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Biomedical subjects

J A Besson

Publications and source records attributed to J A Besson.

At least 37 records · Page 2Linked to original sources

Mortality and causes of death in idiopathic Parkinson's disease: results from the Aberdeen whole population study.

Two hundred and forty-nine patients with Parkinson's disease previously examined by Mutch et al 1,2 were followed up three and a half years after the original study. Cognitive impairment, age, some postural signs and symptoms of Parkinson's disease and high scores on the Hoehn and Yahr scale predicted premature death. Patients were more likely to die from respiratory infections than controls. Respiratory diseases as cause of death recorded on the death certificate were not related to kyphosis, posture scores or Hoehn and Yahr scores before death. The hypothesis is advanced that death of respiratory causes might be associated with signs of general autonomic dysregulation.

Aged

Multimodal imaging in Alzheimer's disease. The relationship between MRI, SPECT, cognitive and pathological changes.

Patients with a clinical diagnosis of Alzheimer's disease were studied using MRI, SPECT, and psychometric tests. Significant correlations between focal perfusion deficits and focal cognitive deficits were found. Significant correlations between regional relaxation time of white matter and psychometric tests of diffuse and focal categories were also found. Pathological examination confirmed Alzheimer's disease as the only diagnosis.

Aged

Clinical features predicting dementia in idiopathic Parkinson's disease: a follow-up study.

We followed up, after 3 1/2 years, a whole population cohort of 249 patients with Parkinson's disease (PD) 1st examined in 1983 to 1984. Of the survivors, 23.6% qualified for a DSM III-R diagnosis of dementia. In univariate tests, age, certain items of the Webster scale, the Hoehn and Yahr scale, a 10-question mental status questionnaire, and a history of smoking were associated with a diagnosis of dementia 3 1/2 years later. Logistic regression with DSM III-R diagnosis (demented versus nondemented) as the dependent variable, and age and symptom scales for PD as predictor variables, revealed that PD symptoms predicted dementia even after controlling for age. We conclude that dementia is probably more common in PD patients than would be expected in the general population and is associated with the severity of PD symptoms and signs independently of age.

Age Factors

Regional cerebral blood flow imaging: a quantitative comparison of technetium-99m-HMPAO SPECT with C15O2 PET.

The aim of this study was to compare technetium-99m-hexamethylpropyleneamineoxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) with regional cerebral blood flow (rCBF) imaging using positron emission tomography (PET). As investigation of dementia is likely to be one of the main uses of routine rCBF imaging, 18 demented patients were imaged with both techniques. The PET data were compared quantitatively with three versions of the SPECT data. These were, first, data normalized to the SPECT cerebellar uptake, second, data linearly corrected using the PET cerebellar value and, finally, data Lassen corrected for washout from the high flow areas. Both the linearly-corrected (r = 0.81) and the Lassen-corrected (r = 0.79) HMPAO SPECT data showed good correlation with the PET rCBF data. The relationship between the normalized HMPAO SPECT data and the PET data was nonlinear. It is not yet possible to obtain rCBF values in absolute units from HMPAO SPECT without knowledge of the true rCBF in one reference region for each patient.

Aged

The effect of clomipramine treatment on plasma lipoproteins and high density lipoprotein subfractions in healthy subjects.

The effect of clomipramine on plasma lipoproteins, including high density lipoprotein (HDL) subfractions in five healthy males was investigated. The concentrations of total plasma cholesterol and low density lipoprotein cholesterol decreased slightly while that of total HDL-cholesterol showed a small increase, giving a decrease (p less than 0.05) in the ratio of total plasma cholesterol to HDL-cholesterol. The level of HDL2-cholesterol increased (p less than 0.01) with clomipramine treatment while there was no significant change in the concentration of HDL3-cholesterol. Gradient gel electrophoresis showed that administration of the drug was associated with an increase in the relative concentration of HDL2a as well as of HDL2b and a decrease in that of HDL3b/3c. The plasma concentration of apolipoprotein (Apo) A-I showed a small but insignificant increase. These changes in lipoprotein profile are characteristic of those associated with a decrease in coronary risk.

Adult

Neuropsychological deficits and morphological MRI brain scan abnormalities in apparently healthy non-encephalopathic patients with cirrhosis. A controlled study.

By means of psychometric testing, we have determined the frequency of latent hepatic encephalopathy in a group of 19 cirrhotics with no clinical evidence of encephalopathy. Magnetic resonance imaging (MRI) of the brain was performed in order to determine whether morphological cerebral abnormalities were associated with latent encephalopathy. Nineteen age and educationally matched patients with normal liver function acted as controls. Significant differences (P less than 0.05) between cirrhotics and controls were found in tests of short-term visual memory and speed of reaction to light (cirrhotics 316 +/- 132 ms vs. controls 225 +/- 36 ms), sound (cirrhotics 361 +/- 152 ms vs. controls 236 +/- 52 ms) and choice (cirrhotics 651 +/- 190 ms vs. controls 406 +/- 101 ms) stimuli (all values mean +/- S.D.). Reitan trail test performance, however, was similar in both groups. (Trail A: cirrhotics 43 +/- 19 s vs. controls 35 +/- 13 s; Trail B: cirrhotics 105 +/- 66 s vs. controls 93 +/- 36 s.) In patients with cirrhosis, MRI revealed statistically significant increases in the maximum fissure width of right frontal sulci, right and left parietal sulci, inter-hemispheric fissure width and in bicaudate index. These changes, indicating cerebral atrophy, were largely confined to alcoholics. There was poor correlation between measurements of cerebral morphology and neuropsychological performance, only 10% of associations achieving statistical significance.

