George W. Fenton

Anticholinergic drug effects on quantitative electroencephalogram, visual evoked potential, and verbal memory.

Electroencephalographic (EEG) power and coherence spectrum and visual evoked potential (VEP) recordings were made in a group of control subjects on two occasions, a week apart, before and after the subcutaneous administration of either 0.6 mg scopolamine (hyoscine-hydrobromide), a centrally acting anticholinergic drug, or 0.5 mg methscopolamine nitrate, a peripherally acting anticholinergic drug. After scopolamine administration, the EEG power spectrum significantly slowed and EEG coherence at the alpha and beta frequencies decreased. Left interhemispheric coherence increased at 1 Hz and 3-7 Hz. Methscopolamine had no significant effect on the quantitative EEG. The latency of the major positive components of the VEPs, to both flash and pattern stimuli, were not significantly affected by either drug. Verbal memory was significantly reduced after scopolamine. The results suggest that previous reports of scopolamine-induced changes in the EEG power spectrum and in verbal memory can be attributed to the central action of the drug rather than to peripheral side effects.

Electroencephalography and single photon emission computed tomography in dementia: a comparative study

A series of elderly patients with dementia of Alzheimer type (AD), multi-infarct dementia (MID) and functional (non-organic) psychiatric illness (major depressive disorder) were selected according to DSM-III-R criteria and received: a battery of cognitive tests, EEG and Single Photon Emission Computed Tomography (SPECT) using 99mTc HMPAO. The EEG and SPECT scans were examined independently of the clinical data. The former were divided into two abnormal categories, those showing AD type change and vascular change respectively, and a normal group. The SPECT scans were classified as follows: a SPECT rCBF pattern showing bilateral temporoparietal perfusion deficits (AD type); those showing single focal perfusion deficits or multiple areas of low perfusion in the cerebral cortex suggestive of ischaemic change (vascular type SPECT picture); a mixed AD/MID pattern; and those with normal scan findings. There were significant associations between clinical diagnosis, EEG rating and SPECT rCBF pattern, approximately three-quarters of AD and MID patients having the predicted EEG and scan changes. Normal EEG recordings were more common in the MID patients. The two tests agreed in about two-thirds of cases, with no consistent pattern apparent in the cases with divergent findings. Each test misclassified a minority of dementia patients, but in only one patient were both investigations normal. Almost half of the so called functionally ill patients had abnormal rCBF changes, showing mainly vascular changes while one-fifth had abnormal EEGs.

Neurophysiology and SPECT cerebral blood flow patterns in dementia.

A series of elderly patients with dementia of Alzheimer type (AD), multi-infarct dementia (MID) and functional (non-organic) psychiatric illness (major depressive disorder) were selected by DSM III-R criteria and had the following investigations: a battery of cognitive tests, EEG with power and coherence spectral analyses of T4-T6, T3-T5, P4-O2, P3-O1 channels, visual evoked potential (flash and pattern reversal) and P300 recordings as well as single photon emission tomography (SPECT) using 99mTc HMPAO. Three subsets of patients were chosen on clinical and SPECT criteria. These were as follows: patients with a clinical diagnosis of AD and a SPECT rCBF pattern showing bilateral temporo-parietal perfusion deficits (AD type), patients with a clinical diagnosis of MID and a SPECT rCBF pattern showing single focal perfusion deficits or multiple areas of low perfusion in the cerebral cortex suggestive of ischaemic change (MID type SPECT picture) and functionally ill patients with normal rCBF (controls). The AD type group differed from the MID rCBF group in having significantly less alpha and more delta 2 (2- < 4 Hz) power. The latter had significantly lower alpha power than the controls. The 2 dementia groups with abnormal rCBF patterns did not differ in terms of coherence spectra or P300 latencies, but both had lower within and between hemisphere alpha coherence values and longer P300 latencies than the controls with normal rCBF. There were no group differences in the flash VEP P2-pattern reversal P100 latency difference values.

EEG power spectra and cognitive change in geriatric psychiatry: a longitudinal study.

Elderly patients with senile dementia of the Alzheimer type (SDAT), multi-infarct dementia (MID) and functional psychiatric illness, along with elderly control subjects, were studied longitudinally at 6 monthly intervals over a 2 year period, with cognitive testing and EEG power spectral analyses being carried out on each occasion. There was no significant change in the EEG power over time although a significant regression effect was noted for cognitive performance in the SDAT group. A number of between-group differences were apparent. The SDAT patients had more delta and theta power and less alpha power than those with MID and the latter group had a higher percentage of delta and theta power than the functional patients. The functional patients and normal subjects were differentiated from each other by a number of EEG power variables. The implications of these findings with respect to differential diagnosis in geriatric psychiatry are discussed.

