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Biomedical subjects

V C Hachinski

Publications and source records attributed to V C Hachinski.

At least 73 records · Page 4Linked to original sources

Neuropsychological improvement versus practice effect following unilateral carotid endarterectomy in patients without stroke.

Patients who were admitted to hospital for a recent transient ischemic attack were entered into one of three groups based on medical and surgical characteristics; those with an abnormal neurological examination or a focal abnormality on CT Scan were omitted from the study. The two surgical groups (12 patients each) underwent either a left or right endarterectomy for a symptomatic atheroma of the ipsilateral carotid artery. The control group consisted of 12 patients who either demonstrated minor or nonexistent carotid abnormalities or a TIA distribution that was contralateral to what would otherwise have been a surgically treatable lesion. Patients were tested before surgery and again 6-8 weeks later with the WAIS, WMS, and other neuropsychological measures. Significant improvement on some measures at follow-up was strictly equivalent across all groups and was attributed to practice effects.

Aged↗

A double-blind, randomized trial of PY108-068 in acute ischemic cerebral infarction.

A double-blind, randomized, pilot trial of the calcium channel antagonist PY108-068 was completed in patients with acute ischemic cerebral infarction. Nine treated patients received PY108-068 orally (150 mg/day in divided doses) and 10 control patients received placebo within 48 hours of stroke onset for 21 days. The mean age of the treated patients (four men, five women) was 63.7 years and of the control patients (seven men, three women) 64.4 years. Most infarctions were in the territory of the middle cerebral artery. One treated patient died of sudden cardiac death on Day 12; one control patient died of cerebral herniation. Two treated patients had episodes of clinically insignificant hypotension during Day 1 of treatment. Two control patients had myocardial infarctions during the trial. The mean Toronto Stroke Scale scores at stroke onset were 67 and 90 and at Week 12 were 22.5 and 34.7 in the treated and control groups, respectively. There was parallel improvement in the two groups, with no significant difference between groups (p = 0.12). The mean Barthel Index functional scores at stroke onset were 32.8 and 33 and at Week 12 were 90 and 78.8 in the treated and control groups, respectively. There was a trend in favor of the treated group, but differences between groups did not reach significance. In this pilot trial, PY108-068 was found to be safe but not effective in patients with acute ischemic cerebral infarction.

Acute Disease↗

Transient ischemic attacks and stroke.

Transient ischemic attacks (TIAs) constitute the most specific and powerful warnings of impending stroke. They are defined as brief, focal neurological events of sudden onset. Their proper recognition and treatment rank second only to the modification of risk factors in importance for stroke prevention. Carotid endarterectomy, although widely used to treat TIAs, remains unproven; randomized clinical trials are attempting to define its role. Anticoagulant therapy appears worth while for suspected cardiac embolism and possibly for disabling TIAs. Acetylsalicylic acid is the only agent that has been found to be effective in controlled trials, but questions persist about its dosage, its efficacy in women and its use after stroke. Another platelet inhibitor, ticlopidine hydrochloride, is being investigated and may prove to be an effective alternative.

Aspirin↗

Sensitivity and specificity of the extended scale for dementia.

The Extended Scale for Dementia was introduced as a test for grading the intellectual function of patients with dementia. Its use in discriminating demented patients from nondemented control subjects has been explored. The test had a sensitivity of 93% and a specificity of 96% in patients over the age of 65 years, but the sensitivity fell to 75% in those younger than 65 years. The scale may be useful, particularly for patients over the age of 65 years, in helping to distinguish dementia from normality.

Aged↗

Migraine and the risks from angiography.

