Alessandro Micarelli, Andrea Viziano, Ivan Granito, Giuseppe Antonuccio, Alessio Felicioni, Marco Loberti, Pasquale Carlino, Riccardo X Micarelli, Marco Alessandrini

Many rehabilitative attempts have been made to prevent or reduce residual deficits in patients with established and long-term facial palsy (FP). In many clinical settings in-situ injection of collagen-based medical devices (MDs) have been demonstrated to provide nutritional support for tissues. To test the effectiveness of a collagen-based treatment for patients complaining of long standing FP, who are following a proprioceptive neuromuscular facilitation protocol (Kabat method) (Group A), compared to a FP group only undergoing the Kabat method (Group B). Randomised controlled trial. Tertiary referral outpatient center and University Hospital. 41 patients with a medical diagnosis of long-term unilateral peripheral FP. Twenty-one Group A patients were compared, after randomization, to nineteen matched Group B patients after 8 weeks of treatment. The outcomes were electromyographic findings, validated questionnaires (Facial Disability Index, FDI and General health-related quality of life assessment, QOL) and clinical grading (House-Brackmann, HB, and synkinesis grading scale). A correlation analysis was performed between pre-/post-treatment differences (Δ) in outcome and clinical-demographic measures. A significant within-subjects improvement, both in electrophysiological and questionnaire scores, was found in both groups. When compared with Group B, Group A patients exhibited a significant reduction of post-treatment polyphasic potentials of voluntary activity of orbicularis oculi (p = 0.017) and oris (p = 0.015) and a significant increase in post-treatment duration of voluntary activity of orbicularis oris (p = 0.018). Group A subjects demonstrated a significant improvement in questionnaire subscales regarding overall disease perception. Although positive correlations between the ΔFDI and Δpercentage of polyphasic potentials of voluntary activity were found in both groups, negative correlations in Group A were found between disease duration and Δduration of voluntary activity of orbicularis oculi and oris. The combination of physical rehabilitative procedures with in-situ collagen injections, possibly acting in redirecting the phenomena of reinnervation/reorganization, demonstrated encouraging results in patients affected by long term FP. In-situ collagen injection could be a safe option enlarging the 'window of opportunity' to improve the voluntary muscle contraction pattern and general and specific disability referred by patients affected by long standing FP.