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.

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.

Chemodenervation Algorithm: Functional and Aesthetic Considerations for Facial Harmony in Patients with Post-Facial Paralysis Synkinesis.

Management of post-facial paralysis synkinesis has evolved for the past decade with diversification of neuromuscular retraining, chemodenervation, and advanced surgical reanimation techniques. Chemodenervation with botulinum toxin-A is a commonly used treatment modality for synkinesis patients. Treatment has shifted from solely weakening the unaffected contralateral facial musculature for rote symmetry to selective reduction of undesired or overactive synkinetic muscles, allowing for a more organized motion of the recovered musculature. Facial neuromuscular retraining should be considered a crucial component of treating patients with synkinesis along with soft tissue mobilization, but specifics of these are beyond the scope of this article. Our goal was to create a descriptive platform for our method of chemodenervation treatment in the evolving field of post-facial paralysis synkinesis. A multi-institutional and multidisciplinary comparison of techniques was performed with photograph and video creation, review, and discussion over an electronic platform with all authors. Anatomic specifics of each region of the face and individual muscles were considered. A muscle by muscle algorithm for synkinesis therapy was created to include chemodenervation with botulinum toxin that should be considered for patients suffering from post-facial paralysis synkinesis.

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.

Outcome evaluation using an artificial intelligence-based facial measurement software for facial nerve grafting in head and neck and skull base surgery.

BACKGROUND: Interposition nerve grafting is an indispensable technique for facial nerve reconstruction in head and neck, and skull base surgery. The prognostic factors are inconclusive, partly due to limited objective assessment systems for facial nerve function. This study aimed to apply an artificial intelligence (AI)-based facial asymmetry measurement system to assess facial nerve grafting outcomes. METHODS: We retrospectively reviewed data of 23 patients who underwent facial nerve grafting between 2011 and 2020. Oral asymmetry and synkinesis severity were measured using AI. RESULTS: Oral movement recovered at 12-18 months postoperatively. Postoperative radiotherapy and a larger number of anastomosed distal stumps were significantly associated with poor and good final oral symmetry, respectively. Synkinesis severity was weakly correlated with the degree of oral movement recovery. CONCLUSIONS: Oral function recovered without a strong correlation with synkinesis. Caution should be exercised in facial nerve grafting for cases with postoperative radiotherapy.

Modified Selective Neurectomy for Post Facial Paralysis Synkinesis Smile Dysfunction.

Following incomplete facial nerve injury, patients may develop aberrant facial nerve reinnervation, which can result in facial synkinesis. The treatment goals for patients with postfacial paralysis synkinesis are to improve resting oral commissure position, oral competence, facial and cervical tightness, and smile symmetry and spontaneity. Modified selective neurectomy of the facial nerve as described by Azizzadeh and colleagues is a targeted surgical method that allows the surgeon to eliminate the antagonist movements of the face and allow the favorable movements of the face to predominate, resulting in a more natural smile.

A Surgeon's Armamentarium for Ocular Management in Facial Paralysis: A Comprehensive Review.

OBJECTIVE: To review the current management paradigm of the eye in patients with facial paralysis. METHODS: A PubMed and Cochrane search was done with no date restrictions for English-language literature on facial synkinesis. The search terms used were "ocular," "facial," "synkinesis," "palsy," "neurotization," and various combinations of the terms. A total of 65 articles were included. RESULTS: Facial paralysis may result in devastating ocular sequelae. Therefore, assessment of the eye in facial paralysis is a critical component of patient management. Although the management should be individualized to the patient, the primary objective should include an ophthalmologic evaluation to implement measures to protect the ocular surface and preserve visual acuity. The degree of facial paralysis, lacrimal secretion, corneal sensation, and position of the eyelids should be assessed thoroughly. Patients with the anticipated recovery of facial nerve function may respond to more conservative temporizing measures to protect the ocular surface. Conversely, patients with expected prolonged paralysis should be appropriately identified as they will benefit from surgical reconstruction and rehabilitation of the periorbital complex. The majority of reconstructive measures within a facial surgeon's armamentarium augment coverage of the eye but are unable to restore blink. Eyelid reanimation restores the esthetic proportionality of the eye with blinking and reestablishes protective functions necessary for ocular preservation and function. CONCLUSIONS: Ocular preservation is the primary priority in the initial management of the patient with facial paralysis. An accurate assessment is a critical component in identifying the type of paralysis and developing an individualized treatment plan.

