Evaluation Of Facial Function Research Articles

Novel continuous and quantitative intraoperative facial nerve-monitoring system for temporal bone lesions.

Intraoperative systems for monitoring facial nerve function, in which temporal electrical stimulation is applied to the facial nerve through electrodes, are used in many surgeries requiring facial nerve preservation; however, continuous stimulation or quantitative evaluation of facial nerve function is difficult with this approach. We examined the usefulness of a continuous and quantitative facial nerve-monitoring system for temporal bone lesions by using our experience to modify the existing methods used for cases involving vestibular schwannomas. Retrospective observational study. Department of Otorhinolaryngology-Head and Neck Surgery at our hospital. We modified the electrode placement and examined the usefulness of the modified system under several conditions. The study population consisted of patients who were operated on for temporal bone lesions at our department and underwent continuous nerve monitoring using the modified system. Case details, electrode-placement sites, and facial nerve function data before and after the surgery were obtained and retrospectively evaluated. Electrodes were placed safely during surgery in all cases. No obvious deterioration in facial nerve function was observed, except in one case. The advantages of this system include its ability to perform quantitative intraoperative evaluations and prevent unexpected nerve damage in cases where the facial nerve shows complicated pathways. This monitoring system is useful, even in complex temporal bone surgeries.

Repetitive transcranial acupuncture stimulation combined with electroacupuncture in treatment of acute facial palsy with retroauricular pain: a randomized controlled trial

To observe the clinical effect of repetitive transcranial acupuncture stimulation (rTAS) combined with electroacupuncture (EA) in treatment of acute facial palsy with retroauricular pain. Sixty-eight patients of acute facial palsy with retroauricular pain were randomly divided into an observation group (34 cases, 3 cases dropped out) and a control group (34 cases, 3 cases dropped out). On the basis of conventional therapy, in the control group, Yangbai (GB 14), Cuanzhu (BL 2), Sibai (ST 2), Quanliao (SI 18), Dicang (ST 4), Yifeng (TE 17), Qianzheng (Extra point) and Taiyang (EX-HN 5) on the affected side, and bilateral Hegu (LI 4) were selected. EA was attached to Yangbai (GB 14) and Cuanzhu (BL 2), and Sibai (ST 2) and Dicang (ST 4), respectively, using intermittent wave. In the observation group, on the basis of the regimen as the control group, rTAS was delivered at Baihui (GV 20) and the 1/5 of the lower motor area on the bilateral sides; EA of dense wave was given at the sites of the mastoidⅠand Ⅱ. The intervention of each group was delivered once a day, 6 times a week as one course for 4 courses and taking a day off every course. Before treatment and at the moment after the first treatment completion, the score of visual analogue scale (VAS) was observed in the two groups and the days of retroauricular pain were recorded. Before and after treatment, the score of Sunnybrook facial grading system (SFGS), the grade of House-Brackmann facial nerve function evaluation system (H-B), the latency and amplitude of the motor conduction from the foramina stylomastoideum to the frontal muscle, the orbicularis oris muscle and the orbicularis oculi muscle on the affected facial nerve, were observed in the patients of two groups and the clinical effect was compared between the two groups after treatment. After treatment, SFGS score was increased (P<0.05), H-B grade was improved (P<0.05), the latency was shortened in the motor conduction from the foramina stylomastoideum to the frontal muscle, the orbicularis oris muscle and the orbicularis oculi muscle on the affected facial nerve (P<0.05) and its amplitude elevated (P<0.05) when compared with those before treatment in the two groups. In the observation group, SFGS score was higher (P<0.05), H-B grade was superior (P<0.05), the latency was shorter in the motor conduction from the foramina stylomastoideum to the frontal muscle, the orbicularis oris muscle and the orbicularis oculi muscle on the affected facial nerve (P<0.05) and its amplitude was higher (P<0.05) when compared with those of the control group after treatment. After the completion of the first treatment, VAS score of either group was reduced in comparison with that before treatment (P<0.05), and the score in the observation group was lower than that of the control group (P<0.05). The duration of retroauricular pain was shortened in the observation group when compared with that of the control group (P<0.05). The total effective rate was 87.1% (27/31) in the observation group, which was higher than 77.4% (24/31) of the control group (P<0.05). The rTAS combined with EA is effective for reducing neurologic impairment of acute facial palsy and alleviating retroauricular pain in the patients.

