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Biomedical subjects

N T Mathew

Publications and source records attributed to N T Mathew.

At least 73 records · Page 4Linked to original sources
PubMed1977

Regional cerebral blood flow statistical patterns and psychological performance in multi-infarct dementia and Alzheimer's disease.

Multivariate data analysis statistical procedures were applied to identify regional cerebral blood flow (rCBF) patterns in patients with multi-infarct dementia (M.I.D.) and Alzheimer's disease (A.D.) when compared to a control group (C.). A fronto-temporal-parietal pattern was identified for the A.D. group. The M.I.D. group demonstrated a predominant temporal parietal pattern. A discriminant function analysis classified 96% of the A.D. and C. patients correctly. One hundred per cent hit rate was obtained in discriminating between M.I.D. and C. Discrimination of A.D. and M.I.D. obtained 82% diagnostic accuracy. When the three groups were compared the hit rate was 93%. Mean rCBF and mean relative weight of the gray matter (Wg) differences were found when each dementia group was compared with C.M.I.D. and A.D. did not differ in mean rCBF but significant differences were found for Wg, with M.I.D. having greater reduction. The performance on standardized psychological tests of two independent samples of A.D. and M.I.D. were compared. The Memory Quotient from the Wechsler Memory Scale was consistently more imparied for the A.D. group. No correlation between degree of psychological impairment and rCBF or Wg reduction was found.

Adult↗
PubMed1976

Hyperlipidemic neuropathy and dementia.

Mixed types of sensory and motor peripheral neuropathy and dementia occurred as neurological complications in patients with established type IV and type V hyperlipoproteinemia. These complications were remedial by control of the hyperlipoproteinemia with diet and/or clofibrate resulting in symptomatic improvement as well as restitution of nerve conduction velocities toward normal. Diabetes mellitus as well as systemic metabolic and toxic disorders which commonly produce neurological complications were excluded. Segmental demyelination with disorganization of myelin lamellae were striking morphological features found on sural nerve biopsy. Fluctuations in memory performance correlated inversely with plasma lipid levels and appear to be a characteristic feature of hyperlipidemic dementia. Hyperlipidemic neuropathy and dementia, although rare, are remediable neurological disorders which should be considered in patients with neuropathy and/or dementia of unknown origin.

Adult↗
PubMed1975

Hyperlipoproteinemia in occlusive cerebrovascular disease.

The distribution of occlusive atherosclerotic lesions in the aortocranial circulation as determined by arteriography was correlated with results of plasma lipid and lipoprotein determinations of patients with symptoms and signs of cerebrovascular disease. The incidence of hyperlipoproteinemia in the total study population was 31.8%. The frequency of hyperlipoproteinemia was signigicantly higher in patients with atherosclerotic lesions limited to extracranial (51%) and intracranial major vessels (44.2%) when compared to the total number of patients and patients with only intracranial small-vessel disease (P less than .05). Type IV hyperlipoproteinemia was the most common abnormality (extracranial group, 42% type IV, 9% type II; intracranial major-vessel group, 35.8% type IV, 8.4% type II). Patients with intracranial small-vessel disease had the lowest frequency of hyperlipoproteinemia (14.2%). The frequency of hypertension with or without hyperlipoproteinemia was higher in patients with intracranial small-vessel disease (P less than .01).

Adult↗
PubMed1975

Abnormal cerebrospinal fluid-blood flow dynamics. Implications in diagnosis, treatment, and prognosis in normal pressure hydrocephalus.

Increased cerebral blood flow (CBF) has been proposed as responsible for the clinical improvement after cerebrospinal fluid (CSF) shunting in patients with normal pressure hydrocephalus (NPH). In order to determine any abnormal CSF-CBF pressure-flow relationships in NPH, measurements of regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV) were made before and after lowering CSF pressure (CSFP) in 15 patients with NPH, and in ten patients with presumed hydrocephalus ex vacuo. Maximal reduction of rCBF and rCBV occurred in the territory of the anterior cerebral artery in NPH but no in dementia due to brain atrophy. Both CBF and rCBV increased after lowering the CSFP by lumbar puncture in patients with NPH. Patients with higher preoperative rCBF and maximal increases in rCBR and rCBV after lowering CSFP showed the most consistent clinical improvement after CSF shunting. Evidence is offered that CBF autoregulation is impaired in NPH. The CBF test assists in both diagnosis and selection of patients for CSF shunting.

