Asymptomatic spinal cord lesions do not predict the time to disability in patients with early multiple sclerosis

BACKGROUND: The presence of asymptomatic spinal cord (SC) lesions in patients with clinically isolated syndrome (CIS) or relapsing-remitting multiple sclerosis (RRMS) predicts conversion to clinically definite multiple sclerosis (CDMS). The relation between asymptomatic SC abnormalities and disability progression warrants further investigation. OBJECTIVE: To determine the prognostic value of asymptomatic SC lesions in CIS and early RRMS with respect to the time to disability development. METHODS: Clinical and demographic data, brain and SC magnetic resonance imaging (MRI) were collected of CIS or early RRMS patients. Two main analyses were performed. For the first analysis, patients were divided into two groups: (1) patients with asymptomatic SC lesions and (2) patients without SC lesions and patients with symptomatic SC lesions. The second analysis excluded patients with symptomatic SC lesions. Incidence curves were used to analyse differences between these groups in time to the development of disability and time to a second relapse. RESULTS: A total of 178 patients were included, and 42 patients (23.6%) had asymptomatic SC lesions. No significant differences were found on the time to disability development or the time to a second event. CONCLUSION: Asymptomatic SC lesions early in the disease course do not predict the time to disability development in patients diagnosed with CIS or early RRMS.