Beyond Spasticity: The Dual Impact of Selective Dorsal Rhizotomy in Spastic Quadriplegic Patients With Generalized Dystonia and the Need for Intrathecal Baclofen

Background Selective dorsal rhizotomy (SDR) is primarily indicated for spastic diplegia, effectively reducing lower limb spasticity. However, its role in generalized dystonia remains controversial, as some reports suggest potential symptom exacerbation. In such cases, intrathecal baclofen (ITB) represents the preferred approach. This study evaluates the effects of SDR as a secondary intervention following insufficient ITB therapy on motor function in patients with spastic quadriplegic cerebral palsy (CP) and generalized dystonia while also introducing a novel surgical strategy to approach mixed movement disorders. Material and methods This retrospective study included patients with spastic quadriplegic cerebral palsy and generalized dystonia treated at our institution between 2018 and 2023. All patients (n = 16) initially received intrathecal baclofen (ITB) therapy. In three patients, ITB monotherapy was effective in symptom control; however, due to insufficient spasticity management in the remaining 13 patients, selective dorsal rhizotomy (SDR) was subsequently performed without removal of the existing ITB system. Due to the worsening of dystonia and the lack of significant improvement in motor functions after SDR, ITB therapy was reintroduced. Clinical outcomes, including Gross Motor Function Classification System (GMFCS), Modified Ashworth Scale (MAS), and dystonia severity, were assessed before and after SDR, as well as following ITB reinitiation. Additionally, alterations in required ITB dosage before and after SDR were analyzed. Results While SDR effectively reduced spasticity in all patients, no improvement in overall motor function was observed. Notably, 69.2% of patients showed worsening of dystonia after SDR. ITB therapy was reinitiated in 11 patients (84.6%). Subsequent clinical evaluation revealed a significant improvement in both dystonia and all motor functions (standing, sitting, and transitional movements) across all patients (p<0.001). Furthermore, the required dosage of ITB to control dystonia after SDR was significantly lower than the required dosage before SDR (p<0.001). Conclusion Our findings suggest that a tailored, multimodal approach is essential for managing complex cases of CP with spasticity and dystonia. Furthermore, retaining the ITB system without explantation when performing SDR may be a viable strategy that could reduce the overall surgical burden and associated risks for the patient.