Supplementary Material for: Radiosurgical Irradiation of Spinal Nerve Roots for the Management of Spasticity—Systematic Review

Background: Spasticity is a common and debilitating sensorimotor disorder resulting from injury to the brain or spinal cord. Conventional treatments, including oral antispasmodic agents, botulinum injections, intrathecal baclofen (ITB) pumps, and selective dorsal rhizotomy (SDR), are often limited by side effects, invasiveness, and/or inconsistent outcomes. Stereotactic radiosurgery (SRS), a non-invasive, image-guided technique traditionally used in oncology and functional neurosurgery, could emerge as a promising alternative for refractory spasticity.
Objective: To review the clinical application, safety, and preliminary efficacy of SRS in managing spasticity
Methods: A systematic literature search was conducted following PRISMA guidelines. Studies were included if they reported spasticity as a primary condition and used SRS as a therapeutic modality. Data on patient characteristics, treatment parameters, outcomes, including Modified Ashworth Scale (MAS) scores and Visual Analog Scale (VAS) pain scores, and adverse events were extracted and analyzed.
Results: Three clinical studies involving a total of seven patients were identified. SRS was delivered to the affected spinal nerve roots at a prescription dose ranging from 45 to 60 Gy. Mean MAS scores improved from 3.66 to 1.5, and mean VAS pain scores decreased from 7.33 to 1.6 over 24 months of follow-up. No major adverse events were reported. Transient side effects, such as reduced trunk control, occurred in one patient. Treatment response varied in onset and duration across cases.
Conclusion: Early evidence suggests that SRS is a feasible approach for the management of spasticity. However, larger prospective studies with longer follow-up are warranted to determine optimal patient selection, dose parameters, and long-term outcomes, including quality of life and potential radiation-related effects.