Infratentorial lesions predict long-term disability in patients with initial findings suggestive of multiple sclerosis

Background: The number and volume of abnormalities on baseline brain magnetic resonance images in patients with initial findings suggestive of multiple sclerosis are known to predict outcome in terms of disability. However, no long-term data exist on specific locations or types of lesions. Objective: To assess the long-term predictive value of baseline magnetic resonance imaging parameters, including location of lesions and gadolinium-enhancing and hypointense lesions in patients with initial findings suggestive of multiple sclerosis for the occurrence of clinically relevant disability as defined by an Expanded Disability Status Scale score of 3. Patients: After a median follow-up period of 8.7 years, the medical records of 42 patients were reviewed and assessed for time until patients received an Expanded Disability Status Scale score of 3. Magnetic resonance imaging parameters were dichotomized according to maximum accuracy and then used to calculate hazard ratios using the Cox model for proportional hazard ratios. Results: Conversion to clinically definite multiple sclerosis was observed in 26 patients (62%), of whom 14 (54%) progressed to an Expanded Disability Status Scale score of 3. Two or more infratentorial lesions best predicted long-term disability (hazard ratio, 6.3). Gadolinium-enhancing and hypointense T1-weighted lesions did not show prognostic value. Conclusion: Infratentorial lesions are related to long-term prognosis for patients with initial findings suggestive of multiple sclerosis and thus may help to identify patients at high risk for earlier occurrence of clinically relevant disability.