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Biomedical subjects

V C Hachinski

Publications and source records attributed to V C Hachinski.

At least 91 records · Page 5Linked to original sources
PubMed1986

Clinical predictors of cardiac and arterial lesions in carotid transient ischemic attacks.

In 205 patients with carotid transient ischemic attacks (TIAs) who underwent full angiographic and cardiac investigations, we found that ipsilateral carotid bruit and triggering of TIA by exertion or standing up suggested a carotid lesion. Angina pectoris or palpitations at onset of TIA suggested a cardiac source of emboli. Patients with only one TIA, multiple identical attacks, progression of symptoms over minutes, and appropriate infarct on computed tomograms (28%) were likely to show a potential arterial or cardiac cause for the TIAs in subsequent investigations. Transient monocular blindness correlated with carotid occlusion, but the severity of the carotid lesion did not influence the duration and repetition of attacks. Transient ischemic attacks in multiple territories, identical attacks, and multiple or silent infarcts on computed tomograms occurred equally in the patients with arterial lesions and those with cardiac lesions. These findings suggest that only a few, albeit important, conclusions regarding etiology can be drawn from the clinical characteristics of TIAs.

Adult↗
PubMed1986

Cell loss from the nucleus basalis of Meynert in Alzheimer's disease.

We examined the degree of neuronal loss from the nucleus basalis of Meynert (nbM) in two groups of Alzheimer patients differing in the degree of intellectual impairment. Significant cell loss from the nbM was found only in the more severely demented group of patients. Mean cell counts (per 10 mu paraffin section) were compiled separately for the anterior, intermediate and posterior subdivisions of the human nbM in three groups of subjects: Group 1 (N = 4) was severely demented and was untestable on the Extended Scale for Dementia (ESD) for at least the last two years of life; Group 2 (N = 4) was less demented and had completed at least one ESD test within 12 months of death; Group 3 (five controls) had died of non-neurological causes. In Group 2 there was a small (but insignificant) trend toward cell loss in the anterior subdivision, and a normal complement of neurons in both the intermediate and posterior subdivisions. There was, however, significant cell loss from all subdivisions of Group 1. How these cell counts may relate to the severity of the dementia is discussed.

Alzheimer Disease↗
PubMed1986

Leuko-araiosis: an ancient term for a new problem.

Recent research with computerized tomography (CT) and magnetic resonance imaging (MR) of the brain has revealed a type of tissue change for which no fitting term exists. The change appears as areas of decreased density on CT and changed signals of the white matter in MR images. Because neither a definite pathological change nor a specific clinical deficit has been linked with the CT and MR changes, a designation is required that limits itself to describing the changes themselves. We propose "leuko-araiosis". The Greek root leuko-, signifying "white", has found wide usage in modern medical terminology: e.g. leucine, leukocyte, leukorrhoea. Also several precedents exist for its application to the white matter of the central nervous system: e.g. leukoencephalitis, leukomyelitis, leukotomy. Araios is an adjective meaning "rarefield", and the suffix -osis converts the adjective to a noun meaning "rarefaction, diminution of density", a word used in the Hippocratic Collection to describe a state of excessive porosity of the lung. A descriptive term precludes premature presuppositions and encourages the search for causes.

Brain↗
PubMed1985

Correlative studies in Alzheimer's disease.

An approach is described for establishing and maintaining a correlative study of Alzheimer's Disease. A sample of the findings by the University of Western Ontario (U.W.O.) Dementia Study Group is provided.

Aged↗
PubMed1985

[Cardiac and arterial causes of transient monocular blindness].

It has been accepted that transient monocular blindness (TMB) is highly suggestive of an ipsilateral carotid artery lesion in patients with arterial risk factors. We confirmed this in 55 patients, who had an internal carotid artery severe stenosis, occlusion or ulceration on angiography in more than 50 per cent of the cases. However, 12-lead-ECG, 2 D--echocardiography and Holter monitoring also showed a potential cardiac source of emboli in 22 per cent of the patients. Most of these patients (83 per cent) also had an appropriate arterial lesion, and the exact cause of the episodes of TMB remained undetermined. Our study shows that every fourth of fifth patient with TMB may have a potential cardiac source of emboli, the detection of which could alter the management. Systematic non-invasive cardiac investigations are warranted, especially in TMB patients with known heart disease.

Adult↗
PubMed1982

Misdiagnosis of stroke.

Among 821 consecutive patients admitted to an acute stroke unit, the initial diagnosis of stroke proved incorrect in 108 (13%). The commonest causes of misdiagnosis were unwitnessed or unrecognised seizures (39%) and confusional states and syncope (24%), conditions that can be diagnosed only clinically. In a series of 93 cases examined post mortem, the diagnostic accuracy for stroke varied with clinical skill and ranged from 38% to 89%. The frequency (but not the type) of incorrect diagnosis was the same in 244 patients investigated with computerised tomographic (CT) scanning as in 345 patients investigated without it. Although CT and other neurological investigations are useful aids in the diagnosis of stroke, they remain a supplement to, and not a substitute for, correct clinical evaluation.

Acute Disease↗
PubMed1977

Cerebral hemodynamics in migraine.

