Cognitive function was examined in 227 patients three months after admission to hospital for ischaemic stroke, and in 240 stroke-free controls, using 17 scored items that assessed memory, orientation, verbal skills, visuospatial ability, abstract reasoning, and attentional skills. After adjusting for demographic factors with standardised residual scores in all subjects, the fifth percentile was used for controls as the criterion for failure on each item. The mean (SD) number of failed items was 3-4 (3.6) for patients with stroke and 0-8 (1.3) for controls (p < 0-001).Cognitive impairment, defined as failure on any four or more items, occurred in 35-2% of patients with stroke and 3-8% of controls (p < 0-001). Cognitive domains most likely to be defective in stroke compared with control subjects were memory, orientation, language, and attention. Among patients with stroke, cognitive impairment was most frequently associated with major cortical syndromes and with infarctions in the left anterior and posterior cerebral artery territories. Functional impairment was greater with cognitive impairment, and dependent living after discharge either at home or nursing home was more likely (55.0% with, v 32-7% without cognitive impairment, p = 0-001). In a logistic model examining the risks related to dependent living after stroke, cognitive impairment was a significant independent correlate (odds ratio, OR = 2-4), after adjusting for age (OR = 5'2, 80 + v 60-70 years) and physical impairment (OR = 3.7, Barthel index < 40 v > 40). It is concluded that cognitive impairment occurs frequently after stroke, commonly involving memory, orientation, language, and attention. The presence of cognitive impairment in patients with stroke has important functional consequences, independent of the effects of physical impairment. Studies of stroke outcome and intervention should take into account both cognitive and physical impairments. (7 Neurol Neurosurg Psychiatry 1994;57:202-207) Cerebrovascular disease is an important cause of morbidity in the elderly, resulting not only in physical disability, but also significant cognitive impairment. Most studies of stroke outcome have focused on physical consequences;' few have examined intellectual deficits.2 In a previous study, we found dementia in 66 (26.3%) of 251 elderly patients examined with neuropsychological tests three months after hospital admission for ischaemic stroke.3 Excluding subjects with functional impairment preceding stroke onset who may have had coexisting Alzheimer's disease, the frequency of dementia in this sample was 16-3% (37 of 227 patients with stroke). Our research criteria for dementia required the presence of memory impairment combined with deficits in two additional cognitive domains. Because the frequency of dementia will depend in part on the diagnostic criteria used,4 the frequency of intellectual decline may be over-represented or underrepresented by focusing on dementia as a diagnosis.An alternative approach to characterising the cognitive conse...

No abstract

Dementia is frequent after ischemic stroke, occurring in one-fourth of the elderly patients in the authors' cohort. The clinical determinants of dementia include the location and severity of the presenting stroke, vascular risk factors such as diabetes mellitus and prior stroke, and host characteristics such as older age, fewer years of education, and nonwhite race/ethnicity. The results also suggest that concomitant AD plays an etiologic role in approximately one-third of cases of dementia after stroke.

Among 251 patients examined 3 months after the onset of acute ischemic stroke, we diagnosed dementia in 66 (26.3%) by using modified DSM-III-R criteria based on neuropsychological, neurological, functional, and psychiatric examinations. We used a logistic regression model to derive odds ratios (ORs) for clinical factors independently related to dementia in this cross-sectional sample. Dementia was significantly associated with age, education, and race. A history of prior stroke (OR = 2.7) and diabetes mellitus (OR = 2.6) was also independently related to dementia, but hypertension and cardiac disease were not. Stroke features associated with dementia included lacunar infarction compared with all other subtypes combined (OR = 2.7) and hemispheric laterality in relation to brainstem or cerebellar location. There was a predominance of dementia in patients with left-sided lesions (OR = 4.7), an effect not explained by aphasia. Dementia was especially common with infarctions in the left posterior cerebral and anterior cerebral artery territories. A major dominant hemispheral syndrome (reflecting size and laterality) was also independently associated with dementia (OR = 3.9). We suggest that dementia after ischemic stroke is a result of multiple independent factors, including both small subcortical and large cortical infarcts especially involving the left medial frontal and temporal regions, with additional contributions by demographic and vascular risk factors.

Background and Purpose-A number of cross-sectional epidemiological studies have reported that one fourth of elderly patients meet criteria for dementia 3 months after ischemic stroke, but few longitudinal studies of the incidence of dementia after stroke have been performed. We conducted the present study to investigate the incidence and clinical predictors of dementia after ischemic stroke. Methods-We administered neurological, neuropsychological, and functional assessments annually to 334 ischemic stroke patients (age, 70.4Ϯ7.5 years) and 241 stroke-free control subjects (age, 70.6Ϯ6.5 years), all of whom were nondemented in baseline examinations. We diagnosed incident dementia using modified Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition criteria requiring deficits in memory and Ն2 additional cognitive domains, as well as functional impairment. Results-The crude incidence rate of dementia was 8.49 cases per 100 person-years in the stroke cohort and 1.37 cases per 100 person-years in the control cohort. A Cox proportional-hazards analysis found that the relative risk (RR) of incident dementia associated with stroke was 3.83 (95% CI, 2.14 to 6.84), adjusting for demographic variables and baseline Mini-Mental State Examination score. Within the stroke cohort, intercurrent medical illnesses associated with cerebral hypoxia or ischemia were independently related to incident dementia (RR, 4.40; 95% CI, 2.20 to 8.85), adjusting for recurrent stroke, demographic variables, and baseline Mini-Mental State Examination score. Conclusions-The risk of incident dementia is high among patients with ischemic stroke, particularly in association with intercurrent medical illnesses that might cause cerebral hypoxia or ischemia, suggesting that cerebral hypoperfusion may serve as a basis for some cases of dementia after stroke.