Differential Contribution of Cerebellar Resting State Functional Connectivity Abnormalities to Cognitive Impairment in Pediatric and Adult Patients with Multiple Sclerosis (S35.004)

OBJECTIVE: We investigated whether resting state (RS) functional connectivity (FC) abnormalities of different functional subregions (right and left CrusI, CrusII and dentate nucleus) of the cerebellum contribute to cognitive impairment in pediatric and adult patients with MS. BACKGROUND: The human cerebellum is a complex structure engaged in motor and cognitive functions. DESIGN/METHODS: RS fMRI scans were acquired from 49 pediatric MS patients, 40 adult MS patients, 27 pediatric healthy controls (HC) and 40 adult HC. Patients with abnormalities in 蠅2 neuropsychological tests at an age- and disease-tailored cognitive evaluation were classified as cognitively impaired (CI). RESULTS: Fourteen (28[percnt]) pediatric and 14 (35[percnt]) adult MS patients were classified as CI. In pediatric and adult HC and CP MS patients, within group analysis of RS FC of the right dentate, CrusI and II showed a distributed pattern of correlations with several regions of the bilateral cerebellum, basal ganglia and fronto-parieto-temporal lobes. Conversely, pediatric and adult CI MS patients had a “reduced” pattern of RS FC between cerebellar subregions and a few frontal and temporal areas. For each cerebellar subregion, compared to pediatric HC, adult HC had a decreased RS FC in a distributed network of anterior areas. Compared to pediatric, adult CP MS patients had a reduced RS FC between the right dentate and anterior areas and an increased RS FC with the cerebellum. Compared to adult, pediatric CI MS patients showed a reduced RS FC between the right dentate nucleus and posterior regions of the brain as well as an increased RS FC with the right caudate nucleus. CONCLUSIONS: Different patterns of cerebellar RS FC abnormalities contribute to cognitive deficits in pediatric and adult MS patients, possibly due to the level of maturation of connections. Study Supported by: Partially supported by a grant from Italian Ministry of Health (GR-2009-1529671).