Guided Self-rehabilitation Contract vs conventional therapy in chronic peripheral facial paresis: VISAGE, a multicenter randomized controlled trial.

BACKGROUND: One year after persistent peripheral facial paresis (PFP), prescriptions of conventional rehabilitation are often downgraded into maintenance rehabilitation or discontinued, the patient entering what is seen as a chronic stage. This therapeutic choice is not consistent with current knowledge about behavior-induced plasticity, which is available all life long and may allow intense sensorimotor rehabilitation to remain effective. This prospective, randomized, multicenter single-blind study in subjects with chronic unilateral PFP evaluates changes in facial motor function with a Guided Self-rehabilitation Contract (GSC) vs. conventional therapy alone, carried out for six months. METHODS: Eighty-two adult subjects with chronic unilateral PFP (> 1 year since facial nerve injury) will be included in four tertiary, maxillofacial surgery (2), otolaryngology (1) and rehabilitation (1) centers to be randomized into two rehabilitation groups. In the experimental group, the PM&R specialist will implement the GSC method, which for PFP involves intensive series of motor strengthening performed daily on three facial key muscle groups, i.e. Frontalis, Orbicularis oculi and Zygomatici. The GSC strategy involves: i) prescription of a daily self-rehabilitation program, ii) teaching of the techniques involved in the program, iii) encouragement and guidance of the patient over time, in particular by requesting a quantified diary of the work achieved to be returned by the patient at each visit. In the control group, participants will benefit from community-based conventional therapy only, according to their physician's prescription. The primary outcome measure is the composite score of Sunnybrook Facial Grading System. Secondary outcome measures include clinical and biomechanical facial motor function quantifications (Créteil Scale and 3D facial motion analysis through the Cara system), quality of life (Facial Clinimetric Evaluation and Short-Form 12), aesthetic considerations (FACE-Q scale) and mood representations (Hospital Anxiety and Depression scale). Participants will be evaluated every three months by a blinded investigator, in addition to four phone calls (D30/D60/D120/D150) to monitor compliance and tolerance to treatment. DISCUSSION: This study will increase the level of knowledge on the effects of intense facial motor streng-          Facial paralysisthening prescribed through a GSC in patients with chronic peripheral facial paresis. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04074018 . Registered 29 August 2019. PROTOCOL VERSION: Version N°4.0-04/02/2021.

Three-Dimensional Quantification of Facial Morphology and Movements Using a Wearable Helmet.

This work proposes a 3D normative database of facial ranges of motion in adults free from facial disorders. Ten facial movements were analyzed, each targeting the activity of specific muscle groups innervated by the facial nerve. The experimental protocol included a test-retest reliability positioning procedure of 25 skin markers based on clinical expertise in facial morphology. Three maximal voluntary contractions were recorded for each facial movement studied, using a 3D facial motion capture helmet. We included 53 adults free from facial disorders (26 men; age 43 ± 14), evaluated twice one week apart. The reliability of marker positioning was expressed as absolute measurement errors. The range of motion vectors of all markers from the best rest to the maximal voluntary contraction was calculated for each muscle group. Primary, secondary, and tertiary markers were extracted for each facial movement. 3D Procruste and asymmetry indices were developed. This allowed the identification of common thresholds of 10% for the asymmetry index and of 6 mm for the Procruste index, beyond which facial motions would be considered abnormally asymmetric. The normative database quantifies facial motions and allows assessment of the degree of clinical disorders by comparison. This protocol is currently being investigated in patients with chronic unilateral peripheral facial paresis.