P1-337: Incidental lacunar infarcts, brain atrophy and white matter hyperintensities in a community population: The path through life study

Abstract

Lacunar infarcts, brain atrophy and white matter hyperintensities (WMH) were commonly found in the ageing brain and have been associated with cognitive decline. However, the relationship between these structural changes has not been adequately addressed in a community sample. A total of 477 participants were recruited by electoral roll from the community residents aged 60–64 years old. Lacunar infarct was defined as small cavitated lesions with a diameter range of 3–20mm. The lesions were characterised by hypointense foci in T1-weighted and FLAIR images, while surrounded by a hyperintense rim on the latter. The WMH were detected and measured quantitatively by an automated procedure, applying a set of in-house computer algorithms and programs. The volume of WMH is a relative value which indicates the ratio of WMH to the total WM. The volumes of hippocampus and amygdala were determined by manual tracing performed by two trained researchers in accordance with an established protocol. Thirty-seven (7.8 %) participants had at least one lacunar infarct on MRI images. Participants with lacunar infarction showed greater total WMH volumes (p = 0.006), including periventricular WMH (p = 0.005), deep white matter WMH (p = 0.010) and amount of severe WMH (p = 0.032). The lacunar infarct group had a higher ratio of anterior ventricle-brain ratio (VBR) and larger hippocampus volumes compared with the group without lacunar infarct. However, this difference did not exist if intracranial volume (ICV) was taken into account. WMHs (OR = 4.9; CI = 1.53 -15.80) contributed to the risk of lacunar infarct independent of hypertension. It is suggested that lacunar infarcts are association with WMH and this association was not eliminated by including the effect of hypertension in this study. The link between lacunar infarction and WMH may reflect similar ongoing vasculopathy in small vessel which is not entirely due to hypertension. There was no evidence that lacunar infarcts were associated with global brain atrophy or hippocampus volumetric changes.