Radiological characteristics predicting early poor drug response in patients with hemifacial spasm.

OBJECTIVES: Patients with hemifacial spasm (HFS) often resort to botulinum toxin injections or microvascular decompression surgery when medication exhibits limited effectiveness. This study aimed to identify MRI and demographic factors associated with poor drug response at an early stage in patients with HFS. METHODS: We retrospectively included patients with HFS who underwent pre-therapeutic MRI examination. The presence, location, severity, and the offending vessels of neurovascular compression were blindly evaluated using MRI. Drug responses and clinical data were obtained from the medical notes or phone follow-ups. Logistic regression analysis was performed to identify potential factors. RESULTS: A total of 116 patients were included, with an average age at the time of first examination of 50.4 years and a median duration of onset of 18 months. Forty-nine (42.2%) patients reported no symptom relief. Thirty-seven (31.9%) patients reported poor symptom relief. Twenty-two (19.0%) patients reported partial symptom relief. Eight (6.9%) patients achieved complete symptom relief. The factors that were statistically significant associated with poor drug responses were contact in the attach segment of the facial nerve and aged 70 and above, with an odds ratio of 7.772 (p = 0.002) and 0.160 (p = 0.028), respectively. CONCLUSIONS: This study revealed that mild compression in the attach segment of the facial nerve in pre-therapeutic MRI increases the risk of poor drug responses in patients with HFS, while patients aged 70 and above showed a decreased risk. These findings may assist clinician to choose optimal treatment at an early stage.

The impact of frailty on facial nerve recovery following Bell's palsy.

OBJECTIVES: Patients with Bell's palsy, the sudden onset of facial paralysis, have variable recovery. Frailty has been recognized as an important factor in predicting recovery. This study investigated the relationship between frailty and facial nerve recovery in Bell's palsy patients. METHODS: A retrospective review was conducted on 95 Bell's palsy patients at a single institution's Department of Otolaryngology from 2014 to 2023. A clinically relevant facial nerve recovery was defined as a House-Brackmann (HB) score decrease>1 between the initial and most recent visit. Patients without follow-up visits or initial HB scores <3 were excluded. Frailty was measured by modified frailty index-5 (mFI-5) at the time of Bell's palsy diagnosis. Elderly patients were those over 65 years at presentation (n = 29). Frail patients had mFI-5 > 1 (n = 8). Chi-squared analyses, Fisher's exact tests, and logistic regression models were conducted in SPSS. RESULTS: The analytic sample included 95 patients (median age = 56.8 years, IQR = 24.1) presenting with an initial HB score > 2. 36 % of patients' HB scores decreased by ≥2 within the follow-up period. Frailty (unadjusted Odds Ratio (OR) = 6.3, 95 % CI = [1.2, 33.1], p = .023) was associated with facial nerve recovery while age was not (unadjusted OR = 1.07, 95 % CI = [0.44, 2.59], p = .889). The mFI-5 adjusted OR was 8.43 (95 % CI = [1.38, 51.4], p = .021) when adjusting for age, gender, treatment modality, access to care, and follow-up duration in a logistic regression. CONCLUSIONS: Frailty correlated with enhanced facial nerve recovery after Bell's palsy in this cohort; age was not significantly associated. Further investigation into factors associated with frailty, including increased surveillance and treatment frequency, is warranted.

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.

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.

Functional outcomes after extracapsular dissection with partial facial nerve dissection for small and large parotid neoplasms.

