Cortical adaptation staging system: a new and simple staging for result evaluation of functioning free-muscle transplantation for facial reanimation.

Abstract

Movement-associated cortical reorganization occurs in patients after functioning free-muscle transplantation (FFMT), which is reinnervated by different neurotizers. Aiming to evaluate the process of recovery of the reinnervated muscle, we defined the cortical reorganization into 5 stages. This staging system has been applied during the past 25 years at our center with great convenience and accessibility. A standardized evaluation method for assessing the recovery after FFMT to reanimate the paralyzed face with at least a 1-year follow-up was applied. The evaluation included the following 5 stages: no movement, dependent movement, independent movement, and spontaneous movement with and without involuntary movement. Reliability of this technique was assessed by 3 examiners, who each evaluated the smiles of 30 unilateral facial paralysis patients 4 times, creating 360 sets of measurements. The intraclass correlation coefficients for interrater and intrarater reliability exceeded 0.929, which is considered excellent and reliable. Chuang's Cortical Adaptation Staging System is simple, quick,and accurate in evaluating patients after FFMT reanimation of the paralyzed face with no additional tools.