Facial nerve regeneration via body-brain crosstalk: The role of stem cells and biomaterials.

The human body is a complex, integral whole, and disruptions in one organ can lead to dysfunctions in other parts of the organ network. The facial nerve, as the seventh cranial nerve, arises from the brainstem, controls facial expression muscles and plays a crucial role in brain-body communication. This vulnerable nerve can be damaged by trauma, inflammation, tumors, and congenital diseases, often impairing facial expression. Stem cells have gained significant attention for repairing peripheral nerve injuries due to their multidirectional differentiation potential. Additionally, various biomaterials have been used in tissue engineering for regeneration and repair. However, the therapeutic potential of stem cells and biomaterials in treating facial nerve injuries requires further exploration. In this review, we summarize the roles of stem cells and biomaterials in the regeneration and repair of damaged facial nerves, providing a theoretical basis for the recovery and reconstruction of body-brain crosstalk between the brain and facial expression muscles.

Electromyographic Study of Facial Nerve Function Using Two Different Surgical Approaches in Low Condylar Fractures of the Mandible: A Randomized Controlled Clinical Trial.

BACKGROUND: Facial nerve (FN) dysfunction is a potential complication during open reduction of mandibular condylar fractures. PURPOSE: The purpose of this study was to measure and compare the postoperative FN function following transparotid (TP) and transmasseteric anterior parotid (TMAP) operative approaches in open reduction and internal fixation of condylar fractures using electromyogram. STUDY DESIGN, SETTING, SAMPLE: A randomized controlled clinical trial was designed. The study was conducted in a single tertiary-care hospital in the inpatient setting. Patients aged above 18 years with unilateral condylar fracture of the jaw or bilateral condylar fractures undergoing surgery on only 1 side were included. Patients were excluded if they had fractures of the head, bilateral condylar fractures with surgery planned on both sides, a previous history of surgery in the retromandibular area, existing lacerations to approach condyle, preoperative signs of FN weakness, or a history of parotid surgery. PREDICTOR VARIABLE: The predictor variable was the operative approach and the subjects were allocated randomly to TMAP and TP. MAIN OUTCOME VARIABLE(S): The primary outcome variable was postoperative FN function in the surgical approach employed using the House-Brackmann scale and electromyography (EMG) to record any subtle weakness in nerve function. The FN function is recorded at 3 time intervals postoperatively 1 week (T1), 1 month (T2), and 3 months (T3). The secondary outcomes studied were operating time and any other complications recorded. COVARIATES: Age, sex, fracture pattern with classification of condylar fractures into condylar neck or base fractures according to Loukata et al.4 Any associated fracture of mandible describing the anatomical location viz symphysis and parasymphysis (anterior mandible), body, contralateral condyle or greater than 1 associated fracture were recorded. Similarly, the presence or absence of any associated midface fracture was also recorded to suggest that the study participants were homogenous in all aspects. ANALYSES: Analytical statistics included χ2 test, t-test, and repeated measures ANOVA followed by post hoc test to compare EMG data (mean power and mean amplitude) between 2 operative approaches (TP vs TMAP) for facial muscles including frontalis, oculi, and buccinator at different time intervals (T0, T1, T2, T3). Patients within each group were also analyzed to check for nerve recovery occurring during the follow-up period. The level of significance was set at P < .05. RESULTS: The study sample was composed of 22 patients with a mean age of 32.82 ± 11.21 years in TMAP and 27.82 ± 8.54 years in the TP group respectively (P = .26); male predominance of 81.8 and 90.9% in TMAP and TP group respectively (P = .53) was noted. The FN deficit as assessed by the House-Brackmann scale clinically, was at 54% (T1), 36.4% (T2), and 9.1% (T3) for the TP group and 27% (T1),9% (T2), and 0% (T3) for TMAP group; however, the results were statistically insignificant (P = .31). In surface EMG evaluation, the mean power for the frontalis muscle was significantly higher in the TMAP approach at the T3 time (105.03 ± 9.7 vs 89.56 ± 10; 95% confidence interval -24.28 to -6.65 with P value = .002). TP approach was faster with a mean exposure time of 9.9 minutes. CONCLUSION AND RELEVANCE: The results show that both approaches give comparable long-term results with the TMAP group showing better frontalis muscle activity.

