence of two subtypes of OCD patients within a clinically homogeneous group of patients who met DSM-III-R criteria for OCD. Following pharmacological treatment, a clear relationship was found between treatment response and neurometric cluster membership. In this study, we have expanded the OCD population, adding patients from a second site, and have replicated the existence of two clusters of patients in an enlarged, statistically more robust population. Cluster 1 was characterized by excess relative power in theta, especially in the frontal and frontotemporal regions; cluster 2 was characterized by increased relative power in alpha. Further, 80.0% of the members of cluster 1 were found to be nonresponders to drug treatment, while 82.4% of the members of cluster 2 were found to be treatment responders.(ABSTRACT TRUNCATED AT 250 WORDS)
— id: 6487, year: 1993, vol: 50, page: 25, stat: Journal Article,

Event-related potentials and factor Z-score descriptors of P3 in psychiatric patients
John ER; Prichep LS
1992 Jul 1;658:256-275, Annals of the New York Academy of Sciences
— id: 13541, year: 1992, vol: 658, page: 256, stat: Journal Article,

Subtyping of psychiatric patients by cluster analysis of QEEG
John ER; Prichep LS; Almas M
1992 Summer;4(4):321-326, Brain topography
We have previously reported successful classification of patients with a variety of psychiatric disorders, using multiple discriminant functions based upon selected neurometric QEEG variables. In independent replications, these functions accurately separate patients with different DSM-III-R diagnoses from one another and from normals. This capability demonstrates that distinctive and replicable patterns of neurometric abnormalities are correlated with the clinical symptom clusters upon which DSM-III-R diagnostic criteria are based. However, patients with the same clinical diagnoses often respond very differently to the same treatments. Similar symptoms may arise from different pathophysiology. This study explored the 'natural structure' of a population of psychiatric patients in 8 diagnostic categories, using uninformed cluster analysis based upon the same set of neurometric variables found useful in separating each of these categories from normal. This preliminary numerical taxonomic approach reveals that groups of patients in each of these DSM-III-R categories contain subtypes with markedly different pathophysiology; further, patients in different DSM-III-R categories were aggregated together within each cluster, displaying similar pathophysiological profiles. Objective classification based on such physiological measurements may add information useful to improve treatment outcomes
— id: 8226, year: 1992, vol: 4, page: 321, stat: Journal Article,

QEEG profiles of psychiatric disorders
Prichep LS; John ER
1992 Summer;4(4):249-257, Brain topography
While reports of EEG correlates of psychiatric disorders date back five decades, clinical sensitivity of the EEG to psychiatric disorders has been greatly enhanced with the advent of quantitative methods of analysis (QEEG). Using a QEEG methodology known as neurometrics we have identified distinctive electrophysiological profiles associated with different psychiatric disorders. With this method quantitative features are extracted from 2 minutes of artifact- free eyes closed resting EEG data, log transformed to obtain Gaussianity, age-regressed, and Z-transformed relative to population norms. Using small subsets of neurometric features, multiple stepwise discriminant analyses were used to construct mathematical classifier functions, the values of which are different for members of different a priori defined diagnostic groups. Using this approach, we have demonstrated high discriminant accuracy in independent replications separating many populations of psychiatric patients from normal as well as from each other, including major affective disorder, schizophrenia, dementia, alcoholism, and learning disabilities, as well as high accuracy of discrimination between known subtypes of depression (unipolar vs bipolar). The use of classification accuracy curves (CACs) which allow one to assess the sensitivity and specificity achieved by the discriminant functions is discussed. In addition, using cluster analysis, neurometric subtypes can be identified in several clinically homogenous populations. Preliminary results suggest that baseline membership in some neurometric subtypes may be highly correlated with response to treatment
— id: 13762, year: 1992, vol: 4, page: 249, stat: Journal Article,

