Impact of combined medial temporal atrophy and white matter lesions on the cognitive and emotional functions in Alzheimer's disease patients

Aim: The purpose of this study was to determine the relationship between the combined presence of medial temporal atrophy (MTA) and white matter lesions (WMLs: periventricular hyperintensity (PVH) and deep white matter hyperintensity) and the cognitive/emotional function in Alzheimer’s disease (AD) patients. Methods: The subjects included 193 patients with AD and 30 normal elderly controls. On MRI, MTA was rated using the Voxel-based specific regional analysis system for AD (VSRAD). WMLs was also estimated using the Fazekas scale. The MRI measurements were classified as follows: MTA = VSRAD<2 or≧2; WML absent (-) 0/1 or present (+) 2/3. A total of five groups were assessed, including four groups with AD and a control group. The cognitive and emotional functions were evaluated with neuropsychological tests (Mini-Mental State Examination (MMSE), Frontal Assessment Battery (FAB), Geriatric Depression Scale (GDS) and Apathy scale). Results: Four AD groups showed significant declines in the both the MMSE and FAB scores compared to that observed in the control group (^***p<0.001,^**p<0.01,^*p<0.05). Among these four AD groups, the MMSE and FAB scores of in the VSRAD<2 and WML (-) groups significantly declined to VSRAD≧2 and WML (+), respectively group (^*p<0.05). VSRAD ≧2 and WML (+) groups showed demonstrated significantly higher scores than the control group on the GDS (^*p<0.05), and the PVH (+) group exhibited significantly higher scores than the control group on the apathy scale (^*p<0.05). Multiple regression analysis identified a VSRAD score of≧2 and the presence of WMLs to be most significantly associated with the cognitive and emotional functions. Conclusions: Combined presence of MTA and WML is associated with lower MMSE and FAB scores. Furthermore, depression is also associated with MTA and WML, while PVH independently affects the degree of apathy.