Diffusion tensor imaging and gait in elderly persons with cerebral small vessel disease.

BACKGROUND AND PURPOSE Although cerebral small vessel disease, including white matter lesions (WML) and lacunar infarcts, is associated with gait disturbances, not all individuals with small vessel disease have these disturbances. Identical-appearing WML on MRI could reflect different degrees of microstructural integrity. Moreover, conventional MRI does not assess the integrity of normal-appearing white matter (NAWM). We therefore investigated the relation between white matter integrity assessed by diffusion tensor imaging in WML, NAWM, several regions of interest, and gait. METHODS A total of 484 nondemented elderly persons between 50 and 85 years old with cerebral small vessel disease were included in this analysis and underwent MRI and diffusion tensor imaging scanning. Mean diffusivity and fractional anisotropy within WML, NAWM, and regions of interest were related to quantitative and semiquantitative gait parameters. RESULTS Mean diffusivity in the WML was inversely related with gait (velocity β=-0.15; P=0.002). For the fractional anisotropy, this relation was less evident. The same was found in the NAWM (velocity β=-0.21; P<0.001) and for some parameters also after additional adjustment for WML and lacunar infarcts. CONCLUSIONS This study indicates that integrity of both WML and NAWM, beyond the detection limit of conventional MRI, is associated with gait disturbances.