Cerebral microbleeds and cognitive functioning in the PROSPER study.

Objectives: Cerebral microbleeds (MBs) are an important indicator of cerebral small-vessel disease, and their prevalence increases with increasing age. Little is known about the functional consequences of MBs in the aging population. In this study we investigated whether the presence and location of MBs are associated with cognition in the PROSPER study.

Methods: For 439 subjects the number and location (cortico-subcortical, deep white matter, basal ganglia, and infratentorial) of the MBs was recorded. Difference in cognitive performance between subjects with and without MBs was calculated by entering the variables sex, age, white matter hyperintensity volume, infarction, and MBs in a linear mixed model. Differences in cognition between subjects with and without one or more MBs at different anatomic locations were assessed using the same model.

Results: We found that after correction for sex, age, white matter hyperintensity volume, and infarction, subjects with infratentorial MBs had a significantly lower score on the Immediate Picture-Word Learning test, Delayed Picture-Word Learning, and Instrumental Activities of Daily Living.

Conclusions: Our data demonstrate that in elderly individuals at increased vascular risk, infratentorial MBs are associated with loss in cognitive functioning.