High-Frequency Spinal Cord Stimulation for the Treatment of Spasticity: A Preliminary Case Series.

Background: Spasticity is a complex and multifactorial condition resulting from upper motor neuron injury. It manifests through muscle contractions, pain, limited range of motion, and clonus, which significantly impair daily activities and quality of life. High-frequency spinal cord stimulation (HF SCS) has shown optimal results in treating chronic neuropathic pain, but its potential role in spasticity remains underexplored. This study aimed to evaluate the efficacy of HF SCS in patients with spasticity. Methods: From April 2021 to July 2024, six patients with spasticity from various etiologies underwent SCS implantation at our institution. Clinical evaluations including the use of the Visual Analog Scale (VAS), Douleur Neuropathique 4 (DN4), and the Ashworth score, as well as ambulation ability and clonus episodes, were performed preoperatively and at a minimum of six months post-surgery. Subjective assessments of motor function, including coordination, movement efficiency, and postural transitions, were also recorded. Results: The mean age of patients was 50.12 ± 9.41 years, with follow-up averaging 24.32 ± 10.83 months. Statistically significant improvements were observed in VAS (p = 0.0412) and DN4 (p = 0.0422) scores, alongside a reduction in clonus episodes. All patients reported subjective improvements in coordination, movement efficiency, and postural transitions. Ambulation remained stable or improved in all cases. No perioperative complications or sensory/motor side effects were noted. Conclusions: HF SCS offers a promising approach to managing spasticity, with improvements in motor function, ambulation, and postural transitions. These findings support further investigation into HF SCS for spasticity, with multicenter trials needed to optimize treatment protocols and identify the most responsive patient populations.