Quantitative EEG correlates of crack cocaine dependence
Alper KR; Chabot RJ; Kim AH; Prichep LS; John ER
1990 Dec;35(2):95-105, Psychiatry research
Evidence for a distinctive syndrome of neuroadaptation in cocaine dependence has accumulated from behavioral, neurophysiological, and preclinical and clinical pharmacological studies. The authors report on the results of a preliminary investigation of the quantitative electroencephalographic (QEEG) correlates of severe DSM-III-R crack cocaine dependence in seven patients abstinent from cocaine for 1 to 68 days. The major QEEG finding was increased absolute and relative alpha power. Increased alpha power has also been reported in multiple previous studies of depressed patients. This series of crack-dependent patients showed significant depressive morbidity; four patients attempted suicide subsequent to initiating their use of crack and the group mean (+/- SD) Beck Depression Scale score was 18.9 (+/- 6.5). These results complement other studies that support the concept of neuroadaptation to chronic cocaine exposure. Prospective studies correlating QEEG measures with subsequent response to pharmacological interventions for cocaine dependence should be considered
— id: 14267, year: 1990, vol: 35, page: 95, stat: Journal Article,

Neurometric studies of aging and cognitive impairment
John, E R; Prichep, L S
1990 ;85:555-565, Progress in brain research
— id: 68153, year: 1990, vol: 85, page: 555, stat: Journal Article,

Neurometric functional imaging II. Cross-spectral coherence at rest and during mental activity
Prichep, Leslie S; et al
Machinery of the mind : data, theory, and speculations about higher brain functions : based on the First International Conference on Machinery of the Mind, February 25-March 3, 1989, Havana City, Cuba Boston : Birkhauser, 1990,
— id: 4963, year: 1990, vol: , page: ?, stat: Chapter,

Neurometric functional imaging: I. Subtyping of schizophrenia
Prichep, Leslie S; John, E. Roy
Machinery of the mind : data, theory, and speculations about higher brain functions : based on the First International Conference on Machinery of the Mind, February 25-March 3, 1989, Havana City, Cuba Boston : Birkhauser, 1990,
— id: 4962, year: 1990, vol: , page: ?, stat: Chapter,

Real-time intraoperative monitoring during neurosurgical and neuroradiological procedures
John ER; Chabot RJ; Prichep LS; Ransohoff J; Epstein F; Berenstein A
1989 Apr;6(2):125-158, Journal of clinical neurophysiology
A real-time intraoperative evoked potential (EP) monitoring system is described and evaluated. Unique features include (1) online artifact rejection to reduce noise contamination, (2) optimum digital filtering to improve the signal-to-noise ratio of the EP signal, (3) statistically defined confidence intervals to determine significant EP peak latency deviations, and (4) sliding windows of EP subaverages of various sizes to minimize feedback time to the surgeon. The reliability and validity of this system were determined by comparison with conventional intraoperative EP averaging and by examining the correlation of EP parameter changes with concurrent surgical and radiological manipulations. This system was clearly superior to conventional averaging systems. Reliable EPs could be obtained from neurologically compromised patients within the electrically hostile operating room environment, in cases in which conventional averaging failed to extract a stable EP signal. EP update times of 10-20 s were quite common and allowed direct moment-to-moment correlations with surgical and radiological events. Case histories are presented that show the utility of this system for aiding in the prevention of neurological complications. This utility is examined for neurosurgical and neuroradiological procedures involving spinal cord, brainstem, midbrain, and cortical structures, and affecting the somatosensory, motor, auditory, and visual system pathways
— id: 10678, year: 1989, vol: 6, page: 125, stat: Journal Article,

Neurometrics: computer-assisted differential diagnosis of brain dysfunctions
John ER; Prichep LS; Fridman J; Easton P
1988 Jan 8;239(4836):162-169, Science
Normative developmental equations provide reliable descriptors of brain electrical activity in people 6 to 90 years old. Healthy persons display only chance deviations beyond predicted ranges. Patients with neurological impairment, subtle cognitive dysfunctions, or psychiatric disorders (including dementia and primary depression) show a high incidence of abnormal values. The magnitude of the deviations increases with clinical severity. Different disorders are characterized by distinctive profiles of abnormal values of brain electrical features. Computerized differential classification of some of these disorders can be achieved with high accuracy. Such classification, providing objective corroboration of brain dysfunctions, may be a useful adjunct to psychiatric diagnosis, which relies primarily on subjective clinical impressions. These methods may provide independent criteria for diagnostic validity, evaluations of treatment efficacy, and more individualized therapy
— id: 11207, year: 1988, vol: 239, page: 162, stat: Journal Article,

