Although a small number of studies has shown that recovery from relapses in multiple sclerosis appears to contribute to long-term outcomes, relapse recovery has largely been ignored as a treatment endpoint and predictor of disability. We hypothesized that relapse recovery in the early stages of disease will impact longer term disability.
The first aim of this study was to identify demographic and clinical predictors associated with incomplete recovery from relapses in the first 3 years from the first MS symptom. The second aim was to examine the relationship between incomplete recovery in first 3 years and 10-year disability outcomes.
Recovery from relapses in the first three years from the first symptom was retrospectively assessed in 360 patients with relapsing remitting multiple sclerosis enrolled in the Comprehensive Longitudinal Investigations in Multiple Sclerosis at Brigham and Women’s Hospital (CLIMB study), a large longitudinal cohort. Complete or incomplete recovery from each relapse was determined based on the return of the Expanded Disability Status Scale (EDSS), Functional System Scale (FSS) and neurologic signs to baseline levels at least 6 months after symptom onset. Univariate and multivariable models were used to associate recovery with demographic and clinical factors and to predict 10-year disability and MRI outcomes (brain parenchymal fraction and T2 lesion volume).
Including their initial episode, the 360 included patients had a total of 736 relapses within the first three years from their first symptom. 44.6% of these relapses had an incomplete recovery at 6 months. Relapses in untreated patients had an incomplete recovery in 51.8% of cases, compared to 28.9% in patients who were being treated with a disease modifying drug (p<0.001). In the multivariable analysis, recovery from relapses in the first 3 years was better younger patients, who were on interferon treatment, had no bowel or bladder symptoms and had a longer interval since their first symptom. For every incomplete recovery in the first three years, the EDSS at 10 years increased by 0.6 points, and the timed 25-foot walk at 10 years increased by 0.5 seconds. Both disability outcomes were also higher with older age at first symptom and higher BMI. Brain atrophy, measured by the brain parenchymal fraction on MRI, was associated only with older age at first symptom, whereas T2-hyperintense lesion volume was only associated with smoking.
Early initiation of first-line disease-modifying treatments can improve relapse recovery, which in turn prevents long-term disability.