Cognitive impairment and intracranial atherosclerotic stenosis in general population.

OBJECTIVE: To investigate the association between asymptomatic intracranial atherosclerosis and cognitive impairment in the Atherosclerosis Risk in Communities (ARIC) cohort.

METHODS: ARIC participants underwent high-resolution 3T magnetic resonance angiography and a neuropsychology battery and neurologic examination adjudicated by an expert panel to detect mild cognitive impairment (MCI) and dementia. We adjusted for demographic and vascular risk factors in weighted logistic regression analysis, accounting for stratified sampling design and attrition, to determine the association of intracranial atherosclerotic stenosis (ICAS) with cognitive impairment.

RESULTS: In 1,701 participants (mean age 76 ± 5.3, 41% men, 71% whites, 29% blacks) with adequate imaging quality and no history of stroke, MCI was identified in 578 (34%) and dementia in 79 (4.6%). In white participants, after adjustment for demographic and vascular risk factors, ICAS ≥50% (vs no ICAS) was strongly associated with dementia (odds ratio [OR] 4.1, 95% confidence interval [CI] 1.7-10.0) and with any cognitive impairment (OR 1.7, 95% CI 1.1-2.8). In contrast, no association was found between ICAS ≥50% and MCI or dementia in blacks, although the sample size was limited and estimates were imprecise.

CONCLUSION: Our results suggest that asymptomatic ICAS is independently associated with cognitive impairment and dementia in whites.