Modern concepts in facial nerve reconstruction

Tensile strength of adhesives in peripheral nerve anastomoses: an in vitro biomechanical evaluation of four different neurorrhaphies

BACKGROUND

The fundamental prerequisite for prognostically favorable postoperative results of peripheral nerve repair is stable neurorrhaphy without interruption and gap formation.

METHODS

This study evaluates 60 neurorrhaphies on femoral chicken nerves in terms of the procedure and the biomechanical properties. Sutured neurorrhaphies (n = 15) served as control and three sutureless adhesive-based nerve repair techniques: Fibrin glue (n = 15), Histoacryl glue (n = 15), and the novel polyurethane adhesive VIVO (n = 15). Tensile and elongation tests of neurorrhaphies were performed on a tensile testing machine at a displacement rate of 20 mm/min until failure. The maximum tensile force and elongation were recorded.

RESULTS

All adhesive-based neurorrhaphies were significant faster in preparation compared to sutured anastomoses (p < 0.001). Neurorrhaphies by sutured (102.8 [cN]; p < 0.001), Histoacryl (91.5 [cN]; p < 0.001) and VIVO (45.47 [cN]; p < 0.05) withstood significant higher longitudinal tensile forces compared to fibrin glue (10.55 [cN]). VIVO, with △L/L0 of 6.96 [%], showed significantly higher elongation (p < 0.001) compared to neurorrhaphy using fibrin glue.

CONCLUSION

Within the limitations of an in vitro study the adhesive-based neurorrhaphy technique with VIVO and Histoacryl have the biomechanical potential to offer alternatives to sutured neuroanastomosis because of their stability, and faster handling. Further in vivo studies are required to evaluate functional outcomes and confirm safety.

Dynamic Surgical Restoration of Mid and Lower Facial Paralysis: A Single-Greek-Centre Experience

Background Facial palsy detrimentally impacts an individual's quality of life due to its effects on function and appearance. There are several reconstructive surgical techniques available that aim to restore facial symmetry. Techniques such as direct neurorrhaphy, nerve grafts, dual reanimation, and reinnervation have the potential to enable varying motor functions, including the re-establishment of a dynamic smile. This study aimed to assess the outcomes of facial palsy reconstructive surgeries undertaken at a tertiary care centre for facial nerve reconstruction in Athens. Methods This study consisted of a comprehensive case series showcasing the outcomes of facial palsy reconstructive surgeries on 29 patients at our Tertiary General Oncological Anti-Cancer Hospital of Athens 'Agios Savvas'. The surgical procedures from October 2004 to December 2023 included reinnervation, nerve grafting, free muscle transfer, and myoplasties following our recommended algorithm. We categorized the patients into two groups: Group A and Group B based on the timing of the reconstruction: delayed or immediate. The House-Brackmann grading scale evaluated the degree and improvement of facial paralysis. Results In Group A, two of the seven patients exhibited activation of the mimetic musculature immediately postsurgery, while the remaining five experienced enhanced facial nerve function in the subsequent months. Adverse outcomes were temporalis dysfunction in one case and tongue atrophy in another. Conversely, in Group B, 21 of 22 patients demonstrated facial activation immediately postsurgery. Only one patient from this group did not show any facial nerve function postoperatively. Two of the 22 patients in Group B encountered complications: one with trismus and another with temporalis dysfunction. All patients were observed for a minimum of 12 months postsurgery. Conclusion With the exception of one patient, all participants showed improved postoperative results, which were satisfactory when weighed against the observed morbidity rate. While our case analysis did not reveal any clear indication of one particular technique being superior, the selection of methods should be based on several factors, and this algorithm could serve as a useful aid in that regard. A comprehensive and standardized clinical assessment of facial palsy, both before and after surgery, is crucial to establish a consensus and plan individualized therapy.

Efficacy of repetitive transcranial magnetic stimulation at different sites for peripheral facial paralysis: a prospective cohort study

Background

There are very few studies on transcranial magnetic stimulation (TMS) therapy for facial paralysis and no studies comparing the efficacy of central and peripheral TMS in the treatment of peripheral facial paralysis (PFP).

Purpose

To observe the therapeutic effect and security of central and peripheral repetitive transcranial magnetic stimulation (rTMS) on PFP.

Methods

Patients with unilateral onset of peripheral facial paralysis within 1 month were prospectively recruited, 97 patients with PFP were divided into the peripheral group, central group, and control group. The control group was given common treatment (drug therapy and acupuncture), and the peripheral and central groups received rTMS in addition to conventional treatment. After 2 weeks of treatment, the House-Brackmann (HB) grading scale, Sunnybrook facial grading system (SFGS), and modified Portmann scale (MPS) were used to evaluate the facial muscle function of patients in the three groups.

Result

After 2 weeks of rTMS treatment, the HBGS/SFGS/MPS scores of the three groups were significantly better than before (p < 0.05), and the mean change values of HBGS, SFGS, and MPS scores were significantly higher in participants in Peripheral Group (p < 0.001; p < 0.001; p = 0.003; respectively) and Central Group (p = 0.004; p = 0.003; p = 0.009; respectively) than in Control Group. But the mean change values of HBGS, SFGS, and MPS scores showed no significant differences in participants in the Peripheral Group than in the Central Group (p = 0.254; p = 0.139; p = 0.736; respectively) after 2 weeks of treatment (p > 0.05).

Conclusion

Our study shows that rTMS can be a safe and effective adjuvant therapy for patients with PFP. Preliminary studies have shown that both peripheral and central stimulation can effectively improve facial nerve function, but there is no significant difference in the efficacy of the two sites.

Selective zygomaticus muscle activation by ball electrodes in synkinetically reinnervated patients after facial paralysis

Introduction

Although many different treatments were developed for facial palsy, only a few therapeutic options are available for facial synkinesis. Electrical stimulation of specific muscles via implants could be useful in restoring facial symmetry in synkinetic patients. A challenge in developing stimulation devices is finding the right stimulation location, type, and amplitude. This work assesses the ability to selectively stimulate the zygomaticus muscle (ZYG) in patients with oral-ocular synkinesis to elicit a visually detectable response of the ipsilateral corner of the mouth (COM), without causing a reaction of the orbicularis oculi muscle (OOM). We aimed to assess how close to the COM the stimulation should be delivered in order to be selective.

Methods

A total of 10 patients (eight females, two males) were enrolled. Facial function was graded according to the Sunnybrook facial grading system. Needle EMG was used to test the activities of the muscles, during volitional and "unintended" movements, and the degree of synkinesis of the ZYG and OOM. Two ball electrodes connected to an external stimulator were placed on the paretic ZYG, as close as possible to the COM.

Results

Independent of the waveform with which the stimulation was presented, a selective ZYG response was observed within 4.5 cm of the horizontal plane and 3 cm of the vertical plane of the COM. When the distance between the electrodes was kept to ≤2 cm, the amplitude necessary to trigger a response ranged between 3 and 6 mA when the stimulation was delivered with triangular pulses and between 2.5 and 3.5 mA for rectangular pulses. The required amplitude did not seem to be dependent on the applied phase duration (PD), as long as the PD was ≥5 ms.

Conclusion

Our results show that selective stimulation of the ZYG presenting synkinetic ZYG-OOM reinnervation can be achieved using a broad PD range (25-1,000 ms) and an average amplitude ≤6 mA, which may be further decreased to 3.5 mA if the stimulation is delivered via rectangular rather than triangular waves. The most comfortable and effective results were observed with PDs between 50 and 250 ms, suggesting that this range should be selected in future studies.

Clinical Trial Registration

[https://drks.de/search/de/trial/DRKS00019992], identifier (DRKS00019992).

Effect of Electrical Stimulation on Nerve-Guided Facial Nerve Regeneration

This study aimed to investigate the effect of electrical stimulation on poly(d,l-lactide-co-ε-caprolactone) nerve guidance conduits (NGCs) in promoting the recovery of facial function and nerve regeneration after facial nerve (FN) injury in a rat model. In the experimental group, both the NGC and transcutaneous electrical nerve stimulation (ES) were used simultaneously; in the control group, only NGC was used. ES groups were divided into two groups, and direct current (DC) and charge-balanced pulse stimulation (Pulse) were applied. The ES groups showed significantly improved whisker movement than the NGC-only group. The number of myelinated neurons was higher in ES groups, and the myelin sheath was also thicker and more uniform. In addition, the expression of neurostructural proteins was also higher in ES groups than in the NGC-only group. This study revealed that FN regeneration and functional recovery occurred more efficiently when ES was applied in combination with NGCs.

