Background: There is growing evidence suggesting that intracranial atherosclerosis is associated with cognitive impairment. We investigated the association between asymptomatic intracranial atherosclerosis and cognitive impairment in the bi-racial Atherosclerosis Risk in Communities (ARIC) cohort.
Methods: ARIC participants who underwent high-resolution 3T magnetic resonance angiography, and a neuropsychology battery and neurological 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 1705 participants (mean age 76 ± 5.3, 41% men, 71% Whites and 29% African-Americans) with adequate imaging quality and no previous 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) and with any-cognitive impairment (OR 1.7, 95% CI 1.06 - 2.8). In contrast, no association was found between ICAS ≥50% and MCI or dementia in African-Americans, though sample size was limited and estimates were imprecise.
Conclusion: Our results suggest asymptomatic ICAS is independently associated with cognitive impairment and dementia in Whites