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Biomedical subjects

J A Besson

Publications and source records attributed to J A Besson.

At least 19 recordsLinked to original sources

Event related potentials, reaction time, and cognitive performance in idiopathic Parkinson's disease.

Sixteen non-demented patients with idiopathic Parkinson's disease (PD) with varying degrees of cognitive impairment and sixteen age-, sex- and education-matched normal controls were examined with (1) an auditory oddball paradigm requiring counting or a motor response in separate determinations, (2) a reaction time task with movement time component and (3) a detailed clinical and neuropsychological test battery. Patients were impaired on a number of neuropsychological tests. They also showed an increased P2 and N2 latency, but no significant increase in P3 latency. Their response initiation times and reaction times during the oddball experiment were not different from controls, whereas movement time was significantly increased. Increased peak latencies, particularly for N2, were moderately associated with Parkinsonian motor impairment in patients and with the Benton Multiple Choice Visual Retention Test in patients and controls. Movement time was associated with P3 latency only in controls and in both groups with the Benton Multiple Choice Visual Retention Test. The observed pattern of results suggests that in non-demented PD patients ERP peak latencies, visuo-spatial task performance and Parkinsonian motor impairment share a significant degree of variance. While impairments in neuropsychological tests and delay in the earlier peaks P2 and N2 do not appear to be sensitive to medication with L-DOPA, normal P3 latencies might indicate good pharmacological symptom control in the absence of dementia.

Aged

Alzheimer's disease in adults with Down's syndrome: the relationship between regional cerebral blood flow equivalents and dementia.

Twenty adult patients suffering from Down's syndrome (DS) were recruited from hospitals and the community, together with 14 age- and sex-matched controls of normal intelligence. Dementia was diagnosed in patients using a structured psychiatric and physical examination as well as a carer interview and case notes. All patients and controls were imaged using single photon emission computerized tomography with 99mTc-exametazime. Four patients were clinically demented and all of them showed regional cerebral blood flow (rCBF) changes commonly found in patients with Alzheimer's disease, namely bilateral temporo-parietal deficits. These changes were also observed in about half of the patients without clinical evidence of dementia, but in none of the healthy controls. Across the group of patients, temporo-parietal rCBF deficits were associated with evidence of deterioration, but not with advancing age.

Adult

Post-mortem proton magnetic resonance spectrometric measures of brain regions in patients with a pathological diagnosis of Alzheimer's disease and multi-infarct dementia.

In-vitro spectrometric measures were made of spin-lattice (T1) and spin-spin (T2) relaxation times of samples of grey and white matter from the brains of 15 patients with a pathological diagnosis of Alzheimer's disease, 5 with multi-infarct dementia, and 11 non-demented subjects. Relaxation times were significantly greater in the parietal white matter and temporal white matter of patients with Alzheimer's disease compared with that of the other subjects. This was associated with an increase in tissue water content. These findings confirm measures obtained in some imaging studies.

Aged

Estimation of premorbid intelligence in schizophrenia.

To determine whether the National Adult Reading Test (NART) would provide a valid estimate of premorbid intelligence in schizophrenia, two schizophrenic samples were recruited, one consisting of 35 patients resident in long-stay wards, the other of 29 patients normally resident in the community. Schizophrenic patients were individually matched for age, sex, and education with a healthy, normal subject. Both schizophrenic samples scored significantly lower on the Wechsler Adult Intelligence Scale (WAIS) than their respective control groups. NART-estimated IQ did not differ significantly between the community-resident schizophrenics and their controls, suggesting that the NART provides a valid means of estimating premorbid intelligence in such a population. NART-estimated IQ was significantly lower in the long-stay sample than in their controls. Although low NART scores in this latter sample could be a valid reflection of low premorbid IQ, the alternative explanation that NART performance was impaired by onset of the disease cannot be ruled out.

Adult

Relationship between observed NMR changes and brain water content following electroconvulsive stimulation in the rat.

The administration of electroconvulsive stimuli to anaesthetised rats results in changes in the relaxation times and water content of grey and white matter, but not in mid brain, hind brain or cerebellum. White matter changes occur in both T1 and T2, are biphasic in character and related to water content. Grey matter changes are confined to T1 and water content only. It is suggested that these changes are related to altered compartmentalisation of water, manifesting in a different manner in the two tissues probably due to their different cellular and biochemical composition.

Animals

Red blood cell NMR proton relaxation times in ill and recovered patients with unipolar and bipolar affective disorders.

Red blood cell NMR relaxation times T1 and T2 and water content were measured in ill and recovered patients with mania, unipolar depressed phase, bipolar depressed phase and control subjects. The results suggest that relaxation times are elevated in ill bipolar manic and ill unipolar depressed patients but are normal in both groups in the recovered phase and in ill bipolar depressed patients. Relaxation times therefore seem to be state-dependent but behave differently in unipolar and bipolar patients.

Bipolar Disorder

Dementia in idiopathic Parkinson's disease: prevalence and relationship with symptoms and signs of parkinsonism.

