DEMENTIA AFTER FIRST STROKE

Background and Purpose Cognitive deficits may significantly worsen the quality of life after stroke. Our aim was to determine the frequency of dementia in a consecutive series of previously nondemented patients between the ages of 40 and 79 years at 3 months after a first ischemi c stroke. Methods All patients admitted to our department during an 18 -month period who met the above criteria were visited and tested and u nderwent a CT scan 3 months after their stroke. Dementia was diagnosed according to criteria of the National Institute of Neurological Disor ders and Stroke and AIREN, but cases with aphasia were not excluded. R esults Of 304 patients admitted for stroke, 146 were eligible for stud y. Eleven refused to participate, 25 were dead at 3 months, and 110 we re tested. Fifteen patients were demented (13.6%; 95% confidence inter val [CT], 7.8% to 21.5%), and six had severe isolated aphasia, neglect , or memory deficit (5.4%). Excluding patients with aphasia, 5.0% of c ases showed dementia (95% CI, 1.6% to 11.3%). The frequency of dementi a was 24.6% (95% CI, 14.5% to 37.3%), considering only patients with s upratentorial lesions and with residual deficits of elementary functio ns (paresis, sensory deficits) at the time of examination. Demented pa tients had significantly more diabetes (P=.029), atrial fibrillation ( P=.032), aphasia at entry (P<.001), large middle cerebral artery infar ctions (P<.001), and a more severe neurological deficit at entry (P=.0 03) and at 3 months (P<.001). At CT scan, demented patients had a larg er mean volume of the recent lesion (P<.001) and more lesions in the f rontal lobe (P=.041). An exploratory multivariate analysis selected ag e between 60 and 69 years (odds ratio [OR], 45.8; 95% CI, 2.9 to 726.0 ), diabetes (OR 59.4; 95% CI, 4.3 to 821.0), aphasia (OR, 14.8; 95% CI , 2.0 to 111.0), a large middle cerebral artery infarction (OR, 30.0; 95% CI, 2.7 to 334.0), and lesions of the frontal lobe (OR, 9.8; 95% C I, 1.3 to 72.8) as significant independent correlates of poststroke de mentia. Conclusions Dementia is relatively frequent after a clinical f irst stroke in persons younger than 80 years, and aphasia is very ofte n associated with poststroke dementia. If aphasic patients are not con sidered, it may be necessary to screen a very large number of subjects to collect an adequate sample of demented cases.