Functional gland-preserving surgery via periauricular incision for pleomorphic adenoma of the parotid gland.

INTRODUCTION: Gland-preserving surgery is often used for benign tumours in the parotid gland. Partial superficial parotidectomy via a periauricular incision may bring satisfactory cosmetic outcomes but the disease control outcome remains unrevealed. This study evaluated functional and disease control outcomes after gland-preserving surgery via periauricular incision for pleomorphic adenoma of the parotid gland. METHODS: This longitudinal study included 248 consecutive patients with parotid pleomorphic adenoma who underwent the preservation of most normal parotid tissues and the facial nerve combined with the en-bloc resection of tumours via periauricular incision. Postoperative complications, subjective satisfaction, salivary function, and tumour recurrence were assessed in each patient. The secretory function of the salivary gland was measured using salivary scintigraphy at 6 months after surgery, and ultrasonography was regularly followed. RESULTS: Median tumour size was 2.5 cm (range, 0.8-5.2 cm) and median operation time was 55 min (range, 39-88 min). All tumours were safely removed by gland-preserving surgery via periauricular incision without extension to Blair or hairline incision and tumour spillage. Temporary and permanent paralysis of the facial nerve was 14 (5.6%) and none of the study patients, respectively. Postoperative complications were minor and Frey's syndrome was found in 6 (2.4%) patients. The Secretary function of the affected gland was equal to that of the unaffected gland. No patients had a recurrence for a median follow-up of 78 months (range, 24-126 months). CONCLUSIONS: Functional gland-preserving surgery via periauricular incision can treat pleomorphic adenoma in the parotid gland with satisfactory functional, cosmetic, and disease control outcomes.

Selective Facial Muscle Activation with Acute and Chronic Multichannel Cuff Electrode Implantation in a Feline Model.

OBJECTIVES: Facial paralysis is a debilitating condition with substantial functional and psychological consequences. This feline-model study evaluates whether facial muscles can be selectively activated in acute and chronic implantation of 16-channel multichannel cuff electrodes (MCE). METHODS: Two cats underwent acute terminal MCE implantation experiments, 2 underwent chronic MCE implantation in uninjured facial nerves (FN) and tested for 6 months, and 2 underwent chronic MCE implantation experiments after FN transection injury and tested for 3 months. The MCE were wrapped around the main trunk of the skeletonized FN, and data collection consisted of EMG thresholds, amplitudes, and selectivity of muscle activation. RESULTS: In acute experimentation, activation of specific channels (ie, channels 1-3 and 6-8) resulted in selective activation of orbicularis oculi, whereas activation of other channels (ie, channels 4, 5, or 8) led to selective activation of levator auris longus with higher EMG amplitudes. MCE implantation yielded stable and selective facial muscle activation EMG thresholds and amplitudes up to a 5-month period. Modest selective muscle activation was furthermore obtained after a complete transection-reapproximating nerve injury after a 3-month recovery period and implantation reoperation. Chronic implantation of MCE did not lead to fibrosis on histology. Field steering was achieved to activate distinct facial muscles by sending simultaneous subthreshold currents to multiple channels, thus theoretically protecting against nerve damage from chronic electrical stimulation. CONCLUSION: Our proof-of-concept results show the ability of an MCE, supplemented with field steering, to provide a degree of selective facial muscle stimulation in a feline model, even following nerve regeneration after FN injury. LEVEL OF EVIDENCE: N/A.

Discerning a smile - The intricacies of analysis of post-neck dissection asymmetry.