QUANTITATIVE BRAIN CORRELATES OF MENTAL TASKS
John, ER; Prichep, LS; Chabot, R
1988 Jul;25(4):429-429, Psychophysiology
— id: 31453, year: 1988, vol: 25, page: 429, stat: Journal Article,

Neuropsychiatric, psychoeducational, and family characteristics of 14 juveniles condemned to death in the United States
Lewis DO; Pincus JH; Bard B; Richardson E; Prichep LS; Feldman M; Yeager C
1988 May;145(5):584-589, American journal of psychiatry
Of the 37 juveniles currently condemned to death in the United States, all of the 14 incarcerated in four states received comprehensive psychiatric, neurological, neuropsychological, and educational evaluations. Nine had major neurological impairment, seven suffered psychotic disorders antedating incarceration, seven evidenced significant organic dysfunction on neuropsychological testing, and only two had full-scale IQ scores above 90. Twelve had been brutally physically abused, and five had been sodomized by relatives. For a variety of reasons the subjects' vulnerabilities were not recognized at the time of trial or sentencing, when they could have been used for purposes of mitigation
— id: 11107, year: 1988, vol: 145, page: 584, stat: Journal Article,

Diagnosis and subtyping of depressive disorders by quantitative electroencephalography: I. Discriminant analysis of selected variables in untreated depressives
Lieber, A L; Prichep, L S
1988 ;10(1):71-83, Hillside journal of clinical psychiatry
Of 88 inpatients admitted for assessment of affective illness, 70 met RDC criteria for major depressive disorder. All patients had a quantitative electroencephalogram (QEEG) after ten days drug-free. Several QEEG variables were examined by multivariate stepwise discriminant analysis of data from patients and controls. Measures of interhemispheric coherence, beta activity, and slow wave excess were potent discriminators. Depressives were discriminated from normals with an accuracy of eighty-six percent. Primary depressives were discriminated from alcoholics, primary dementias and normals with an overall accuracy of 76% (25% expected by chance). Primary and secondary major depressives were correctly classified with 77% accuracy. Unipolar depressives were discriminated from bipolar depressives with 88% accuracy. Differential diagnosis and treatment implications are discussed
— id: 68154, year: 1988, vol: 10, page: 71, stat: Journal Article,

NEUROMETRIC QEEG IN THE EVALUATION OF PSYCHIATRIC-PATIENTS
Prichep, LS; John, ER
1988 May;69(5):P85-P85, Electroencephalography & clinical neurophysiology
— id: 31488, year: 1988, vol: 69, page: P85, stat: Journal Article,

Intraoperative real-time monitoring of brain stem facial evoked response (BFER)
Hammerschlag, P E; John, E R; Prichep, L S; Berg, H M; Cohen, N L; Ransohoff, J
1987 Jan;97(1):57-62, Laryngoscope
Injury to the facial nerve is of concern in surgery of cerebellopontine angle tumors. The crossed acoustic reflex provides a way to monitor the ipsilateral facial nerve with the auditory stimuli delivered to the contralateral side. Using the method of optimum digital filtering, it is possible to monitor the resulting brain stem facial evoked response (BFER) in real time. This paper presents preliminary experiences in more than 18 such operations monitored using this method. This preliminary study demonstrates a trend for a high (88.8%) correlation between BFER and postoperative facial nerve function. Identical latencies from simultaneous BFER and facial nerve recordings along with findings after facial nerve transection suggest that some portion of the complex BFER waveform derives from facial nerve depolarization
— id: 67631, year: 1987, vol: 97, page: 57, stat: Journal Article,

