A Magnetic Resonance Imaging Voxel-Based Morphometry Study of Regional Gray Matter Atrophy in Patients With Benign Multiple Sclerosis

Background Evidence is accumulating that indicates that a selected assessment of gray matter (GM) damage is able to provide strong paraclinical correlates of multiple sclerosis (MS) severity. Objective To investigate the pattern of regional GM atrophy in patients with benign MS (BMS) vs those with secondary progressive MS (SPMS) to better elucidate the factors associated with a favorable status in patients with MS. Design Cross-sectional survey from January 2006 to August 2007. Setting Referral, hospital-based MS clinics. Patients Sixty patients with BMS, 35 patients with SPMS, and 21 healthy volunteers. Main Outcome Measures Neuropsychological tests exploring memory, attention, and frontal lobe cognitive domains were administered to BMS patients. A voxel-based morphometry analysis of GM concentration was performed using statistical parametric mapping and a threshold of 0.05, corrected for multiple comparisons. Results Twelve BMS patients (20%) had an abnormal performance on 3 or more neuropsychological tests. Compared with healthy individuals, BMS patients had a reduced GM volume in the subcortical and frontoparietal regions. Compared with BMS patients, those with SPMS had a significant GM loss in the cerebellum. No differences between BMS and SPMS patients were found when only BMS patients with cognitive impairment or those with shorter disease duration (15-19 years) and higher Expanded Disability Status Scale scores (>2.0) were considered. Conclusions Cerebellar GM atrophy seems to be a major determinant of irreversible locomotor disability in MS. The absence of cognitive impairment and a longer disease duration or lower Expanded Disability Status Scale score may identify those BMS patients with the potential for a favorable disease evolution.