INTRODUCTION: Iatrogenic facial nerve palsy is distressing to the patient and clinician. The deformity is aesthetically displeasing, and can be functionality problematic for oral competence, dental lip trauma and speech. Furthermore such injuries have litigation implications. Marginal mandibular nerve (MMN) palsy causes an obvious asymmetrical smile. MMN is at particular risk during procedures such as rhytidoplasties, mandibular fracture, tumour resection and neck dissections. Cited causes for the high incidence are large anatomical variations, unreliable landmarks, an exposed neural course and tumour grade or nodal involvement dictating requisite nerve sacrifice. An alternative cause for post-operative asymmetry is damage to the cervical branch of the facial nerve or platysmal dysfunction due to its division. The later tends to have a transient course and recovers. Distinction between MMN palsy and palsy of the cervical branch of the facial nerve or platysma division should therefore be made. In 1979 Ellenbogen differentiated between MMN palsy and "Pseudo-paralysis of the mandibular branch of the facial nerve". Despite this, there is paucity in the literature & confusion amongst clinicians in distinguishing between these palsies, and there is little regarding these post-operative sequelae and neck dissections. METHOD: This article reflects on the surgical anatomy of the MMN and cervical nerve in relation to danger zones during lymphadenectomy. The authors review the anatomy of the smile. Finally, case studies are utilised to evaluate the differences between MMN palsy and its pseudo-palsy to allow clinical differentiation. CONCLUSION: Here we present a simple method for clinical differentiation between these two prognostically different injuries, allowing appropriate reassurance, ongoing therapy & management.

Potential Therapeutic Strategies and Substances for Facial Nerve Regeneration Based on Preclinical Studies.

Despite advances in microsurgical technology and an improved understanding of nerve regeneration, obtaining satisfactory results after facial nerve injury remains a difficult clinical problem. Among existing peripheral nerve regeneration studies, relatively few have focused on the facial nerve, particularly how experimental studies of the facial nerve using animal models play an essential role in understanding functional outcomes and how such studies can lead to improved axon regeneration after nerve injury. The purpose of this article is to review current perspectives on strategies for applying potential therapeutic methods for facial nerve regeneration. To this end, we searched Embase, PubMed, and the Cochrane library using keywords, and after applying exclusion criteria, obtained a total of 31 qualifying experimental studies. We then summarize the fundamental experimental studies on facial nerve regeneration, highlighting recent bioengineering studies employing various strategies for supporting facial nerve regeneration, including nerve conduits with stem cells, neurotrophic factors, and/or other therapeutics. Our summary of the methods and results of these previous reports reveal a common feature among studies, showing that various neurotrophic factors arising from injured nerves contribute to a microenvironment that plays an important role in functional recovery. In most cases, histological examinations showed that this microenvironmental influence increased axonal diameter as well as myelination thickness. Such an analysis of available research on facial nerve injury and regeneration represents the first step toward future therapeutic strategies.

Is Decorin a Promising New Agent for Facial Nerve Regeneration? An Experimental Study.

OBJECTIVE: The aim of this study was to investigate the effects of systemic administration of decorin (DC) on facial nerve (FN) regeneration. METHODS: A total of 32 female albino Wistar rats were divided into 4 groups: control (C) group: no bilateral FN neurorrhaphy (B-FNN), no DC application, sham-operated group: B-FNN without DC application, DC group: DC application without B-FNN, and B-FNN + DC group: B-FNN and DC application. Nerve conduction studies were performed before and after skin incisions at 1st, 3rd, 5th, and 7th weeks in all groups. The amplitude and latency of compound muscle action potentials were recorded. FN samples were obtained and were investigated under light microscopy and immunohistochemical staining. The nerve and axon diameter, number of axons, H score, Schwann cell proliferation, and myelin and axonal degeneration were recorded quantitatively. RESULTS: In the sham group, the 3rd and 5th postoperative week, amplitude values were significantly lower than those of the B-FNN + DC group (p < 0.05). Nerve diameters were found to be significantly larger in the sham, DC, and B-FNN + DC groups than in the C group (p < 0.05). The number of axons, the axon diameter, and the H scores were found to be significantly higher in the B-FNN + DC group than in the sham group (p < 0.05). The Schwann cell proliferation, myelin degeneration, and axonal degeneration scores were significantly lower in the B-FNN + DC group than in the sham group (p < 0.05). CONCLUSION: Electrophysiological and histopathological evaluation revealed the potential benefits provided by DC. This agent may increase FN regeneration.

Intraoperative transcranial facial motor evoked potential monitoring in surgery of cerebellopontine angle tumors predicts early and late postoperative facial nerve function.

