Characterizing Intracranial Atherosclerotic Stenosis Associated With Cognitive Phenotypes Among Older Adults Who Are Dementia Free: A Population‐Based Study

Background Evidence has linked intracranial atherosclerotic stenosis (ICAS) with cognitive impairment in patients with stroke. We characterized ICAS associated with cognitive phenotypes in the general older population. Methods This study included 1031 participants without dementia from the community‐based MIND‐China (Multimodal Interventions to Delay Dementia and Disability in Rural China) magnetic resonance imaging substudy. The degree of stenosis was assessed using the Warfarin–Aspirin Symptomatic Intracranial Disease criteria. ICAS was defined as arterial stenosis ≥50%. The ICAS burden was assessed according to the number and severity of ICAS. Mild cognitive impairment (MCI) was defined following Petersen's criteria. Amnestic MCI was defined as MCI with the presence of memory impairment. Data were analyzed using multivariable logistic and linear regression models. Results Of the 1031 participants, 240 (23.28%) had MCI. Higher ICAS burden was associated with increased likelihoods of MCI (odds ratio OR, 1.89 95% CI, 1.02–3.41) and amnestic MCI (OR, 2.11 95% CI, 1.13–3.92), and reduced Z scores of global cognition (β, −0.21 95% CI, −0.35 to −0.07), memory (β, −0.40 95% CI, −0.61 to −0.18), and verbal fluency (β, −0.28 95% CI, −0.47 to −0.08). More severe ICAS was associated with lower memory Z score and a greater number of ICAS was associated with lower Z scores of global cognition, memory, and verbal fluency (all P <0.05). Furthermore, the presence of ICAS in anterior cerebral, internal carotid, posterior cerebral, and basilar artery was associated with reduced Z scores of memory, verbal fluency, and attention (all P <0.05). Conclusions The severity and location of ICAS are crucial for the associations of ICAS with MCI, amnestic MCI, and poor cognition in older adults. Cognitive assessments are warranted for older adults with ICAS.