Postoperative Radiotherapy and Facial Nerve Outcomes Following Nerve Repair: A Systematic Review

OBJECTIVE

To compare outcomes of facial nerve repair or grafting following facial nerve-sacrificing procedures among patients treated with and without postoperative radiotherapy (RT).

DATA SOURCES

PubMed, OVID, Conference Papers Index, Cochrane Library, ClinicalTrials.gov.

REVIEW METHODS

Databases were searched using terms including "facial nerve," "graft," "repair," and "radiotherapy." Abstracts mentioning facial nerve repair and evaluation of facial nerve function were included for full-text review. Studies that utilized the House-Brackmann or similar validated scale for evaluation of postoperative facial nerve function were selected for review. All identified studies were included in a pooled t test analysis.

RESULTS

Twelve studies with 142 patients were included in the systematic review. All 12 studies individually demonstrated no significant difference in facial nerve outcomes between patients who received postoperative radiation and patients who did not. A pooled t test of data from all studies also demonstrated no significant difference in postoperative facial nerve function between the postoperative RT and non-RT groups (t stat = 0.92, p = .36).

CONCLUSION

This analysis, including 12 studies, demonstrated that among patients undergoing facial nerve grafting or repair, there was no significant difference in postoperative facial nerve function between postoperative RT and non-RT patients. Due to the small sample size and variability in study methods, further studies directly comparing outcomes between patients with and without postoperative RT would be beneficial.

Smile Reanimation with Masseteric-to-Facial Nerve Transfer plus Cross-Face Nerve Grafting in Patients with Segmental Midface Paresis: 3D Retrospective Quantitative Evaluation

Facial paresis involves functional and aesthetic problems with altered and asymmetric movement patterns. Surgical procedures and physical therapy can effectively reanimate the muscles. From our database, 10 patients (18–50 years) suffering from unilateral segmental midface paresis and rehabilitated by a masseteric-to-facial nerve transfer combined with a cross-face facial nerve graft, followed by physical therapy, were retrospectively analyzed. Standardized labial movements were measured using an optoelectronic motion capture system. Maximum teeth clenching, spontaneous smiles, and lip protrusion (kiss movement) were detected before and after surgery (21 ± 13 months). Preoperatively, during the maximum smile, the paretic side moved less than the healthy one (23.2 vs. 28.7 mm; activation ratio 69%, asymmetry index 18%). Postoperatively, no differences in total mobility were found. The activity ratio and the asymmetry index differed significantly (without/with teeth clenching: ratio 65% vs. 92%, p = 0.016; asymmetry index 21% vs. 5%, p = 0.016). Postoperatively, the mobility of the spontaneous smiles significantly reduced (healthy side, 25.1 vs. 17.2 mm, p = 0.043; paretic side 16.8 vs. 12.2 mm, p = 0.043), without modifications of the activity ratio and asymmetry index. Postoperatively, the paretic side kiss movement was significantly reduced (27 vs. 19.9 mm, p = 0.028). Overall, the treatment contributed to balancing the displacements between the two sides of the face with more symmetric movements.

Endoscopic Optic Nerve Decompression for Direct Traumatic Optic Neuropathy : Our 10 Years Experience

Traumatic optic neuropathy (TON) can be classified into direct or indirect types. Direct optic injury usually results from optic nerve avulsion ,laceration or compression by fracture, fracture segment impingement or a resultant hematoma. Indirect optic injury is caused by increased intracanalicular pressure resulting in ischemia and disruption of neurofeedback channels. The prognosis of TON is usually quite poor. To date, no standardized treatment protocol has been developed for TON. In this study we are assessing the visual improvement in patients with direct TON who underwent endoscopic optic nerve decompression in the last 10 years. A retrospective study of 32 cases of optic nerve decompression for direct TON in the last 10 years. Preoperative and postoperative visual assessment were done and followed up for 3 months. There was complete improvement in vision in 17% of patients when optic nerve decompression was done within 72 h of trauma; whereas 31% cases had only partial improvement when done between 3 and 7 days. And there was no improvement when done after 7 days. Endoscopic optic nerve decompression is a minimally invasive surgery for direct traumatic optic neuropathy; with minimal or no complications when done by an experienced ENT surgeon. Other important prognostic factors include timing of surgery and preoperative visual status.

A Comprehensive Approach to Facial Reanimation: A Systematic Review

Purpose: To create a systematic overview of the available reconstructive techniques, facial nerve grading scales, physical evaluation, the reversibility of paralysis, non-reconstructive procedures and medical therapy, physical therapy, the psychological aspect of facial paralysis, and the prevention of facial nerve injury in order to elucidate the gaps in the knowledge and discuss potential research aims in this area. A further aim was to propose an algorithm simplifying the selection of reconstructive strategies, given the variety of available reconstructive methods and the abundance of factors influencing the selection. Methodological approach: A total of 2439 papers were retrieved from the Medline/Pubmed and Cochrane databases and Google Scholar. Additional research added 21 articles. The primary selection had no limitations regarding the publication date. We considered only papers written in English. Single-case reports were excluded. Screening for duplicates and their removal resulted in a total of 1980 articles. Subsequently, we excluded 778 articles due to the language and study design. The titles or abstracts of 1068 articles were screened, and 134 papers not meeting any exclusion criterion were obtained. After a full-text evaluation, we excluded 15 papers due to the lack of information on preoperative facial nerve function and the follow-up period. This led to the inclusion of 119 articles. Conclusions: A thorough clinical examination supported by advanced imaging modalities and electromyographic examination provides sufficient information to determine the cause of facial palsy. Considering the abundance of facial nerve grading scales, there is an evident need for clear guidelines regarding which scale is recommended, as well as when the postoperative evaluation should be carried out. Static procedures allow the restoral of facial symmetry at rest, whereas dynamic reanimation aims to restore facial movement. The modern approach to facial paralysis involves neurotization procedures (nerve transfers and cross-facial nerve grafts), muscle transpositions, and microsurgical free muscle transfers. Rehabilitation provides patients with the possibility of effectively controlling their symptoms and improving their facial function, even in cases of longstanding paresis. Considering the mental health problems and significant social impediments, more attention should be devoted to the role of psychological interventions. Given that each technique has its advantages and pitfalls, the selection of the treatment approach should be individualized in the case of each patient.

Congenital Facial Paralysis Revealing an Aplasic Facial Nerve: A Report of Two Cases

ABSTRACT

Congenital facial palsy is a rare condition, usually related to a traumatic event during birth or as a feature of a syndrome. In this report, two cases of infants with peripheral facial palsy since birth are described, in which magnetic resonance imaging demonstrated unilateral aplasia of the facial nerve. There are only a few cases with similar findings described in the literature. A multidisciplinary approach is recommended to provide the best care. Although no reinnervation of the facial muscles is likely to occur, rehabilitative therapies may be valuable as complementary treatments.

Facial Nerve Palsy Secondary to Parotid Abscess: Report of a Rare Case and Review of the Literature

A parotid lesion with facial nerve involvement almost always indicates malignancy. Facial nerve palsy as a complication of parotid abscess is extremely rare. The postulated mechanisms include ischaemic neuropathy secondary to the compression of the facial nerve by the parotid swelling, local toxic effect and perineuritis from the inflammatory process. Here, we present our experience in managing a case of facial nerve palsy due to a parotid abscess in an otherwise healthy 44-year-old female. The abscess was drained surgically and the facial nerve function returned to normal at two months. Histopathological examination of the parotid tissue showed no features of malignancy. The severity of facial nerve impairment varied from grade II to total palsy. The mainstay of treatment of a parotid abscess is surgical drainage along with medical therapy including broad-spectrum antibiotics, adequate hydration and sialogogues.

