A case of Miller Fisher syndrome with delayed onset peripheral facial nerve palsy after COVID-19 vaccination: a case report.

BACKGROUND: To prevent the spread of the novel coronavirus disease 2019 (COVID-19) infection, various vaccines have been developed and used in a large number of people worldwide. One of the most commonly used vaccines is the mRNA vaccine developed by Moderna. Although several studies have shown this vaccine to be safe, the full extent of its side effects has not yet been known. Miller-Fisher syndrome (MFS) is a rare condition that manifests ophthalmoplegia, ataxia, and loss of tendon reflexes. It is a subtype of Guillain-Barré syndrome and an immune-mediated disease related to serum IgG anti-GQ1b antibodies. Several vaccines including those for COVID-19 have been reported to induce MFS. However, there have been no reports of MFS following Moderna COVID-19 vaccine administration. CASE PRESENTATION: A 70-year-old man was referred to our hospital due to diplopia that manifested 1 week after receiving the second Moderna vaccine dose. The patient presented with restricted abduction of both eyes, mild ataxia, and loss of tendon reflexes. He was diagnosed with MFS based on his neurological findings and detection of serum anti-GQ1b antibodies. The patient was administered intravenous immunoglobulin, and his symptoms gradually improved. Five days after admission, the patient showed peripheral facial paralysis on the right side. This symptom was suggested to be a delayed onset of peripheral facial nerve palsy following MFS that gradually improved by administration of steroids and antiviral drugs. CONCLUSION: There have been no previous reports of MFS after Moderna COVID-19 vaccination. This case may provide new information about the possible neurological side effects of COVID-19 vaccines.

Endoscopic transcanal facial nerve decompression in Bell's palsy: A pilot study.

PURPOSE: To explore the surgical effects of endoscopic facial nerve decompression in Bell's palsy. MATERIALS AND METHODS: This retrospective study included 15 patients with Bell's palsy. All had grade VI (House-Brackmann grading system) complete unilateral facial paralysis before surgery and a >95% reduction in amplitude on electroneurography testing compared to the unaffected side. Their MRI results indicated perineural edema in the geniculate ganglion area. Endoscopic decompression surgery was performed soon after they presented at our hospital. The time between onset of facial paralysis and surgery ranged from 25 to 93 days. All patients had no relevant surgical history or ear diseases. RESULTS: At 1-year follow-up, 13 of the 15 (87%) patients had recovered to normal or near-normal facial function (House-Brackmann grade I-II), and all patients had reached House-Brackmann grade III or lower facial function. No obvious air-bone gap or sensorineural hearing loss occurred after surgery, and there were no severe complications or synkinesis. CONCLUSIONS: Endoscopic transcanal facial nerve decompression provides a less traumatic and improved exposure of the geniculate ganglion, and may also help prevent permanent severe facial sequela. Results of intraoperative facial nerve stimulation may be related to the length of time required for recovery. The optimal time of surgery after onset of paralysis needs to be investigated further, to identify a post-drug surgical therapy which may be more acceptable for patients. Patients' response to conservative treatments should be assessed as soon as possible so as not to delay surgery.

Facial nerve sacrifice in lateral approaches to the skull base: Simultaneous reconstruction by graft interposition.

PURPOSE: To evaluate the outcome of facial nerve (FN) cable graft interposition in lateral skull base surgery. MATERIALS AND METHODS: A group of 16 patients who underwent FN graft interposition procedure was retrospectively considered. Postoperative FN function was evaluated using the House-Brackmann (HB) grading system, the Sunnybrook Facial Grading System (SFGS), the Facial Disability Index (FDI) and the Oral Functioning Scale (OFS) questionnaires. RESULTS: 56.2% of patients had a good postoperative FN outcome (HB grade II-III). Postoperative electromyography (EMG) showed re-innervation potentials in 60% of patients; median age of these patients was significantly lower compared to who did not manifest re-innervation (p = 0.039). CONCLUSION: FN primary reconstruction remains the advisable rehabilitative option when the nerve is interrupted during lateral skull base surgeries, allowing to satisfactory postoperative results in more than half of patients. EMG confirmed the restoring of nerve conduction and it was more frequent in younger patients. The SFGS, the FDI and the OFS are important tools especially in the setting of a rehabilitation program.