Analysis of the outcome of 12 cases of facial nerve tumors

Objective:This study aims to provide a comprehensive summary of the pathogenesis, screening modalities, treatment strategies, repair modalities and preliminary results associated with facial nerve tumors. Methods:A retrospective analysis was conducted on the clinical data of 12 patients with facial nerve tumors who were admitted to our department between May 2018 and February 2023. The study population consisted of 5 males and 7 females, with ages ranging from 35 to 90 years. Clinical symptoms observed in these patients included facial nerve palsy, hearing loss, tinnitus, headache, and otalgia, etc. The severity of facial nerve dysfunction was assessed using the House-Brackmann（H-B） facial nerve function classification, with 3 cases classified as grade Ⅰ, 4 cases as grade Ⅲ, 2 cases as grade Ⅳ, and 3 cases as grade Ⅴ. There was a total of 11 patients who presented with hearing loss. Among these patients, 7 cases were diagnosed with conductive hearing loss, 2 cases with sensorineural hearing loss, and 2 cases with mixed hearing loss. The selection of the observation or surgical route for tumor localization was based on clinical symptoms, facial nerve function grading, and imaging examination results including temporal bone CT and enhanced MRI. Specifically, the location of the tumor was selected for observation or the best surgical route: 2 cases were followed up for observation, 1 case underwent biopsy, and 9 cases underwent tumor resection（7 cases of trans-mastoid approach, 2 cases of combined parotid-mastoidal approach）, concurrent repair of the facial nerve（4 cases of auricular nerve grafting, 3 cases of facial nerve diversion anastomosis, 2 cases of peroneal nerve grafting）. （4 cases of auricular nerve graft, 3 cases of facial nerve diversion anastomosis and 2 cases of peroneal nerve grafting）. Periodic postoperative evaluation of facial nerve function was conducted. Results:1-year follow-up was available. Intraoperatively, it was observed that 66.7%（6 out of 9） of the facial nerve tumors were present in multiple segments. Among these segments, the vertical segment had the highest proportion, accounting for 77.8%（7 out of 9）, followed by the labyrinthine segment/geniculate ganglion with 66.7%（6 out of 9） and the horizontal segment with 55.6%（5 out of 9）. Postoperative pathology confirmed 8 cases with nerve sheath meningioma, Ⅰ with seminal fibroma and 1 with hemangioma. Postoperative facial nerve function was graded as H-B grade I in one patient）, grade Ⅲ in three, grade Ⅳ in four, grade Ⅴ in 2, and grade Ⅵ in 2 patients. The auditory outcomes following surgery are as follows: 8 individuals experienced postoperative hearing loss, while 2 individuals demonstrated postoperative hearing preservation. Conclusion:In the case of patients presenting with facial nerve palsy as their initial symptom, it is imperative to consider the potential presence of a facial nerve tumor. To determine the appropriate course of action, it is necessary to ascertain the size and location of the tumors through imaging examinations. This information will aid in the decision making process regarding whether surgical intervention is warranted, and so, the most suitable approach. Additionally, the choice of repair method during the operation should be guided by the extent of facial nerve defect.

Hypoglossal Nerve Transfer for Facial Nerve Paralysis: A Systematic Review and Meta-Analysis.

Background: Hypoglossal-facial nerve (12-7) anastomosis can restore symmetry and voluntary movement on the face in patients with facial nerve paralysis. Traditional 12-7 transfer includes direct end-to-end nerve anastomosis, sacrificing the entire hypoglossal nerve. Contemporary, end-to-side anastomosis, or split anastomosis techniques limit tongue morbidity by preserving some hypoglossal nerve. Direct outcome comparisons between these techniques are limited. Objective: To compare reported outcomes of facial movement, tongue, speech, and swallow outcomes among the different types of hypoglossal-facial nerve anastomosis schemes. Evidence Review: For this systematic review and meta-analysis, a comprehensive strategy was designed to search PubMed, Scopus, and the Cochrane Database from inception to January 2021, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis, reporting guideline yielding 383 results. Any participant who underwent 12-7 transfer using any of the three techniques, with or without an interposition graft, and had documented preoperative and postoperative evaluation of facial nerve function with a validated instrument such as House-Brackmann (HB), was considered for inclusion. Secondary outcomes of synkinesis, tongue atrophy, and speech or swallowing dysfunction were also compared. Forty-nine studies met inclusion criteria, representing data from 961 total patients who underwent 12-7 transfer. Results: The proportion of good HB outcomes (HB I-III) did not differ by anastomosis type: End-to-side and end-to-end anastomosis (73% vs. 59%, p = 0.07), split and end-to-end anastomosis (62% vs. 59%, p = 0.88), and end-to-side anastomosis and split anastomosis (73% vs. 62%, p = 0.46). There was no difference in reported synkinesis rates between the anastomosis types. However, end-to-side anastomosis (z = 6.55, p < 0.01) and split anastomosis (z = 3.58, p < 0.01) developed less tongue atrophy than end-to-end anastomosis. End-to-side anastomosis had less speech/swallowing dysfunction than end-to-end anastomosis (z = 3.21, p < 0.01). Conclusion: End-to-side and split anastomoses result in similar HB facial nerve outcomes as the traditional end-to-end 12-7 anastomosis. End-to-side anastomosis has decreased complications of tongue atrophy and speech/swallow dysfunction compared to end-to-end anastomosis. In addition, split anastomosis has decreased rates of tongue atrophy compared to end-to-end anastomosis.