PURPOSE: Multiple surgical options exist for benign parotid tumors without agreement upon a single, best approach. We evaluated the short-term outcomes and rate of complications using the ECD-FND technique for small and large parotid neoplasms involving the superficial and deep lobes of the parotid gland using a categorical approach. MATERIAL AND METHODS: A single surgeon retrospective cohort study with analysis of patient demographics, outcomes, and complication rates was conducted of patients undergoing the ECD-FND for benign parotid neoplasm. Cases from May 2014 to May 2020 with at least 6 months follow up were considered. Complications were assessed by chart review and tumors were categorized by size and by European Salivary Gland Society (ESGS) classification assigned by a neuroradiologist. RESULTS: Fifty-one patients who underwent ECD-FND of suspected benign parotid mass met inclusion criteria. The most common histology was pleomorphic adenoma (56.9%) followed by Warthin's tumor (19.6%). Overall rate of complications was 31.4% with no major complications. Most patients (88.2%) had normal facial nerve function immediately after surgery and all recovered completely in the post operative period. Sialocele occurred in 15.7% of patients with 87.5% resolved within one month and seromas occurred in four patients (7.8%). There was no significant difference in complication rates between the size of tumor (p = 0.889), depth (p = 0.770), or ESGS classification (p = 0.846). CONCLUSIONS: The ECD-FND technique achieved excellent facial nerve outcomes among our cohort, which included a - proportion of large (>3 cm) and deep lobe tumors. Complications rates and outcomes were similar for larger and deep lobe tumors that underwent a ECD-FND approach. LEVEL OF EVIDENCE: 3.

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.

Sensitivity and specificity of repetitive nerve stimulation with lower cutoffs for abnormal decrement in myasthenia gravis.

INTRODUCTION: The sensitivity of repetitive nerve stimulation (RNS) in myasthenia gravis (MG) is dependent on the cutoff for abnormal decrement. METHODS: RNS data of adults with and without MG from 2014 to 2017 were reviewed retrospectively. The maximum reliable RNS amplitude/area decrement before and after exercise from facial, spinal accessory (SA), ulnar, and fibular nerves was recorded. Sensitivity/specificity using 5%, 7%, and 10% cutoffs were calculated. RESULTS: Seventy-nine of 141 patients had MG (46 generalized, 21 ocular, 12 bulbar). A total of 608 unique RNS recordings were analyzed. Overall RNS sensitivity/specificity at ≥5%, ≥7%, and ≥10% amplitude cutoffs were as follows: SA, 65.6%/86.3%, 49.2%/94.1%, and 29.5%/96.1%; facial, 51.0%/82.5%, 43.1%/95.0%, and 37.3%/100%; ulnar, 43.6%/100%, 41.0%/100%, and 41.0%/100%; and fibular, 52.6%/89.5%, 42.1%/94.7%, and 42.1%/100%. DISCUSSION: Lowering amplitude cutoff from 10% to 7% increased or maintained sensitivity with little loss in specificity. Post-exercise and area analysis resulted in increased sensitivity in some circumstances.

Surface electrical stimulation for facial paralysis is not harmful.

INTRODUCTION: Does electrical stimulation (ES) of denervated muscles delay or prevent reinnervation, or increase synkinesis? In this retrospective study we evaluate the outcome, with and without ES, of patients with acutely denervated facial muscles. METHODS: The effect of ES was analyzed in two experiments. In the first experiment, 39 patients (6 with home-based ES, median 17.5 months) underwent facial nerve reconstruction surgery. Time to recovery of volitional movements was analyzed. The second experiment involved 13 patients (7 with ES, median 19 months) during spontaneous reinnervation. Sunnybrook and eFACE scores provided functional outcome measures. RESULTS: No difference in time of reinnervation after facial nerve reconstruction surgery was seen between the patients with and without ES (median [interquartile range]: 4.5 [3.0-5.25] vs 5.7 [3.5-9.5] months; P = .2). After spontaneous reinnervation, less synkinesis was noted (Sunnybrook synkinesis score: 3.0 [2.0-3.0] vs 5.5 [4.75-7.0]; P = .02) with ES. DISCUSSION: We find no evidence that ES prevents or delays reinnervation or increases synkinesis in facial paralysis.

Does NF2 status impact the results of combined surgery and adjunctive Gamma Knife surgery for large vestibular schwannomas?

