Cortical cerebral microinfarcts predict cognitive decline in memory clinic patients

Area of Science:

• Neurology
• Neuroimaging
• Vascular Neurology

Background:

• Cortical cerebral microinfarcts (CMIs) are emerging MRI markers of cerebral vascular pathology.
• Previous cross-sectional studies linked CMIs to dementia and cognitive impairment.
• The predictive value of baseline CMIs for future cognitive decline remains unclear.

Purpose of the Study:

• To investigate whether baseline cortical CMIs predict cognitive decline in a prospective memory clinic cohort.
• To quantify the association between the burden of cortical CMIs and the rate of cognitive decline.

Main Methods:

• A prospective cohort of 313 patients with baseline 3T MRI and serial neuropsychological assessments (≥1 year apart) was analyzed.
• Cortical CMIs were quantified using a validated MRI protocol.
• Cognition was assessed using the Montreal Cognitive Assessment (MoCA) and a comprehensive neuropsychological battery.

Main Results:

• Higher baseline cortical CMI counts were associated with significantly greater annual decline in MoCA scores and global cognition.
• Patients with >2 CMIs experienced accelerated cognitive decline, with MoCA scores decreasing by an average of 2 points and global cognition by 0.5 points at year two.
• Cortical CMIs independently predicted accelerated decline in memory and language domains, even within the subgroup of patients with dementia.

Conclusions:

• Baseline cortical CMIs are a significant predictor of future cognitive decline in a memory clinic population.
• Cortical CMIs represent a valuable imaging biomarker for identifying individuals at risk for progressive cognitive impairment.
• Integrating cortical CMIs with other cerebrovascular markers may enhance clinical trial design for vascular cognitive impairment.