Preliminary application of combined auditory monitoring technique in resection of vestibular neurinoma

Objective: To explore the value of electrically evoked auditory brainstem response (EABR) monitoring combined with brainstem auditory evoked potential (BAEP) and compound action potential (CAP) monitoring during vestibular schwannoma resection for the protection of the cochlear nerve. Methods: Clinical data from 12 patients with vestibular schwannomas who had useful hearing prior to surgery were analyzed at the PLA General Hospital from January to December 2021. Among them, there were 7 males and 5 females, ranging in age from 25 to 59 years. Before surgery, patients underwent audiology assessments (including pure tone audiometry, speech recognition rate, etc.), facial nerve function evaluation, and cranial MRI. They then underwent vestibular schwannoma resection via the retrosigmoid approach. EABR, BAEP, and CAP were simultaneously monitored during surgery, and patients' hearing preservation was observed and analyzed after surgery. Results: Prior to surgery, the average PTA threshold of the 12 patients ranged from11 to 49 dBHL, with a SDS of 80% to 100%. Six patients had grade A hearing, and six patients had grade B hearing. All 12 patients had House-Brackman grade I facial nerve function prior to surgery. The MRI indicated tumor diameters between 1.1 and 2.4 cm. Complete removal was achieved in 10/12 patients, while near-total removal was achieved in 2/12 patients. There were no serious complications at the one-month follow-up after surgery. At the three-month follow-up, all 12 patients had House-Brackman grade I or II facial nerve function. Under EABR with CAP and BAEP monitoring, successful preservation of the cochlear nerve was achieved in six of ten patients (2 with grade B hearing, 3 with grade C hearing, and 1 with grade D hearing). Successful preservation of the cochlear nerve was not achieved in another four patients (all with grade D hearing). In two patients, EABR monitoring was unsuccessful due to interference signals; however, Grade C or higher hearing was successfully preserved under BAEP and CAP monitoring. Conclusion: The application of EABR monitoring combined with BAEP and CAP monitoring during vestibular schwannoma resection can help improve postoperative preservation of the cochlear nerve and hearing.

Application of two kinds of electrophysiological monitoring techniques for the prediction of facial nerve outcomes after vestibular Schwannoma surgery

Objective: To investigate the application of transcranial facial nerve motor evoked potential (FNMEP) and direct nerve electrical stimulation (DNES) for the prediction of facial nerve function after vestibular schwannoma surgery. Methods: The clinical data of 106 patients who underwent vestibular schwannoma surgery under electrophysiological monitoring of facial nerve between 2017 and 2021 were retrospectively examined, and there were 57 males and 49 females, with a mean age of (51±11) years. Neuroelectrophysiological monitoring was performed in all patients during the operation. After the tumor was removed, FNMEP and DNES were used for electrophysiological evaluation of facial nerve function. The amplitude ratios of FNMEP to baseline (M1) and the brainstem segment to the internal auditory canal segment of DNES (M2) were recorded after the tumor was removed, respectively. The correlation between these two ratios and facial nerve function at 1 day, 1 month and 3 months after the operation were compared. According to the House-Brackmann (HB) scale, Grade Ⅰ-Ⅱ refers to good facial nerve function, and grade Ⅲ-Ⅵ refers to moderate and severe facial nerve dysfunction. Non-parameter Spearman correlation coefficient was used to evaluate the correlation between M1 and M2 and facial nerve function at 1 day, 1 month and 3 months after operation, and the receiver operating characteristic (ROC) curves were plotted to verify the diagnostic efficacy of M1 and M2 for predicting the prognosis of postoperative facial nerve function. Results: Among 106 patients, 102 cases (96.3%) underwent total tumor resection, 4 patients (3.7%) underwent subtotal resection, 104 patients (98.1%) had anatomical preservation of facial nerves, and there were no deaths reported. All patients could evoke reliable FNMEP and 2 patients could not evoke DNES in the brainstem segment of the facial nerve. There were 81 (76.4%), 99 (93.4%) and 103 patients (97.2%) with satisfactory function of facial nerve at 1 day, 1 month and 3 months after surgery, respectively. M1 had large absolute values of Spearman correlation coefficient at 1 day (ρ=|-0.648|) and 1 month (ρ=|-0.552|) after surgery (both P<0.001), while M2 showed a greater absolute value of Spearman correlation coefficient at 3 months (ρ=|-0.395|) than that of M1 (ρ=|-0.378|) (P<0.001). Cut-off value of M1 was 0.58 (sensitivity=0.92, specificity=0.64), and that of M2 was 0.36 (sensitivity=0.64, specificity=1.00). Meanwhile, M1<0.58 or M2<0.36 suggested moderate and severe impairment of facial nerve function. Conclusions: Both FNMEP and DNES during vestibular schwannoma surgery can effectively evaluate the postoperative facial nerve function. FNMEP is better than DNES in predicting the early postoperative facial nerve function, but DNES is better for predicting the long-term postoperative facial nerve function.