Adult

Magnetic resonance imaging in Alzheimer's disease, multi-infarct dementia, alcoholic dementia and Korsakoff's psychosis.

Regional spin lattice relaxation times (T1) measured during nuclear magnetic resonance imaging of the brain were compared in patients with Alzheimer's disease, multi-infarct dementia, alcoholic dementia, Korsakoff's psychosis and control subjects. Regional differences were found between all patient groups compared with controls and within patient groups, with the exception of the comparison between Korsakoff's psychosis and alcoholic dementia. Correlations between regional T1 change and cognitive test scores were also found, with particular emphasis between visuospatial deficits and parietal T1. The possible role of T1 measures in the pathophysiology of these disorders is discussed.

Aged

Estimating premorbid IQ from demographic variables: regression equations derived from a UK sample.

The purpose of the study reported here was to build regression equations for the estimation of premorbid IQ from demographic variables in a UK population. Subjects (n=151) free of neurological, psychiatric or sensory disability, were administered the Wechsler Adult Intelligence Scale (WAIS) and had their demographic details recorded (age, sex, occupation and education). WAIS Full Scale (FSIQ), Verbal (VIQ), and Performance IQ (PIQ) were regressed on the demographic variables. The regression equations generated by this procedure predicted 50, 50, and 30 percent of the variance in FSIQ, VIQ, and PIQ respectively. These equations should provide a convenient and useful supplement to psychometric estimates of premorbid IQ. Unlike psychometric estimates, demographic estimates are entirely independent of a patient's current cognitive status.

Adolescent

Effects of ethanol on the NMR characteristics of rat brain. Acute administration, dependency, and long-term effects.

In rats, neither acute administration of ethanol nor the establishment of ethanol dependence by chronic administration for 28 days produced significant 1H-NMR relaxation changes. However, chronic ethanol intake for six months produced a transient rise in T1, with no change in T2 or water content. The significance of these results for study in man is discussed and a hypothesis is proposed to explain discrepant differences between T1, T2 and water content. It is suggested that T1 change with long-term ethanol exposure is related to altered free/bound water state secondary to cell membrane changes.

Alcoholic Intoxication

A comparison of Tc-99m HM-PAO and I-123 IMP cerebral SPECT images in Alzheimer's disease and multi-infarct dementia.

SPECT images of the brain can be obtained using either 123I labelled amines or 99mTc-hexamethylpropyleneamineoxime (HM-PAO). Both materials produce images which are blood flow dominated and so appear similar in normal subjects, although the respective mechanisms of uptake are not yet finally established. It seems likely, however, that the different mechanisms of uptake are responsible for recent reports of some differences seen in images obtained with the two types of agent in patients with cerebral pathology, mainly cerebrovascular disease. In this study, 12 demented patients, 6 with dementia of the Alzheimer type (DAT) and 6 with multi infarct dementia (MID), were imaged with 123I-isopropylamphetamine (IMP) and 99mTc-HM-PAO and the images compared. Significantly more lesions were seen with IMP than HM-PAO (P less than 0.02); out of a possible 120 sites, 41 lesions were seen with IMP compared to 28 with HM-PAO, 23 being seen with both agents. However, it is concluded that either agent can be used for the differential diagnosis of dementia, a task for which the new cerebral blood flow agents seem well suited.

Aged

The use of technetium-99m-HM-PAO in the assessment of patients with dementia and other neuropsychiatric conditions.

One hundred fourteen patients suffering from neuropsychiatric conditions have been studied using 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) and single photon emission computed tomography (SPECT). Ninety-one patients had a firm clinical diagnosis while 23 were examined without knowledge of the clinical diagnosis. Of the 91 patients, 51 were suffering from dementia, 25 multi-infarct type and 26 Alzheimer's disease. In 19 of the Alzheimer's patients, a characteristic pattern of decreased perfusion in the parieto-occipital regions was demonstrated while those with multi-infarct type showed varying degrees of irregular uptake in the cerebral cortex. These appearances are similar to those shown with positron emission tomography (PET) and we believe that HM-PAO will provide a widely available method for identifying patients with Alzheimer's disease. Twenty-nine patients were suffering from diseases involving the basal ganglia. Fifteen patients with Parkinson's disease showed no significant abnormality in basal ganglia uptake, while 7 or 8 patients with Huntington's disease who had full examinations showed decreased uptake in the caudate nuclei. Similarly, four of six patients with other basal ganglia diseases showed impaired uptake by basal ganglia, and it is concluded that HM-PAO may be useful for the diagnosis and management of this type of patient. Twenty-three patients received HM-PAO imaging as part of their diagnostic work-up; in 19 of them, detailed follow-up was obtained, which indicated that in 7 cases the result of the HM-PAO scan altered the clinical diagnosis and in 9 cases resulted in a change in management. In the remaining 13 cases, the study was found to be helpful in confirming the diagnosis.

Adult

The relationship between demographic variables and NART performance in normal subjects.

The relationship between NART performance and demographic variables was examined in a group of subjects free of neurologic or psychiatric disorder (n = 201). NART estimated IQ was significantly correlated with education, social class and age. The correlation between age and NART IQ was no longer significant after partialling out either education or social class. There was no evidence of a curvilinear relationship between age and NART performance. There was no significant sex difference in NART performance. Nelson's (1982) report of a high split-half reliability was confirmed.

Adolescent

Imaging of cerebral blood flow markers in Huntington's disease using single photon emission computed tomography.

Single photon emission computed tomography (SPECT) imaging of six Huntington's disease patients revealed a striking reduction in regional uptake of cerebral blood flow markers in vivo. Similar changes were found in one patient with "early stage" disease. The findings are compared with parallel magnetic resonance imaging (MRI) studies, and in one case, results of postmortem examination.

Adult