A whole population cohort of 157 patients with idiopathic Parkinsonism, most of whom had previously been clinically examined by Mutch (1986a), were assessed to determine prevalence figures for dementia and examine the relationship between dementia, cognitive impairment and Parkinsonian signs. Dementia according to DSM-III-R criteria was diagnosed in 23.3% of all patients (95% confidence interval: 17.1 to 32.4%). Dementia and cognitive impairment were associated with overall measures of Parkinsonian impairment and rigidity, but not tremor, even after controlling for age, sex and education.

Adult

Red cell caesium, lithium and selenium in abstinent alcoholics.

Using inductively coupled plasma source mass spectrometry, we have studied the red cell element concentrations of alcoholic subjects with different periods of abstinence before testing. We found consistently elevated red cell caesium concentrations and also reduced red cell selenium concentrations. These may represent persistent abnormalities in oxidation/anti-oxidation mechanisms, and red cell caesium in particular may be a long-term marker of alcohol dependence. Erythrocyte lithium, cerium and boron concentrations were also reduced in the abstinent alcoholic groups.

Adult

The effects of progressive abstinence from alcohol on red blood cell proton NMR relaxation times and water content.

Red blood cell proton relaxation times T1 and T2 were measured in samples from chronic alcoholic patients abstinent for varying periods from 1 week to over 6 months. T1 and T2 were elevated in the early stages of abstinence and declined to the values of controls after 8 weeks. Changes in the water content of the red blood cells and the mean corpuscular volume paralleled these changes but were more closely associated with T2. It is suggested that T1 and T2 may reflect different aspects in water content and free-to-bound ratio of water. The significance of these findings is discussed in the context of changes previously observed in the brains of alcoholic patients, and in rats fed a diet supplemented with alcohol for 6 months.

Adult

The clinical manifestation of mental disorder in Huntington's disease: a retrospective case record study of disease progression.

All cases (86) of Huntington's Disease presenting between 1970 and 1987 in the Grampian Health Board region were identified and a case note analysis of neurological and psychiatric syndromes carried out--the latter using the PSE syndrome check-list. The commonest syndromes were organic impairment, irritability, loss of interest and concentration and simple depression and these were often the presenting psychiatric syndromes. General anxiety, worrying and social unease occurred early, commonly before movement disorder and were associated with longer survival.

Anxiety Disorders

Intermittent alexia.

A case of intermittent alexia, sometimes accompanied by severe dysgraphia and sometimes by mild dysgraphia, which had a probable migrainous origin, is described. On some occasions the patient could write to dictation, although with many errors, while unable to read words or letters. On other occasions the patient's writing to dictation was seriously disordered in terms of content and the letters were produced clumsily. Reading of numbers, colour vision and colour naming were normal although impairments on right-left orientation and visual short term memory were present and a mild finger agnosia was apparent. Blood flow scans (SPECT) taken under normal and alexic conditions support the view that the disturbance had a vascular origin.

Adolescent

Parkinson's disease in Aberdeen: survival after 3.5 years.

The increasing age of the general population and of patients suffering from Parkinson's disease suggests that a reappraisal of mortality rates and factors related to increased mortality should be carried out. A 3.5 year follow-up of a whole population sample of 267 patients and 233 controls matched by age, sex and general practitioner, yielded a relative mortality rate of 2.35 (99%-confidence interval: 1.60-3.43). Factors predicting death within the follow-up period were: cognitive impairment, old age, late age of onset, long history of smoking, lower blood pressure, and a variety of signs, symptoms and sequelae of Parkinson's disease associated with decreased mobility. However, age less than 70 years, age of onset before 66 years, absence of kyphosis or normal Webster posture score, mild impairment on the Hoehn & Yahr scale (1-2), or no impairment in a 10-question mental status questionnaire (9-10), were not associated with an increased risk of death.

Aged

P300 and smooth eye pursuit: concordance of abnormalities and relation to clinical features in DSM-III schizophrenia.

Twenty-five DSM-III-diagnosed schizophrenics and 37 normal and age-matched controls were examined using an oddball paradigm for the generation of P300 and smooth eye-pursuit tasks. Results were compared between groups and related to clinical characteristics, including a family history of psychiatric illness. Group differences were found for P300 amplitudes, latencies and eye-tracking. A family history of psychiatric illness was associated with normal eye-tracking in patients. Small P300 amplitudes alone and in combination with long P300 latencies were associated with a family history in controls.

Adult

A comparison of the WAIS and WAIS-R in matched UK samples.

A matched samples design was employed to compare WAIS and WAIS-R IQ in UK subjects. The WAIS yielded significantly higher mean Full Scale, Verbal and Performance IQs. The mean differences were 7.5, 6.4 and 7.9 IQ points respectively. The WAIS and WAIS-R samples were broadly representative of the UK adult population in terms of age, sex and social class distribution, and therefore provide tentative estimates of population mean scores for both Wechsler scales. Mean WAIS IQ was 108.6, suggesting that the WAIS yields inflated IQ scores in the contemporary UK population. Encouragingly, mean WAIS-R Full Scale IQ was 101.1, suggesting that it neither markedly underestimates nor overestimates IQ in the UK.

Adolescent