Intracranial artery stenosis and progression from mild cognitive impairment to Alzheimer disease

OBJECTIVE:To assess the impact of intracranial arterial stenosis on the progression from mild cognitive impairment (MCI) to Alzheimer disease (AD). METHODS:A total of 423 participants with MCI were included and evaluated with clinical and neuropsychological examinations annually for 4 years. The incidence of dementia due to AD was investigated. CT angiography was used to measure the stenosis of major intracranial arteries in the studied population. A mixed-effects regression model was used to analyze the association between intracranial arterial stenosis and the progression of MCI, which was assessed with the Mini-Mental State Examination and the Activities of Daily Living scale. Cox proportional hazards models were used to identify the association between intracranial arterial stenosis and dementia progression. RESULTS:At the end of the follow-up, 116 participants had progressed to dementia due to AD, while 223 remained in the MCI stage. Participants with moderate or severe intracranial arterial stenosis had a faster decline in cognition and function relative to participants without such stenosis. The presence of moderate or severe intracranial arterial stenosis significantly increased the risk of dementia progression, even after controlling for age, sex, education, vascular risk factors, and silent MRI lesions. CONCLUSIONS:Intracranial arterial stenosis increased the risk of developing AD dementia after MCI.