Impairments in Walking Ability, Dexterity, and Cognitive Function in Multiple Sclerosis Are Associated with Different Regional Cerebellar Gray Matter Loss

Both histological and neuroimaging studies highlight the role of the cerebellum in multiple sclerosis (MS). There is at least some evidence for associations of cerebellar gray matter (GM) loss with motor and cognitive ability. We therefore correlated motor and cognitive ability scores (the multiple sclerosis functional composite MSFC) with regional cerebellar GM volumes. We used voxel-based morphometry (VBM) to assess the regional GM volume loss in a cohort of 45 MS patients. For the regression analysis, we used the clinical subscores of the multiple sclerosis functional composite (25-ft walk test (T25FW), nine-hole peg test (9HPT), paced auditory serial addition task (PASAT)). Decreased GM in distinct cerebellar areas was associated with different subscores of the MSFC in Larsell's lobule VI with the T25FW (t = 5.16), in lobule IX with the 9HPT (t = 3.95), and in lobule IX with the PASAT (t = 4.81). Regional volume decrease in distinct cerebellar areas involved in motor and cognitive domains were associated with clinical impairment in these fields. Our data confirm the relationship between cerebellar GM volume loss and disability, extending the knowledge in the functional neuroanatomical perspective.