Multivariate analyses of the EEG in normal adolescents
Volkow, N D; Gomez-Mont, F; Inamdar, S; Lamella, M; Prichep, L; John, R
1987 Feb;22(2):199-204, Biological psychiatry
We investigated the computerized electroencephalography (cEEG) in a group of 85 normal adolescents. The spatial frequency of the cEEG was analyzed using various multivariate statistical techniques. The factor analyses revealed three factors that accounted for most of the variability in the data and that could be interpreted as a low versus high frequency, a beta frequency, and a frontal versus posterior factor. The cluster analysis revealed various EEG patterns that distinguished among subgroups of normal individuals
— id: 68595, year: 1987, vol: 22, page: 199, stat: Journal Article,

Real-time monitoring of brainstem auditory evoked response (BAER) during cerebellopontine angle (CPA) surgery
Hammerschlag, P E; Berg, H M; Prichep, L S; John, E R; Cohen, N L; Ransohoff, J
1986 Dec;95(5):538-542, Otolaryngology, head & neck surgery
The signal-to-noise ratio of brainstem auditory evoked responses (BAER) can be greatly enhanced by use of optimal digital filtering before averaging. This permits accurate assessment of auditory nerve status every 5 to 10 seconds, making real-time intraoperative monitoring possible. The major advantages yielded by real-time monitoring--in our experience thus far--have been identification of potentially adverse functional consequences of apparently uneventful surgical maneuvers, reducing postoperative dysfunction, early indication of potential for improved clinical function, and potential identification and localization of neural tissue in the face of absent surgical landmarks. Examples of these advantages will be provided from case studies, and the possibility that real-time monitoring may improve ability to preserve hearing will be discussed
— id: 67633, year: 1986, vol: 95, page: 538, stat: Journal Article,

REAL-TIME INTRAOPERATIVE MONITORING OF EVOKED-POTENTIALS USING OPTIMIZED DIGITAL FILTERING
John, R; Prichep, LS; Ransohoff, J; Epstein, F
1985 ;61(2):P20-P20, Electroencephalography & clinical neurophysiology
— id: 30848, year: 1985, vol: 61, page: P20, stat: Journal Article,

EFFECT OF THIOPENTAL ON BRAIN-STEM AUDITORY EVOKED-RESPONSES
Sommer, RM; Prichep, L; Malarik, P; Turndorf, H
1985 ;64(2):286-286, Anesthesia & analgesia
— id: 30983, year: 1985, vol: 64, page: 286, stat: Journal Article,

Neurometric evaluation of cognitive dysfunctions and neurological disorders in children
John, E R; Prichep, L; Ahn, H; Easton, P; Fridman, J; Kaye, H
1983 ;21(4):239-290, Progress in neurobiology
— id: 68596, year: 1983, vol: 21, page: 239, stat: Journal Article,

Electroncephalogram Tests for Brain Dysfunation: A Question of Validity
Ahn H; Prichep L; John ER
1982 Jul 2;217(4554):82-82, Science
— id: 92795, year: 1982, vol: 217, page: 82, stat: Journal Article,

Neuropsychology of childhood
Cohen, Richard; Tarter, Ralph E.; Williams, Roger; Prichep, Leslie; Hartlage, Patricia; Rourke, Byron; Hartlage, Lawrence; Boller, Francois; Goldstein, Gerald; Klonoff, Harry; Painter, Michael; Taylor, Garry; Gordan, Harold W.; Holland, Audrey L.; Chabon, Rochelle; Perel, James
Pittsburgh PA : Western Psychiatric Insitute & Clinic, 1981,
— id: 1111, year: 1981, vol: , page: , stat: ,

Neurometric evaluation of learning disabled children
Kaye, H; John, E R; Ahn, H; Prichep, L
1981 ;13(1):15-25, International journal of neuroscience
A quantified electrophysiological system called Neurometrics is described in terms of procedures, reliability and validity. The role of the computer in both acquisition and analysis is noted. In terms of the application of Neurometrics to issues of diagnostic validity five studies are discussed. The first describes a study showing that normal functioning and at risk children differ markedly in terms of the percentage showing EEG abnormalities; the second reports the difference between children who are poor achievers in verbal, arithmetic or both skills; the third shows that Neurometric indices differentiate between epileptic children who are achieving or not achieving at grade appropriate levels; the fourth describes Neurometric EEG differences between learning disabled children who do or do not have reading reversal problems; and the fifth describes the behavioral differences constructed on the basis of their Neurometric profiles
— id: 68597, year: 1981, vol: 13, page: 15, stat: Journal Article,

