Cerebellar Contribution to Motor and Cognitive Impairment in Multiple Sclerosis Patients: A Sub-Regional Structural MRI Analysis (P4.128)

Objective: To assess the role of cerebellar global and sub-regional involvement on motor and cognitive impairment in multiple sclerosis (MS) patients. Background: The cerebellum plays a role in a wide variety of complex behaviors. Many evidences support a topographic division into “motor” and “non-motor” regions mapped to the anterior and posterior lobe of the cerebellum, respectively. Currently, no study has investigated the impact of structural cerebellar sub-regional involvement on motor and cognitive manifestations in MS patients. Methods: Cerebellar segmentation and lobular parcellation was performed on the 3D-T1-weighted brain images from 95 MS patients (53 relapsing remitting [RR] MS, 20 benign MS and 22 secondary progressive [SP] MS) and 32 healthy controls (HC) using the SUIT tool from SPM12. For all subjects, the Nine Hole Peg Test (9-HPT) was obtained as a measure of motor performance. MS patients also underwent cognitive evaluation, including the Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT) and Wisconsin Card Sorting Test (WCST). Spearman’s correlations between normalized cerebellar volumes vs motor and cognitive scores were estimated (p<0.05). Results: Global and regional cerebellar volumes did not differ between MS patients and HC. In MS patients, better 9-HPT performance correlated with higher global and regional cerebellar volumes, with stronger correlation with the anterior regions (lobules I-V) (p=0.02, r=0.24). In RRMS patients, better cognitive performance (SDMT, WCST) correlated with higher global and posterior-inferior (lobules VI-X) cerebellar volumes (p range: 0.008-0.01, r range: 0.30-0-32). Conclusions: Cerebellar posterior-inferior volume accounted for variance in cognitive measures in MS patients, whereas anterior cerebellar volume accounted for variance in motor performance, supporting a critical contribution of regional cerebellar damage to the clinical manifestations of MS. This study has been partially supported by a grant from FISM 2011/R/19 and Italian Ministry of Health (GR-2009-1529671).