Hemifacial spasm is not affected by state of consciousness: a case report.

BACKGROUND:  Hemifacial spasm (HFS) is a movement disorder caused by mechanical compression of the facial nerve after it has left the brainstem and is characterized by brief or sustained twitching of the muscles innervated by that nerve. Often we observe spasm in an awakening situation. Actually contractions persist during sleep. To our knowledge, there were no reports on how HFS manifests under disturbance of consciousness. Here, we report a case of primary HFS in which the patient's symptoms persisted in a coma. CASE PRESENTATION: A 74-year-old female with right-sided primary HFS for 20 years and had received botulinum toxin injections in our hospital. Unfortunately she was carried to emergency department after traumatic right pneumothorax by accident. During the emergency treatment, she lost consciousness due to simultaneous cardiac arrest and respiratory arrest. She was then admitted to the emergency intensive care unit for further treatment. During her hospitalization, she was in a coma with stable vital signs and persisting symptoms of HFS. Thus, a multidisciplinary consultation was requested to identify whether it was focal cortical seizures involving the right-side facial muscles. Physical examination revealed brief involuntary clonic or tonic contractions accompanied with the 'Babinski-2 sign'. A combination of relevant data, including her past history, clinical presentation and a negative computed tomography scan of the head, led to a diagnosis of right-sided HFS. As the symptoms of HFS are not life-threatening, the use of anticonvulsants is unnecessary. CONCLUSIONS: For the layperson, it is crucial to seek a multidisciplinary consultation to obtain a correct diagnosis.

Timing of Acupuncture Treatment in Peripheral Facial Paralysis: A Systematic Review and Meta-Analysis.

OBJECTIVE: Investigate the optimum time of acupuncture treatment in peripheral facial paralysis in order to provide evidence for clinical treatment. METHODS: CNKI, Wanfang, PubMed, Cochrane Library, and EMBASE databases were systematically searched from the inception dates to February 20, 2020. Studies limited to participants with acute peripheral facial paralysis treated with acupuncture and patients without information of the stage were excluded. The primary outcomes were effective rate and cure rate (based on facial nerve function scores). This meta-analysis is registered with PROSPERO, number CRD42020169870. RESULTS: 15 randomized controlled trials that enrolled 2847 participants met the selection criteria. There was no significant differences in the effective rate (RR, 1.22; 95% CI, 0.70-2.11) when comparing acupuncture to prednisone therapy in acute facial paralysis. Acupuncture treatment in the acute stage increased both the effective rate (RR, 1.03; 95% CI, 1.00-1.07) and the cure rate (RR, 1.34; 95% CI, 1.14-1.58) compared to that in the nonacute stage. CONCLUSIONS: In this meta-analysis, acupuncture showed a better effect in the acute stage than the nonacute stage for participants with peripheral facial paralysis. There was no statistical difference in the effective rate no matter the choice of acupuncture or prednisone therapies in the acute stage. These findings encourage early acupuncture treatment in peripheral facial paralysis.

Microanatomy of the Frontal Branch of the Facial Nerve: The Role of Nerve Caliber and Axonal Capacity.

BACKGROUND: A commonly seen issue in facial palsy patients is brow ptosis caused by paralysis of the frontalis muscle powered by the frontal branch of the facial nerve. Predominantly, static methods are used for correction. Functional restoration concepts include the transfer of the deep temporal branch of the trigeminal nerve and cross-facial nerve grafts. Both techniques can neurotize the original mimic muscles in early cases or power muscle transplants in late cases. Because axonal capacity is particularly important in cross-facial nerve graft procedures, the authors investigated the microanatomical features of the frontal branch to provide the basis for its potential use and to ease intraoperative donor nerve selection. METHODS: Nerve biopsy specimens from 106 fresh-frozen cadaver facial halves were obtained. Histologic processing and digitalization were followed by nerve morphometric analysis and semiautomated axon quantification. RESULTS: The frontal branch showed a median of three fascicles (n = 100; range, one to nine fascicles). A mean axonal capacity of 1191 ± 668 axons (range, 186 to 3539 axons; n = 88) and an average cross-sectional diameter of 1.01 ± 0.26 mm (range, 0.43 to 1.74 mm; n = 67) were noted. In the linear regression model, diameter and axonal capacity demonstrated a positive relation (n = 57; r2 = 0.32; p < 0.001). Based on that equation, a nerve measuring 1 mm is expected to carry 1339 axons. CONCLUSION: The authors' analysis on the microanatomy of the frontal branch could promote clinical use of cross-facial nerve graft procedures in frontalis muscle neurotization and free muscle transplantations.