There is some suggestion in the literature that patients with migraine may be at an increased risk for developing complications as a result of cerebral angiography. To assess this risk, we reviewed the charts of 142 patients with migraine. A total of 149 angiograms were performed for acute headache (55), new focal symptoms (40), exertional (including coital) headaches (nine), hemiplegic migraine (three), ophthalmoplegic migraine (five), vertebrobasilar migraine (six), migraine accompaniments (three), and other causes (14). Transient events were seen in six patients and these were transient amnesia (one), hemisensory changes (two), hemiparesis (one), global confusion (one), and angina (one). One patient with a history of severe ischemic heart disease developed a myocardial infarction two hours after angiography. Focal cerebral events occurred in 2.6% of cases. This compares with a rate of complications of 2.8% caused by angiography in a prospective study of 1002 patients from our center. According to our findings, it appears that a history of migraine does not increase the risk of complications caused by angiography. Angiography during episodes of acute headaches would also appear to be a safe procedure. Transient focal neurologic symptoms, however, are not infrequent, especially in cases of classic migraine.

Adolescent↗

The Canadian American Ticlopidine Study (CATS) in thromboembolic stroke. Design, organization, and baseline results.

The Canadian American Ticlopidine Study is a randomized, placebo-controlled, double-blind, multicenter study to assess the efficacy and safety of ticlopidine hydrochloride in patients who have suffered a thromboembolic stroke no less than 1 week and no more than 4 months before entry into the study. The primary assessment of efficacy will be based on the cluster of outcome events recurrent stroke, myocardial infarction, or vascular death. Twenty-five clinical centers, 12 in Canada and 13 in the United States, entered a total of 1,072 patients during a 3-year recruitment period; these patients were randomly allocated to receive either 250 mg ticlopidine or identical-appearing placebo tablets twice daily for up to 3 years. Patient recruitment was completed in December 1986. Patients were followed for a maximum of 3 years or until the close of the study in December 1987; at that time an average follow-up of 25 months had been achieved. We summarize the protocol and organization of the study and document the methods of execution and analysis, with corresponding criteria, before disclosure of the treatment code to any of the study investigators. We also provide a clinical description of the patients at entry into the study.

Aged↗

Transient ischemic attacks and normal cerebral angiograms: a follow-up study.

To determine the outcome of patients with carotid transient ischemic attacks (TIAs) and normal cerebral angiograms, we assessed 68 patients (40 men, 28 women) aged 24-72 (mean 53.5) years for recurrent TIAs and strokes and for the development of cardiac disease over 2-6 (mean 4.4) years. All but one patient had a follow-up interview in early 1987; that patient had died of an unrelated cause (lung cancer) 18 months after the presenting TIA. The diagnosis was changed at the follow-up interview in three patients (multiple sclerosis, meningioma, migraine). Among the 64 remaining patients, at admission cranial computed tomography had shown cerebral infarction in 11 of 64, two-dimensional echocardiography had been abnormal in nine of 61, Holter monitoring had been abnormal in eight of 45, and twelve-lead electrocardiography had been abnormal in three of 64. Two patients had abnormalities on both echocardiography and Holter monitoring. At the follow-up interview of the 64 remaining patients, TIAs had recurred in nine and three had developed a completed stroke; cardiac disease (angina in seven, myocardial infarction in four) was noted in 11 patients. Findings from cardiac investigations on admission in the nine patients with recurrent TIAs had been abnormal in six and normal in three; all three patients who developed a stroke had had abnormal cardiac findings. Overall, further neurologic or cardiac events occurred in 12 of 46 patients (26%) with normal and in 10 of 18 patients (55.5%) with abnormal findings on admission (p less than 0.01). In the presence of normal angiograms, extensive cardiac investigations may help predict the outcome of patients with TIAs.

Adult↗

Leuko-araiosis.

Problems in the literature in the appraisal of brain deep white-matter changes are considered. The identification of the changes with Binswanger's disease alone is rejected, and evidence is reviewed that demonstrates that they are associated with cognitive impairment and, to some extent, with vascular disease. Possible causes of white-matter changes and their relationships to Alzheimer's disease are examined, and it is argued that a neutral term, exact enough to define white-matter changes, sufficient as a description or label, and demanding enough to require precise clinical and imaging descriptions is needed. We suggest herein the term "leuko-araiosis" on the basis of Greek etymology and Hippocratic usage.

Brain↗

The clinical diagnosis of Alzheimer's disease.

