Frontal and temporal microbleeds are related to cognitive function: the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort (RUN DMC) Study.

BACKGROUND AND PURPOSE: Cerebral small vessel disease, including white matter lesions and lacunar infarcts, is related to cognitive impairment. Cerebral microbleeds (MBs) are increasingly being recognized as another manifestation of small vessel disease and are also related to cognitive function. However, it remains unclear whether this relation is independent of white matter lesions and lacunar infarcts and if location of MB plays a role. We investigated the relation between the presence, number, and location of MB and cognitive performance adjusted for white matter lesions and lacunar infarcts.

METHODS: Presence, number, and location of MB were rated on a gradient echo T2*-weighted MRI in 500 nondemented elderly patients with small vessel disease. Cognitive performance was assessed in different domains. Analyses were adjusted for age, sex, education, depressive symptoms, total brain volume, white matter lesion volume, and lacunar and territorial infarcts.

RESULTS: Mean age was 65.6 years (SD 8.8) and 57% were male. MBs were present in 10.4% of the participants. Subjects with MBs were significantly older, had a higher white matter lesion volume, and more lacunar infarcts (P<0.001). Presence and number of MBs were related to global cognitive function (β-0.10, P=0.008; β-0.20, P=0.002), psychomotor speed (β-0.10, P=0.012; β-0.19, P=0.006), and attention (β-0.10, P=0.02; β-0.205, P=0.001). The relations with cognitive performance were mainly driven by frontal, temporal, and strictly deep located MB.

CONCLUSIONS: Frontal and temporal located MBs correlate with cognitive performance in nondemented elderly patients independent of coexisting other small vessel disease-related lesions. MBs are clinically not silent and may help to understand the role of vascular disease in cognitive decline.