In order to verify whether neurofibromatosis type 2 (NF2) could influence the oncological and functional outcome in large vestibular schwannoma (VS) surgery, we compared a group of NF2 patients operated with a facial nerve-sparing technique to a group of sporadic VSs of similar volume that underwent the same treatment regimen in the same period. Single-center retrospective cohort study about 12 consecutive NF2 and 69 non-NF2 patients operated on for large VS between September 2006 and November 2016. After resection, patients were allocated to an upfront Gamma Knife surgery policy of the tumor residue. At last follow-up examination, the facial nerve function was good (House-Brackmann grades I or II) in 92% of the NF2 and 83% of the non-NF2 patients (p = .90). The median volume of tumor residue was .92 cc in the NF2 group and .54 cc in the non-NF2 group (p = .14). Tumor control was achieved in 83% and 81% of cases in the NF2 and the non-NF2 populations, respectively, with a mean follow-up of 73 months in both groups. The 1-, 5-, and 7-year progression-free survival were 92%, 83%, and 83% respectively in the NF2 group, and 99%, 83%, and 80% in the non-NF2 group (p = .96). Our analysis of 12 NF2 and 69 non-NF2 patients operated on by the same surgical team with the same treatment regimen did not show any functional or tumor control difference between those groups.

Acute Peripheral Facial Palsy: Recent Guidelines and a Systematic Review of the Literature.

BACKGROUND: This study reviews recent literature on facial palsy guidelines and provides systematic reviews on related topics of interest. METHODS: An electronic database search was performed to identify recent guidelines dealing with facial nerve palsy, systematic reviews and recent meta-analysis published between 2011 and 2019 (inclusive). The literature search used the search terms "Bell's palsy," "Ramsay-Hunt syndrome," "Facial palsy," "Facial paralysis," "Facial paresis," "Guideline," "Meta-analysis," "Systematic review," and "Randomized controlled trial." Only studies written in English were used. RESULTS: The characteristics of treatment trends for facial palsy have been reviewed over the past decade. The most prominent change noted may be the shift from the conventional House-Brackmann facial nerve grading system to the Sunnybrook and eFACE systems. In addition, the results of serial meta-analyses indicate increasing agreement with the use of surgical decompression of the facial nerve. Beyond steroids or combined steroid-antiviral treatment, various novel drugs and treatments have been tried. For long-standing facial paralysis and postparetic synkinesis sequelae after facial palsy, facial reanimation has been highlighted and the necessity of new paradigms have been raised. CONCLUSION: For peripheral facial paralysis, various changes have been made, not only in the facial nerve grading systems, but also in medical treatments, from surgical procedures to rehabilitation, during the last decade.

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.

Stapes surgery with a persistent stapedial artery.

PURPOSE: To review surgical outcomes of stapes surgery for otosclerosis with persistence of the stapedial artery. MATERIALS AND METHODS: A retrospective case review of a tertiary neurotology referral center of patient with otosclerosis undergoing primary stapes surgery between 2010 and 2017 found to have a persistent stapedial artery. Stapedectomy was performed with or without cauterization of the stapedial artery. The primary outcome measures include pre- and postoperative hearing as well complications. Hearing was measured by air conduction (AC) and bone conduction (BC) pure-tone averages (PTA), air-bone gap (ABG), and word recognition scores (WRS). Neurologic complications, including facial nerve function, were assessed. RESULTS: Four patients out of 853 with otosclerosis undergoing stapedectomy were found to have a persistence of the stapedial artery. Mean AC PTA was 55 dB preoperatively, and 24 dB postoperatively (p = .0041), while the ABG improved on average from 31 dB to 6 dB (p = .0014). Mean follow-up time was 32 months, and there were no significant complications. Facial nerve function was preserved in all patients (House-Brackmann grade I/VI). CONCLUSIONS: In the case of a persistent stapedial artery, excellent hearing outcomes are achievable for otosclerosis via stapedectomy without an apparent increased risk of neurologic complication.

The Efficacy of Electro-Acupuncture Added to Standard Therapy in the Management of Bell Palsy.

