White Matter Lesion Subtypes and Cognitive Deficits in Patients with Memory Impairment

Abstract

Aim: To analyze the relationship between periventricular (PV) and subcortical (SC) white matter lesions (WML) and cognitive function in patients with memory impairment. Methods: In total, 253 patients with Global Deterioration Scale scores ≧3 who had been referred to a university-based memory unit due to memory complaints were included (mean age 69.7 years, 124 females). Cognitive function was assessed with the Mini-Mental State Examination (MMSE) and the Neurobehavioral Cognitive Status Examination (Cognistat), and full test results were available for 217 patients. PV and SC WML loads (semi-quantitative rating on axial T₂-weighted MRI scans) were used in linear regression as predictors of cognition. Results: MMSE was significantly correlated with SC WML (p = 0.005), but not with PV WML (p = 0.19). Cognistat tests for orientation, comprehension, visuoconstruction, calculation, similarities, and judgment were negatively correlated with SC WML (p < 0.01), as was verbal memory with parieto-occipital SC WML (p < 0.05). Visuoconstruction and calculation were negatively correlated with PV WML (p < 0.05). Parieto-occipital WML were more strongly related to cognition than fronto-temporal WML. Only SC WML were significantly correlated with cognition when PV and SC WML were entered simultaneously in the regression model. Conclusion: In patients with cognitive impairment, SC WML, in particular in parieto-occipital regions, were associated with reduced cognitive function.