Is the severity of dilated Virchow-Robin spaces associated with cognitive function?

Abstract

Virchow-Robin spaces (VRS) are perivascular spaces surrounding the perforating cerebral arteries or arterioles. The detection of dilated VRS (dVRS) is not uncommon in the normal brain and dVRS have been regarded as benign variants. However, there are accumulating evidences that dVRS are associated with MRI markers of small vessel disease and cognitive decline. We investigated whether the severity of dVRS would be associated with cognitive function by comparing the subjects with subjective memory impairment (SMI), mild cognitive impairment (MCI), and dementia. Also, we examined whether there were differences in the degree of correlation between dVRS and MRI markers of small vessel disease among three groups. In this retrospective study, a total of 225 patients were included: those with SMI (n = 65), MCI (n = 100), and dementia (n = 60). We rated the severity of dVRS according to a three-level arbitrary scale in the slice containing the greatest number of dVRS in BG (dVRS-BG) and CS (dVRS-CS) separately. We also assessed baseline characteristics including vascular risk factors and MRI markers of small vessel disease such as white matter hyperintensities (WMH), lacunar infarcts and microbleeds. A cumulative logit model revealed that the severity of cognitive dysfunction was associated with age, hypertension, diabetes mellitus, the severity of dVRS-BG, the severity of WMH and the presence of lacunar infarcts and microbleeds in univariate analysis. However, after adjusting for other confounding variables, the severity of dVRS-BG was not a significant discriminating factor among patients with SMI, MCI and dementia. Spearman's correlation analysis showed a trend that the correlation between the severity of dVRS-BG and the severity of WMH became more prominent in patients with dementia than in those with MCI or SMI, and the same is true of the severity of dVRS-BG and the number of lacunar infarcts. The severity of dVRS was associated with cognitive dysfunction, which seemed to be confounded by other well-known risk factors. The correlation between dVRS-BG and small vessel disease markers was more significant in patients with MCI and dementia. These results suggest that dVRS may be considered another marker of small vessel disease and implicated in cognitive impairment.