OBJECTIVE: To investigate the comparative efficacy of electro-acupuncture when added to standard therapy in patients with Bell palsy in terms of clinical and neurophysiologic outcomes. METHODS: A total of 88 patients with Bell palsy who received standard treatment (ST group; n = 40, mean ± standard deviation age: 39.2 ±â€Š6.6 years, 60.0% were males) or standard treatment plus electro-acupuncture (ST-EA group; n = 48, mean ±â€Šstandard deviation age: 39.5 ±â€Š6.9 years, 58.3% were males) were included. Data on patient demographics, symptoms, comorbidities, and 3-month outcomes on treatment response assessed via House-Brackmann grading system and facial nerve recovery profile and electromyography were recorded. RESULTS: Application of ST-EA versus ST was associated with a significantly higher rate of normal nerve function on 12th week electromyography (66.7% versus 25.0%, P = 0.020), higher frequency of patients with House-Brackmann grade ≤2 in the 3rd week (79.2% versus 45.0%, P = 0.029), 6th week (87.5% versus 45.0%, P = 0.004), and 12th week (95.8% versus 50.0%, P = 0.001), and those with facial nerve recovery profile scores ≥8 in the 6th week (83.3% versus 45.0%, P = 0.011) and 12th week (87.5% versus 50.0%, P = 0.009) of treatment. CONCLUSION: In conclusion, our findings in patients with Bell palsy revealed superiority of electro-acupuncture added to standard therapy over standard therapy alone in terms of improvement of nerve dysfunction, decrease in paralysis severity, and better functional recovery. This seems to indicate the likelihood of electro-acupuncture to be a safe and promising adjunct in the achievement of more satisfactory clinical outcomes in the management of Bell palsy when used in combination with standard medical and physiotherapy.

Advance in Functional Restoration of Injured Nerve with Low Level Laser and its Utilization in the Dental and Maxillofacial Region.

The inferior alveolar nerve and facial nerve are the two most important nerves in the dental and maxillofacial region. The injury to them is one of the major postoperative complications after alveolar surgery and orthognathic surgery. However, recovering the nerve function after injury takes a long time and the recovery effect tends to be unsatisfactory. In recent years, an intensively investigated technique, low level laser which has been applying in assisting the recovery of nerve function, has been gradually proved to be effective in clinically treating postoperative nerve injury. In this article we review in terms of the mechanisms involved in low level laser-assisted functional restoration of nerve injury and its clinical application in the recovery of nerve function in the dental and maxillofacial area as well.

Prognostic factors for the outcome of Bells' palsy: A cohort register-based study.

OBJECTIVES: There is a lack of data on patients' and diagnostic factors for prognostication of complete recovery in patients with Bell's palsy. DESIGN AND SETTING: Cohort register-based study of 368 patients with Bell's palsy and uniform diagnostics and standardised treatment in a university hospital from 2007 to 2017 (49% female, median age: 51 years). MAIN OUTCOME MEASURES: Clinical data, facial grading, electrodiagnostics, motor function tests, non-motor function tests and onset of prednisolone therapy were assessed for their impact on the probability of complete recovery using univariable and multivariable statistics. RESULTS: Median onset of treatment was 1.5 days. 46% of patients had a House-Brackmann scale at baseline of ≥ III. The median recovery time was 2.6 months (95% confidence interval [CI] = 2.1-3.0). 54.9% achieved a complete recovery. If prednisolone therapy started later than 96 hours after onset, the recovery rate decreased significantly. Beyond less severe palsy, no abnormal electroneurography side difference, no pathological spontaneous activity in electromyography and normal stapedius reflex testing were the most powerful tool for prognostication of recovery after Bell's palsy. CONCLUSION: Beyond severity of the palsy, facial electrodiagnostics and stapedius reflex testing are the most powerful tool for prognostication of recovery time after Bell's palsy. Prednisolone therapy should have started at best within a time window of 96 hours after onset to reach the highest probability of complete recovery.

[Hemifacial Spasm Caused by Vertebral Artery Fusiform Aneurysm and the Anterior Inferior Cerebellar Artery].