OBJECTIVE: We propose a novel method that predicts facial nerve function (FNF) calculated from the drop and recovery of facial motor evoked potential (FMEP) amplitude ratio during the surgery of cerebellopontine angle tumors. METHODS: We enrolled 73 patients with cerebellopontine angle tumor, and used a biphasic, constant current, and suprathreshold stimulation (BCS) protocol to record FMEP of the orbicularis oris. We measured the intraoperative minimum-to-baseline amplitude ratio (MBR), the final-to-baseline amplitude ratio (FBR), and the recovery value (RV). RV was measured by subtracting MBR from FBR. Using those values, we evaluated FNF both at early postoperative (EP) and late postoperative (LP) periods. RESULTS: We successfully obtained 62 FMEP readings. Facial palsies occurred in 22 patients during the EP period, and 14 patients recovered during the LP period. Both MBR and FBR showed a significant correlation with FNF in the EP period. RV showed a good predictive power of FNF recovery during the LP period for the first time. CONCLUSIONS: RV is a new and useful predictor of FNF recovery. MBR can be an intraoperative predictor of FNF in the EP period. SIGNIFICANCE: FNF outcome in the early and late postoperative periods can be predicted by FMEP.

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.

The Regenerative Potential of Facial Nerve Motoneurons following Chronic Axotomy in Rats.

Background: The precise mechanisms of nerve regeneration remain unclear. The potential of facial nerve regeneration and probable mechanisms involved following chronic facial nerve injury should be further studied. Methods: Adult male Wistar rats were used to model either (i) facial nerve injury (axotomy) or (ii) reinjury (chronic axotomy followed by a second axotomy within 5 months). The rats were housed in the animal facility of the Eye and ENT Hospital of Shanghai Medical School, Fudan University (Shanghai, China). Expression of Shh (sonic hedgehog) and growth-associated protein 43 (GAP43, a neuronal marker) was detected in bilateral facial nuclei using reverse transcriptase PCR, western blotting analysis, and immunohistochemistry. The number of surviving motoneurons was quantified, and facial nerve regeneration was examined using transmission electron microscopy. Results: Reinjury of the facial nerve 12 weeks after the first axotomy resulted in upregulation of GAP43 mRNA and protein expression in neurons ipsilateral to the axotomy; immunohistochemistry revealed that Shh expression was higher compared with control side facial nuclei at the same time point. GAP43 expression subsequently decreased. Conclusion: The greatest regeneration potential of the facial nerve occurred within 5 months following chronic axotomy in rats, and regeneration may involve the Shh signaling pathway.

Neutralizing BDNF and FGF2 injection into denervated skeletal muscle improve recovery after nerve repair.

BACKGROUND: After facial nerve injury and surgical repair in rats, recovery of vibrissal whisking is associated with a high proportion of mono-innervated neuro-muscular junctions (NMJs). Our earlier work with Sprague Dawley (SD)/Royal College of Surgeons (RCS) rats, which are blind and spontaneously restore NMJ-monoinnervation and whisking, showed correlations between functional recovery and increase of fibroblast growth factor-2 (FGF2) and brain-derived neurotrophic factor (BDNF) in denervated vibrissal muscles. METHODS: We used normally sighted rats (Wistar), in which NMJ-polyinnervation is highly correlated with poor whisking recovery, and injected the vibrissal muscle levator labii superioris (LLS) with combinations of BDNF, anti-BDNF, and FGF2 at different postoperative periods after facial nerve injury. RESULTS: Rats receiving anti-BDNF+FGF2 showed low NMJ-polyinnervation and best recovery of whisking amplitude. CONCLUSIONS: Restoration of target reinnervation after peripheral nerve injury requires a complex mixture of trophic factors with a specific time course of availability for each of them.

Facial Nerve Surgery in the Rat Model to Study Axonal Inhibition and Regeneration.