Evaluation of Vestibular Function in Diagnosis of Vestibular Schwannomas.

Vestibular schwannomas (VS) are benign tumors of the vestibular nerve. The common first symptoms are hearing loss and tinnitus, followed by imbalance, vertigo, and facial nerve involvement. The subjective symptoms of VS patients are not consistent with the severity of vestibular lesions and the results of vestibular tests, which often interfere with clinicians' diagnoses. Thus, the main screening and diagnostic methods for VS are audiometry and magnetic resonance imaging (MRI), ignoring the evaluation of vestibular function at the source of pathological lesions. With the development and improvement of vestibular evaluation technology and its wide application in the clinic, modern vestibular examination technology can reflect the severity and frequency of vestibular lesions and compensation from multiple perspectives, providing an objective basis for the diagnosis and treatment of vestibular diseases. In this report, we review the results and characteristics of vestibular tests in VS patients and further clarify the clinical value of vestibular function assessment in the diagnosis and treatment of VS.

A bibliometric analysis of research on the treatment of facial nerve palsy.

BACKGROUND: There are various treatments for facial nerve palsy, and research into this topic is ongoing. In the present study, we carried out bibliometric and visualized analyses to identify the trends of research into facial nerve palsy treatment. METHODS: To identify articles, the SCOPUS database was searched for articles published from its inception to December 27, 2020. The search was conducted twice, with Search 1 investigating general treatment trends and Search 2 narrowing the scope to complementary and alternative treatment. The extracted keywords were analyzed using the Visualization Of Similarities (VOS) viewer. Through analysis of keywords, research hotspots in the treatment of facial nerve palsy were identified. RESULTS: A total of 1609 and 223 articles were identified in Searches 1 and 2, respectively. The number of articles published each year showed a tendency to increase, and most of the studies were only conducted in a few countries. In terms of subject area, "medicine" was overwhelmingly the most common(77.6%). Based on the analysis of 316 keywords in Search1, "medication treatment," and "complementary and alternative treatment" were the hotspots of research. CONCLUSION: This study provides the overall trends of facial nerve palsy treatment. To date, research on medication treatment has been main focus, and antiviral use among medication treatment and complementary and alternative treatment has emerged in recent years.

Outcomes after semisitting and lateral positioning in large vestibular schwannoma surgery: A single-center comparison.

OBJECTIVE: The semisitting position (SSP) and lateral position (LP) in vestibular schwannoma (VS) surgery each have advantages and disadvantages, and which position is superior overall is debatable. Our objective was to determine the optimal position for surgical treatment of VSs with a diameter ≥3 cm. METHODS: We retrospectively evaluated consecutive patients with a large VS treated between January 2010 and July 2020. Patients were grouped by surgical position and analyzed. RESULTS: We enrolled 259 patients (LP group, n = 156; SSP group, n = 103). The resection extent was not significantly different between the SSP (gross-total resection [GTR], n = 89 [88.1%], near-total resection [NTR], n = 10 [9.9%], subtotal resection [STR], n = 2 [2.0%]) and LP (GTR, n = 125 [80.1%]; NTR, n = 24 [15.4%]; STR, n = 7 [4.5%]) groups. The rate of GTR with facial nerve (FN) functional preservation was higher in the SSP group than in the LP group (P = 0.014) at eight days after the operation. However, during follow-up (SSP group median, 31.5 months; LP group median, 19.5 months), there was no significant between-group difference in FN functional preservation. Two patients in the SSP group required conversion to the LP due to severe intraoperative venous air embolism (VAE). CONCLUSION: Compared with the LP, the SSP did not produce significantly better FN outcomes in patients with a large VS. The duration of surgery was significantly longer in SSP cases than in LP cases. Given the risk of VAE associated with the SSP, the selection of the optimal surgical position should be made with caution on an individual basis.

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.

The research for the function evaluation of facial nerve and the mechanisms of rehabilitation training.

