Deep Dive into Denervation: Institutional Experience with Selective Denervation in Nonflaccid Facial Palsy

Changes in Perceived Emotions in Facial Paralysis Patients After Depressor Anguli Oris Excision

OBJECTIVES

Depressor anguli oris (DAO) excision can improve clinician-graded, objective, and patient-reported smile outcomes in patients with nonflaccid facial paralysis (NFFP). However, no prior research has studied changes in perceived emotions after surgery. This study quantifies changes in perceived emotions with smiling after DAO excision in the largest case series presented to date.

METHODS

Prospectively collected data from patients with NFFP who underwent DAO excision at a tertiary care facial nerve center were reviewed. Patient-reported, clinician-graded, and objective smile metrics were compared before and after surgery. Videos of faces at rest and while smiling were analyzed by artificial intelligence-derived facial expression analysis software to quantify perceived emotions.

RESULTS

Sixty-eight patients underwent isolated DAO excision between August 2021 and August 2023. Patients conveyed significantly more perceived happiness with smile and at rest after surgery (p < 0.001 and p = 0.012, respectively). DAO excision improved oral commissure excursion (p < 0.001), dental show (p < 0.001), and smile angle (p < 0.001) symmetry. Patients reported significant improvements in smiling and social function after surgery.

CONCLUSIONS

This study demonstrates DAO excision increases perceived happiness conveyed by patients with NFFP while smiling and at rest. It confirms improved objective, clinician-graded, and patient-reported smile outcomes after surgery.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:4028-4035, 2024.

Selective Neurectomy for Postfacial Paralysis Synkinesis: A Systematic Review

Facial synkinesis is characterized by unintentional contractions of facial musculature secondary to aberrant facial nerve healing. The associated impairment in facial functioning results in a significant decrease in patients' quality of life. The mainstay treatment for postfacial paralysis synkinesis (PFPS) is chemodenervation and physiotherapy, which requires long-term maintenance neurotoxin injections. This can lead to treatment resistance. Selective neurectomy of the distal branches of the facial nerve has been suggested as an effective surgical treatment of PFPS. This study aims to provide a comprehensive systematic review evaluating the efficacy of selective neurectomy for patients presenting with PFPS. Ovid MEDLINE, Ovid Embase, PubMed, Web of Science, and CINAHL were searched from inception until July 2022. Studies that investigated postoperative outcomes of pediatric and/or adult patients who underwent selective neurectomy as a treatment for PFPS were included. The database search identified 1,967 studies, and 11 were ultimately included based on inclusion and exclusion criteria. These 11 studies represented 363 patients. Studies reported on outcomes following selective neurectomy with or without adjuvant therapies for patients with PFPS. The main outcome categories identified were clinician-reported outcomes and patient-reported outcomes. The studies that used clinician-reported outcomes found an improvement in both synkinesis and facial nerve paralysis (FNP) outcomes following selective neurectomy according to their respective grading systems. Three studies looked at patient-reported outcomes and found increased patient-reported quality of life and satisfaction following selective neurectomy. The most reported complications were upper lip contracture, uneven cheek surface, lagophthalmos, and temporary oral incompetence. Selective neurectomy has demonstrated stable or improved synkinesis, FNP, and quality of life outcomes in patients with PFPS. This approach should be considered for patients with PFPS, particularly for patients with refractory symptoms or those who are unable to undergo continued medical management.

Evaluation of the Patient with Facial Palsy: A Multidisciplinary Approach

This article aims to provide an overview of the management of facial palsy within a multidisciplinary team setting and discusses considerations used to develop patient-specific management plans. The national landscape of facial function services is also discussed including suggestions on what may enable a more equitable and sustainable service for the future.

Surgical Pearls for Safe and Precise Decision-Making during Modified Selective Neurectomy Surgery

In this short communication: (1) A transcutaneous electrical nerve stimulaton stimulator is a cost-effective solution for the predictable stimulation of mimicry and for precise decision-making. (2) Positioning a simple shatterproof mirror in front of an operated facial half enables the primary surgeon to simultaneously see and stimulate at the operative site and to scrutinize the mimicry for decision-making. (3) A misconception in the literature regarding colors used for tagging "branches for transection" and "branches for preservation" is clarified, and a third tag-color is suggested for times of ambiguity. (4) The principle of distal execution of the surgery and technical considerations are underlined for maximal transection and maximal preservation. The modified selective neurectomy surgery is the current golden standard of post facial paralysis synkinesis treatment, and developing a learning curve in this type of surgery is like walking a tightrope, where the surgeon must keep pushing the limits with precise decision-making and a small margin of error. It is important to be reminded that the first aim is primum non nocere, and the second aim is to improve the condition of patients as much as possible. The above-mentioned principles and solutions increase precision and safety, assisting surgeons to achieve better outcomes.