This protocol describes consistent and reproducible methods to study axonal regeneration and inhibition in a rat facial nerve injury model. The facial nerve can be manipulated along its entire length, from its intracranial segment to its extratemporal course. There are three primary types of nerve injury used for the experimental study of regenerative properties: nerve crush, transection, and nerve gap. The range of possible interventions is vast, including surgical manipulation of the nerve, delivery of neuroactive reagents or cells, and either central or end-organ manipulations. Advantages of this model for studying nerve regeneration include simplicity, reproducibility, interspecies consistency, reliable survival rates of the rat, and an increased anatomic size relative to murine models. Its limitations involve a more limited genetic manipulation versus the mouse model and the superlative regenerative capability of the rat, such that the facial nerve scientist must carefully assess time points for recovery and whether to translate results to higher animals and human studies. The rat model for facial nerve injury allows for functional, electrophysiological, and histomorphometric parameters for the interpretation and comparison of nerve regeneration. It thereby boasts tremendous potential toward furthering the understanding and treatment of the devastating consequences of facial nerve injury in human patients.

Repair of temporal branch of the facial nerve with novel polyglycolic acid-collagen tube: a case report of two cases.

Autologous nerve transplantation has been the gold standard in the treatment of facial nerve injury, however it has not been achieved satisfactory result and needs donor sacrifice. A polyglycolic acid collagen conduit (Nerbridge, Toyobo Co., Japan) has the potential to compare to or exceed autologous nerve grafts in promoting nerve regeneration. Here we report two cases of traumatic temporal facial nerve injury repairs with Nerbridge. The severed temporal branch of the facial nerve was repaired with Nerbridge conduits in two patients. Recovery of movement was assessed by clinical photography and needle electromyography. The frontal muscle started moving five months postoperatively in both cases. Electromyography at twelve months showed polymorphic electric discharge, suggesting connection of the injured nerve to the frontal muscle. In the final results, each patient had good eyebrow elevation distance and moderate forward gaze recovery in comparison to their healthy sides. Considering that facial nerves are reported to recover incompletely even in autologous nerve graft repair cases, our two cases showed reasonable recovery comparable to nerve autografting. The Nerbridge conduit is a promising alternative to standard treatments for facial nerve recovery.

Interference with SRF expression in skeletal muscles reduces peripheral nerve regeneration in mice.

Traumatic injury of peripheral nerves typically also damages nerve surrounding tissue including muscles. Hence, molecular and cellular interactions of neighboring damaged tissues might be decisive for successful axonal regeneration of injured nerves. So far, the contribution of muscles and muscle-derived molecules to peripheral nerve regeneration has only poorly been studied. Herein, we conditionally ablated SRF (serum response factor), an important myofiber transcription factor, in skeletal muscles of mice. Subsequently, the impact of this myofiber-restricted SRF deletion on peripheral nerve regeneration, i.e. facial nerve injury was analyzed. Quantification of facial nerve regeneration by retrograde tracer transport, inspection of neuromuscular junctions (NMJs) and recovery of whisker movement revealed reduced axonal regeneration upon muscle specific Srf deletion. In contrast, responses in brainstem facial motor neuron cell bodies such as regeneration-associated gene (RAG) induction of Atf3, synaptic stripping and neuroinflammation were not overly affected by SRF deficiency. Mechanistically, SRF in myofibers appears to stimulate nerve regeneration through regulation of muscular satellite cell (SC) proliferation. In summary, our data suggest a role of muscle cells and SRF expression within muscles for regeneration of injured peripheral nerves.

Dual Coaptation of Facial Nerve Using Masseteric Branch of Trigeminal Nerve for Iatrogenic Facial Palsy: Preliminary Reports.