Multidisciplinary Care of Patients with Facial Palsy: Treatment of 1220 Patients in a German Facial Nerve Center

To determine treatment and outcome in a tertiary multidisciplinary facial nerve center, a retrospective observational study was performed of all patients referred between 2007 and 2018. Facial grading with the Stennert index, the Facial Clinimetric Evaluation (FaCE) scale, and the Facial Disability Index (FDI) were used for outcome evaluation; 1220 patients (58.4% female, median age: 50 years; chronic palsy: 42.8%) were included. Patients with acute and chronic facial palsy were treated in the center for a median of 3.6 months and 10.8 months, respectively. Dominant treatment in the acute phase was glucocorticoids ± acyclovir (47.2%), followed by a significant improvement of all outcome measures (p < 0.001). Facial EMG biofeedback training (21.3%) and botulinum toxin injections (11%) dominated the treatment in the chronic phase, all leading to highly significant improvements according to facial grading, FDI, and FaCE (p < 0.001). Upper eyelid weight (3.8%) and hypoglossal–facial-nerve jump suture (2.5%) were the leading surgical methods, followed by improvement of facial motor function (p < 0.001) and facial-specific quality of life (FDI, FaCE; p < 0.05). A standardized multidisciplinary team approach in a facial nerve center leads to improved facial and emotional function in patients with acute or chronic facial palsy.

The Offprint of an Abnormal Pre-Parotidectomy Electrodiagnostic Finding in a Normally Functioning Facial Nerve: Correlation with Intraoperative Findings, Histology and Postoperative Facial Nerve Function

The aim of this study was to search for associations between an electrodiagnostically abnormal but clinically normal facial nerve before parotidectomy and the intraoperative findings, as well as the postoperative facial nerve function. The records of all patients treated for parotid tumors between 2002 and 2021 with a preoperative House–Brackmann score of grade I but an abnormal electrophysiologic finding were studied retrospectively. A total of 285 patients were included in this study, and 222 patients had a benign lesion (77.9%), whereas 63 cases had a malignant tumor (22.1%). Electroneurographic facial nerve involvement was associated with nerve displacement in 185 cases (64.9%) and infiltration in 17 cases (6%). In 83 cases (29.1%), no tumor–nerve interface could be detected intraoperatively. An electroneurographic signal was absent despite supramaximal stimulation in 6/17 cases with nerve infiltration and in 17/268 cases without nerve infiltration (p < 0.001). The electrophysiologic involvement of a normal facial nerve is not pathognomonic for a malignancy (22%), but it presents a rather rare (~6%) sign of a “true” nerve infiltration and could also appear in tumors without any contact with the facial nerve (~29%). Of our cases, two thirds of those with an anatomic nerve preservation and facial palsy had already directly and postoperatively recovered to a major extent in the midterm.

Impact of fetal brain tissue derived mesenchymal stem cell and fibrin glue on facial nerve crash injury

Background/aim

To evaluate the clinical and histopathological effects of fetal brain tissue derived mesenchymal stem cells (FBTMSC) and fibrin glue (FG) on the facial nerve (FN) regeneration in rats with traumatic FN injury.

Materials and methods

Twenty-eight Sprague Dawley rats were included in the study and divided into 4 groups. Traumatic FN injury (FP) was created by a surgical clamp compression to the main trunk of left FN in all groups. In the control group (group 1) no treatment was applied, in group 2 (FBTMSC group) 2 × 106 FBTMSC was injected, in group 3 (FG group) only FG was applied, in group 4 (FBTMSC and FG groups) both FBTMSC and FG were applied to the injured section of the nerve. The FN functions were evaluated clinically, immediately after the procedure and at 3rd, 5th, and 8th weeks postoperatively. The FNs of all subjects were excised after the 8th week; then the rats were sacrificed. The presence of stem cells in the injured zone was assessed using bromo-deoxyuridine (BrdU), and apoptosis was determined by the TUNEL method.

Results

After the damage, total FP was observed in all subjects. Statistically significant functional improvement was observed in group 4 compared to all other groups (P < 0.005). TUNEL-positive cell count was statistically significantly higher in the control group than the other groups (P < 0.001). TUNEL-positive cell count was statistically significantly lower in group 4 than the other groups. The proportion of BrdU-stained cells in group 4 (5%) was higher than group 2 (2%).

Conclusion

Clinically and histopathologically FBTMSC applied with FG may play a promising role as a regenerative treatment in posttraumatic FP.

Hemihypoglossal-facial nerve anastomosis: results and electromyographic characterization

INTRODUCTION

The facial nerve surgery belongs to the basic procedures during lateral skull base approaches. Its damage has serious medical and psychological consequences, and therefore mastery of reconstruction and correction techniques should belong to the repertoire of skull base surgeons. The goal of this study was to demonstrate usefulness of electromyographic follow-up in facial nerve reconstruction.

MATERIAL AND METHODS

A total of 16 patients underwent hemihypoglossal-facial anastomosis between 2005 and 2017. Most of the primary lesions came from vestibular schwannoma surgery. All patients were examined with electromyography and scored according to the House-Brackmann and IOWA grading scales. Function of the tongue has been evaluated.

RESULTS

Ten patients achieved definitive House-Brackmann grade 3 score (62.5%). We did not observe any association with the patient's age, previous irradiation and the etiology of the damage. Electromyography showed pathological spontaneous activity after the first surgery. Incipient regeneration potentials were detected in 4-17 months (average 7.6) and reached maximum in 6.5-18 months (average 16). Electromyographic assessment of the effect of tongue movement showed better mimic voluntary activity by swallowing or by moving the tongue up. There was no relationship between the start of activity and the interval to achieving maximal activity.

CONCLUSION

Hemihypoglossal-facial nerve anastomosis is a safe procedure and it is an optimal solution for cases lacking a proximal stump or in the case of reconstruction in the second stage. Electromyography can predict initial reinnervation activity after reconstructive procedures. During subsequent follow-up it can help to discover insufficiently recovering patients, however clinical characteristics are crucial.

Sensibility, Sensation, and Nerve Regeneration after Reconstructive Genital Surgery: Evolving Concepts in Neurobiology

BACKGROUND

Sensory recovery following phalloplasty and vaginoplasty for gender dysphoria is essential to the overall success of gender-confirming surgery. Anecdotal evidence suggests that superior reinnervation results are seen in genitoplasty compared to other peripheral nerve repair scenarios. Despite these observed differences, the quality of available literature is poor.

METHODS

The authors reviewed the body of English language literature regarding sensory outcomes following genitoplasty for gender confirmation.

RESULTS

The available body of literature discussing the basic science and clinical science aspects of sensory recovery following gender-confirming genitoplasty is small. Available data show that sensory recovery following vaginoplasty produces high rates of reported orgasmic ability, largely through the neoclitoris, and a neovagina with vibratory and pressure sensation similar to that of the native vagina. Phalloplasty sensory outcomes are variable, with the largest series reporting return of sensation in the neophallus that is slightly less than what is measured in control men. Erogenous sensation, including the ability to orgasm, is present in nearly all patients after several months.

CONCLUSIONS

Existing series indicate that genitoplasty patients experience faster and more complete recovery than any other peripheral nerve regeneration scenarios. However, there are many potential confounding factors in assessment and reporting, and more consistent and reproducible measure endpoints measures are needed. Further research is needed to better understand both the basic science and clinical science of peripheral nerve regeneration in genitoplasty, which may change fundamental aspects of current paradigms of peripheral nerve regeneration.

Facial nerve regeneration using silicone conduits filled with ammonia-functionalized graphene oxide and frankincense-embedded hydrogel

Background

Silicone tube (ST) conduits have been accepted as a therapeutic alternative to direct nerve suturing in the treatment of nerve injuries; however, the search for optimal adjuncts to maximize the outcomes is still ongoing. Frankincense (Fr) and graphene oxide (GO) have both been cited as neuroregenerative compounds in the literature. This study assesses the efficacy of these materials using a ST conduit in a rat facial nerve motor neuron axotomy model, distal to the stylomastoid foramen.

Methods

Ammonia-functionalized graphene oxide (NH2-GO) and/or Fr extract were embedded in a collagen-chitosan hydrogel and were injected inside a ST. The ST was inserted in the gap between the axotomized nerve stumps. Return of function in eye closure, blinking reflex, and vibrissae movements were assessed and compared to control groups through 30 days following axotomy. To assess the histological properties of regenerated nerves, biopsies were harvested distal to the axotomy site and were visualized through light and fluorescence microscopy using LFB and anti-MBP marker, respectively.

Results

There was no significant difference in behavioral test results between groups. Histological analysis of the nerve sections revealed increased number of regenerating axons and mean axon diameter in NH2-GO group and decreased myelin surface area in Fr group. Using both NH2-GO and Fr resulted in increased number of regenerated axons and myelin thickness compared to the hydrogel group.

