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.