Incidence of dementia after ischemic stroke: results of a longitudinal study.

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, 70.4+/-7.5 years) and 241 stroke-free control subjects (age, 70.6+/-6.5 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 > or =2 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.

Mortality in patients with dementia after ischemic stroke.

OBJECTIVE: Although dementia is typically considered to be a consequence of a variety of neurologic diseases, it can also serve as a risk factor for other adverse outcomes. The authors investigated dementia as a predictor of long-term survival among patients with ischemic stroke. METHODS: Neurologic, neuropsychological, and functional assessments were administered to 453 patients (mean age +/- SD, 72.0 +/- 8.3 years) 3 months after ischemic stroke. The authors diagnosed dementia in 119 (26.3%) of the patients using modified Diagnostic and Statistical Manual of Mental Disorders, Revised 3rd Edition, criteria requiring deficits in memory and two or more additional cognitive domains as well as functional impairment. Dementia as a predictor of long-term survival during up to 10 years of follow-up was then investigated. RESULTS: The mortality rate was 15.90 deaths per 100 person-years among patients with dementia and 5.37 deaths per 100 person-years among nondemented patients. A Cox proportional hazards analysis found that the relative risk (RR) of death was increased in association with dementia (RR = 2.4; 95% CI = 1.6 to 3.4), adjusting for the following: a major hemispheral stroke syndrome (RR = 1.4); a middle cerebral artery territory index stroke (RR = 1.7); a Stroke Severity Scale score of > or = 4, representing more severe stroke (RR = 1.8); atrial fibrillation (RR = 1.8); congestive heart failure (RR = 2.2); recurrent stroke occurring during follow-up (RR = 3.9); and demographic variables. The risk of death increased in association with the severity of dementia, but it did not differ by dementia subtype. CONCLUSIONS: Dementia is a significant independent risk factor for reduced survival after ischemic stroke, adjusting for other recognized predictors of mortality. The authors hypothesize that patients with dementia are at an elevated risk of mortality because of their increased burden of cerebrovascular disease, a tendency toward undertreatment for stroke prophylaxis among clinicians, or patient noncompliance with treatment regimens.

The Oxfordshire Community Stroke Project classification: correlation with imaging, associated complications, and prediction of outcome in acute ischemic stroke.

This preliminary study investigates the risk factor profile, post stroke complications, and outcome for four OCSP (Oxfordshire Community Stroke Project Classification) subtypes. One hundred seventeen consecutive ischemic stroke patients were clinically classified into 1 of 4 subtypes: total anterior (TACI), partial anterior (PACI), lacunar (LACI), and posterior (POCI) circulation infarcts. Study evaluations were performed at admission, 2 weeks, and 6 months. There was a good correlation between clinical classification and radiological diagnosis if a negative CT head was considered consistent with a lacunar infarction. No significant difference in risk factor profile was observed between subtypes. The TACI group had significantly higher mortality (P < .001), morbidity (P < .001, as per disability scales), length of hospital stay (P < .001), and complications (respiratory tract infection and seizures [P < .01]) as compared to the other three groups which were all similar at the different time points. The only significant difference found was the higher rate of stroke recurrence within the first 6 months in the POCI group (P < .001). The OCSP classification identifies two major groups (TACI and other 3 groups combined) who behave differently with respect to post stroke outcome. Further study with larger numbers of patients and thus greater power will be required to allow better discrimination of OCSP subtypes in respect of risk factors, complications, and outcomes if the OCSP is to be used to stratify patients in clinical trials.

The Orpington Prognostic Scale within the first 48 hours of admission as a predictor of outcome in ischemic stroke.

This study investigates the prognostic ability of the Orpington Prognostic Scale within 48 hours (OPS-1) after admission in predicting outcome at 6 months and 2 years in acute ischemic stroke and compares it with the 2 week OPS (OPS-2). All consecutive ischemic stroke patients (n = 117) were scored on the OPS, Barthel activities of daily living, Oxford handicap scale, European stroke scale, and Rivermead motor assessment at 48 hours, 2 weeks, 6 months, and 2 years post-stroke. Baseline OPS scores at 48 hours and 2 weeks were used to predict outcomes at 6 months and 2 years. The OPS-1 was an excellent predictor of length of hospital stay (P < .001), place of discharge (P < .01), and outcome at 6 months and 2 years (P < .0001, Fisher's exact). The OPS-2 was marginally better than the OPS-1 though this benefit was outweighed by the earlier stratification of the 48-hour measure. The sensitivity, specificity, and positive predictive values (PPV) of the "good" OPS-1 versus the OPS-2 at predicting independence at 6 months were 85% vs 92%, 85% vs 63% and 87% vs 92%, respectively. The sensitivity, specificity, and PPV of the "poor" OPS-1 versus OPS-2 were 48% v 35%, 97% v 100%, and 93% v 100% respectively. The OPS at 48 hours is a good predictor of outcome at 6 months and 2 years after ischemic stroke and allows early identification of 3 prognostic groups, which may help in identifying patients most likely to benefit from intensive rehabilitation.

Ischemic stroke and depression.

Previous studies of depression after stroke have reported widely variable findings, possibly due to differences between studies in patient characteristics and methods for the assessment of depression, small sample sizes, and the failure to examine stroke-free reference groups to determine the base rate of depression in the general population. In an effort to address certain of those methodologic issues and further investigate the frequency and clinical determinants of depression after stroke, we administered the Structured Interview Guide for the Hamilton Depression Rating Scale (SIGH-D) and neurological, neuropsychological, and functional assessments to 421 patients (age = 71.5 +/- 8.0 years) 3 months after ischemic stroke and 249 stroke-free control subjects (age = 70.8 +/- 6.7 years). We required a SIGH-D total score > 11 for the identification of depression. We found that depression was less frequent (47/421 patients, or 11.2%, and 13/249 control subjects, or 5.2%), less severe, and less persistent in our stroke cohort than previously reported, possibly due to the underrepresentation of patients with a premorbid history of affective illness. Depression was associated with more severe stroke, particularly in vascular territories that supply limbic structures; dementia; and female sex. SIGH-D item analyses suggested that a reliance on nonsomatic rather than somatic symptoms would result in the most accurate diagnoses of depression after ischemic stroke.