Conclusions

The findings suggest a synergistic effect of the substances above in axon regrowth, notably in myelin regeneration, where Fr supposedly decreases myelin synthesis.

The Experience of a Facial Nerve Unit in the Treatment of Patients With Facial Paralysis Following Skull Base Surgery

: The management of facial paralysis following skull base surgery is complex and requires multidisciplinary intervention. This review shows the experience of a facial nerve (FN) unit in a tertiary university referral center. A multidisciplinary approach has led to the breaking of some old treatment paradigms. An overview of five FN scenarios is presented. For each setting a contemporary approach is proposed in contrast to the established approach. 1) For patients with an anatomically preserved FN with no electrical response at the end of surgery for vestibular schwannoma, watchful waiting is usually advocated. In these cases, reinforcement with an interposed nerve graft is recommended. 2) In cases of epineural FN repair, with or without grafting, and a poor expected prognosis, an additional masseter-to-facial transfer is recommended. 3) FN transfer, mainly hypoglossal-to-facial and masseter-to facial, are usually chosen based on the surgeons' preference. The choice should be based on clinical factors. A combination of techniques improves the outcome in selected patients. 4) FN reconstruction following malignant tumors requires a combination of parotid and temporal bone surgery, involving different specialists. This collaboration is not always consistent. Exposure of the mastoid FN is recommended for lesions involving the stylomastoid foramen, as well as intraoperative FN reconstruction. 5) In patients with incomplete facial paralysis and a skull base tumor requiring additional surgery, consider an alternative reinnervation procedure, "take the FN out of the equation" before tumor resection. In summary, to achieve the best results in complex cases of facial paralysis, a multidisciplinary approach is recommended.

Facial Nerve Repair: Bioengineering Approaches in Preclinical Models

Injury to the facial nerve can occur after different etiologies and range from simple transection of the branches to varying degrees of segmental loss. Management depends on the extent of injury and options include primary repair for simple transections and using autografts, allografts, or conduits for larger gaps. Tissue engineering plays an important role to create artificial materials that are able to mimic the nerve itself without extra morbidity in the patients. The use of neurotrophic factors or stem cells inside the conduits or around the repair site is being increasingly studied to enhance neural recovery to a greater extent. Preclinical studies remain the hallmark for development of these novel approaches and translation into clinical practice. This review will focus on preclinical models of repair after facial nerve injury to help researchers establish an appropriate model to quantify recovery and analyze functional outcomes. Different bioengineered materials, including conduits and nerve grafts, will be discussed based on the experimental animals that were used and the defects introduced. Future directions to extend the applications of processed nerve allografts, bioengineered conduits, and cues inside the conduits to induce neural recovery after facial nerve injury will be highlighted.

Selective Surface Electrostimulation of the Denervated Zygomaticus Muscle

This article describes a first attempt to generate a standardized and safe selective surface electrostimulation (SES) protocol, including detailed instructions on electrode placement and stimulation parameter choice to obtain a selective stimulation of the denervated zygomaticus muscle (ZYG), without unwanted simultaneous activation of other ipsilateral or contralateral facial muscles. Methods: Single pulse stimulation with biphasic triangular and rectangular waveforms and pulse widths (PW) of 1000, 500, 250, 100, 50, 25, 15, 10, 5, 2, 1 ms, at increasing amplitudes between 0.1 and 20 mA was performed. Stimulations delivered in trains were assessed at a PW of 50 ms only. The stimulation was considered successful exclusively if it drew the ipsilateral corner of the mouth upwards and outwards, without the simultaneous activation of other ipsilateral or contralateral facial muscles. I/t curves, accommodation quotient, rheobase, and chronaxie were regularly assessed over 1-year follow-up. Results: 5 facial paralysis patients were assessed. Selective ZYG response in absence of discomfort and unselective contraction of other facial muscle was reproducibly obtained for all the assessed patients. The most effective results with single pulses were observed with PW ≥ 50 ms. The required amplitude was remarkably lower (≤5 mA vs. up to 15 mA) in freshly diagnosed (≤3 months) than in long-term facial paralysis patients (>5 years). Triangular was more effective than rectangular waveform, mostly because of the lower discomfort threshold of the latter. Delivery of trains of stimulation showed similar results to the single pulse setting, though lower amplitudes were necessary to achieve the selective ZYG response. Initial reinnervation signs could be detected effectively by needle-electromyography (n-EMG). Conclusion: It is possible to define stimulation parameters able to elicit an effective selective stimulation of a specific facial muscle, in our case, of the ZYG, without causing discomfort to the patient and without causing unwanted unspecific reactions of other ipsilateral and/or contralateral facial muscles. We observed that the SES success is strongly conditioned by the correct electrode placement, which ideally should exclusively interest the area of the target muscles and its immediate proximity.

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.

A Morphometric Study of Stylomastoid Foramen with Its Clinical Applications

Background To prevent damage to the facial nerve while doing surgery and to give facial nerve block by anesthetics near the stylomastoid foramen we should know its distance from the important anatomical landmarks. So, this study aims to study the location of stylomastoid with respect to nearby anatomical landmarks.

Materials and Method The study was performed on 58 dry skulls. Measurements of stylomastoid foramen were taken from various anatomical landmarks on both sides of the skull. Data analysis was done by using the Statistical Package for Social Sciences (SPSS) 19 version.

Results The mean distance of the center of the stylomastoid foramen (CSMF) to the tip of the mastoid process was 1.60, 1.57 cm on the right and left side, respectively. The mean distance of CSMF to the upper end of the anterior border of the mastoid process was 1.42, 1.39 cm on the right and left side, respectively. The mean angle between CSMF and tip of the mastoid process was 51.6 degrees, 53.5 degrees on right and left side, respectively. The mean distance of CSMF to the center of jugular foramen was 1.27, 1.26 cm on the right and left side, respectively. The position of the stylomastoid foramen in relation to a transverse line passing through the upper end of the anterior border of both mastoid processes was anterior in 82.7%, 94.8% of cases on the right and left side, respectively.

Conclusion These measurements will aid neurosurgeons in doing surgeries near the stylomastoid foramen or anesthetics to give facial nerve block near the foramen.

The Diagnosis and Treatment of Idiopathic Facial Paresis (Bell's Palsy)

BACKGROUND

Peripheral facial nerve palsy is the most com- mon functional disturbance of a cranial nerve. 60-75% of cases are idiopathic.

METHODS

This review is based on a selective literature search proceeding from the current, updated German-language guideline on the diagnosis and treatment of idiopathic facial nerve palsy.

RESULTS

The recommended drug treatment consists of prednisolone 25 mg bid for 10 days, or 60 mg qd for 5 days followed by a taper to off in decrements of 10 mg per day. This promotes full recovery (number needed to treat [NNT] = 10; 95% confidence interval [6; 20]) and lessens the risk of late sequelae such as synkinesia, autonomic disturbances, and contractures. Virostatic drugs are optional in severe cases (intense pain or suspicion of herpes zoster sine herpete) and mandatory in cases of varicella-zoster virus (VZV) infection. Corneal protection with dexpanthenol ophthalmic ointment, artificial tears, and a nocturnal moisture- retaining eye shield has been found useful in practice. In cases of incomplete recovery with residual facial weakness, both static and microsurgical dynamic methods can be used to restore facial nerve function.

CONCLUSION

Because 25-40% of cases of facial nerve palsy are not idiopathic, differential diagnosis is very important; key diagnostic methods include a clinical neurological examin- ation, otoscopy, and a lumbar puncture for cerebrospinal fluid examination. High-level evidence supports corticosteroid treatment for the idiopathic form of the disorder.

A Preliminary Study of CT Texture Analysis for Characterizing Epithelial Tumors of the Parotid Gland

Objective

The aim of this study was to explore and validate the diagnostic performance of whole-volume CT texture features in differentiating the common benign and malignant epithelial tumors of the parotid gland.

Materials and Methods

Contrast-enhanced CT images of 83 patients with common benign and malignant epithelial tumors of the parotid gland confirmed by histopathology were retrospectively analyzed, including 50 patients with pleomorphic adenoma (PA) and 33 patients with malignant epithelial tumors. Quantitative texture features of tumors were extracted from CT images of arterial phase. The diagnostic performance of texture features was evaluated via receiver operating characteristic (ROC) curve and area under ROC curve (AUC). The specificity and sensitivity were respectively discussed by the maximum Youden’s index.