BACKGROUND: Peripheral facial paralysis (PFP) is a common peripheral neural disease. Acupuncture treatment combined with PFP rehabilitation exercises is a routine method of PFP treatment. This article is to provide a new visual and objective evaluation method for exploring the mechanism and efficacy of acupuncture treatment on PFP, and develop an interactive augmented facial nerve function rehabilitation training system with multiple training models. METHODS: This prospective and observational trial will recruit 200 eligible participants for the following study. In the trial, the laser speckle contrast analysis (LASCA) technology will be applied to monitor the microcirculation of facial blood flow during acupuncture, and real-time monitoring algorithms, data sampling, and digital imaging methods will be conducted by machine learning and image segmentation. Then, a database of patient facial expressions will be built, the correlation between surface blood flow perfusion volume and facial structure symmetry will be analyzed, combined with scale assessment and electrophysiological detection. In addition, we will also explore the objectivity and effectiveness of LASCA in the evaluation of facial paralysis (FP), and the changes in blood flow microcirculation before and after acupuncture treatment will be analyzed. RESULTS: The standard image of the facial target area with facial nerve injury will be manually segmented by the convolutional neural network method. The blood flow images of the eyelid, cheek, and mandible of the patients' affected and healthy side will be compared and evaluated. Laser speckle blood flow symmetry Pr and its changes in FP condition evolution and prognosis outcome will be measured, and relevant characteristic signals values will be extracted. Finally, COX regression analysis method is conducted to establish a higher accuracy prediction model of FP with cross-validation based on laser speckle blood flow imaging technology. CONCLUSIONS: We use modern interdisciplinary high-tech technologies to explore the mechanism of acupuncture rehabilitation training in PFP. And we will provide evidence for the feasibility of using the LASCA technique as a typing diagnosis of FP in the acupuncture rehabilitation treatment of PFP. REGISTRATION NUMBER: ChiCTR1800019463.

Preoperative Differences in Intracranial Facial Versus Vestibular Schwannomas: A Four Nerve Assessment.

OBJECTIVES: Assesses whether preoperative functional testing can distinguish vestibular schwannomas from facial nerve schwannomas medial to the labyrinthine segment. STUDY DESIGN: Retrospective cohort. METHODS: Retrospectively review surgically managed intracranial facial and vestibular schwannomas between January 2015 and December 2019 at two tertiary care centers. Patients with neurofibromatosis 2 and surgery for recurrence were excluded. Preoperative functional testing to include House-Brackmann scores, electroneuronography (ENoG), cervical vestibular evoked myogenic potentials (cVEMP), caloric testing, acoustic brainstem responses (ABRs), acoustic reflexes, and audiograms was compared between the two groups of schwannomas. RESULTS: Twelve facial and 128 vestibular schwannomas met inclusion criteria. In only one case was a facial schwannoma diagnosed preoperatively from imaging. No statistically significant difference was found in preoperative House-Brackmann scores, ENoG, cVEMP, caloric testing, ABRs, or acoustic reflexes. Pure tone average was worse in the vestibular schwannoma group (63 dB [95% CI: 58-68 dB] vs. 46 dB [95% CI: 34-58 dB], P = .01), and the difference was more apparent in the lower frequencies. Word recognition score was better in the facial schwannoma group (66% [95% CI: 45-86%] vs. 41% [95% CI: 34-47%], P = .02). CONCLUSION: Specialized preoperative functional evaluation of the nerves of the internal auditory canal cannot reliably predict the presence of an intracranial facial schwannoma. Hearing is better in facial schwannomas, particularly in the lower frequencies. This should raise the index of suspicion for an intracranial facial schwannoma, especially in candidates for hearing preservation vestibular schwannoma surgery. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:2098-2105, 2021.

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.

Acoustic Reflexes in Aural Atresia Patients: Evidence of an Intact Efferent System?