Facial Aberrant Reinnervation Syndrome Following Facial Nerve Injury and Recovery

A common sequela of peripheral nerve injury is aberrant regeneration and recovery. Aberrant regeneration of injured motor nerves can affect all aspects of the nerve circuit from the motor cortex to the target muscle. A more comprehensive term for the symptoms that develop after aberrant motor neuromuscular reinnervation is aberrant reinnervation syndrome (ARS). Injury to the facial nerve followed by aberrant reinnervation results in a spectrum of symptoms that has been called many things in the literature. The authors support that this commonly encountered sequela of facial nerve injury be called facial aberrant reinnervation syndrome (FARS), a term that is more descriptive of the underlying pathophysiology and more inclusive of the clinical symptoms: facial synkinesis, facial muscle hypertonicity, and facial muscle spasm/twitching, which occur following facial nerve injury and recovery. In the following article, we present the clinical manifestations and sequelae of facial nerve injury and recovery and briefly discuss our evolving understanding of the pathophysiology and treatment of FARS.

Pre-Operative Factors May Predict Outcome in Selective Neurectomy for Synkinesis

Background: While there has been great interest in offering selective neurectomy (SN) to patients with nonflaccid facial palsy (NFFP), postoperative outcomes are inconsistent. Objective: To assess overall SN outcome in NFFP patients and to examine correlation between preoperative factors and SN outcome. Methods: SN cases were retrospectively identified between 2019 and 2021. Patient factors and facial function were assessed using chart review, the Facial Clinimetric Evaluation (FaCE), the electronic clinician-graded facial function tool (eFACE), and an automated computer-aided facial assessment tool (Emotrics). Correlations between preoperative factors and patients outcome were established. Results: Fifty-eight SN cases were performed; 88% were females, and median age was 53 years (range 11-81). Outcome assessment was 8 months on average (1-24 months). Postoperatively, multiple eFACE and Emotrics parameters improved significantly, including ocular, perioral, and synkinesis metrics. In preoperative factors assessment, age >50, facial palsy (FP) duration >2 years, poor preoperative facial function, and nontrauma etiology all correlated with greater improvements compared with younger patients, those with shorter duration facial palsy, trauma etiology, and better preoperative facial function. Conclusions: SN can significantly improve facial function; we have identified several preoperative factors that correlated to outcome.

Mid-Term Effects of Selective Denervation Surgery on Facial Symmetry in Patients with Nonflaccid Facial Paralysis: Intermediate Follow-Up of Rest and Smile Symmetry

Introduction: Although selective denervation (SD) improves clinician-graded, objective, and patient-reported smile symmetry, changes in resting symmetry have not been comprehensively studied. Objective: To assess mid-term changes in resting facial symmetry after SD, and to evaluate changes in perceived emotions in faces at rest and with smiling. Methods: Nonflaccid facial paralysis (NFFP) patients undergoing SD were studied from September 2021 to October 2022. Patient-reported, clinician-graded, and objective metrics of resting and smile symmetry were quantified. Results: Fourteen patients (median age 59.5 years; median paralysis duration 76.5 months; median follow-up 249.5 days (138-400); average of 5.7 branches sacrificed) underwent SD. Resting oral commissure (OC) symmetry (p = 0.028) and upper lip symmetry (p = 0.030) improved after surgery. In smiling faces, OC excursion (p = 0.004), smile angle (p = 0.016), and dental show (p = 0.012) improved. There were significant increases in perceived happiness at rest (p = 0.006) and with smile (p = 0.002). Clinician grading revealed improved nasolabial fold depth at rest (p = 0.087) after surgery, and patients reported improved facial function and happiness with the decision to undergo surgery. Conclusion: Intermediate follow-up suggests SD can improve objective resting and smile symmetry in patients with NFFP. After surgery, patients' faces convey more happiness in repose and with smile.