We report a case of hemifacial spasm in which the root exit zone(REZ)of the facial nerve was compressed by both the vertebral artery(VA)aneurysm and the anterior interior cerebellar artery(AICA). A 60-year-old female had suffered left hemifacial spasm for 2 years. Three-dimensional rotational angiography with selective arterial infusion of contrast medium(3DRA-IA)revealed that a distal part of the left AICA looping at the cisternal region was contacting the dome of the left VA aneurysm, although other imaging modalities did not show the exact course of the ipsilateral AICA. Constructive interference steady state magnetic resonance imaging revealed that both the left VA aneurysm and the left AICA had compressed the REZ of the left facial nerve. She underwent aneurysm clipping and decompression of the REZ by transposition of both the clipped aneurysm and the AICA using TachoSil®. Her hemifacial spasm disappeared immediately after surgery without complication. Some fine arteries might compress the REZ in patients with hemifacial spasm associated with VA aneurysms. 3DRA-IA was more effective for accurate evaluation than other imaging modalities. Transposition of vascular structures using TachoSil® is safe and effective for microvascular decompression surgery in such complicated cases.

Outcomes of large vestibular schwannomas following subtotal resection: early post-operative volume regression and facial nerve function.

INTRODUCTION: Subtotal resection (STR) of vestibular schwannoma (VS) tumors remains controversial and little is known regarding post-operative volume changes. METHODS: Authors retrospective reviewed the medical records from January 1st 2002 to January 1st 2018, for all patients who had undergone primary STR of large VS at a single tertiary academic institution. RESULTS: Our series consists of 34 patients with a mean age of 53.9 (median 53; range 21-87) years that had STR of their VS tumor. The mean pre-operative tumor diameter and volume was 3.9 cm (median 3.0 cm; range 1.6-6.0 cm) and 11.7 cm3 (median 9.6 cm3; range 2.8-44.3 cm3), respectively, with a mean extent of resection of 86% (median 90%; range 53-99%). The mean radiographic and clinical follow-up was 40 months (range 6-120 months) and 51 months (range 7-141 months), respectively. 85% of patients had optimal House-Brackmann (HB) scores (Grade 1 & 2) immediately post-operatively, and 91% at 1 year; 94% of patients had normal (HB 1) at last follow-up. There was significant regression of residual tumor volume at 1 year (p = 0.006) and 2 years (p = 0.02), but not at 3 years (p = 0.08), when compared to the prior year. There was significant regression of size over time, with a mean slope estimate of - 0.70 units per year (p < 0.001). CONCLUSION: Excellent clinical facial nerve outcomes can be obtained with STR of large VS tumors. Maximal reduction in tumor size occurs at 2-year post-operatively. Thus, in patients undergoing surgery for large VS, STR and a "watch and wait" strategy is a reasonable treatment option that may optimize facial nerve outcomes.

Latency shift in compound muscle action potentials during electroneurography in facial palsy.

OBJECTIVE: Electroneurography (ENoG) reliably predicts the prognosis of facial palsy. However, the results of ENoG are dependent on the location, where the wave is detected, as a compound muscle action potential (CMAP) arising from the facial muscles. To minimize errors in prognostic prediction, we analysed the latencies of facial CMAPs. MATERIALS AND METHODS: Fifty-seven patients with unilateral peripheral facial palsy and 24 healthy volunteers were enrolled. Amplitudes, negative peak latencies (NPL), and rise latencies (RL) of CMAPs were measured on the paralysed and healthy sides in patients and in healthy volunteers. The relationships of these latencies with ENoG values and the lowest House-Brackmann (H-B) scores were also analysed. RESULTS: The amplitude of CMAP on the paralysed side was smaller, and NPL and RL were longer, than those on the healthy side in patients and healthy volunteers (p < 0.01). In patients, there was no difference in NPL between the ENoG < 40% group and the ENoG ≥ 40% group. Conversely, there was a significant difference in RL between the ENoG < 40% group and ENoG ≥ 40% group (p = 0.03). No relationships were observed between NPL or RL and the lowest H-B score. CONCLUSIONS: NPL and RL of CMAP on the paralysed side were equivalent or longer than those on the healthy side. During ENoG for facial palsy, CMAP should be measured on the healthy side first, and then detected (and the amplitude measured) on the paralysed side with reference to CMAP latency on the healthy side, to reduce errors in detecting facial CMAPs.