Results

All the texture features were subject to normal distribution and homoscedasticity. Energy, mean, correlation, and sum entropy of epithelial malignancy group were significantly higher than those of PA group (P<0.05). There were no statistically significant differences between PA group and epithelial malignancy group in uniformity, entropy, skewness, kurtosis, contrast, and difference entropy (P>0.05). The AUC of each texture feature and joint diagnostic model was 0.887 (energy), 0.734 (mean), 0.739 (correlation), 0.623 (sum entropy), 0.888 (energy-mean), 0.883 (energy-correlation), 0.784 (mean-correlation). The diagnostic efficiency of energy-mean was the best. Based on the maximum Youden’s index, the specificity of energy-correlation was the highest (97%) and the sensitivity of energy was the highest (97%).

Conclusion

Energy, mean, correlation, and sum entropy can be the effective quantitative texture features to differentiate the benign and malignant epithelial tumors of the parotid gland. With higher AUC, energy and energy-mean are superior to other indexes or joint diagnostic models in differentiating the benign and malignant epithelial tumors of the parotid gland. CT texture analysis can be used as a noninvasive and valuable means of preoperative assessment of parotid epithelial tumors without additional cost to the patients.

Functional Outcome and Quality of Life After Hypoglossal-Facial Jump Nerve Suture

Background: To evaluate the face-specific quality of life after hypoglossal-facial jump nerve suture for patients with long-term facial paralysis.

Methods: A single-center retrospective cohort study was performed. Forty-one adults (46% women; median age: 55 years) received a hypoglossal-facial jump nerve suture. Sunnybrook and eFACE grading was performed before surgery and at a median time of 42 months after surgery. The Facial Clinimetric Evaluation (FaCE) survey and the Facial Disability Index (FDI) were used to quantify face-specific quality of life after surgery.

Results: Hypoglossal-facial jump nerve suture was successful in all cases without tongue dysfunction. After surgery, the median FaCE Total score was 60 and the median FDI Total score was 76.3. Most Sunnybrook and eFACE grading subscores improved significantly after surgery. Younger age was the only consistent independent predictor for better FaCE outcome. Additional upper eyelid weight loading further improved the FaCE Eye comfort subscore. Sunnybrook grading showed a better correlation to FaCE assessment than the eFACE. Neither Sunnybrook nor eFACE grading correlated to the FDI assessment.

Conclusion: The hypoglossal-facial jump nerve suture is a good option for nerve transfer to reanimate the facial muscles to improve facial motor function and face-specific quality of life.

Hypoglossal Facial Nerve Anastomosis for Post-Operative and Post-Traumatic Complete Facial Nerve Paralysis

AIM:

This study aims to evaluate the outcome of patients with complete facial paralysis following surgery to cerebellopontine angle tumours or following traumatic petrous bone fractures after reanimation by hypoglossal-facial anastomosis as regards clinical improvement of facial asymmetry and facial muscle contractility as well as complications associated with hypoglossal-facial reanimation procedure.

METHODS:

This thesis included a prospective study to be carried out on 15 patients with unilateral complete lower motor neuron facial paralysis (11 patients after cerebellopontine angle tumour resection and 4 patients after traumatic transverse petrous bone fracture) operated upon by end to end hypoglossal-facial nerve anastomosis in Cairo university hospitals in the period between June 2015 and January 2017.

RESULTS:

At one year follow up the improvement of facial nerve functions were as follows: Three cases (20%) had improved to House Hrackmann grade II, eleven cases (73.33%) had improved to grade III, and one patient (6.66%) had improved to House Brackmann grade IV.

CONCLUSION:

Despite the various techniques in facial reanimation following facial nerve paralysis, the end to end hypoglossal-facial nerve anastomosis remains the gold standard procedure with satisfying results in cases of the viable distal facial stump and non-atrophic muscles. Early hypoglossal-facial anastomotic repair after acute facial nerve injury is associated with better long-term facial function outcomes and should be considered in the management algorithm.

Facial Nerve Injury and Repair: A Practical Review for Cutaneous Surgery

BACKGROUND

The facial nerve and its branches are at risk of injury during dermatologic surgery. Few publications in the dermatologic literature discuss facial nerve injury and management.

OBJECTIVE

To review facial nerve injury and management, including static and dynamic repair techniques, and to review outcomes in facial nerve reconstruction.

METHODS

Two detailed literature reviews were performed using PubMed. First, articles reporting facial nerve injury and/or management in the dermatologic literature were identified. In addition, articles pertaining to outcomes in facial nerve reconstruction with a minimum of 20 patients were included.

RESULTS

Fifty-three articles reporting outcomes in facial nerve reconstruction were identified and consist of retrospective reviews and case series. Most patients achieve improvement in facial symmetry and movement with nerve repair.

CONCLUSION

Timing of facial nerve repair is an important consideration in management of facial nerve injury, with earlier repairs achieving better outcomes. Facial nerve repair does not result in normal facial movement, and improvements may require a year or more to be realized. Many options exist for facial nerve reconstruction, and patients with long-standing facial nerve injuries may still benefit from treatment.

Effects of repeated transection and coaptation of peripheral nerves on axonal regeneration and motoneuron survival

BACKGROUND AND PURPOSE

Salvage procedures for facial reanimation can involve a second neurorrhaphy operation. It remains unclear whether reuse of the original donor nerve in the salvage procedure remains likely to produce successful outcome. This study aimed to investigate the effect of repeated transection and coaptation of a nerve on axonal regrowth and motoneuron survival.

MATERIALS AND METHODS

The sciatic nerves of Sprague Dawley rats were transected and microsutured once (the one-time group) or repeatedly at eight-week intervals (the repeated group), and the animals remained alive for eight weeks before sacrifice. The gastrocnemius muscle was weighed, and muscle fiber diameter was measured with hematoxylin-eosin staining. Axonal count of the distal nerve stump was calculated by toluidine blue staining. Myelin thickness and axonal diameter were analyzed by transmission electronic microscopy. Finally, motoneurons were retrogradely traced to the spinal cord using Fluoro-Gold.

RESULTS

Repeated coaptation of nerves resulted in significant decreases of the wet weight ratio of gastrocnemius and muscle fiber diameter. The axonal counts and myelin thicknesses of the distal stumps were comparable between the groups, whereas axonal diameter was significantly smaller after repeated injury. Additionally, retrograde tracing demonstrated significantly less motoneurons in the L4-L6 spinal segments of the repeatedly injured animals than that of the one-time group.

CONCLUSIONS

Compared with one-time nerve injury, repetitive transection and coaptation of nerves resulted in compromised axonal regeneration, motoneuron survival, and target muscle recovery. It is possible that the final functional outcome could also be compromised, and the patients should be counseled accordingly.

Temporalis Muscle Transfer with Fascia Lata Sling: A Novel Technique for Facial Reanimation

Bell's palsy is an idiopathic facial paralysis which is a lower motor neuron disorder. The ultimate goal of treatment is normalization of paralyzed hemi -face with symmetrical smile and face along with corneal protection. The aim of this article is to revisit all the current options available for management of facial nerve paralysis with main concentration on best surgical management in long-standing cases i.e. regional muscle transfer using temporalis tendon with fascia lata. A Case Report of a 38 year old Indian male is reported with chronic facial palsy. Static Facial paralysis reanimation with fascia lata and tarsorrhaphy is explained step by step. Others Treatment modalities are explained. This present case report adds one more case to the scanty number of publications.

Management of the facial nerve in parotid cancer: preservation or resection and reconstruction

PURPOSE

Management of the facial nerve is instrumental in the surgical treatment of parotid cancer.

METHODS

A literature search was conducted using PubMed and ScienceDirect database. A total of 195 articles were finally included into the analysis, based on relevance, scientific evidence and actuality.

RESULTS

In the majority of cases the facial nerve is not involved by tumor. In these cases, identification and preservation of the nerve, in addition to complete tumor removal, are essential for successful surgery. When the nerve is infiltrated by tumor, the affected portion of the nerve must be resected as part of radical parotidectomy. Primary nerve reconstruction or other reanimation techniques give the best long-term functional and cosmetic results. A comprehensive diagnostic evaluation with current imaging and electrophysiological studies will provide the surgeon with the best knowledge of the relationship of the facial nerve to the tumor. Several standardized methods are helpful in finding, dissecting and preserving the nerve during parotid cancer surgery. When radical parotidectomy is indicated, the initial diagnostic work-up can assist in defining the need for adjuvant postoperative therapy and facial reanimation. The aim of rehabilitation is to restore tone, symmetry, and movement to the paralyzed face.