Prospective Assessment of Intraoperative Facial Nerve Monitoring in Patients Undergoing Partial Parotidectomy.

The most significant complication of parotid gland tumor surgery is facial weakness. This study compares the occurrence of transient facial palsy in patients with parotid gland tumors who underwent surgery without monitoring to those who underwent surgery with monitoring. The study's aim was to investigate facial nerve function in patients undergoing parotidectomy as well as the effect of intraoperative facial nerve monitoring and the effect of certain risk factors on the surgery and onset of postoperative facial palsy. This prospective study included 100 patients who underwent parotidectomy. The study cohort was divided into two groups. Group I included 50 patients who underwent surgery without neuromonitoring and group II included 50 patients who underwent surgery with neuromonitoring. The neurological assessment was conducted using the House–Brackmann scale. Preoperatively and one month postoperatively, electroneuronography (ENoG) and blink reflex tests were done. The analyses showed a significant reduction of the compound muscle action potential (CMAP) amplitude of the orbicularis oculi and orbicularis oris muscles and prolonged R1 and R2 blink reflex latencies 1 month after surgery. On neurological and electrophysiological studies, the rate of postoperative transient facial nerve dysfunction was significantly different between the groups. Significantly more patients, operated with use of facial nerve monitoring, presented postoperatively normal nerve function (i.e., House–Brackmann grade I) compared to those who underwent surgery without monitoring (78% and 26%, respectively; p < 0.001). Monitoring had a statistically significant impact on the prevalence of facial nerve conduction disorders in patients who underwent surgery, according to the blink reflex and ENoG studies. The duration of the surgical procedure was not affected by monitoring in any way. The clinical evaluation of facial nerve function (House–Brackmann scale) and some ENoG results 1 month after surgery were found to have a significant correlation. To summarize, using monitoring considerably reduced the negative impact of local factors and the prevalence of transient facial nerve palsy.

Effect of Penetration Electroacupuncture Combined with Intermediate Frequency Electrotherapy, Facial Acupoint Massage, and Cervical Reduction on Facial Nerve Function and Curative Effect of Senile Refractory Facial Paralysis.

Objective This study aimed to explore the curative effects on senile refractory facial paralysis treated by penetration electroacupuncture combined with intermediate frequency electrotherapy, facial acupoint massage, and cervical reduction on facial nerve. Methods 106 elderly patients with intractable facial paralysis that were retrospectively analyzed were all admitted from January 2019 to June 2020. The 106 patients were evenly divided into 2 groups according to the treatment method. The control group was treated with penetration electroacupuncture, while the observation group was treated with penetration electroacupuncture plus intermediate frequency electrotherapy + facial acupoint massage + cervical reduction treatment. Then, House–Brackmann (H-B) facial nerve function evaluation, RPA score, TCM syndrome score, disease remission rate, and incidence of adverse events were evaluated and compared between the two groups. Results After 4 weeks of treatment, the H-B facial nerve function grading in the observation group was better than that in the control group (P < 0.05). And the disease remission rate after 1 week, 2 weeks, and 4 weeks of treatment was higher than that in the control group (P < 0.05). Meanwhile, the TCM syndrome score and RPA score after 2 weeks and 4 weeks of treatment were better than that in the control group (P < 0.05). Conclusion For the elderly patients with refractory facial paralysis, the application of the combined treatment that penetration electroacupuncture + medium frequency electrotherapy + facial acupoint massage + cervical adjustment can significantly improve the facial nerve function and reduce various diseases, and the effect of this combined treatment plan is more significant than that of penetration electroacupuncture treatment.

