Differential cerebellar activation on functional magnetic resonance imaging during working memory performance in persons with multiple sclerosis.

Abstract

To explore the potential role of the cerebellum in working memory dysfunction in multiple sclerosis (MS). Blood oxygen level dependent functional magnetic resonance imaging (fMRI) was used to examine cerebellar activation during a working memory task. University-affiliated medical rehabilitation facility. Eight persons with MS and 5 healthy controls. Not applicable. Change in hemodynamic response. fMRI data were acquired and subsequently analyzed by using Statistical Parametric Mapping. Both the control and MS groups showed significantly greater activations in the right cerebellar hemisphere as compared with the left side. Persons with MS, however, showed no detectable activations in 4 cerebellar substructures that were significantly active in controls (ie, right vermis, right dentate nucleus, right tonsil, cerebellar peduncle). The significantly decreased cerebellar activation in the MS group suggests that the cerebellum may play a role in the working memory impairment observed in MS.