68 * CEREBRAL MICROBLEEDS ARE NOT ASSOCIATED WITH PHYSICAL OR COGNITIVE FUNCTION IN COMMUNITY DWELLING OLDER PEOPLE

Introduction: Cerebral microbleeds are small (2-10mm) hypointensities visualised on T2*-weighted MRI scans. They are considered small vessel disease markers and are associated with stroke and Alzheimer's disease severity; their clinical significance in the general older population is poorly understood. We aimed to determine: the prevalence of microbleeds in a community-dwelling cohort of people age >75 years and if microbleed presence was associated with cognitive or physical function. Methods: Subjects were recruited from a longitudinal community cohort examining predictors of cognitive impairment. Participants underwent: detailed cognitive testing (MMSE, CAMCOG-R, reaction times), Tinetti assessment of gait and balance and a MRI brain scan. T2*-weighted scans were reviewed independently for microbleeds by two authors (KEM & CMcD) using the Microbleed Anatomical Rating Scale criteria. Inter-rater disagreements were decided by a third author (MF.) Results: Fifty-three subjects underwent MRI scanning; one was excluded due to poor scan quality leaving a cohort of 52 (median age (IQR) 79.0 (76.3-83.8); 57.7% male.) Ten subjects had microbleed(s); most (n = 7) displayed a single microbleed. Comparing cognitive function and Tinetti scores in microbleed–negative and -positive groups did not reveal any significant differences (Table 1). Conclusions: Microbleeds were found infrequently and in low numbers in our cohort and were not associated with cognitive or physical function. This is in keeping with findings from 2 similar studies in community cohorts. It is likely that as with other small vessel disease markers that there is a threshold effect with small numbers of microbleeds constituting incidental findings.