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Biomedical subjects

E G Spokes

Publications and source records attributed to E G Spokes.

At least 19 recordsLinked to original sources

A 10-year study of the incidence of and factors predicting dementia in Parkinson's disease.

OBJECTIVE: To compare the incidence of dementia in PD with that of a control group without PD, and to assess the relationship between dementia and other features of PD. METHODS: The authors recruited 83 patients with PD and 50 controls, all without dementia at initial assessment, and assessed them at regular intervals over a maximum period of 122 months. Dementia was diagnosed according to objective criteria, and included a judgment by researchers masked to subject group and to variables putatively associated with dementia. RESULTS: Seventeen patients fulfilled dementia criteria; no controls did so. The cumulative proportion of PD patients becoming demented by 112 months was 0.38 (95% CI 0.20 to 0.55), or 42.6 cases per 1000 years of observation. Univariate analyses showed that incident dementia in patients with PD was associated with older age at entry into the study, greater severity of neurologic symptoms, longer duration of PD, greater disability, and male sex. The association of age at onset of PD with incident dementia was of only borderline significance. Multivariate analysis found that age at entry into the study and severity of motor symptoms were significant predictors of dementia but duration of PD and age at onset of PD were not. CONCLUSIONS: Dementia in PD is likely to reflect interaction of the neuropathology of the basal ganglia and age-related pathology. The findings do not support the division of PD into early and late-onset cases.

Age of Onset↗

A controlled, longitudinal study of dementia in Parkinson's disease.

Serial assessments of cognition, mood, and disability were carried out at nine month intervals over a 54 month period on a cohort of 87 patients with Parkinson's disease (PD) and a matched cohort of 50 control subjects. Dementia was diagnosed from data by rigorously applying DSM-III-R criteria. Initially, 6% (5/87) PD patients were demented, compared with none of the 50 control subjects. A further 10 PD patients met the dementia criteria during the follow up period; this was equivalent, with survival analysis, to a cumulative incidence of 19%. With the number of person years of observation as the denominator, the incidence was 47.6/1000 person years of observation. None of the control subjects fulfilled dementia criteria during the follow up period. The patients with PD who became demented during follow up were older at onset of Parkinson's disease than patients who did not become demented, had a longer duration of Parkinson's disease, and were older at inclusion to the study.

Aged↗

Cognitive impairment and dementia in Parkinson's disease: a controlled study.

The performance of 47 patients with Parkinson's disease on a battery of tests of cognition, motor function, disability and mood was compared with the performance of 47 healthy control subjects who were matched to the patients on the basis of age, sex and pre-morbid IQ. An increased prevalence of impairment over a range of cognitive functions was observed in the Parkinson's disease patients as compared with their matched controls. The differences between the Parkinson's disease patients and controls could not be accounted for by factors such as depressed mood, effects of medication or motor impairment. Our findings are discussed in relation to the methodology of previous studies in this area and to the need for a comprehensive clinico-pathological longitudinal study.

Activities of Daily Living↗

Brain monoamine oxidase activity in schizophrenics and controls.

Postmortem samples of caudate nucleus and frontal cortex from schizophrenic, schizophrenic-like, and control subjects were examined for monoamine oxidase activity using dopamine, phenylethylamine, and 5-hydroxytryptamine as substrates. There were no significant differences between the diagnostic groups with any of the three substrates. Neither was there a difference between the sexes, nor a consistent relationship of enzyme activity to age.

Aged↗

Human post-mortem pineal enzyme activity.

The synthetic enzymes for melatonin production, serotonin-N-acetyltransferase (SNAT) and hydroxy-indole-O-methyltransferase (HIOMT) were measured in post-mortem pineal organs from eighty-eight men and women. The activity of each enzyme was correlated with age and sex. No difference was seen in either parameter when the maximum or minimum activities were measured in the death time periods of the diurnal rhythm established earlier. However, an annual bimodal rhythm was seen in HIOMT activity with maximal values occurring in January and July and minimum activities in March and October. The SNAT and HIOMT enzymes have previously been shown to be stable when measured in pineal organs held under the usual post-mortem conditions. Pineal HIOMT has also been measured in twenty-one psychotic individuals. Whilst the schizophrenic group showed significantly increased values, the schizophrenic-like group had normal values. The results were not affected by ante-mortem or post-mortem states or by drug treatment. Any clinical interpretation of pineal dysfunction in disease states need not, therefore, take into consideration age, or possible sex, but should be aware of the normal diurnal rhythm as well as the bimodal annual rhythm.

Acetylserotonin O-Methyltransferase↗

Distribution of GABA in post-mortem brain tissue from control, psychotic and Huntington's chorea subjects.

Gamma-aminobutyric acid (GABA) concentrations were measured in 10 regions of post-mortem brain from control, psychotic and choreic subjects; glutamate decarboxylase (GAD) activities were estimated in substantia nigra. In agreement with earlier observations, agonal status profoundly affected GAD measurements in the substantia nigra but had no effect on GABA levels in any brain region. Although GAD and GABA levels were significantly correlated in nigral tissue from sudden death control and psychotic cases, the association was lost in patients dying slowly. In Huntington's chorea significant reduction in GABA content were observed in the nucleus accumbens, lateral pallidum, subthalamic nucleus, substantia nigra and ventrolateral thalamic nucleus. In psychotic patients there were significant decreases in GABA concentrations in the amygdala and nucleus accumbens. Division of the psychotic group into schizophrenia and schizophrenia-like categories and into early-onset and later-onset cases revealed that GABA levels in the amygdala were diminished in all 4 psychotic subgroups, whereas in the nucleus accumbens the deficit was confined to cases of early-onset schizophrenia.

Brain↗