Evoked potentials can predict future disability in people with clinically isolated syndrome

Background and purpose The aim was to evaluate whether the addition of evoked potentials (EPs) which evaluate brainstem function to the EP score improves its ability to predict disease progression in people with clinically isolated syndrome (pwCIS). Methods For 94 pwCIS, data on disease activity and progression after 2.9 (1.4-4.1) years of follow-up were available. Baseline characteristics included magnetic resonance imaging (MRI) parameters, visual EPs, auditory EPs, somatosensory EPs of the median and tibial nerves, vestibular evoked myogenic potentials and tongue somatosensory EPs. Results A multivariable regression model including age, sex, total number of T2 lesions on baseline MRI and EP score >13 showed that the total number of T2 lesions on baseline MRI and EP score >13 increase the likelihood for sustained accumulation of disability (SAD). After controlling for age, sex and the total number of T2 lesions on baseline MRI, the hazard of SAD for participants with EP score >13 is 4.093 times that of participants with EP score <= 13. EP score >13 also increases the likelihood for progression measured with a composite measure of progression which uses the Expanded Disability Status Scale, the nine-hole peg test and the timed 25-ft walk (exp(B) = 5.577, 95% confidence interval 1.520-20.468, P = 0.01). Conclusion The addition of EPs that evaluate brainstem function to the EP score enables prediction of the progression of disability in pwCIS.