Biomedical subjects

K E Shy

Publications and source records attributed to K E Shy.

3 recordsLinked to original sources

PubMed1989

Predictive value of electroencephalography for electroconvulsive therapy.

The EEG has been a widely-used screening procedure before ECT. Previous studies have correlated seizures and post-ECT slowing with ECT efficacy. We investigated the utility of pre-ECT EEG in predicting therapeutic response and post-ECT confusion. EEGs were normal in 54 of 100 patients undergoing first courses of ECT for refractory depression. Patterns within the normal range, were present in 26/100 while 2/100 had paroxysmal discharges without clinical evidence of epilepsy. Focal and generalized EEG slowing were each present in 9/100 records. Full recovery occurred after ECT in 66.6 per cent of those with normal pre-ECT records, 61.5 per cent with borderline EEGs, 55.5 per cent of patients with diffuse EEG slowing, and 22.2 of cases with focal slow waves. Of those with EEG slowing 22.2 percent had little or no response to ECT as compared to 19.2 per cent with EEGs within normal limits and 9.3 per cent with normal EEGs. Four of 6 patients with prolonged confusion had normal EEGs, while 1 each had focal and generalized slowing. EEG slowing was related to incomplete ECT response, but not to therapeutic failure or post-ECT confusion. The limited predictive power of pre-ECT EEG may reflect the prevalence of normal or nonspecifically abnormal EEGs in psychiatric patients and the general efficacy of ECT. Other neurophysiologic methods may yield more definitive information about the mechanism and use of ECT.

Affective Disorders, Psychotic↗

PubMed1989

Quantitation of photic driving in dementia with normal EEG.

The EEG is frequently normal when early dementia is clinically suspected. The presence or absence of occipital driving with intermittent photic stimulation is not helpful in detecting cerebral pathology, but quantitation of photic driving was shown to distinguish between dementia and depression in geriatric patients. We quantified photic driving in twenty clinically demented patients without diffuse or focal EEG abnormality, and compared this in 20 age-matched normal controls. Intermittent stimulation at odd-numbered frequencies between 1 and 31 Hz was carried out. The product of frequency of stimulation and duration of driving response was determined, and the incidence of absent, subharmonic and supraharmonic photic driving was determined. The quantitative measure of frequency times following duration was significantly greater in the nondemented individuals than in demented patients with normal EEGs. More nondemented individuals demonstrated supraharmonic and subharmonic responses than did demented patients. The range of normal variability in persistence, duration, and symmetry of photic driving is great, and caution in determining abnormality on this basis is appropriate. Subtle but measurable changes in photic driving may occur early in dementing illnesses, however.

Aged↗

PubMed1988

EEG evidence of epileptiform paroxysms in rapid cycling bipolar patients.

Electroencephalographic (EEG) abnormalities have been described in patients with mood disorders. In an effort to determine if rapid cycling bipolar affective disorder patients may demonstrate more prevalent EEG paroxysmal activity than patients with non-rapid cycling mood disorders, we studied five consecutively identified bipolar patients who cycled at least four times a year. They were compared with 25 consecutive affective disorder patients who received an EEG before electroconvulsive therapy. Three of the five rapid cycling patients had bitemporal paroxysmal sharp waves as demonstrated by EEG but no psychomotor evidence of epilepsy. None of the 25 comparison patients had EEG abnormalities. Four of the five rapid cyclers reported a family history of affective disorder, including the three who had paroxysms.

Adolescent↗