OBJECTIVES: Immediate facial nerve substitution or graft technique has been used for the repair of facial nerve defects occurring as a result of tumour dissection. However, some patients report unsatisfactory outcomes, such as difficulty in maintaining resting or smiling symmetry, due to persistent flaccid facial palsy. Here we evaluated the functional outcomes of transferring the masseteric branch of the trigeminal nerve to the facial nerve adjunct to facial nerve graft. METHODS: We reviewed the medical records of seven patients who underwent facial reanimation surgery between 2014 and 2016. The patients were divided into two groups according to the type of facial reanimation surgery: group A, masseteric nerve innervation with interposition graft; group B, interposition graft only. The postoperative resting symmetry and dynamic movement were compared. RESULTS: Facial contraction was first observed in group A at 4 months and in group B at 7.3 months. Most of the patients achieved reliable resting symmetry; however, one patient in group B exhibited unsatisfactory facial weakness on the affected side. Group A patients showed better dynamic movement than group B patients. Eye closure, oral excursion and oral continence were better in group A than in group B patients. Smile symmetry in both groups was similar due to hyperkinetic movement in group A patients and flaccidity in group B patients. CONCLUSIONS: Dual innervation of the masseteric branch of the trigeminal nerve improves the dynamic movement of paralysed facial muscles and shortens the recovery period in patients with iatrogenic facial palsy.

Parotidectomy-related facial nerve lesions: proposal for a modified Sunnybrook Facial Grading System.

OBJECTIVE: Facial nerve injury, affecting mainly the marginal mandibular branch, is the most frequent neurologic complication from parotidectomy. To test a modified Sunnybrook Facial Grading System as a new tool to assess the facial nerve function following parotidectomy, emphasizing the marginal mandibular branch. METHODS: We reviewed the medical records of 73 post-parotidectomy patients (40 female, 18-84 years old, mean age 53.2 years) with facial nerve sparing, referred to the Department of Physical Therapy. All patients had parotid neoplasms or advanced skin cancer, and were followed by the principal author between 2006 and 2014. RESULTS: The muscles innervated by the marginal mandibular branch were the most frequently affected (72.6%), particularly in patients undergoing neck dissection (p = 0.023). The voluntary movement scores obtained with the modified system were significantly lower compared with the original version (p < 0.001). The best and worst scores were observed in patients with benign parotid tumors and skin cancer, respectively. Patients requiring neck dissection (p = 0.031) and resection of other structures (p = 0.021) had the lowest scores, evidenced only with the modified version. Patients with malignant tumors had significantly worse ratings, regardless of the Sunnybrook system version. The post-physiotherapy analysis involved 50 patients. The worst facial rehabilitation outcomes were related to the marginal mandibular branch function. CONCLUSION: The modified Sunnybrook Facial Grading System improved the marginal mandibular branch assessment, preserving the evaluation of other facial nerve branches.

Parotidectomy-related facial nerve lesions: proposal for a modified Sunnybrook Facial Grading System / Lesões do nervo facial relacionadas à parotidectomia: proposta de um sistema Sunnybrook de graduação facial modificado

ABSTRACT Facial nerve injury, affecting mainly the marginal mandibular branch, is the most frequent neurologic complication from parotidectomy. Objective To test a modified Sunnybrook Facial Grading System as a new tool to assess the facial nerve function following parotidectomy, emphasizing the marginal mandibular branch. Methods We reviewed the medical records of 73 post-parotidectomy patients (40 female, 18-84 years old, mean age 53.2 years) with facial nerve sparing, referred to the Department of Physical Therapy. All patients had parotid neoplasms or advanced skin cancer, and were followed by the principal author between 2006 and 2014. Results The muscles innervated by the marginal mandibular branch were the most frequently affected (72.6%), particularly in patients undergoing neck dissection (p = 0.023). The voluntary movement scores obtained with the modified system were significantly lower compared with the original version (p < 0.001). The best and worst scores were observed in patients with benign parotid tumors and skin cancer, respectively. Patients requiring neck dissection (p = 0.031) and resection of other structures (p = 0.021) had the lowest scores, evidenced only with the modified version. Patients with malignant tumors had significantly worse ratings, regardless of the Sunnybrook system version. The post-physiotherapy analysis involved 50 patients. The worst facial rehabilitation outcomes were related to the marginal mandibular branch function. Conclusion The modified Sunnybrook Facial Grading System improved the marginal mandibular branch assessment, preserving the evaluation of other facial nerve branches.