CONCLUSIONS

The surgical management of facial paralysis has undergone many improvements in recent years. This review gives an overview of recent advances in the diagnostic work-up, surgical techniques and any necessary rehabilitation of the facial nerve in parotid cancer surgery.

Contemporary Management of Benign and Malignant Parotid Tumors

To report the standard of care, interesting new findings and controversies about the treatment of parotid tumors. Relevant and actual studies were searched in PubMed and reviewed for diagnostics, treatment and outcome of both benign and malignant tumors. Prospective trials are lacking due to rarity of the disease and high variety of tumor subtypes. The establishment of reliable non-invasive diagnostics tools for the differentiation between benign and malignant tumors is desirable. Prospective studies clarifying the association between different surgical techniques for benign parotid tumors and morbidity are needed. The role of adjuvant or definitive radiotherapy in securing loco-regional control and improving survival in malignant disease is established. Prospective clinical trials addressing the role of chemotherapy/molecular targeted therapy for parotid cancer are needed. An international consensus on the classification of parotid surgery techniques would facilitate the comparison of different trials. Such efforts should lead into a clinical guideline.

3D bio-printed scaffold-free nerve constructs with human gingiva-derived mesenchymal stem cells promote rat facial nerve regeneration

Despite the promising neuro-regenerative capacities of stem cells, there is currently no licensed stem cell-based product in the repair and regeneration of peripheral nerve injuries. Here, we explored the potential use of human gingiva-derived mesenchymal stem cells (GMSCs) as the only cellular component in 3D bio-printed scaffold-free neural constructs that were transplantable to bridge facial nerve defects in rats. We showed that GMSCs have the propensity to aggregate into compact 3D-spheroids that could produce their own matrix. When cultured under either 2D- or 3D-collagen scaffolds, GMSC spheroids were found to be more capable of differentiating into both neuronal and Schwann-like cells than their adherent counterparts. Using a scaffold-free 3D bio-printer system, nerve constructs were printed from GMSC spheroids in the absence of exogenous scaffolds and allowed to mature in a bioreactor. In vivo transplantation of the GMSC-laden nerve constructs promoted regeneration and functional recovery when used to bridge segmental defects in rat facial nerves. Our findings suggest that GMSCs represent an easily accessible source of MSCs for 3D bio-printing of scaffold-free nervous tissue constructs with promising potential application for repair and regeneration of peripheral nerve defects.

Resection of the Posterior, Middle, and Anterior Superior Alveolar Nerves and Infraorbital Nerve Neurolysis for Refractory Maxillary Pain

Trigeminal injury can cause intractable facial pain. However, surgical approaches to the superior alveolar nerves have not been widely described. We report resection of the anterior superior alveolar nerve (ASAN), middle superior alveolar nerve (MSAN), and posterior superior alveolar nerve (PSAN) in a patient with refractory facial pain and outline an algorithmic approach to the treatment of trigeminal nerve injury. A 56-year-old woman presented with a 3-year history of refractory facial pain in the distribution of the right superior alveolar nerves after dental trauma. As a comorbidity, central sensitization developed in the patient, manifesting in the uninjured oral areas being painful. After several temporary nerve blocks and medical management, the patient underwent resection of the ASAN, MSAN, and PSAN, as well as neurolysis of the infraorbital nerve, through a Caldwell-Luc approach. One week postoperatively, she reported substantial improvement in pain symptoms, including burning and temperature sensitivity, in the right maxilla. These findings were maintained at 7 months, without any maxillary sinus complications. Central sensitization caused continued intraoral symptoms. The ASAN, MSAN, and PSAN can be surgically resected within the maxillary sinus to treat refractory neuropathic pain. An etiology-based approach can guide successful treatment of trigeminal neuropathy. Central sensitization as a comorbidity must be addressed medically.

Neural Crest Stem-Like Cells Non-genetically Induced from Human Gingiva-Derived Mesenchymal Stem Cells Promote Facial Nerve Regeneration in Rats

Non-genetic induction of somatic cells into neural crest stem-like cells (NCSCs) is promising for potential cell-based therapies for post-traumatic peripheral nerve regeneration. Here, we report that human gingiva-derived mesenchymal stem cells (GMSCs) could be reproducibly and readily induced into NCSCs via non-genetic approaches. Compared to parental GMSCs, induced NCSC population had increased expression in NCSC-related genes and displayed robust differentiation into neuronal and Schwann-like cells. Knockdown of the expression of Yes-associated protein 1 (YAP1), a critical mechanosensor and mechanotransducer, attenuated the expression of NCSC-related genes; specific blocking of RhoA/ROCK activity and non-muscle myosin II (NM II)-dependent contraction suppressed YAP1 and NCSC-related genes and concurrently abolished neural spheroid formation in NCSCs. Using a rat model of facial nerve defect, implantation of NCSC-laden nerve conduits promoted functional regeneration of the injured nerve. These promising findings demonstrate that induced NCSCs derived from GMSCs represent an easily accessible and promising source of neural stem-like cells for peripheral nerve regeneration.

Restoration of orbicularis oculi muscle function in rabbits with peripheral facial paralysis via an implantable artificial facial nerve system

The purpose of the present study was to restore orbicularis oculi muscle function using the implantable artificial facial nerve system (IAFNS). The in vivo part of the IAFNS was implanted into 12 rabbits that were facially paralyzed on the right side of the face to restore the function of the orbicularis oculi muscle, which was indicated by closure of the paralyzed eye when the contralateral side was closed. Wireless communication links were established between the in vivo part (the processing chip and microelectrode) and the external part (System Controller program) of the system, which were used to set the working parameters and indicate the working state of the processing chip and microelectrode implanted in the body. A disturbance field strength test of the IAFNS processing chip was performed in a magnetic field dark room to test its electromagnetic radiation safety. Test distances investigated were 0, 1, 3 and 10 m, and levels of radiation intensity were evaluated in the horizontal and vertical planes. Anti-interference experiments were performed to test the stability of the processing chip under the interference of electromagnetic radiation. The fully implanted IAFNS was run for 5 h per day for 30 consecutive days to evaluate the accuracy and precision as well as the long-term stability and effectiveness of wireless communication. The stimulus intensity (range, 0–8 mA) was set every 3 days to confirm the minimum stimulation intensity which could indicate the movement of the paralyzed side was set. Effective stimulation rate was also tested by comparing the number of eye-close movements on both sides. The results of the present study indicated that the IAFNS could rebuild the reflex arc, inducing the experimental rabbits to close the eye of the paralyzed side. The System Controller program was able to reflect the in vivo part of the artificial facial nerve system in real-time and adjust the working pattern, stimulation intensity and frequency, range of wave and stimulation time. No significant differences in the stimulus intensities were observed during 30 days. The artificial facial nerve system chip operation stable in the anti-interference test, and the radiation field strength of the system was in a safe range according to the national standard. The IAFNS functioned without any interference and was able to restore functionality to facially paralyzed rabbits over the course of 30 days.

Quantitative facial electromyography monitoring after hypoglossal-facial jump nerve suture

Objectives/Hypothesis

The time course of the reinnervation of the paralyzed face after hypoglossal‐facial jump nerve suture using electromyography (EMG) was assessed. The relation to the clinical outcome was analyzed.

Study Design

Retrospective single‐center cohort study

Methods

Reestablishment of motor units was studied by quantitative EMG and motor unit potential (MUP) analysis in 11 patients after hypoglossal‐facial jump nerve suture. Functional recovery was evaluated using the Stennert index (0 = normal; 10 = maximal palsy).

Results

Clinically, first movements were seen between 6 and >10 months after surgery in individual patients. Maximal improvement was achieved at 18 months. The Stennert index decreased from 7.9 ± 2.0 preoperatively to a final postoperative score of 5.8 ± 2.4. EMG monitoring performed for 2.8 to 60 months after surgery revealed that pathological spontaneous activity disappeared within 2 weeks. MUPs were first recorded after the 2nd month and present in all 11 patients 8–10 months post‐surgery. Polyphasic regeneration potentials first appeared at 4–10 months post‐surgery. The MUP amplitudes increased between the 3rd and 15th months after surgery to values of control muscles. The MUP duration was significantly increased above normal values between the 3rd and 24th months after surgery.

