Biomedical subjects

A J Okaya

Publications and source records attributed to A J Okaya.

3 recordsLinked to original sources

PubMed1993

Quantitative EEG in obsessive-compulsive disorder.

Electroencephalograms (EEGs) were recorded from 13 unmedicated and nondepressed patients with DSM-III-R obsessive-compulsive disorder (OCD) and from 10 age-matched controls. All subjects were also administered the Wechsler Memory Scale Delayed Logical Memory and Delayed Visual Reproduction tests. Quantitative analysis of the EEG revealed lower log absolute power in the delta, beta 1, and beta 2 bandwidths for OCD patients at frontal and right-hemisphere locations. OCD patients displayed greater hemispheric asymmetries in EEG activity based on difference measures of EEG power from homologous electrode pairs, indicative of severe right hemisphere EEG hypoactivity. Standardized measures of hemispheric asymmetry for the beta 2 bandwidth accurately predicted group membership and were correlated both with poorer patient performance on the visual-spatial memory task and better performance on the verbal memory task. OCD patients were significantly impaired on the visual-spatial task, but not on the verbal memory test, relative to controls.

Adult↗

PubMed1991

Longitudinal measurements of brainstem auditory evoked potentials in patients with dementia of the Alzheimer type.

Brainstem auditory evoked potentials (BAEPs) were recorded from 33 patients with mild-to-moderate dementia of the Alzheimer type (DAT) and 16 age-matched normal controls. There were no significant differences between the two groups on any latency measure (wave V latency, I-V and III-V interpeak latencies). Within the DAT group, there was no association between BAEP latency measures and cognitive status, indexed by scores on the Mini-Mental Status Exam (MMSE). Eight of the DAT subjects were retested 6 months and one year later. Despite significant evidence of continued cognitive decline, there were no changes in BAEP latency measures over time. Furthermore, BAEP latency measures at initial testing did not predict the degree of cognitive decline over the one year time interval. The results show that BAEP latency is unaffected in patients with mild-to-moderate DAT.

Aged↗

PubMedDate not supplied

Rate of cognitive decline in Alzheimer's disease is associated with EEG alpha power.

Fifteen patients with Alzheimer's disease who were initially mildly or moderately impaired were followed for up to 4 years. Scores of the Mini-Mental State Examination (MMSE) were regressed on time of examination (measured at 6-month intervals) to estimate cognitive progression rates in individual patients. A quantitative electroencephalographic (EEG) examination was administered to each patient. Log-absolute EEG power in the alpha bandwidth (8-12 Hz) was found to be correlated with the computed rate of MMSE decline. This association was present for electrode sites across all regions of the scalp and remained significant when the effects of current cognitive severity were partialled out. These data suggest that a quantitative EEG measure (absolute alpha power) is related to the rate of cognitive decline in patients with Alzheimer's disease.

Alpha Rhythm↗