Clinical and angiographic findings in migraine are briefly reviewed in relation to cerebral hemodynamic changes shown by regional cerebral blood flow (rCBF) studies. Three cases of migraine studied by the intracarotid xenon 133 method during attacks are reported. In classic migraine, with typical prodromal symptoms, a decrease in cerebral blood flow has been demonstrated during the aura. Occasionally, this flow decrease persists during the headache phase. In common migraine, where such prodromata are not seen, a flow decrease has not been demonstrated. During the headache phase of both types of migraine, rCBF has usually been found to be normal or in the high range of normal values. The high values may represent postischemic hyperemia, but are probably more frequently secondary to arousal caused by pain. Thus, during the headache phase rCBF may be subnormal, normal or high. These findings do not exclude the possibility of distension of the larger intracranial arteries during migraine headache, but the angiographic evidence, however limited, does not support this speculation.

Adult↗
PubMed1976

Cerebral blood flow changes in cluster headache.

Serial cerebral blood flow studies performed by the intra-carotid 133Xenon method were fortuitously determined during the course of a cluster headache in a 32 year old man. The initial study was performed about 10 min after the headache began and showed values at the upper limit of normal. Twenty min after the headache started a second procedure showed that the autoregulatory response on hyperventilation was normal. Ergotamine tartrate was given intra-muscularly 23 min after the headache began and there was partial relief. A third cerebral blood flow estimation showed abnormally high values. The probable reasons for this are discussed.

Adult↗
PubMed1975

Changes in cerebral blood flow during a migraine attack.

Regional cerebral blood flow studies during a typical prodromal phase of a migraine attack in a young woman showed a global decrease of cerebral blood flow in the carotid artery territory. These studies were repeated during the subsequent headache phase of the same attack and hemispheric blood flow increased considerably. Ergotamine tartrate was then administered intramuscularly which brought definite relief of symptoms but no change in cerebral blood flow. Carotid angiography performed immediately afterwards showed retrograde filling of the proximal portion of the basilar artery, which suggested that the brain stem was the site of hyper-perfusion. These findings illustrate certain features underlying both the pathophysiology of migraine itself and its response to ergotamine preparations.

Adolescent↗
PubMed1975

Alzheimer degeneration in Down syndrome. Electrophysiologic alterations and histopathologic findings.

Progressive electroencephalographic disorganization and decreased voltage amplitude in the late components of the averaged visual evoked potentials were recorded in the last two years of life of a patient with Down disease and Alzheimer degeneration. Taken together with quantitative histopathologic findings, the electrophysiologic alterations are interpreted in terms of recent evidence from an experimental animal model of dementia. Neurons with neurofibrillary degeneration become electrically inactive and contribute to the loss of voltage generators associated with neuron death in Alzheimer disease. Loss of voltage generators may result in disfacillitation and disinhibition of surviving neurons, thus causing the loss of normal rhythms.

Adult↗
PubMed1975

Cerebral blood flow in dementia.

Twenty-four patients of comparable age, blood pressure, and degree of dementia were classified by an "Ischemic Score" based on clinical features into "multi-infarct" and "primary degenerative" dementia. Regional cerebral blood flow (CBF) was measured by the intracarotid xenon 133 method. Both groups showed a decreased proportion of rapidly clearing brain tissue (largely gray matter). Cerebral blood flow per 100 gm brain per minute was normal in the primary degenerative group but low in the multi-infarct group. This suggests the blood flow is adequate for metabolic needs of the brain in patients with primary degenerative dementia but inadequate for those with multi-infarct dementia. There was no correlation between degree of dementia and CBF in the primary degenerative group but an inverse relationship existed in the multi-infarct group. Reactivity of blood vessels to reduction of arterial carbon dioxide pressure was normal in both groups.

Aged↗
PubMed1975

The nature of primary vocal tremor.

Three elderly women with marked progressive voice tremor, without other neurological symptoms, and negative family histories were investigated. All had a 4-5 Hz respiratory tremor in expiration and, to a lesser degree, in inspiration; and all had vocal tremulousness synchronous with their respiratory irregularity. Articulation of phonemes was normal. In two cases the neurological examination was otherwise normal; in the third case there was a minimal 71/2 Hz tremor in the left thumb and index finger. Simultaneous speech and vocal air pressure recordings, as well as cinematographic studies of the vocal apparatus and diaphragm were carried out. It is suggested that these cases represent primarily an action tremor of respiration, that they belong in the spectrum of essential tremor, and hence may be amenable to treatment with propranolol.

Aged↗
PubMedDate not supplied

Profiles of cognitive decline in Alzheimer disease.

Most recent studies have used only two observations to estimate the rate of cognitive decline in patients with Alzheimer disease (AD); few have data taken from more than a 2-year period; and none report on autopsy-verified cases. Repeated observations over the complete course of the disease are necessary to quantitatively evaluate hypotheses such as the triphasic linear model of Brooks et al. (1993). The goal of this study is to compare the triphasic linear and quadratic models of decline in a group of 12 AD patients confirmed at autopsy with a group of age- and sex-matched normal control subjects. Both groups were taken from the University of Western Ontario Dementia Study, and the Extended Scale for Dementia was used as the outcome measure. The squared multiple correlation as a measure of goodness of fit suggested the superiority of the more parsimonious quadratic model over the triphasic linear model. Quantitative models more accurately reflect the profiles of change in AD and may prove more sensitive in measuring the effects of drugs on these patterns.

Aged↗