Multisequence MRI in clinically isolated syndromes and the early development of MS

OBJECTIVE: To apply multisequence MRI techniques to patients with clinically isolated syndromes, to document the pattern and frequency of abnormalities at baseline and early follow-up, and to determine their predictive values for the early development of clinical MS. BACKGROUND: Disseminated lesions on T2-weighted brain MRI confer an increased risk of progression to clinically definite MS. Newer MRI techniques increase detection of lesions in both brain and spinal cord, and clarify further their pathology. The predictive value of such techniques for the development of clinical MS needs to be defined. METHODS: Brain and spinal MRI were performed on 60 patients after their first demyelinating event. A total of 50 patients were followed for 1 year, and 49 underwent repeat brain MRI 3 months after the initial scan. RESULTS: At baseline, 73% of patients had lesions on T2-weighted fast spin-echo (FSE) brain images and 42% had asymptomatic spinal cord lesions. Fast fluid-attenuated inversion-recovery brain did not improve detection of brain lesions. Repeat brain MRI demonstrated new FSE lesions in 43% of patients. After 1 year, 26% of patients developed MS. The MRI features that provided the best combination of sensitivity and specificity for the development of MS were the presence of new FSE lesions at follow-up and enhancing lesions at baseline. The frequency of developing clinical MS was higher for those with both brain and spinal cord lesions at baseline (48%) than brain lesions alone (18%). CONCLUSIONS: The combination of baseline MRI abnormalities and new lesions at follow-up, indicating dissemination in space and time, was associated with a high sensitivity and specificity for the early development of clinical MS. These data suggest a potential role for new diagnostic criteria for MS based on early MRI activity. Such criteria may be useful in selecting patients for therapeutic trials at this early clinical stage.