Quantifying Effects of Cross-facial Nerve Grafts on the Nonparalyzed Side

Introduction: The cross facial nerve graft is commonly turned to in facial reanimation to allow for neuronal input from the nonparalyzed facial nerve to innervate previously paralyzed facial musculature of the contralateral face. The crossface nerve graft is commonly grafted from the sural nerve and involves neurolysis of a branch of the working side in order to provide input; to our knowledge, the impact of this neurolysis has not yet been quantified.

Methods: Via retrospective chart review, thirty patients who underwent sural cross face nerve graft between 2018-2022 for facial reanimation were identified. These patients had facial paralysis, most commonly due to vestibular schwannoma. Their preoperative and postoperative photographs were compared measuring palpebral fissure opening, facial asymmetry index, and oral commissure excursion among other measures by three otolaryngologists. Past medical history, facial nerve quality of life surveys, and operative details were also collected.

Results: There is noticeable downgrade of facial movement of the donor, nonparalyzed face after neurolysis for sural crossface nerve graft.

Conclusions: For the first time we describe and quantify the changes of the nonparalyzed face after crossface nerve graft. However, the result is subtle, and often results in a more symmetric and relaxed smile once movement is finally accomplished in the once paralyzed side