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Biomedical subjects

A Burns

Publications and source records attributed to A Burns.

At least 163 records · Page 9Linked to original sources
PubMed1991

Modelling length bias in a longitudinally-linked record system of HIV cases.

We compare numbers of hospital admissions for intravenous drug using (IVDU) HIV patients and other HIV patients in acute-care facilities in New York State. Data consist of routinely collected hospital-discharge reports from New York's Statewide Planning and Research Cooperative System, linked into longitudinal case histories. Because recognition of an IVDU depends on an opioid diagnosis on any record in the case history, the observed distribution of the number of admissions per case for recognized IVDU's is biased towards greater numbers of admissions. We develop and apply a model to overcome this biasing. Our findings reveal that the mean numbers of admissions for the two groups differ significantly, but less so than without recognition of the length biasing.

Bias↗
PubMed1991

Centrum semiovale white matter CT changes associated with normal ageing, Alzheimer's disease and late life depression with and without reversible dementia.

A standardized, reliable means of assessing CT attenuation numbers in the centrum semiovale and surrounding grey matter was developed. This was applied to cranial CT scans of 60 normal controls (36 aged greater than 60 years), 25 elderly patients with major depression (14 of whom had the dementia syndrome of depression), and 10 patients with Alzheimer's disease (AD). Subjects received neuropsychological evaluation. Centrum semiovale (CSO) CT attenuation numbers decreased with increasing age for both white and grey matter. White matter attenuation values best discriminated elderly controls from the three patient groups. Both white and grey matter CSO attenuation values correlated with performance on a number of cognitive tasks.

Adult↗
PubMed1991

Factors affecting survival in Alzheimer's disease.

Factors affecting survival of 178 patients diagnosed using NINCDS/ADRDA criteria for Alzheimer's disease were studied. All patients were drawn from the Camberwell Health Authority Area and so were a representative sample of subjects from a clinical old age psychiatry service. The mortality rate of the sample was 3.5 times that expected after adjustment for age. Younger subjects had a higher standardized mortality ratio than older subjects. The cumulative three-year mortality of the sample was 47%. Factors shown to be associated with a reduced survival included: increasing age, longer duration of illness, male sex, presence of physical illness, poor cognitive function, observed depression and absence of misidentification syndromes. Apraxia was a stronger predictor of early death than aphasia or dysmnesia.

Aged↗
PubMed1991

Psychiatric, neurological and medical aspects of misidentification syndromes: a review of 260 cases.

Two hundred and sixty case reports of misidentification syndromes were evaluated. One hundred and seventy-four patients had a Capgras syndrome misidentifying other persons, 18 a Fregoli syndrome, 11 intermetamorphosis, 17 reduplicative paramnesia and the rest had other forms or combinations of mistaken identification. Schizophrenia (127 cases), mostly of paranoid type, affective disorder (29), and organic mental syndromes including dementia (46) were the most common diagnoses in patients who misidentified others or themselves. The patients with reduplicative paramnesia more frequently suffered from head trauma or cerebral infarction and showed more features of right hemisphere lesions on neuropsychological testing or CT scan than the patients with other misidentification syndromes. Forty-one case-reports implicated underlying medical conditions. Forty-six of the patients were reported to show violent behaviour. The misidentification of persons can be a manifestation of any organic or functional psychosis, but the misidentification of place is frequently associated with neurological diseases, predominantly of the right hemisphere. Misidentification syndromes show a great degree of overlap and do not represent distinctive syndromes nor can they be regarded as an expression of a particular disorder. These patients deserve special diagnostic and therapeutic attention because of the possible underlying disorders and their potentially dangerous behaviour.

Adult↗
PubMed1991

Neurological signs in Alzheimer's disease.

Neurological signs were assessed in 178 patients satisfying NINCDS/ADRDA criteria for Alzheimer's disease. A snout reflex was present in 41%, extrapyramidal signs in 12%, drug-induced extrapyramidal signs in 3%, myoclonus in 5%, and a history of epileptic fits in 3%. A grasp reflex, extrapyramidal signs and symptoms were associated with severe cognitive impairment. On CT scanning, extrapyramidal signs were associated with increased 3rd ventricular size and basal ganglia calcification, a grasp reflex with frontal lobe atrophy and a history of epilepsy with left temporal lobe atrophy. Lateral ventricular size was greater in patients developing a grasp reflex during a 12 month follow-up. Extrapyramidal signs and primitive reflexes were associated with a higher mortality.

