Impact of Brain MRI Markers on Major and Mild Vascular Cognitive Impairment in CADASIL

Abstract

Background: Cognitive impairment is the second most common clinical manifestation in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). However, understanding of cognitive impairment in CADASIL has been hampered by lack of consensus on diagnosis of vascular cognitive impairment (VCI). We used vascular impairment of cognition classification consensus study principles (VICCCS-1) and protocols (VICCCS-2) to assess the cognitive impairment in CADASIL. We also evaluated the impact of MRI markers on major and mild VCI in CADASIL.Methods: We prospectively recruited 64 patients who underwent standardized brain MRI and detailed neuropsychological test. MRI analysis included number of lacunes, number of cerebral microbleeds (CMB), normalized volume of white-matter hyperintensities (nWMH), and brain parenchymal fraction (BPF). BPF has been used to measure brain atrophy. The patients were divided into three groups: those with normal cognition (CADASIL-NC, n=14), those with mild VCI (CADASIL-mild VCI, n=38), and those with major VCI (CADASIL-major VCI, n=11).Results: The three groups differed according to age, with the major VCI group being older. The major VCI group had more lacunes, more CMB, more extensive white matter lesions and lower BPF than NC group. There were no significant differences between NC and mild VCI groups in BPF. BPF and age were the independent predictors of major VCI. There was a tendency that women were at higher risk for mild VCI, though it did not reach statistical significance. Women were older than men, but had lower number of lacunes in mild VCI.Conclusions: These findings suggest that brain atrophy and age are the main predictors of major VCI in CADASIL.