Embellishing Emotrics for a More Complete Emotion Analysis: Addition of the Nasolabial Fold

Background: The nasolabial fold (NLF) greatly contributes to facial aesthetics; changes to NLF depth and vector are disfiguring in patients with facial paralysis (FP). NLF parameters are integral to clinician-graded outcomes, but automated programs currently lack NLF identification capabilities. Objective: To incorporate an automated NLF identification and quantification function into the facial landmark program, Emotrics, and to compare new Emotrics-derived NLF data to clinician-graded electronic facial paralysis assessment (eFACE) data for accuracy. Methods: Photographs of 135 patients with FP were marked bilaterally, using identification markers manually placed on each NLF. A machine learning model was trained to automatically localize the markers using these data. Once Emotrics accurately identified the NLF and its corresponding vector, photographs of 20 additional patients who underwent facial reanimation procedures were assessed by the algorithm. Results: The enhanced Emotrics algorithm successfully identified the NLF, and measured the vector from midline, in a series of patients with FP. NLF vector data closely matched corresponding eFACE parameters. Furthermore, changes in NLF presence and vector were detected following facial reanimation procedures. Conclusion: The Emotrics program now provides critical NLF data, providing objective parameters for clinicians interested in changing NLF dynamics after FP.

Selective neurectomy for nonflaccid facial palsy

PURPOSE OF REVIEW

To review the evolving role of selective neurectomy in the management of patients with synkinesis including the history of selective neurectomy, operative techniques, and clinical outcomes.

RECENT FINDINGS

Modified selective neurectomy alone or in conjunction with other procedures achieves more durable outcomes based on objective measures such as time to recurrence of symptoms and units of botulinum toxin required postoperatively. This is also reflected on patient reported quality of life outcome measures. Regarding operative technique, lower rates of oral incompetence are reported with division of an average of 6.7 nerve branches as opposed to more branches.

SUMMARY

Chemodenervation has long been the mainstay of treatment in facial synkinesis, but in recent years, the paradigm has begun to shift in favor of incorporating interventions with more durable outcomes such as modified selective neurectomy. Modified selective neurectomy is often performed with other simultaneous surgeries such as nerve transfer, rhytidectomy, lid surgery and static facial reanimation primarily to address periocular synkinesis and synkinetic smile. The outcomes have been favorable with improvement in quality-of-life measures and a decrease in botulinum toxin requirements.

Selective Neurectomy for Treatment of Post-Facial Paralysis Synkinesis: A Systematic Review

BACKGROUND

 Synkinesis is commonly encountered after flaccid facial paralysis and can have a detrimental impact on a patient's life. First-line treatment of synkinesis is chemodenervation with botulinum toxin (Botox) and neuromuscular retraining. Surgical options include selective myectomy, selective neurectomy (SN), cross-facial nerve grafting, nerve substitution, and free gracilis muscle transfer. Data on surgical management of synkinesis using SN is limited.

EVIDENCE REVIEW

 PubMed, Embase, Cochrane CENTRAL, Cochrane Neuromuscular Register, Clinicaltrials.gov, and World Health Organization International Clinical Trials Registry Platform were searched using a comprehensive keyword strategy in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All English-only texts published in the past 20 years were included. Two independent investigators reviewed 906 abstracts and 7 studies met inclusion criteria. Demographics, etiology of paralysis, time to surgery, and primary outcomes studied were collected.

FINDINGS

 A total of 250 patients were included across 7 studies. In 6 out of 7 studies, Botox was used prior to surgical intervention. Two studies showed significant reduction in Botox dosage postoperatively, while one study showed no difference. Other primary outcomes included the House-Brackmann Score, palpebral fissure width, electronic clinician-graded facial function scale (eFACE) score, Facial Clinimetric Evaluation (FaCE) scale, and Synkinesis Assessment Questionnaire (SAQ). Three studies showed significant improvement in the eFACE score, two studies showed significant improvement in the FaCE scale, while one study showed improvement in quality of life measured by the SAQ.

CONCLUSION

 SN can be considered as an adjunct to other management options including neuromuscular retraining, Botox, selective myectomy, and reanimation procedures. While there is great heterogeneity of study design in the studies included, many cohorts showed improvement in facial symmetry, facial function, and quality of life. There remains a great gap in knowledge in this subject matter and a need for large well-designed prospective studies comparing this technique to other management options.

Facial paralysis: timing of repair and management of the nonflaccidly paralyzed face

PURPOSE OF REVIEW

To explore recent advances in therapeutic interventions for nonflaccid facial paralysis (NFFP), including new evidence for surgical and nonsurgical treatments. Timing of treatment is also discussed, along with possible future treatments.

RECENT FINDINGS

NFFP remains a difficult disease to treat. Chemodenervation with botulinum toxin remains a first-line treatment to suppress aberrant and antagonistic movements during voluntary use of muscles. More permanent treatments such as selective neurectomy, myectomy, and nerve and muscle transfers have been shown to offer promising results for the nonflaccidly paralyzed face.

SUMMARY

NFFP is commonly seen in patients who have incomplete recovery from facial paralysis, and carries high psychosocial morbidity. A large array of treatments have been described in the literature, both procedural and nonprocedural. Both treatment type and timing are important in optimal patient recovery.