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.

Surgical Treatment for Postparalytic Facial Synkinesis: A 35-Year Experience.

BACKGROUND: Surgical intervention with combined myectomy and neurectomy followed by functioning free muscle transplantation has been proposed to effectively resolve the problem of postparalytic facial synkinesis since 1985, and it continues to be the authors' standard of care. The authors aim to provide evidence that this surgical strategy is effective for treatment of synkinesis and smile quality. METHODS: One hundred three patients with postparalytic facial synkinesis were investigated (1985 to 2020). They all underwent extensive removal of the synkinetic muscles and triggered facial nerve branches in the cheek, nose, and neck regions, followed by gracilis functioning free muscle transplantation for facial reanimation. Ninety-four patients (50 with type II and 44 with type III postparalytic facial synkinesis), all of whom had at least 1 year of postoperative follow-up, were included in the study. Patient demographics and functional and aesthetic evaluations before and after surgery were collected. RESULTS: In the yearly distribution of the facial paralysis reconstruction, the incidence of surgical intervention increased from 15 percent before 2012 up to 24 percent in the years after. Young adults (79 percent) and female patients (63 percent) were the dominant population. Results showed a significant improvement of the facial smile quality, with more teeth visible while smiling, and a long-lasting decrease of facial synkinesis. Ninety-six percent of patients did not require botulinum toxin type A injection after surgery. Revision surgery for secondary deformity was 53 percent. CONCLUSIONS: Combined myectomy and neurectomy followed by functioning free muscle transplantation for type II and III synkinetic patients leads to promising and long-lasting results despite high revision rates. Refined techniques to decrease the revision rates are needed in the future. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Do Preoperative Depressor Anguli Oris Muscle Blocks Predict Myectomy Outcomes? A Single-Cohort Comparison in Postparetic Facial Synkinesis.

SUMMARY: The complexity of facial synkinesis will likely benefit from an individualized approach to intervene on discrete synkinetic facial subunits. This overarching treatment algorithm requires understanding each synkinetic mimetic subunit. The depressor anguli oris muscle, because of its antagonistic relationship to the zygomaticus major, is of particular interest. This study aims to provide outcomes of depressor anguli oris muscle myectomies and the predictive value of preoperative lidocaine blocks. Preoperative depressor anguli oris muscle lidocaine blocks were administered to patients with postparetic facial synkinesis, and subsequent isolated depressor anguli oris muscle myectomies were performed on those who showed improvement and elected to proceed. Twenty synkinetic patients underwent isolated depressor anguli oris myectomies after lidocaine blockade, with an average follow-up of 9 months. Facial mimetic parameters and measurements were recorded and analyzed by Massachusetts Eye and Ear Infirmary Emotrics and National Institutes of Health ImageJ software to compare results from both blocks and myectomies. Both lidocaine block and depressor anguli oris myectomy improved dental show by 14.42 mm 2 and 23.012 mm 2 , respectively, and open mouth smile angles above a horizontal plane by 4.66 and 3.32 degrees, respectively. There was no statistical difference between the groups in terms of improvements noted in closed and open mouth smile angles above a horizontal plane, or in dental show ( p = 0.695, p = 0.351, and p = 0.242, respectively). Preoperative lidocaine blockade accurately predicts the improvement in dental show and modiolus smile angle that is provided by isolated depressor anguli oris muscle myectomy. This furthers our understanding of depressor anguli oris muscle abnormality in the overall spectrum of facial synkinesis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Synkinetic Brow Dysfunction: Diagnosis and Treatment Algorithm.

Importance: The diagnosis and management of brow dysfunction in patients with postfacial paralysis with synkinesis can be perplexing and challenging for the treating physician. Objective: To describe a novel diagnostic and treatment algorithm for brow dysfunction in patients with postfacial paralysis with synkinesis. Design: Surgical pearls-description of novel surgical technique. Setting: A private practice. Participants: Patients who underwent the operation.

Depressor Anguli Oris Myectomy versus Transfer to Depressor Labii Inferioris for Facial Symmetry in Synkinetic Facial Paralysis.

