Alexander Zemcov

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Over 5 years, we followed 199 patients with dementia of the Alzheimer type (DAT), 69 with multi-infarct dementia (MID), and 43 with mixed dementia (MIX). All three diagnostic categories had comparable progression of behavioral and cognitive impairment and need for home care or institutionalization at follow-up. However, 50% survival from diagnosis was 2.6(More)
Alzheimer's disease can be considered a late-onset system degeneration, characteristically involving certain populations of cholinergic neurons but eventually involving other cells as well. Decreases in cerebral metabolic rate occur in it and may reflect not only decreased neuronal activity, but also deficiencies in metabolic enzymes. Abnormalities reported(More)
The study investigated the effects of fatigue and task repetition on the relationship between integrated electromyogram and force output during subjective clinical testing of upper extremity muscles. Muscles were studied under two conditions differing in the nature and duration of constant force production (SHORT-F) and (LONG-F). The findings included a(More)
Global and regional cerebral blood flow (CBF) has been reported to be decreased immediately after head injury. Since neuropsychological deficits in patients with chronic head injury syndrome persist long after the initial trauma, we studied CBF, which reflects cerebral metabolism and activity, and evaluated the results of neuropsychological tests in 12(More)
With a computerized data base, a data retrieval system, and a computer program using the actuarial method of life-table analysis, we compared survival rates in different subgroups of patients with dementia of the Alzheimer type (DAT; n = 199). Men (n = 71) had a shorter duration of survival than women (n = 128), with 500-day survival (mean +/- SEM) 84 +/-(More)
To determine whether cerebral blood flow (CBF) progressively decreases as dementia progresses, we studied 133Xe washout at two or three different times in 23 demented patients. All 15 patients with Alzheimer's and 5 of 8 patients with vascular dementias had more rapid declines of CBF than did nondemented age-matched controls. Mean rate of change in(More)
Cerebral blood flow was measured by the 133Xenon washout method in 44 cognitively intact subjects. Regression analysis of cerebral blood flow with age was performed on data from 33 subjects without arteriosclerotic cardiovascular disease, hypertension, or chronic obstructive pulmonary disease, factors which have been previously shown to lower cerebral blood(More)
In the course of evaluating and following more than 600 geriatric outpatients referred to a subspecialty clinic because of cognitive impairment, standardized computer-compatible evaluation and follow-up forms were developed, as well as a computerized data base. The forms cover medical, neurologic, psychiatric, psychometric, and clinical laboratory(More)
Receiver operating characteristic (ROC) curves were used to quantitatively assess the ability of individual detectors in a 32-detector 133Xe inhalation system to discriminate between two populations over the range of regional cerebral blood flow (rCBF) values. These populations were clinically evaluated as normal (age 63.1 +/- 13.1, n = 23) and presumed(More)