A research study to find out if brief intraoperative electrical stimulation therapy improves nerve regeneration and smile outcomes following two-stage cross face nerve graft facial reanimation surgery.

Participants that choose to enroll in this study will be randomly assigned in a 2:1 ratio to a "treatment" or "control" group. In either group, patients will receive the same care as they normally would except for two minor differences. First, patients in both groups undergo nerve biopsies during surgery; these biopsies do not affect the length or outcome of surgery. Second, the treatment group will receive brief electrical stimulation therapy for approximately 10 minutes during the first stage cross-face nerve graft surgery.

The purpose of this study is to evaluate efficacy of an intraoperative dose of brief electrical stimulation (BES) to improve axonal regeneration across a cross-face nerve graft (CFNG) using nerve histology and to evaluate clinical outcomes of treatment and control groups using clinician graded, patient reported, and objective smile metric.

Inclusion Criteria:

1. Patients 18-80 years-old with unilateral facial paralysis who are candidates for two- stage CFNG smile reanimation surgery (i.e. CFNG-driven free gracilis muscle transfer (FGMT) or dual innervation FGMT).
2. Agree to participate in the study.

Exclusion Criteria:

1. Bilateral facial paralysis
2. Age less than 18 years-old or older than 80 years-old
3. Comorbid medical condition preventing two-stage CFNG surgery

This is a randomized, controlled, double-blinded (patient and evaluator) prospective study. Plan is to enroll up to 30 patients, with a minimum of 20 completing full follow-up. Randomization 2:1 treatment to control due to previous peripheral nerve research demonstrating intraoperative stimulation accelerates axonal regeneration