BACKGROUND: Postparalytic synkinesis presents with a combination of hypo- and hypertonic muscles, leading to facial asynchrony with animation and at rest. One ubiquitous finding is a hypertonic depressor anguli oris (DAO) muscle and a weak depressor labii inferioris (DLI) muscle. The goal of this study was to evaluate the utility of DAO myectomy with or without its transfer to the weakened DLI in improving critical components of the dynamic smile. METHODS: From 2018 to 2020, this single-center, prospective study included of postparetic facial synkinetic patients with evidence of DAO hypertonicity who underwent DAO myectomy with or without transfer to DLI. Objective facial measurements were used to compare the effectiveness of DAO to DLI transfer to pure DAO myectomy in improving asymmetry of the synkinetic hemiface. RESULTS: Twenty-one patients with unilateral postparetic facial synkinesis with DAO hypertonicity were included; 11 underwent DAO myectomy, while 10 underwent DAO to DLI transfer. Baseline demographics and facial measurements were similar between the groups. DAO myectomy resulted in increased modiolus resting position, closed-mouth smile modiolus angle and excursion, open-mouth smile modiolus angle, excursion, dental show, and decreased lower lip height deviation. DAO to DLI transfer demonstrated similar findings but lacked significant increase in excursion and resulted in worsened lower lip height deviation. CONCLUSION: These findings illustrate the utility of DAO myectomy in improving imbalance in the synkinetic patient and necessitate further technical refinements for DAO transfers or a different approach for improving lower lip depression in this subgroup of patients.

Epineurectomy of Facial Nerve Trunk for Refractory Oral-Ocular and Oculo-Oral Synkinesis Following Bell Palsy.

BACKGROUND: Synkinesis is a common sequelae after incomplete recovery from Bell palsy. Current first-line treatments include botulinum toxin injection and physical therapy. However, patients unresponsive to these treatments may require further surgery. Various surgical treatments have been reported, but no consensus has been reached for the optimal surgery. In a guinea pig model of synkinesis, the facial nerve trunk (FNT) was observed using a scanning electron microscope. Based on the results of scanning electron microscope and clinical ultrasonography, the authors chose FNT as the therapeutic target. METHODS: The authors performed epineurectomy of FNT for 11 patients with refractory oral-ocular and oculo-oral synkinesis under abnormal muscle response and facial electromyography monitoring. The postoperative assessments at 1 year were conducted using Sunnybrook Facial Grading System and Facial Disability Index scale. Furthermore, the epineurium excised during the operation was collected as the specimen and submitted for histopathological examination; the cadaveric FNT served as the control group. RESULTS: The follow-up results showed significant relief from synkinesis (4.91 ±â€Š0.37 versus 10.18 ±â€Š0.64, P < 0.01), improvement of physical (84.55 ±â€Š1.96 versus 73.18 ±â€Š3.65, P < 0.01) and social functions (77.09 ±â€Š3.24 versus 61.82 ±â€Š6.28, P < 0.01), with no worsening of facial paralysis in the patients. The histopathological examination revealed many nerve fibers in the epineurium, suggesting that FNT was the area of aberrant axon regeneration. CONCLUSIONS: Epineurectomy of FNT is a safe and effective surgical remedy. It can be considered as a surgical option for patients with refractory oral-ocular and oculo-oral synkinesis following Bell palsy.

Modified Selective Neurectomy: A New Paradigm in the Management of Facial Palsy with Synkinesis.

All patients with postparalytic facial paralysis are at risk of developing synkinesis due to aberrant nerve regeneration. Synkinesis can result in smile dysfunction, tension, and eyelid aperture narrowing due to overactive and uncoordinated muscle activity. When the synkinesis causes an asymmetric smile, there are several treatment modalities including neurotoxin, neuromuscular retraining, and surgery. Modified selective neurectomy of the facial nerve is a treatment option that potentially can improve the smile mechanism by reducing the activity of counterproductive facial muscles while preserving the natural neural pathway.

Comparison of results utilizing one-step and two-step triple innervation techniques.

A retrospective comparison between two groups of patients who underwent one-step or two-step triple innervation was performed to reveal the role of scar tissue in axonal regeneration. The surgical technique used was the same in all cases, but the first group underwent a one-time triple innervation procedure, while patients in the second group underwent delayed performance of neurorrhaphies between the distal ends of the cross-face grafts and the terminal branches of the injured facial nerve. The Wilcoxon signed-rank test for paired groups showed a statistically significant improvement in both facial symmetry and voluntary movements in both groups of patients. Separately, the Mann-Whitney test confirmed no statistically significant difference between the two groups regarding the restoration of facial symmetry and voluntary movements, and the development of postoperative synkinesis. A comparison of median values for each spontaneous parameter between the groups revealed greater effectiveness of the two-step surgery, with both blinking and laughing demonstrating better results. The greater effectiveness of the double-step technique in restoring spontaneous movements strongly supports the use of a two-stage triple innervation technique in patients with facial palsy.

