Do cerebral microbleeds affect cognition in patients with symptomatic small vessel disease?

Background: Dementia and cognitive impairment are becoming increasingly a major health problem, pronounced by increased life expectancy. Cerebral small vessel disease (cSVD) is among the major causes of cognitive deterioration, yet cerebral microbleeds (CMBs) which are a common association of cSVD are still not sure to be related to cognition. Aim of the study: The study aims to determine whether the number and localization of CMBs correlate with cognition in patients with symptomatic small vessel disease (SVD), according to Montreal Cognitive Assessment (MoCA) test. Subjects and methods: This cross-sectional study included 85 Egyptian patients with symptomatic SVD, from the neuropsychiatry clinic of the Main Suez Hospital in Suez City, in the period between February 2017 and February 2018. Subjects were classified according to CMB presence into CMB-positive and CMB-negative groups. Both groups are assessed using MRI imaging and MoCA test for cognitive function. Results: In our study, CMBs recorded a high prevalence rate of SVD patients. Subjects with MBs were mainly males and significantly older, with higher white matter lesion volume and more lacunar infarcts. MoCA test detected significant impairment in visuospatial/executive function, attention, and total scores in CMB-positive group. Both frontal and parietal MBs showed independent association with visuospatial/executive impairment. Deep MBs in the basal ganglia were proved to be independent risk factor for attention affection. Conclusion: Number and localization of MBs proved to be important in determining cognitive consequences. The relations with cognitive performance were mainly driven by frontal, parietal, and deep located MBs in the basal ganglia. Memory affection in frontal MBs was dependent to severe white matter intensities and lacunes.