Developmental equations reflect brain dysfunctions
Ahn, H; Prichep, L; John, E R; Baird, H; Trepetin, M; Kaye, H
1980 Dec 12;210(4475):1259-1262, Science
Developmental equations, which predict 32 parameters of the electroencephalogram recorded from the healthy human as a function of age, were tested in diverse groups of children. Few significant deviations were found in normal children, even in a culture different from the one on which the equations were based. A high incidence of significant deviations was found in children with learning disabilities and those at risk for various neurological disorders
— id: 68598, year: 1980, vol: 210, page: 1259, stat: Journal Article,

Developmental equations for the electroencephalogram
John, E R; Ahn, H; Prichep, L; Trepetin, M; Brown, D; Kaye, H
1980 Dec 12;210(4475):1255-1258, Science
Thirty-two linear regression equations predict the frequency composition of the electroencephalogram within four frequency bands, for four bilateral regions of the brain, as a function of age. Equations based on such data from large groups of healthy children in the United States and Sweden are closely similar. These equations describe the development of the electrical activity of the normal human brain, independent of cultural, ethnic, socioeconomic, or sex factors
— id: 68599, year: 1980, vol: 210, page: 1255, stat: Journal Article,

Angel dust use in an outpatient setting--clinical profile and implications for treatment
Goldstein, G; Levy, B; Prichep, L
1979 ;6(2):163-172, American journal of drug & alcohol abuse
The study attempts to identify two populations of 20 young people who are self-reporting marijuana use in one group and angel dust in the other. We have examined these populations and evaluated them on a series of variables in an attempt to discover whether there are significant differences between them and, if so, whether there is in fact a clinical profile which may be descriptive of nonacute reactions to angel dust. Results indicate that there are significant differences on variables that distinguish angel dust users in an outpatient setting
— id: 68600, year: 1979, vol: 6, page: 163, stat: Journal Article,

Neurometrics
John ER; Karmel BZ; Corning WC; Easton P; Brown D; Ahn H; John M; Harmony T; Prichep L; Toro A; Gerson I; Bartlett F; Thatcher F; Kaye H; Valdes P; Schwartz E
1977 Jun 24;196(4297):1393-1410, Science
— id: 63338, year: 1977, vol: 196, page: 1393, stat: Journal Article,

Evoked potentials in hyperkinetic and normal children under certainty and uncertainty: a placebo and methylphenidate study
Prichep, L S; Sutton, S; Hakerem, G
1976 Sep;13(5):419-428, Psychophysiology
— id: 68155, year: 1976, vol: 13, page: 419, stat: Journal Article,

Psychiatric evaluation services to court referred drug users
Prichep, L S; Cohen, M; Kaplan, J; Kalin, E; Klein, D
1975 ;2(2):197-213, American journal of drug & alcohol abuse
This paper reports on the description and outcome of one hundred youthful drug abusers referred from family court for psychiatric evaluation and treatment recommendation. The average referral, both male and female, was a 16-year-old white Catholic from a middle class background who was diagnosed as having a personality disorder. Significantly more males than females showed pathology in early childhood such as behavior problems in school and hyperactivity. Follow-up data collected up to 6 months after evaluation and treatment recommendation indicated that approximately half of the clients showed improvement in terms of work and/or school adjustment, social relations, and drug use
— id: 68156, year: 1975, vol: 2, page: 197, stat: Journal Article,

Attention and the auditory evoked potential in hyperkinetic children treated with methylphenidate and in normal children
Prichep, Leslie S.
[S.l. : s.n.], 1975,
— id: 1110, year: 1975, vol: , page: , stat: ,