BRAIN AND SPINAL-CORD MR IN BENIGN MULTIPLE-SCLEROSIS - A FOLLOW-UP-STUDY

We performed a clinical and magnetic resonance (MR) longitudinal study in 19 patients with benign multiple sclerosis (MS) to achieve a bette r definition of the nature of disability in MS. Patients with higher l esion volumes on conventional T-2-weighted images at entry were those with more frequent relapses (p = 0.0004) and more new MR lesions (p = 0.003) during the follow up. However, 1/3 of these new lesions were lo cated periventricularly and about 2/3 were small or intermediate in si ze. Two of the 11 patients (18%) with higher lesion volumes at entry d eveloped progressive neurological deficits: in these two patients the new lesions seen on conventional T-2 images had lower magnetization tr ansfer ratios (p = 0.005) than those present in patients who remained clinically stable and a marked increase in hypointense lesion volumes on T-1-weighted images was also found. Spinal cord cross-sectional are a at C5 and MTR values for the seemingly normal white matter were simi lar to those found in normal controls. This study suggests that patien ts with benign MS have two different patterns of disease evolution, on e characterized by very low clinical and MR activities, the other in w hich the lack of disabling symptomatology might be related to factors like site, size and nature of lesions. It also indicates that in patie nts with benign MS and high MR lesion loads the risk of developing a s econdary progressive form of the disease is still present even after m any years after onset.