Conclusion

Reinnervation can be detected at least 2 months earlier by EMG than by clinical evaluation. Changes should be followed for at least 18 months to assess outcome. EMG changes reflected the remodeling of motor units due to axonal regeneration and collateral sprouting by hypoglossal nerve fibers into the reinnervated facial muscle fibers.

Level of Evidence

3b.

High variability of facial muscle innervation by facial nerve branches: A prospective electrostimulation study

OBJECTIVES/HYPOTHESIS

To examine by intraoperative electric stimulation which peripheral facial nerve (FN) branches are functionally connected to which facial muscle functions.

STUDY DESIGN

Single-center prospective clinical study.

METHODS

Seven patients whose peripheral FN branching was exposed during parotidectomy under FN monitoring received a systematic electrostimulation of each branch starting with 0.1 mA and stepwise increase to 2 mA with a frequency of 3 Hz. The electrostimulation and the facial and neck movements were video recorded simultaneously and evaluated independently by two investigators.

RESULTS

A uniform functional allocation of specific peripheral FN branches to a specific mimic movement was not possible. Stimulation of the whole spectrum of branches of the temporofacial division could lead to eye closure (orbicularis oculi muscle function). Stimulation of the spectrum of nerve branches of the cervicofacial division could lead to reactions in the midface (nasal and zygomatic muscles) as well as around the mouth (orbicularis oris and depressor anguli oris muscle function). Frontal and eye region were exclusively supplied by the temporofacial division. The region of the mouth and the neck was exclusively supplied by the cervicofacial division. Nose and zygomatic region were mainly supplied by the temporofacial division, but some patients had also nerve branches of the cervicofacial division functionally supplying the nasal and zygomatic region.

CONCLUSIONS

FN branches distal to temporofacial and cervicofacial division are not necessarily covered by common facial nerve monitoring. Future bionic devices will need a patient-specific evaluation to stimulate the correct peripheral nerve branches to trigger distinct muscle functions.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:1288-1295, 2017.

The effectiveness of ayurvedic oil-based nasal instillation (Nasya) medicines in the treatment of facial paralysis (Ardita): a systematic review

BACKGROUND

Ardita (facial paralysis) is a medical condition that disfigures or distorts the facial appearance of the sufferer causing facial asymmetry and malfunction. Ardita patients may benefit from considering alternative treatments such as Ayurveda, including Taila Nasya (nasal instillation of medicated oil).

OBJECTIVES

To synthesize the best available evidence on the effectiveness of different Nasya oils in the treatment of Ardita.

INCLUSION CRITERIA TYPES OF PARTICIPANTS

Studies conducted on adult sufferers (18-70 years) of Ardita (chronic or acute) in any setting were considered. Studies including participants who were pregnant or suffered allergic rhinitis, fever, intracranial tumor/hemorrhage and bilateral facial palsy were excluded.

INTERVENTION(S)/COMPARATOR(S)

Standalone treatment of Nasya (at all dosages and frequencies) compared to Nasya in combination with other Ayurvedic treatments was considered. Comparisons between different interventions including Taila Nasya alone, Taila Nasya in combination with other Ayurvedic interventions and Ayurvedic interventions that did not include Taila Nasya were also considered.

OUTCOMES AND MEASURES

Changes in Ardita symptoms, including facial distortion, speech disorders and facial pain, were measured.

TYPES OF STUDIES

All quantitative study designs (experimental, quasi-experimental and observational) were considered.

SEARCH STRATEGY

Relevant studies were identified following a comprehensive literature search. References provided within these key studies identified additional resources. Indian universities were also contacted for results of Ardita studies undertaken in their institutions.A three-step search strategy aimed to find studies of published and unpublished studies was undertaken. Studies published in the English language were considered for inclusion, irrespective of publication date/year. Following an initial limited search of MEDLINE and CINAHL, the text words contained in the title and abstract, and of the index terms used to describe each articles were analyzed. From the identified keywords and index terms, searches were undertaken across all relevant databases such as PubMed, CINHAL, Cochrane (CENTRAL), Scopus, Centre for Review and Dissemination databases, Turning Research into Practice (TRIP), EMBASE, EBM Reviews, DHARA, Google Scholar, MedNar and ProQuest Dissertations. Finally, reference lists of identified theses and articles were searched for additional studies. Universities and website operators related to Ayurvedic research in India were contacted, including the National Institute of Ayurveda for relevant studies. Besides this, the University of Adelaide librarian was contacted to retrieve those studies identified in the reference lists of theses and articles.

METHODOLOGICAL QUALITY

Studies were critically assessed by the review author and a secondary reviewer prior to inclusion in the review using the standardized critical appraisal instrument from the Joanna Briggs Institute.

DATA EXTRACTION

Data was extracted by the primary reviewer using the standardized data extraction tool from the Joanna Briggs Institute.

DATA SYNTHESIS

Different interventions and comparators across studies precluded meta-analysis. Narrative synthesis was performed.

RESULTS

Only two pseudo randomized studies with a small number of participants met inclusion criteria and were included in the review. One study with 20 participants, divided equally into two groups compared the effectiveness of two nasal instillations in alleviating four Ardita symptoms. The second study of 15 participants each in two groups compared the effectiveness of nasal instillation with placement of medicated oil on the head on seven Ardita symptoms. Observational measurements of Ardita symptoms were graded as Mild, Moderate or Marked at baseline and after one month. The study conducted on 30 participants using Nasya intervention showed participants had better relief from the symptoms of facial pain, speech disorder and earache within the range of 78.2% to 90.9%, graded as Marked. Along with statistical data available in the studies, this review found low levels of evidence favoring Taila Nasya intervention. The review did not include any studies examining effectiveness of Nasya compared to conventional treatment for Ardita.

CONCLUSIONS

This review presents extremely limited evidence from only two small experimental studies that administration of Nasya oil alone may provide some relief from Ardita symptoms of facial distortion, speech disorder, inability to shut eyelids/upward eye rolling and dribbling of saliva in adult patients. No strong conclusions may be drawn from the evidence included in the review due to the limited number of studies, limited number of participants and poor quality of studies.

IMPLICATIONS FOR PRACTICE

Practitioners should advice Ardita patients that there is extremely limited evidence suggesting the potential effectiveness of Nasya oils alone or Nasya in conjunction with other Ayurvedic treatments in managing symptoms. However, given the absence of a strong evidence base, practitioners should be guided by clinical wisdom and patient preference.

IMPLICATIONS FOR RESEARCH

Well controlled clinical trials comparing standalone Nasya therapy to other Ayurvedic treatments and/or conventional medicine for Ardita symptoms need to be conducted to examine the relative effectiveness of different Nasya oils in treating Ardita.

Approaches to Peripheral Nerve Repair: Generations of Biomaterial Conduits Yielding to Replacing Autologous Nerve Grafts in Craniomaxillofacial Surgery

Peripheral nerve injury is a common clinical entity, which may arise due to traumatic, tumorous, or even iatrogenic injury in craniomaxillofacial surgery. Despite advances in biomaterials and techniques over the past several decades, reconstruction of nerve gaps remains a challenge. Autografts are the gold standard for nerve reconstruction. Using autografts, there is donor site morbidity, subsequent sensory deficit, and potential for neuroma development and infection. Moreover, the need for a second surgical site and limited availability of donor nerves remain a challenge. Thus, increasing efforts have been directed to develop artificial nerve guidance conduits (ANCs) as new methods to replace autografts in the future. Various synthetic conduit materials have been tested in vitro and in vivo, and several first- and second-generation conduits are FDA approved and available for purchase, while third-generation conduits still remain in experimental stages. This paper reviews the current treatment options, summarizes the published literature, and assesses future prospects for the repair of peripheral nerve injury in craniomaxillofacial surgery with a particular focus on facial nerve regeneration.

[Rehabilitation of facial palsy and vertigo in patients with vestibular schwannoma]

BACKGROUND

Facial palsy and vertigo, as symptoms of vestibular schwannoma (VS) or consequences of its therapy, have a significant impact on patients' quality of life.

