PRL and multiple sclerosis: It has been previously shown that the neurodegeneration due to multiple sclerosis lesions may impact both the axonal terminal and the cell soma, which may then lead to atrophy in the connected GM regions.42 WM lesion volume was shown to be associated with GM atrophy at both global and regional levels.43-45 Thus, the structural disconnectivity due to PRL in the motor-related regions might cause atrophy in these regions.