Clinical and pathologic diagnoses are compared in 65 patients who had dementia and who had been studied longitudinally during life. The sensitivity of diagnosis for dementia of the Alzheimer type (DAT) without any other diagnosis was 87%, and the specificity was 78%. The ischemic scale score did not discriminate well between patients with pure multi-infarct dementia and those with both DAT and multi-infarct dementia. However, 35 of 38 cases of pure DAT had a score of 4 or less on the ischemic scale.

Adult↗

Cognitive and neurologic findings in subjects with diffuse white matter lucencies on computed tomographic scan (leuko-araiosis).

As part of a prospective clinicopathologic study, a cohort of 105 "normal" elderly volunteers was investigated with computed tomographic scans, psychometric testing (Extended Scale for Dementia [ESD]) and neurologic examination. Computed tomographic scans were evaluated for the presence or absence of white matter lucencies, termed leuko-araiosis. These are defined as patchy or diffuse areas of decreased attenuation involving only white matter and with no change in adjacent ventricles or sulci. The nine controls with leuko-araiosis had lower scores on the ESD than the 96 controls without leuko-araiosis (mean ESD with leuko-araiosis, 227.1 +/- 14; without leuko-araiosis, 237.1 +/- 8), and the difference remains significant even after adjusting for the possible confounding effects of age, sex, education, and infarct detected on computed tomography. Significant differences were also found comparing subjects with leuko-araiosis and those without in respect to abnormal gait, limb power, plantar response, and the rooting and palmomental reflexes. Leuko-araiosis may represent a marker for early dementia. The pathophysiology of this finding remains uncertain. Our results suggest that white matter abnormalities play a role in the development of intellectual impairment in the elderly.

Aged↗

Cognitive and neurologic findings in demented patients with diffuse white matter lucencies on computed tomographic scan (leuko-araiosis).

A series of patients referred to the University of Western Ontario, London, Dementia Study for investigation of possible dementia underwent computed tomographic scans, psychometric testing (Extended Scale for Dementia [ESD]), and neurologic examination. Thirty-nine of the 113 patients studied (ischemic score, less than or equal to 4) were found to have leuko-araiosis, which we have defined as patchy or diffuse lucencies in the white matter. Patients with leuko-araiosis had significantly lower mean scores on the ESD, 109.7 +/- 61.2, compared with mean scores of 148.5 +/- 78.0 in those without. However, only a trend toward lower scores on the ESD was observed when age, sex, education, and infarct were taken into account in the analysis of covariance. Leuko-araiosis was found to be associated with increasing age, hypertension, abnormalities of power in the limbs, and extensor-plantar responses in this sample of patients. In patients with Alzheimer's disease (AD) alone, diagnosed clinically, 29 out of 91 demonstrated leuko-araiosis on computed tomography, but scores on the ESD in this group overall were not significantly different when those with and without leuko-araiosis were compared. In less advanced cases, however, a highly significant trend was evident for leuko-araiosis to be associated with increased dementia in AD. The results are consistent with the hypothesis that leuko-araiosis is associated with dementia in AD, and that this is either most marked or most easily identifiable before the dementia becomes very severe.

Aged↗

Vascular risk factors and leuko-araiosis.

Leuko-araiosis was found in 49 of 140 demented patients compared with 12 out of 110 control subjects. Thirty-one of 95 patients with dementia of the Alzheimer's type had leuko-araiosis. A history of stroke was four times more frequent in patients with leuko-araiosis than in those without leuko-araiosis (17.4% and 4.4%, respectively). It occurred in 25% of controls with leuko-araiosis compared with only 2% of those without leuko-araiosis. Mean systolic blood pressure was associated with leuko-araiosis. No association was found for diastolic blood pressure, myocardial infarction, angina, diabetes, or carotid bruits. On logistic regression analysis, the strong association between dementia and leuko-araiosis was mainly explained by a history of stroke. There are common factors in leuko-araiosis and stroke, but stroke alone does not account for leuko-araiosis.

Aged↗

The electroencephalogram in Alzheimer-type dementia. A sequential study correlating the electroencephalogram with psychometric and quantitative pathologic data.