RESUMO A lesão do nervo facial é a principal complicação neurológica relacionada às parotidectomias e, em geral, o ramo marginal mandibular é o mais frequentemente acometido. Objetivo Testar um Sistema Sunnybrook de Graduação Facial modificado (mS-FGS) como uma nova ferramenta para avaliar a função do nervo facial após a parotidectomia, enfatizando o ramo marginal mandibular. Métodos Estudo retrospectivo, baseado em prontuários de 73 casos (40 do sexo feminino, 18-84 anos, idade média = 53,2), submetidos à parotidectomia, com preservação do nervo facial. Todos os pacientes apresentavam neoplasias parotídeas ou câncer de pele avançado, e foram tratados pela autora principal entre 2006 e 2014. Resultados Neste estudo, os músculos inervados pelo ramo marginal mandibular foram os mais acometidos (72,6% dos casos), principalmente nos pacientes que realizaram esvaziamento cervical (p = 0,023). Os Escores de Movimento Voluntário obtidos pelo sistema modificado foram inferiores aos obtidos pelo original (p < 0,001). As melhores pontuações foram observadas em pacientes com tumores benignos parotídeos e os piores resultados, naqueles com câncer de pele. Pacientes que necessitaram de esvaziamento cervical e ressecção de outras estruturas, além da parótida, apresentaram escores menores (p = 0,031 e p = 0,021), evidenciados apenas pelo sistema modificado. Os tumores malignos geraram escores significativamente menores, independentemente do instrumento empregado. A análise pós fisioterapia envolveu 50 casos. Os piores resultados, após a intervenção fisioterapêutica, também foram observados nos músculos inervados pelo ramo marginal mandibular. Conclusão A avaliação da disfunção facial pós-parotidectomia, através do Sistema Sunnybrook com a modificação proposta permitiu uma apreciação mais detalhada do ramo marginal mandibular, sem prejuízo à avaliação dos demais ramos.

Nicotinic acetylcholine receptor subunit expression in the gastrocnemius and in the orbicularis oris before and after facial nerve injury in rats.

Objectives: To observe the expression of nicotinic acetylcholine receptor (AChR) subunits in normal orbicularis oris and gastrocnemius muscles and to explore the relationships between the expression of AChR subunits and the severity of facial nerve injury. Methods: Gene and protein expression of AChR subunits in the orbicularis oris and gastrocnemius muscles of male Sprague-Dawley rats was measured by reverse transcription polymerase chain reaction and western blotting, respectively, 1-90 days after graded facial nerve injury. Results: Expression of ε-AChR in the normal orbicularis oris was significantly higher than that in the gastrocnemius, whereas no γ subunit expression was observed. Expression of α, ß, δ, ε, and γ subunits was upregulated in the orbicularis oris and was positively correlated with the degree of facial nerve injury. Discussion: We demonstrated the higher expression of the AChR subunits in the orbicularis oris, compared to gastrocnemius muscles. The differences in expression of these subunits between muscles innervated by the facial nerve and somatic nerves and the correlation of AChR subunit expression with the degree of facial nerve injury yield insights into the sensitivity to muscle relaxants during intraoperative facial nerve monitoring.

An investigation of life quality of patients after two different acoustic neuroma resections.

Background: Patients may suffer postoperative facial nerve injury, hearing loss, or other postoperative complications after the operation, which seriously affect their postoperative life quality. Aims/objectives: To investigate the differences in QOL (quality of life) of patients with acoustic neuroma resection by the translabyrinthine or retrosigmoid approach. Material and methods: Patients with acoustic neuroma resection in our department were enrolled in this experimental study, among which fifty patients underwent the translabyrinthine approach resection, the other 50 patients underwent the retrosigmoid approach resection. Different scores by the SF-36 scale between these two groups of patients one month after discharge were then analyzed. Results: Scores of patients undergoing the retrosigmoid approach were higher in the three dimensions of Social Functioning, Role-emotional and Mental Health than those of patients undergoing the translabyrinthine approach with statistical significance. However, scores of patients undergoing the translabyrinthine approach were higher in the two dimensions of Body Pain and Vitality than those of the patients undergoing the retrosigmoid approach. Conclusions and significance: The results indicated that individual nursing interventions for different patients are necessary to improve the QOL of patients after hospitalization. Moreover, the operated patients with translabyrinthine approach were more advantage than patients with retrosigmoid approach.