OBJECTIVE: To record crossed acoustic reflex thresholds (xART's) postoperatively from patients after surgical repair of unilateral congenital aural atresia (CAA). To seek explanations for when xARTs can and cannot be recorded. We hope to understand the implications for this central auditory reflex despite early afferent deprivation. METHODS: Patients who underwent surgery to correct unilateral CAA at a tertiary academic medical were prospectively enrolled to evaluate for the presence of xART. Preoperative ARTs in the normal (non-atretic) ear, and postoperative ipsilateral ARTs (stimulus in the normal ear) and contralateral ARTs (stimulus in the newly reconstructed atretic ear; record in the normal ear) were measured at 500, 1000, and 2000 Hz. RESULTS: Four of 11 patients with normal ipsilateral reflex thresholds preoperatively demonstrated crossed acoustic reflexes postoperatively (stimulus in reconstructed ear; record from normal ear). Four other patients demonstrated normal ipsilateral thresholds preoperatively but did not have crossed reflexes postoperatively. No reflexes (pre- or postoperatively) could be recorded in 3 patients. Crossed reflex threshold is significantly correlated with the postoperative audiometric threshold. There was no correlation between ipsilateral and contralateral reflex thresholds. CONCLUSION: Crossed acoustic reflexes can be recorded from some but not all postoperative atresia patients, and the thresholds for those reflexes correlate with the postoperative pure tone threshold. The presence of acoustic reflexes implies an intact CN VIII-to-opposite CN VII central reflex arc despite early unilateral sound deprivation.

Utilization of Smartphone Depth Mapping Cameras for App-Based Grading of Facial Movement Disorders: Development and Feasibility Study.

BACKGROUND: For the classification of facial paresis, various systems of description and evaluation in the form of clinician-graded or software-based scoring systems are available. They serve the purpose of scientific and clinical assessment of the spontaneous course of the disease or monitoring therapeutic interventions. Nevertheless, none have been able to achieve universal acceptance in everyday clinical practice. Hence, a quick and precise tool for assessing the functional status of the facial nerve would be desirable. In this context, the possibilities that the TrueDepth camera of recent iPhone models offer have sparked our interest. OBJECTIVE: This paper describes the utilization of the iPhone's TrueDepth camera via a specially developed app prototype for quick, objective, and reproducible quantification of facial asymmetries. METHODS: After conceptual and user interface design, a native app prototype for iOS was programmed that accesses and processes the data of the TrueDepth camera. Using a special algorithm, a new index for the grading of unilateral facial paresis ranging from 0% to 100% was developed. The algorithm was adapted to the well-established Stennert index by weighting the individual facial regions based on functional and cosmetic aspects. Test measurements with healthy subjects using the app were performed in order to prove the reliability of the system. RESULTS: After the development process, the app prototype had no runtime or buildtime errors and also worked under suboptimal conditions such as different measurement angles, so it met our criteria for a safe and reliable app. The newly defined index expresses the result of the measurements as a generally understandable percentage value for each half of the face. The measurements that correctly rated the facial expressions of healthy individuals as symmetrical in all cases were reproducible and showed no statistically significant intertest variability. CONCLUSIONS: Based on the experience with the app prototype assessing healthy subjects, the use of the TrueDepth camera should have considerable potential for app-based grading of facial movement disorders. The app and its algorithm, which is based on theoretical considerations, should be evaluated in a prospective clinical study and correlated with common facial scores.

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

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

Investigating Facial Nerve Stimulation After Cochlear Implantation in Adult and Pediatric Recipients.

OBJECTIVES/HYPOTHESIS: Facial nerve stimulation (FNS) can occur after cochlear implantation for a small number of recipients. This study aimed to investigate if a correlation exists between the variables involved in FNS. STUDY DESIGN: Retrospective cohort review. METHODS: There were 32 out of 1,100 cochlear implant recipients who experienced FNS in our clinic between 2010 and 2019. The following variables were recorded from a retrospective chart review: grade of FNS, onset of FNS, the number of channels stimulating FNS, and radiological findings of abnormalities in the inner ear. Statistical analyses were performed to identify a correlation between any of the variables involved. The techniques used to reduce FNS were analyzed. RESULTS: Eleven adult ears had progressive hearing loss, three had idiopathic sudden sensorineural hearing loss (SNHL), and one congenital SNHL. All pediatric ears were diagnosed with congenital SNHL, except for one ear with idiopathic sudden SNHL. The grade of FNS ranged from mild stimulation or slight motion in the eye, mouth, nasolabial, or forehead regions (n = 8) to total severe stimulation of the facial musculature and/or severe pain (n = 3). The onset of FNS occurred immediately after activation for nine ears, and up to 16 months later for the other subjects. A significant correlation was observed between the number of channels stimulating FNS, the grade of FNS, and the radiological findings of the inner ear. FNS was completely resolved for 30 ears and partially resolved for two ears. CONCLUSIONS: FNS can occur any time after cochlear implantation and can affect both adult and pediatric. However, it can be effectively resolved using specific fitting techniques. LEVEL OF EVIDENCE: 2c Laryngoscope, 131:374-379, 2021.