Violence ratings of special hospital patients

Abstract The male population of a high security hospital is described in terms of the profile of patients pre-admission violence (index offence and previous convictions), using a rating scale described by Robertson et al. (1987). The ratings show that Broadmoor Hospital patients exhibit a high level of violence both in terms of previous convictions and related to their index offence. Only one patient was admitted after a non-violent index offence. At Broadmoor 55 per cent of the population had previous convictions of violence before the index offence; 17 per cent had a previous history of unprosecuted violence before the present admission; 19 per cent were admitted to the hospital following a single severely violent index offence which resulted in the death or serious injury of the victim; 72 per cent of this last group have the clinical diagnosis of schizophrenia. In this study, the rating scale was noted as a useful screening instrument that can describe the violence profile of Special Hospital patient...

Teaching Medical Students About Epilepsy

Summary: A small study was designed to evaluate three seminars on epilepsy for junior medical students. A self‐completion questionnaire on knowledge and atétéudes was constructed and administered to case and control students and, as part of a parallel study, to senior medical students, general pracétéioners, and a sample of patients attending general practice. Students undertaking seminars on epilepsy showed significant improvement in overall knowledge, but not in atétéudes. Many students had observed an epileptic seizure before entering medical school, but neither this, nor close acquaintance with persons with epilepsy, appeared to affect their responses. Age appeared to influence knowledge in the sample of general practice attenders, with those aged 30–59 scoring a significantly higher mean score than older and younger subgroups.

How successful is teaching on terminal care

Summary. Teaching on terminal care in the Dundee University Medical School is being evaluated over the next 4 years (1985–89). The paper describes the present course and the intended procedures of evaluation. A pilot evaluation was conducted on a class of fourth‐year students during the academic year 1984–85. Students recall of factual information presented 2 years and also 2 terms prior to the pilot evaluation was acceptable although questions relating to pain relief were not well answered. When asked to rate ten areas of medical management from most to least satisfying and worrying, the majority of students saw both the care of the terminally ill and speaking with those about to face bereavement as relatively high on worry and low on satisfaction. The overall results of the pilot study challenged teachers to consider the cost‐effectiveness of their chosen methods of teaching on terminal care.

Serial visual evoked potential recordings in geriatric psychiatry

Serial visual evoked potentials to flash and pattern reversal stimuli were recorded in elderly patients with senile dementia of the Alzheimer type (SDAT), multi-infarct dementia (MID) and functional psychiatric illness, and in a group of elderly control subjects. Recordings were made at 6 monthly intervals over a 2 year period. Latency and amplitude of the main components were measured and the flash P2-pattern reversal P100 latency difference value was calculated. In all groups significant changes over time did not occur for any parameters but in the SDAT group the regression coefficient for the latency of the flash P2 component and the flash P2-pattern reversal P100 latency difference was significant, reflecting a trend towards increasing flash P2 latency as time progressed. The flash P2-pattern reversal P100 latency difference was longer in the SDAT and MID groups than in the functional patients, confirming the findings of previous reports. The latency difference in the SDAT group only was significantly greater than that in the control group.

The use of methohexitone in sleep electroencephalography

Abstract The use of methohexitone in sleep electroencephalography was assessed by comparing its effect with that of an equivalent dose of thiopentone in the same subject. 32 patients were examined. Methohexitone produced the classical EEG patterns of barbiturate narcosis, but the induced fast rhythms were slightly less abundant than those seen with thiopentone. However, there were always sufficient to compare the symmetry between the two hemispheres. Slow activity appeared more quickly with methohexitone and was more prominent. Paroxysmal phenomena occurred equally commonly with both drugs. Spontaneous muscle movements and hiccup were more common with methohexitone but were never severe enough to cause a serious problem. The recovery time after methohexitone was substantially shorter than after thiopentone. Methohexitone is a useful drug for inducing sleep, especially in out-patients.

Clinical electroencephalography in a psychiatric service.

An audit of the use of clinical electroencephalography in a psychiatric service was carried out by examining the referrals for an EEG from the service over one year (11% of all referrals), comparing them with matched patient controls, rating the EEGs blindly and estimating the clinical value of the investigation for each patient; 37% were abnormal, 19% anomalous and 44% normal. The following two clusters of symptoms and signs were associated with EEG referral — the patients with “organic” mental state phenomena and/or CNS signs; EEG usually abnormal and the patients with behavioural changes that raise the suspicion of an organic process but, taken alone, are not compelling evidence of such (for example, impulsive behaviour, acute and atypical psychoses, perceptual or behavioural phenomena of the type associated with temporal lobe epilepsy in the absence of frank complex partial seizures); EEG usually normal or anomalous. Ninety-two percent of EEGs were judged to be of clinical value; 53% positive and 39% negative. Eight percent of referrals made no contribution to the clinical evaluation.