Conditioning Electrical Stimulation to Improve Outcomes in Carpal Tunnel Syndrome

Carpal tunnel syndrome is common, identified in 3% of the general population. Symptoms including numbness and pain are due to compression of the median nerve as it travels through a tunnel entering the wrist and can result in weakened grip strength and poor dexterity. Despite surgical release, nerve damage due to chronic compression often cannot be completely reversed, with resulting sensorimotor deficits. Postoperative electrical stimulation (ES) has been well-reported to improve nerve regeneration and is currently standard of practice at our institution. Investigators of this study have recently shown in an animal model that by changing the timing of the ES from postoperative to preoperative, this "conditioning" electrical stimulation (CES) significantly improves nerve regeneration. Patients with severe carpal tunnel syndrome will be identified in plastic surgery clinics. Patients who consent to participating will undergo baseline testing including nerve conduction studies, sensory evaluation, motor testing, and patient-reported outcomes. Participants will be randomized to three groups: i) CES, ii) postoperative ES, and iii) no ES. CES will be delivered in clinic by placing a percutaneous needle alongside the median nerve, and stimulation will be delivered for one hour, with patient comfort dictating the voltage of stimulation. At the completion of one hour, the needle will be removed, and a standard carpal tunnel release will be performed by their plastic surgeon 4-7 days later. Patients will the second cohort will undergo postoperative ES immediately following their carpal tunnel release, using the same stimulation parameters as CES. The third cohort will receive only carpal tunnel release without stimulation.In all patients, sensory and motor reinnervation, using the same testing modalities as preoperative assessment, will be evaluated at 3, 6, and 12 months post-operative.