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L Prichep

Publications and source records attributed to L Prichep.

11 recordsLinked to original sources
PubMed2005

Decreased EEG synchronization in Alzheimer's disease and mild cognitive impairment.

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.

Aged↗
PubMed2005

[Topographic electroencephalography: endotracheal intubation during anaesthesia with propofol/fentanyl].

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.

Adult↗
PubMed2001

The clinical role of computerized EEG in the evaluation and treatment of learning and attention disorders in children and adolescents.

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.

Adolescent↗
PubMed1999

Progressive catatonia.

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.

Activities of Daily Living↗
PubMed1987

Multivariate analyses of the EEG in normal adolescents.

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.

Adolescent↗
PubMed1981

Neurometric evaluation of learning disabled children.

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.

Brain↗
PubMed1980

Developmental equations for the electroencephalogram.

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.

Adolescent↗
PubMed1980

Developmental equations reflect brain dysfunctions.

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.

Adolescent↗
PubMed1979

Angel dust use in an outpatient setting--clinical profile and implications for treatment.

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.

Adolescent↗
PubMed1977

Neurometrics.

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Aged↗