As part of a longitudinal cohort study of dementia, 139 patients with Alzheimer's disease (dementia of the Alzheimer type, senile dementia of the Alzheimer type, and mixed type [ischemic score, 4 to 7]) and 148 age-matched control subjects were evaluated for electroencephalographic (EEG) abnormalities and their evolution. Electroencephalograms were significantly different in the two groups; EEGs worsened overall in the two groups during a period of one to four years, but most subjects showed no alteration in their EEGs. Some patients showed improvement in their EEG findings during the follow-up period. A strong correlation between EEG grade and psychometric scores was consistently found over sequential studies. In a subgroup of patients on whom autopsies were performed, morphometric neuron loss correlated significantly with EEG severity.

Aged↗

Prognosis of acute stroke.

We evaluated factors affecting mortality and quality of life in 1,013 patients with acute stroke followed for 2 to 8 years. In cerebral infarction, the major determinants for short-term mortality were impaired consciousness, leg weakness, and increasing age. The major determinants for long-term mortality were low level of activity at hospital discharge, advanced age, male sex, heart disease, and hypertension.

Aged↗

Changes in plasma catecholamine levels after insula damage in experimental stroke.

The effect of permanent occlusion of the left middle cerebral artery (MCA) on plasma catecholamine levels was investigated in chloralose-anesthetized cats. Two-5 h after occlusion of the MCA the plasma levels of norepinephrine, epinephrine and dopamine were significantly elevated (33%, 44% and 28%, respectively) compared to preocclusion levels only in animals in which the cerebral infarction involved the insular cortex. No significant changes were observed in plasma catecholamine levels in animals in which either the infarction did not involve the insula or in sham-stroked animals. These data suggest that withdrawal of inhibitory inputs from the insula on central cardiovascular regulating centers after stroke results in an increase in the activity of the sympathoadrenal system.

Animals↗

High dose steroid treatment in cerebral infarction.

Steroid treatment is widely used in acute cerebral infarction yet its value is controversial. High dose dexamethasone (480 mg over 12 days) was given in a double blind, randomised controlled trial to 113 consecutive eligible patients with acute cerebral infarction admitted to an acute stroke unit. Those with stroke for more than 48 hours, known embolic sources, diabetes, and infection were excluded. Death and quality of survival were recorded over 21 days. The active drug group (54 patients) matched the placebo group (59 patients) for age, initial stroke score, delay in beginning treatment, and other relevant variables. The two groups did not differ significantly in death rate or quality of survivorship. The small difference in mortality between the two groups may have represented a marginal therapeutic effect, which might reach significance in a larger sample. The widespread use of steroids in response to such a marginal therapeutic gain would expose large numbers of patients with stroke to more serious hazards of steroid treatment and convert patients who would otherwise have died into neurovegetative survivors. High dose steroid treatment was ineffective in ischaemic stroke, and the data suggest that further evaluation by a larger multicentre trial is not justified.

Aged↗

Cardiac and arterial lesions in carotid transient ischemic attacks.

Two hundred fifty consecutive patients with carotid transient ischemic attacks (TIAs) and no previous stroke were assessed with cerebral angiography (95%), two-dimensional echocardiography (86%), electrocardiography (100%), and Holter monitoring (99 selected patients). Angiography disclosed a lesion appropriate to the TIAs in 84%. Lesions also occurred in the asymptomatic carotid artery, but stenosis of more than 75% of the lumen diameter and ulcers were significantly more frequent on the symptomatic side. Twenty-three percent of the patients had a potential source of emboli from the heart, usually in the context of symptomatic heart disease. Among the 205 patients who underwent full angiographic and cardiac investigations, 6% had an isolated potential cardiac source of emboli and 19% had a potential cardiac source of emboli associated with appropriate carotid disease. The search for a potential cardiac source of emboli is strongly indicated in patients with carotid TIAs and known heart disease. In the patients with no history of heart disease, the yield of this search is low, but our results suggest that at least 14 of such patients have an undetected potential cardiac source of emboli. Cardiac and arterial lesions commonly coexist in carotid TIAs.

Adult↗