Aged↗
PubMed1991

Progression of cognitive impairment in Alzheimer's disease.

Change in cognitive function was assessed over 12 months in 110 patients over the age of 65 satisfying National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS/ADRDA) criteria for "probable" Alzheimer's Disease. A highly significant deterioration in cognitive function was observed. Decline in cognitive scores was relatively normally distributed. Patients who died during the follow-up had more apraxia at entry to the study than survivors. A greater rate of decline was seen in patients whose parents suffered from dementia (but not in those where a sibling or other relative was affected), in subjects who had moderate dementia, and those who had been ill for less than 24 months. Age, age of onset, and the presence or absence of aphasia or apraxia had no influence on rate of progression. A cluster analysis revealed three patterns of decline.

Age Factors↗
PubMed1991

Physostigmine in Alzheimer's disease: effects on cognitive functioning, cerebral glucose metabolism analyzed by positron emission tomography and cerebral blood flow analyzed by single photon emission tomography.

The effect of acute, intravenous administration of physostigmine on measures of brain activity and cognitive functioning were investigated in 14 patients with Alzheimer's disease. Regional cerebral glucose metabolism was assessed using (18F)-fluoro-2-deoxy-D-glucose and positron emission tomography, and cerebral blood flow was assessed using 123I-iodoamphetamine single photon emission tomography. Although physostigmine enhanced cerebral blood flow in most patients, only one patient showed significant clinical improvement. This patient, however, also showed a very pronounced improvement in cerebral glucose metabolism. It is concluded that these preliminary findings hold considerable promise for our appreciation of the pathophysiology of dementing illness as well as our understanding of centrally acting compounds of interest in Alzheimer's disease.

Aged↗
PubMed1991

Medical disorders in Alzheimer's disease and vascular dementia.

The clinical and postmortem findings of 29 patients with Alzheimer's disease were evaluated and compared to the findings of 19 patients with vascular dementia. The patients with Alzheimer's disease had received treatment for an average of 2.0 internal medical disorders, the patients with vascular dementia for 2.1 disorders. The average number of medical diseases found at postmortem was 3.7 in the group with Alzheimer's dementia and 4.1 in vascular dementia. Apart from a marginally increased rate of peripheral occlusive artery disease in vascular dementia, the proportions of the most common disorders of the cardiovascular, genitourinary, gastrointestinal and endocrinological disorders and the most common causes of death did not differ significantly between these groups. Therefore patients with Alzheimer's disease should receive the same internal medical attention as patients with vascular dementia.

Aged↗
PubMed1991

Computerised tomography in Alzheimer's disease. Methods of scan analysis, comparison with normal controls, and clinical/radiological associations.

One hundred and thirty-eight patients satisfying NINCDS/ADRDA criteria for Alzheimer's disease (AD) and 36 normal controls underwent cranial CT. A comparison of methods of scan analysis showed good agreement between computer-assisted methods and visual ratings and planimetry. The CT scans of controls differed significantly from patients and a discriminant analysis, based on all CT measures, predicted group membership (control or patient) in 81% of cases. Within the AD group, cortical atrophy correlated with age and duration of illness. Global tests of cognitive function correlated significantly with both cortical atrophy and ventricular size. Subjects who died in a three-year follow-up had more atrophy and larger third ventricles than survivors, but this effect was due entirely to increased age.

Aged↗
PubMed1991

[Paraphrenia in the elderly. Psychopathologic and computer tomography indications of two subtypes].

Psychopathological and cranial computed tomography findings in 48 patients with late paraphrenia were compared with the findings in 40 normal controls. 19 patients with late paraphrenia and first rank symptoms showed significantly less cortical atrophy than 29 patients without first rank symptoms (p less than 0.01). There were no significant differences of ventricular enlargement, cerebellar atrophy, the presence of leukoaraiosis or basal ganglia mineralisation between the late paraphrenic and control groups. In contrast to the controls, cortical atrophy, ventricular enlargement and the presence of leukoaraiosis were not age-related. These results may indicate different origins of late paraphrenia with or without first rank symptoms.

Aged↗
PubMed1991

Neuroanatomical correlates of clinical misidentification and misperception in senile dementia of the Alzheimer type.

