Baseline T2 lesion volume predicted subsequent changes in Paced Auditory Serial Addition Test ( PASAT ) ( p = 0.004 ) , whereas baseline measures of atrophy including BPV , GMV , and NAWMV predicted longitudinal changes in MSFC ( p = 0.016 , p = 0.040 , p = 0.021 , respectively ) and Timed-25 Foot Walk ( p < 0.05 ) .