Long-term outcomes of intrathecal baclofen in ambulatory multiple sclerosis patients: A single-center experience

Background: Intrathecal baclofen (ITB) is traditionally reserved for non-ambulatory patients. Objective: To investigate outcomes of ITB in ambulatory multiple sclerosis (MS) patients. Methods: Changes in outcome measures were estimated by a mixed effect model, while the complication rate was calculated using a logistic regression. Predictors of non-ambulatory status were identified by Cox model. Results: In all, 256 patients received an ITB test injection and 170 underwent ITB surgery. Aggregate Modified Ashworth Scale (MAS) scores for the ambulatory ITB cohort decreased from 13.5 +/- 6.96 to 4.54 +/- 4.18 at 5 years (p < 0.001). There was no significant change in walking speed 1 year post ITB surgery (0.45 m/second +/- 0.30 vs 0.38 m/second +/- 0.39,p = 0.80) with 77.8% of patients remaining ambulatory which decreased to 41.7% at year 5. Longer MS disease duration (hazard ratio (HR): 1.04; 95% confidence interval (CI): 1.01-1.07;p = 0.018) and lower hip flexor strength (HR: 0.40; 95% CI: 0.27-0.57;p < 0.001) predicted non-ambulatory status after surgery. Complications were more likely in the ambulatory cohort (odds ratio (OR): 3.30, 95% CI: 2.17-5.02;p = 0.017). Conclusion: ITB is effective for ambulatory MS patients without compromising short-term walking speed, although a higher complication rate was observed in this cohort.