BACKGROUND: Impaired frontal lobe and/or nondominant hemisphere lesions have been described in patients with typical misidentification syndromes (e.g., Capgras' syndrome or reduplicative paramnesia) who had various underlying psychiatric or neurologic disorders. In a prospective long-term study, the authors examined computed tomography measurements of patients with senile dementia of the Alzheimer type (DAT) to determine whether the forms of misidentification they suffered might correlate with organic factors. METHOD: One hundred twenty-eight consecutive DAT patients were examined by means of standardized clinical instruments (Mini-Mental State score, CAMCOG, the Benton facial recognition test, the Kendrick object learning test, CAMDEX, and the Geriatric Mental State Schedule) and computed tomography. RESULTS: Of the 128 patients, 40 showed symptoms of misidentification; 25 of them misidentified other people in their homes, 7 misidentified their own mirror images, and 7 misidentified television images as being real. Computer-assisted planimetric computed tomography measurements showed that patients with misidentification syndromes had significantly larger right anterior horn areas of the lateral ventricle and significantly larger left anterior brain areas than did patients without such symptoms. CONCLUSIONS: The authors conclude that an accentuated degeneration of the right frontal lobe (and a relative preservation of the left frontal lobe) may be associated with delusional misidentification symptoms in DAT.

Aged↗
PubMed1990

Platelet and erythrocyte membrane changes in Alzheimer's disease.

Previous reports have suggested that the physical properties of cell membranes and calcium homeostasis in both the central and peripheral nervous system are changed in Alzheimer's disease (AD). This study has examined the biophysical properties of erythrocyte and platelet membranes by measuring the fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH) and possible related changes in lipid peroxidation. In addition, we have studied calcium homeostasis by measuring thrombin-stimulated changes in intraplatelet free calcium and Ca2(+)-ATPase activity in AD and healthy age and sex-matched controls. Our results show that there was no significant difference in the fluorescence anisotropy of DPH in erythrocyte membranes isolated from the three groups. There was also no significant difference in lipid peroxidation levels in erythrocytes and plasma of AD patients compared to controls. However, there was a significant reduction in the fluorescence anisotropy of DPH in platelet membranes from AD patients, compared with healthy controls. Recent evident suggests that the increase in platelet membrane fluidity results from alterations in internal membranes. We measured the specific activities of enzyme markers associated with intracellular and plasma membranes in platelets from AD patients and healthy controls. There was a significant reduction in the specific activity of antimycin A-insensitive NADH-cytochrome-c reductase (a specific marker for smooth endoplasmic reticulum (SER)), in AD patients compared to controls, but no change in the specific activity of bis(p-nitrophenyl)phosphate phosphodiesterase (a specific marker for plasma membrane). We have also shown that SER mediated [Ca2+] homeostasis is possibly impaired in AD platelets, i.e., the percentage of thrombin-stimulated increase in intraplatelet [Ca2+] above basal levels was significantly higher in AD compared to matched controls and there were significant reductions in the specific activities of Ca2+/Mg2(+)-ATPase and Ca2(+)-ATPase (but not Mg2(+)-ATPase) in AD platelets. Finally electron microscopic analysis of platelets showed that there was a significant increase in the incidence of abnormal membranes in AD patients compared to controls. The ultrastructural abnormalities seem to consist of proliferation of a system of trabeculated cisternae bounded by SER. These results suggest that both SER structure and function might be defected in AD platelets, which could explain the fluidity changes observed here.

Alzheimer Disease↗
PubMed1990

Behavioral abnormalities and psychiatric symptoms in Alzheimer's disease: preliminary findings.

Behavioral abnormalities and psychiatric symptoms were assessed in 178 patients diagnosed as having Alzheimer's disease by NINCDS/ADRDA criteria. The subjects were selected from a defined catchment area and therefore were representative of a group of patients with Alzheimer's disease of varying severity. Auditory hallucinations were found in 10%, visual hallucinations in 13%, and delusions in 16%. Symptoms suggestive of depression were reported by 39% of the patients and features of depression observed in 25%. Twenty percent were aggressive, and 7% were sexually disinhibited. Nineteen percent exhibited excessive walking behavior and 10% binge eating. Nearly 50% of the sample were incontinent. Patients in the hospital were more often aggressive, incontinent, and seemingly less depressed. Patients with severe dementia displayed excessive walking behavior, were more likely to be incontinent, and reported less depressive symptoms than those with moderate or mild dementia.

Activities of Daily Living↗