A New Neurorehabilitative Postsurgery Intervention for Facial Palsy Based on Smile Observation and Hand-Mouth Motor Synergies

Abstract

Objective. To perform a preliminary test of a new rehabilitation treatment (FIT-SAT), based on mirror mechanisms, for gracile muscles after smile surgery. Method. A pre- and postsurgery longitudinal design was adopted to study the efficacy of FIT-SAT. Four patients with bilateral facial nerve paralysis (Moebius syndrome) were included. They underwent two surgeries with free muscle transfers, one year apart from each other. The side of the face first operated on was rehabilitated with the traditional treatment, while the second side was rehabilitated with FIT-SAT. The FIT-SAT treatment includes video clips of an actor performing a unilateral or a bilateral smile to be imitated (FIT condition). In addition to this, while smiling, the participants close their hand in order to exploit the overlapped cortical motor representation of the hand and the mouth, which may facilitate the synergistic activity of the two effectors during the early phases of recruitment of the transplanted muscles (SAT). The treatment was also aimed at avoiding undesired movements such as teeth grinding. Discussion. Results support FIT-SAT as a viable alternative for smile rehabilitation after free muscle transfer. We propose that the treatment potentiates the effect of smile observation by activating the same neural structures responsible for the execution of the smile and therefore by facilitating its production. Closing of the hand induces cortical recruitment of hand motor neurons, recruiting the transplanted muscles, and reducing the risk of associating other unwanted movements such as teeth clenching to the smile movements.

Post-surgery Rehabilitative Intervention Based on Imitation Therapy and Mouth-Hand Motor Synergies Provides Better Outcomes in Smile Production in Children and Adults With Long Term Facial Paralysis

“…The FIT-SAT is performed at home for at least 6 months under the supervision of an expert speech therapist that modulates the exercises to be performed (for a detailed description of the treatment, [see ( 6 , 15 )]. Specifically, the FIT-SAT includes the observation and execution of corner-of-the-mouth smile ( 29 , 30 ) accompanied by the closing of the hand and it is divided into two phases: the first phase begins as soon as the patient starts to recruit the transplanted muscle and aims at increasing muscle strength with unilateral exercises.…”

“…This phase of the rehabilitation consists in watching a series of video clips of an actor performing unilateral smiles that patients have to observe and reproduce ( Figure 1A ). The second phase can start only when patients are able to perform at least three consecutive repetitions of the unilateral movement, maintaining the posture for at least three seconds ( 15 ). Only at this point of the rehabilitation process the second phase begins.…”

“…Secondly, the use of teeth clenching results in unpleasant lips movements and poor postures that are difficult to correct. In addition to this, patients have little awareness of the muscle/s contraction force ( 15 ).…”

“…We propose a new neurorehabilitation treatment (FIT-SAT) that aims at recruiting the transplanted muscle without grinding teeth ( 8 , 15 ). FIT-SAT is based on the principle of action observation (AO) and aims at enhancing motor learning and promote neural reorganization in patients after SS.…”

“…On the basis of this mechanism, FIT-SAT exploits motor and premotor activations present during smile observation to facilitate the activation of the corresponding cortical motor representation. The FIT-SAT treatment also requires that patients simultaneously close their hand during smile execution (hand/mouth synergies) with the aim of facilitating the recruitment of the motor programs of opening the mouth involved in the smile, avoiding teeth contraction ( 8 , 15 ). The concept of synergy indicates functional modules that simplify the control of complex motor activation patterns by combining elemental movements that are represented at different brain locations ( 24 – 26 ), but adjacent to each other with partially overlapping fields (e.g., the hand and mouth cortical motor representations).…”