The Association of Vestibular Schwannoma Volume With Facial Nerve Outcomes After Surgical Resection.

OBJECTIVE: To explore the relationship between tumor size and facial nerve outcomes following vestibular schwannoma (VS) resection. STUDY DESIGN: Single institutional retrospective chart review of all adult patients with untreated sporadic VS who underwent surgical resection from 2008 to 2018 with preoperative magnetic resonance imaging (MRI) and 1 year of follow-up. The primary outcome measure was facial nerve outcome as assessed by the House-Brackmann facial nerve grading system. RESULTS: One hundred sixty-seven patients, 54.5% female, with a median age of 49 years (20-76 years), were identified who underwent VS resection. Surgical resection was performed by translabyrinthine (76.7%), middle cranial fossa (14.4%), retrosigmoid (7.2%), and transpromontorial (1.8%) approaches. The median tumor diameter and volume were 25.3 mm (range: 4.1-47.1 mm) and 3.17 cm3 (range: 0.01-30.6 cm3 ), respectively. The median follow-up was 24.2 months (range: 12-114.2 months). Gross total resection was performed in 79% of cases, with residual tumor identified on MRI in 17% of cases. For patients with tumors <3 cm3 , 92.7% had grade 1 or 2 facial function after at least 1 year follow-up, compared to 81.2% for those with tumors >3 cm3 (univariate logistic regression OR = 2.9, P = .03). Tumor volume >3 cm3 was predictive of facial weakness on multivariate regression analysis (OR = 7.4, P = .02) when controlling for surgical approach, internal auditory canal extension, anterior extension, age, gender, and extent of resection. CONCLUSIONS: Tumor volume >3 cm3 is associated with worse facial nerve outcomes 12 months following surgical resection. LEVEL OF EVIDENCE: IV Laryngoscope, 131:E1328-E1334, 2021.

Fibrovascular Tumor-Like Lesions of the Facial Nerve.

BACKGROUND: Facial nerve tumors (FNTs) are relatively rare benign lesions that arise from any segment of the facial nerve (FN). About half of all patients present with FN dysfunction, mainly long-standing or progressive facial paralysis. Diagnosis of an FNT is usually based on radiological imaging and confirmed by histological study. Most reported cases of FNTs are schwannomas and hemangiomas. OBJECTIVES: The aim of this study was to review 4 cases of lesions with clinical, radiological, and surgical findings that suggested an FNT, the pathology revealing a fibrovascular proliferation with no clear signs of a specific tumor. METHOD: Medical records of patients who had surgery due to an FN lesion were reviewed. Cases with known tumoral lesions were excluded. Four patients with tumor-like lesions were identified. Their imaging studies were re-evaluated. The pathological study included hematoxylin-eosin, Masson's trichrome, and immunohistochemistry for S100 protein, neurofilaments, CD31, Wilms' tumor 1 (WT1), and D240. RESULTS: The 4 cases revealed tumor-like fibrovascular lesions that could not be classified as typical pathological entities. All cases had a complete facial palsy preoperatively. Computed tomography and magnetic resonance imaging (MRI) suggested schwannoma or hemangioma. A complete excision was achieved, and a facial reconstruction was performed immediately after interruption. Postoperative FN function was improved in all cases. The histological study showed nervous tracts of normal morphology, with fibrous and vascular tissue interspersed in variable proportions. All cases showed areas of fibrosis with Masson's stain. In all cases, nervous tissue and Schwann cells tested positively for neurofilaments and S100, respectively. In vascular areas, endothelial cells stained positively for CD31, and negatively for D240 and WT1. CONCLUSIONS: Fibrovascular lesions of the FN may mimic primary FNTs, especially schwannomas and hemangiomas. Surgical excision with grafting or nerve transfer is the procedure of choice if a complete facial paralysis is found. This unusual condition should be considered when counseling patients with FN lesions. The lack of hyperintensity on MRI T2-weighted images may suggest the presence of fibrous tissue.