Intrathecal Baclofen Trial as a Predictor of Long-Term Outcomes After Selective Dorsal Rhizotomy in Children with Spastic Cerebral Palsy

Purpose To assess whether short-term clinical changes observed during an intrathecal baclofen (ITB) trial approximate long-term outcomes following selective dorsal rhizotomy (SDR) in children with spastic cerebral palsy. Methods We reviewed a cohort of patients ≤ 21 years old who underwent an ITB trial followed by SDR between 2015 and 2024. Modified Ashworth Scale (MAS), passive range of motion (ROM), and Observational Gait Scale (OGS) outcomes were recorded at baseline, 2 and 4 hours after ITB injection, and at least 12 months after SDR. Time points were compared using Wilcoxon signed-rank tests, and caregivers completed a postoperative survey. Results Twenty-one patients were included (median follow-up, 26.2 months). Composite MAS scores decreased by 2.0 points after ITB and 2.6 points after SDR (both p < 0.001), with no significant difference between ITB and post-SDR assessments (p = 0.115). Straight leg raise improved by 10° after ITB (p < 0.001) and remained improved after SDR (p = 0.003), with no difference between ITB and post-SDR values (p = 0.330). Hip abduction improved after ITB (p = 0.005) but not long term; ankle dorsiflexion did not significantly change. OGS improved by 2.0 points after ITB (p = 0.014) and 2.5 points after SDR (p < 0.001), with no significant difference between ITB and post-SDR scores (p = 0.151). Caregiver reports were concordant, with most describing similar improvements after SDR and finding the ITB trial useful for expectation setting and decision-making. Conclusion At the cohort level, changes observed during the ITB trial approximated those measured at long-term follow-up after SDR. An ITB trial may support patient selection and expectation setting; larger studies are needed to determine individual-level predictive performance.