Adult↗
PubMed1975

Analysis of intellectual and cognitive performance in patients with multi-infarct dementia, vertebrobasilar insufficiency with dementia, and Alzheimer's disease.

A prominent feature in dementia is intellectual deterioration. Review of the clinical literature indicates a lack of suitably quantitated studies of specific intellectual defects in dementia. The present study investigated the performance of patients with multi-infarct dementia (MID), dementia due to Alzheimer's disease (AD), and vertebrobasilar insufficiency (VBI) with dementia using the Wechsler Adult Intelligence Scale (WAIS). Forty-two patients ranging in age from 45 to 85 years (x 66) were included. Significant differences in cognitive and intellectual performance were found between patients with dementia due to VBI and MID versus neuronal atrophy of the Alzheimer's type. The group with AD performed significantly and consistently lower on all measures. There were no significant differences between the two cerebrovascular disease groups, even though the MID group performed consistently more poorly than the VBI group. A discriminant function analysis classified 74% of the patients correctly based on the individual WAIS scores. The diagnosis was more easily made when tasks measuring visual motor coordination and abstract reasoning were included in the analysis.

Age Factors↗
PubMed1975

Circulatory and metabolic effects of glycerol infusion in patients with recent cerebral infarction.

The effect of intravenous infusion of 10 per cent glycerol on regional cerebral blood flow (using hydrogen bolus and Xenon-133 (133Xe) clearance methods) and metabolism was investigated in 57 patients with recent cerebral infarction. Hemispheric blood flow (HBF) increased, together with increase in regional cerebral blood flow (rCBF) and cerebral blood volume (rCBV), in foci of brain ischemia. Hemispheric oxygen consumption (HMIO2) decreased together with hemispheric respiratory quotient. Systemic blood levels of glucose, lactate, pyruvate, and triglycerides also increased after glycerol while free fatty acids (FFA) and inorganic phosphate (Pi) decreased. Hemispheric glucose consumption was unaltered after glycerol so that hemispheric glucose to oxygen ratio tended to rise. Pyruvate and lactate production by brain was unchanged. Glycerol moved across the blood brain barrier into brain and cerebrospinal fluid (CSF). Release of FFA and Pi from infarcted brain was reversed by glycerol. Total phosphate balance was maintained actoss brain both before and after glycerol infusion. Triglycerides increased in CSF after glycerol, originating either from cerebral blood or as a result of lipogenesis in cerebral tissue. The EEG Recording and neurological status of the patients improved despite decreased brain oxygen consumption. Results of this study suggest that after intravenous infusion of 10 per cent glycerol in patients with recent cerebral infarction, glycerol rapidly enters the CSF and brain compartments and favorably affects the stroke process in two ways: first, by redistribution of cerebral blood flow with increase in rCBF and rCBV in ischemic brain secondary to reduction in focal cerebral edema; and second glycerol may become an alternative source of energy either by being directly metabolized by the brain, or indirectly, by enhancing lipogenesis, or by both processes. Involvement of glycerol in lipogenesis with esterification to accumulated FFA might lead to improved coupling of oxidative phosphorylation, a hypothesis that fits the finding of improved neuronal function despite further decrease in cerebral hemispheric oxygen consumption.

Aged↗
PubMed1975

Increased cerebral blood volume in benign intracranial hypertension.

In two patients with benign intracranial hypertension, the regional cerebral blood volume was markedly elevated (mean of 85 percent) while regional cerebral blood flow was slightly reduced (mean of 10 percent). Reduction of cerebrospinal fluid pressure by removal of cerebrospinal fluid reduced the mean values of regional cerebral blood volume by 13 percent without significant change in regional cerebral blood flow. The abnormal regional volume and regional flow returned to normal concurrent with the clinical improvement. Vinous engorgement and increased intracranial blood volume appear to play an important part in the pathophysiology of increased intracranial pressure in benign intracranial hypertension. A unified concept of the pathogenesis of benign intracranial hypertension is proposed.

Adult↗