Quality of Life Outcomes After Modified Selective Neurectomy for Postfacial Paralysis Synkinesis.

Background: Until now, quality of life (QOL) outcomes after modified selective neurectomy for postfacial paralysis synkinesis (PFPS) have not been assessed. Objective: To evaluate QOL outcomes among patients with PFPS who underwent modified selective neurectomy. Methods: The medical records of patients aged ≥18 years with PFPS who underwent modified selective neurectomy during a 6-year period were reviewed. QOL outcomes were measured using the Facial Clinimetric Evaluation (FaCE) scale and Synkinesis Assessment Questionnaire (SAQ). Results: At <1 year after selective neurectomy, there was improvement in mean SAQ (from 26.6 [95% confidence interval {CI}, 23.7-29.5] to 21.4 [95% CI, 19.5-23.3]; p < 0.0001). Mean FaCE scores improved (from 47.1 [95% CI, 43.6-50.6] to 62.6 [95% CI, 58.7-66.5]; p < 0.0001), with improvements in all subscores except lacrimal control scores (from 61.7 [95% CI, 52.6-70.9] to 62.2 [95% CI, 53.6-70.9]; p = 0.91). At >1 year after surgery, there was improvement in mean SAQ score (from 28.8 [95% CI, 26.0-31.6] to 23.4 [95% CI, 21.0-25.7]; p < 0.0001). Mean FaCE scores improved (from 45.9 [95% CI, 41.6-50.3] to 59.4 [95% CI, 53.6-65.2]; p < 0.0001), with improvements in all subscores except eye comfort and lacrimal control (from 52.4 [95% CI, -40.8-64.0] to 56.8 [95% CI, 45.5-68.0]; p = 0.36), and lacrimal control scores worsened (from 68.0 [95% CI, 56.7-79.2] to 56.3 [95% CI, 44.8-67.7]; p = 0.023). Conclusions: Modified selective neurectomy results in QOL improvements in patients with PFPS.

Synkinetic Unilateral Lower Lip Palsy: Diagnosis and Technical Considerations for Facial Reanimation.

Importance: There are no universally adopted surgical techniques to treat depressor labii inferioris (DLI) dysfunction in patients with postfacial paralysis synkinesis. We describe a novel description of this disorder and technical surgical considerations for reanimation. Objective: To describe a new classification for DLI dysfunction and a surgical option to restore a natural appearing full dentition smile. Design: Surgical pearls-description of novel surgical technique. Setting: A private practice. Participants: Patients who underwent the operation.

Syngeneic Transplantation of Rat Olfactory Stem Cells in a Vein Conduit Improves Facial Movements and Reduces Synkinesis after Facial Nerve Injury.

BACKGROUND: Posttraumatic facial paralysis is a disabling condition. Current surgical management by faciofacial nerve suture provides limited recovery. To improve the outcome, the authors evaluated an add-on strategy based on a syngeneic transplantation of nasal olfactory stem cells in a rat model of facial nerve injury. The main readouts of the study were the recording of whisking function and buccal synkinesis. METHODS: Sixty rats were allocated to three groups. Animals with a 2-mm facial nerve loss were repaired with a femoral vein, filled or not with olfactory stem cells. These two groups were compared to similarly injured rats but with a faciofacial nerve suture. Olfactory stem cells were purified from rat olfactory mucosa. Three months after surgery, facial motor performance was evaluated using video-based motion analysis and electromyography. Synkinesis was assessed by electromyography, using measure of buccal involuntary movements during blink reflex, and double retrograde labeling of regenerating motoneurons. RESULTS: The authors' study reveals that olfactory stem cell transplantation induces functional recovery in comparison to nontransplanted and faciofacial nerve suture groups. They significantly increase (1) maximal amplitude of vibrissae protraction and retraction cycles and (2) angular velocity during protraction of vibrissae. They also reduce buccal synkinesis, according to the two techniques used. However, olfactory stem cell transplantation did not improve axonal regrowth of the facial nerve, 3 months after surgery. CONCLUSIONS: The authors show here that the adjuvant strategy of syngeneic transplantation of olfactory stem cells improves functional recovery. These promising results open the way for a phase I clinical trial based on the autologous engraftment of olfactory stem cells in patients with a facial nerve paralysis.