Hyperselective Neurectomy for Upper-Limb Spasticity: Clinical Outcomes From a Systematic Review

Upper-limb spasticity after stroke, traumatic brain injury, cerebral palsy, multiple sclerosis, or spinal cord injury limits function and care. Hyperselective neurectomy (HSN)-partial resection of selected motor branches at the muscle entry point-aims to lower tone while preserving voluntary strength. Following PRISMA 2020 guidelines, 10 studies (260 adults) were identified, almost all performed under general anesthesia, with 1 small series using wide-awake local anesthesia with no tourniquet (WALANT). Across studies, HSN reduced spasticity by about 1 to 2.5 points on the Modified Ashworth Scale; where data allowed pooling (6 studies), the average improvement was 1.64 points on the 0 to 4 scale (95% CI, 1.36-1.92). These reductions were durable up to 4 to 5 years and were accompanied by better function (higher House scores), improved resting posture and range of motion, and easier care. Recurrence was uncommon and usually manageable with revision or staged treatment of untreated synergists. Complications were rare and transient, and no modern series reported permanent weakness in treated muscles. Early experience with WALANT is limited to a single small case series but suggests that intraoperative testing of tone and voluntary movement is feasible and may help titrate resection. Overall, HSN appears to provide safe, effective, and durable tone reduction with meaningful functional gains; future studies should refine patient selection, use more robust spasticity measures, and formally compare anesthesia strategies, including WALANT.Level of Evidence: IV (Systematic review of non-comparative case series).