Spinal cord lesions: A modest contributor to diagnosis in clinically isolated syndromes but a relevant prognostic factor

Background: The usefulness of performing a spinal cord (SC) magnetic resonance imaging (MRI) in all clinically isolated syndromes (CIS) is controversial. Objective: To assess the value of SC lesions for predicting multiple sclerosis (MS) diagnosis and disability accrual in CIS. Methods: Concerning SC lesions and MS diagnosis (2010 McDonald), adjusted Cox regression analyses were performed in increasingly specific CIS groups: all cases (n = 207), non-SC CIS (n = 143), non-SC CIS with abnormal brain MRI (n = 90) and non-SC CIS with abnormal brain MRI not fulfilling 2010 MS (n = 67). For the outcome Expanded Disability Status Scale (EDSS) >= 3.0, similar analyses were performed in all cases (n = 207), non-SC CIS (n = 143) and SC CIS (n = 64). Performance at 2 years was assessed for all outcomes. Results: The presence of SC lesions increased MS risk 2.0-2.6 times independently of factors like brain lesions. If considering lesion number, the risk ranged from 1.6 to 2.1 for one lesion to 2.4-3.3 for >= 2. SC lesions increased the short-term disability risk around fivefold, better demonstrated in non-SC CIS. SC lesions were very specific for evolution to MS and showed very high sensitivity for EDSS >= 3.0. Conclusion: SC lesions are independent predictors of MS in all CIS and contribute to short-term disability accrual. SC MRIs in CIS could be useful to estimate their prognosis.