Dilated Virchow-Robin spaces (dVRS) are not uncommon findings in the normal brain, particularly in the old people, and have been largely regarded as benign lesions. However, there is accumulating evidence that dVRS may serve as an neuroimaging marker of small vessel disease and are associated with cognitive decline. We investigated whether the severity of dVRS would be associated with cognitive dysfunction by comparing the subjects with subjective memory impairment (SMI), mild cognitive impairment (MCI), and Alzheimer's disease (AD). We also examined whether there were differences in the degree of correlation between dVRS and magnetic resonance imaging (MRI) markers of small vessel disease among the three groups.

In this retrospective study, a total of 225 subjects were included: those with SMI ( n =65), MCI ( n =100), and AD ( n =60). We rated the severity of dVRS using the axial MRI slice containing the greatest number of dVRS in the basal ganglia (dVRS-BG) and in the deep white matter (dVRS-WM), 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 ( p <0.001), hypertension ( p =0.006), diabetes mellitus ( p =0.042), the severity of dVRS-BG ( p =0.001), the severity of WMH ( p =0.074) and the presence of lacunar infarcts ( p <0.001) and microbleeds ( p =0.003) in univariate analysis. However, after adjusting for other confounding variables, the severity of dVRS-BG was not a significant discriminating factor among subjects with SMI, MCI, and AD. 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 subjects with AD than in those with MCI or SMI ( r =0.191 in SMI; r =0.284 in MCI; r =0.312 in AD), 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 appeared to be confounded by other well-known risk factors. The correlation between dVRS-BG and small vessel disease markers tended to be more significant with the advancement of cognitive impairment. These results suggest that severe dVRS may reflect cerebral small vessel disease and contribute to cognitive impairment.