White matter hyperintensities in mild cognitive impairment: clinical impact of location and interaction with lacunes and medial temporal atrophy.

This study was to evaluate the influence on cognition and activities of daily living (ADL) by white matter hyperintensities (WMHs) based on the severity and location, as well as the interactions among WMHs, lacunes, and medial temporal atrophy (MTA). In 150 patients with amnestic mild cognitive impairment, WMHs were quantified with the use of a semiautomated volumetric method. Lacune counting and MTA assessment were performed by visual rating. The severer WMHs were, the more executive functions decreased. The influence on executive functions such as verbal fluency test and Stroop color reading test were greater in periventricular (PV) WMHs than deep WMHs, as well as bigger in anterior, middle, and posterior areas in order. The instrumental (I) ADL was strongly associated with the anterior (P = .028) and middle area (P = .014) of PVWMHs only. WMHs had synergistic interactions with lacunes in Controlled Oral Word Association Task-semantic (ß = -1.12; R(2) = .24; P = .039), Stroop color (ß = -2.07; R(2) = .15; P = .049), and IADL (ß = .23; R(2) = .20; P = .009). Anterior PVWMHs demonstrated the most powerful impact on frontal executive dysfunction and poor performance of IADL. WMHs had synergistic effects with the number of lacunes on them. Therefore, it is desirable to consider WMHs and lacunes simultaneously as potential imaging biomarkers for predicting cognition and IADL in aMCI.