OBJECTIVE

This review analyzed current literature on the topic and deduced recommendations for rehabilitation of facial palsy and vertigo.

METHODS

The present review describes a PubMed-based search of the literature of the past 10 years.

RESULTS

There is no evidence-based drug therapy for the treatment of acute facial palsy after VS surgery. Several surgical procedures for facial nerve reconstruction, muscle transfer, and static techniques have been established. Physiotherapeutic movement therapy, optimally with biofeedback, seems to improve facial function in patients with post-paralytic syndrome. Botulinum toxin injections are the method of choice for synkinesis treatment. For treatment of acute and chronic vertigo in patients with VS, the same antivertiginous drugs as for other vertigo patients are used. If the patient shows retained vestibular stimulation function, preoperative intratympanic gentamycin therapy followed by compensation training is a promising approach to decreasing postoperative vertigo. Good vestibular rehabilitation comprises intensive and regular movement training, preferably with real-time feedback and therapy control.

CONCLUSION

There are several conservative, surgical, or combined conservative-surgical treatment options for individualized facial nerve rehabilitation of VS patients, as confirmed by clinical studies. In cases of acute vertigo, standard antivertiginous pharmacotherapy is indicated. In cases of acute and also of chronic vertigo, intensive balance and movement training relieves complaints.

Secondary Improvement in Static Facial Reanimation Surgeries: Increase of Nasal Function

OBJECTIVE

The aim of this study was to measure the effect of the static reanimation operation administered to patients with facial paralysis on nasal function area by comparing patients' preoperative and postoperative subjective perception of the nasal airflow.

MATERIALS AND METHOD

We applied the Nasal Obstruction Symptom Evaluation (NOSE) scale to 13 patients who underwent static reanimation because of facial palsies, both preoperatively and postoperatively, and results were compared statistically. The changes in nasal base angulation were recorded and compared based on the photographs of patients taken before and after the surgery.

RESULTS

Following the static reanimation operation, 76% (10/13) of the patients reported a subjective improvement in the nasal airflow, whereas 24% (3/13) did not report any change. Mean preoperative and postoperative NOSE scale scores were 66.92 ± 9.90 and 36.15 ± 9.61, respectively. The change in mean NOSE scale score was statistically significant (P < 0.001). In the preoperative and postoperative comparison of the photographs taken from the front view of the patients, a decreased nasal base angulation compared with preoperative period was detected in 8 (61.6%) patients.

CONCLUSIONS

A statistically significant increase in subjective perception about nasal function was observed after the static facial reanimation; however, it is not certain whether this effect can be considered persistent. Long-term studies conducted on a larger patient population will provide beneficial results.

Human olfactory stem cells for injured facial nerve reconstruction in a rat model

BACKGROUND

The purpose of this study was to show the efficacy of olfactory stem cells for injured facial nerve reconstruction in a rat model.

METHODS

Olfactory stem cells were isolated from the olfactory mucosa of human participants. A 2-mm excision was performed on the right facial nerve of all rats. Reconstruction was performed with a conduit in group 1 (n = 9); a conduit and phosphate-buffered saline in group 2 (n = 9); and a conduit and labeled olfactory stem cell in group 3 (n = 9). Rats were followed for whisker movements and electroneuronography (ENoG) analyses.

RESULTS

The whisker-movement scores for group 3 were significantly different from other groups (p < .001). ENoG showed that the amplitude values for group 3 were significantly different from group 1 and group 2 (p = .030; p < .001). Group 3 showed marked olfactory stem cell under a fluorescence microscope.

CONCLUSION

This study suggests that olfactory stem cells may be used as a potent cellular therapy for accelerating the regeneration of peripheral nerve injuries. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2011-E2020, 2016.

Nonmotor disabilities in patients with facial palsy measured by patient-reported outcome measures

OBJECTIVES/HYPOTHESIS

To describe changes of motor and nonmotor disabilities in patient with peripheral facial palsy (FP) during treatment using the patient-reported outcome measures (PROMs) Facial Clinimetric Evaluation (FaCE), Facial Disability Index (FDI), and Short Form 36-Item Questionnaire (SF-36) and to analyze predictors for these changes

STUDY DESIGN

Prospective, single-center longitudinal study.

METHODS

One hundred twenty patients with FP underwent at least two PROMs between 2012 and 2015. Predictors for changes of the PROMs were analyzed univariately using Pearson's correlation and multivariately using linear regression models.

RESULTS

The mean interval between onset of FP to first presentation was 29 ± 64 months and between first and final assessment 8.7 ± 7.2 months. Initial House-Brackmann grading was 4.0 ± 1.3 and final House-Brackmann grading was 2.8 ± 1.6 (P < .001). All mean FaCE and FDI but only some SF-36 subscores improved over time (all P < .05). Adjuvant treatment was an independent predictor for improvement of the FaCE Facial Comfort subscore (P = .015) and a malignant tumor as primary disease for improvement of the FaCE Oral Function subscore (P = .044). Unemployment was a predictor for improvement of the FDI Social/Well-Being Function (P = .035). First assessment <90 days after onset was a predictor for improvement of the SF-36 Bodily Pain subscore (P = .025), a primary malignant disease for improvement of the SF-36 General Health perception (P = .004), and idiopathic FP for improvement of the SF-36 Social Functioning subscore (P = .017).

CONCLUSIONS

Changes of motor function revealed by classical grading systems mostly do not correlate with changes of nonmotor disabilities during treatment of FP. Many other factors are associated with changes of PROMs during the FP treatment.

LEVEL OF EVIDENCE

4. Laryngoscope, 126:1516-1523, 2016.

The role of great auricular-facial nerve neurorrhaphy in facial nerve damage

BACKGROUND

Facial nerve is easy to be damaged, and there are many reconstructive methods for facial nerve reconstructive, such as facial nerve end to end anastomosis, the great auricular nerve graft, the sural nerve graft, or hypoglossal-facial nerve anastomosis. However, there is still little study about great auricular-facial nerve neurorrhaphy. The aim of the present study was to identify the role of great auricular-facial nerve neurorrhaphy and the mechanism.

METHODS

Rat models of facial nerve cut (FC), facial nerve end to end anastomosis (FF), facial-great auricular neurorrhaphy (FG), and control (Ctrl) were established. Apex nasi amesiality observation, electrophysiology and immunofluorescence assays were employed to investigate the function and mechanism.

RESULTS

In apex nasi amesiality observation, it was found apex nasi amesiality of FG group was partly recovered. Additionally, electrophysiology and immunofluorescence assays revealed that facial-great auricular neurorrhaphy could transfer nerve impulse and express AChR which was better than facial nerve cut and worse than facial nerve end to end anastomosis.

CONCLUSIONS

The present study indicated that great auricular-facial nerve neurorrhaphy is a substantial solution for facial lesion repair, as it is efficiently preventing facial muscles atrophy by generating neurotransmitter like ACh.

[Rehabilitation of facial paralysis]

Rehabilitation takes an important part in the treatment of facial paralysis, especially when these are severe. It aims to lead the recovery of motor activity and prevent or reduce sequelae like synkinesis or spasms. It is preferable that it be proposed early in order to set up a treatment plan based on the results of the assessment, sometimes coupled with an electromyography. In case of surgery, preoperative work is recommended, especially in case of hypoglossofacial anastomosis or lengthening temporalis myoplasty (LTM). Our proposal is to present an original technique to enhance the sensorimotor loop and the cortical control of movement, especially when using botulinum toxin and after surgery.

Fluorescently labeled peptide increases identification of degenerated facial nerve branches during surgery and improves functional outcome

Nerve degeneration after transection injury decreases intraoperative visibility under white light (WL), complicating surgical repair. We show here that the use of fluorescently labeled nerve binding probe (F-NP41) can improve intraoperative visualization of chronically (up to 9 months) denervated nerves. In a mouse model for the repair of chronically denervated facial nerves, the intraoperative use of fluorescent labeling decreased time to nerve identification by 40% compared to surgeries performed under WL alone. Cumulative functional post-operative recovery was also significantly improved in the fluorescence guided group as determined by quantitatively tracking of the recovery of whisker movement at time intervals for 6 weeks post-repair. To our knowledge, this is the first description of an injectable probe that increases visibility of chronically denervated nerves during surgical repair in live animals. Future translation of this probe may improve functional outcome for patients with chronic denervation undergoing surgical repair.