The Efficacy Of Computer Guided Surgery In Preserving Ramal Height And Skull Base During Gap-Arthroplasty In Patients With TMJ Bony Ankylosis

The aim of the study was to compare between computer guided surgery and the traditional method in preserving vertical ramus height (VRH) and the skull base thickness during gap arthroplasty in patients with the TMJ bony ankylosis. Material and methods: Twelve patients with 15 joints suffering from true bony TMJ ankylosis were included in this study. The patients were divided into 2 groups: Group A (8 joints); The ankylosis was released by computer-assisted 1cm gap arthroplasty. Group B (7 joints); The ankylosis was released by traditional 1cm gap arthroplasty. Pre and postoperative clinical examinations included: measurements of maximum interincisal opening, midline deviations or deflections during mouth opening or closing, presence of open bite, recording any sign/symptoms of infection, facial nerve function evaluation. Preoperative radiograph were measure the preoperative VRH, and aid in construction of the surgical guide for group A, while, postoperative radiograph performed for measure the VRH and skull base thickness. Result: Clinically improvement in the midline shift and occlusion during physiotherapy period postoperatively for all cases in group A except in one patient. While, clinical result in group B revealed increase in the midline shift, and change in occlusion postoperatively. Radiographically: there was no statistical significant difference between the 2 groups in postoperative VRH loss measurements. There was statistical significant difference between the 2 groups in postoperative skull base thickness. Conclusion: Computer assisted surgical simulation could help the surgeon to preserve the VRH and the skull base that reflects positively on the postoperative clinical outcomes.

Application of small current perioperative stimulation threshold in evaluation of facial nerve function post acoustic neuroma surgery(report of 96 cases)

Objective To explore the predictive value of small current stimulation threshold for the facial nerve outcome after acoustic neuroma surgery. Methods Ninety-six acoustic neuroma patients underwent tumor resection by a single team at Department of Neurosurgery, Huashan Hospital, Fudan University from January 2013 to April 2015 and were enrolled into a prospective cohort study. We defined the minimal stimulation intensity of facial nerve proximal to the brainstem to induce action potential after tumor total resection as stimulation threshold (ST) and a ST of ≤ 0.05 mA as small current. Facial nerve function was evaluated using House-Brackmann (H-B) scale preoperatively and postoperatively (1, 3, 6, 12 months). By means of binary, ordinal and linear regression analysis, the facial nerve function outcomes in the small current and control (> 0.05 mA) groups were compared.The sensitivity and specificity of the small current prediction facial nerve function were calculated by the four-grid method. Results The ST in all 96 cases was 0.01-0.35 mA with an average of 0.06±0.02 mA. Seventy-four patients were included in the small current group and 22 in the control group. While adjusting for the following covariates: ages, tumor size, tumor location, tumor texture, Samii scale and preoperative H-B scale, binary logistic regression analysis showed that the rate of good facial nerve outcome (H-B score of Ⅰ-Ⅱ) in small current group was significantly better than that in control group [43.2%(32/74) vs. 4.5%(1/22) at 1 month; 62.2%(46/74) vs. 31.8%(7/22) at 3 months; 70.3%(52/74) vs. 40.9%(9/22) at 6 months; 81.1%(60/74)vs. 45.5%(10/22) at 12 months; all P<0.05]. Ordinal regression analysis revealed that compared with the control group the facial nerve outcome in small current group shifted toward a better condition at 1, 3, 6, and 12 months postoperatively. A faster recovery rate was found in small current group among patients with H-B score of Ⅳ at 1 month postoperatively (slope: -0.163 vs. -0.057, P=0.004). The sensitivity and specificity of small current for predicting facial nerve function 1 year after surgery were 85.7% and 46.2%, respectively. Conclusions Small current seems to be a better short-term and long-term predictor of postoperative facial nerve function. For patients with H-B Ⅳ at 1 month post operation, small current could predict faster recovery rate of facial nerve function. Key words: Neuroma, acoustic; Facial nerve; Small current; Prognosis

The transotic approach for vestibular schwannoma: indications and results

To analyze retrospectively the indications and the results obtained with the transotic approach in a series of patients with vestibular schwannoma. The study included 36 patients from 2007 to 2013 with a vestibular schwannoma that was removed with a transotic approach. All patients underwent preoperative pure tone audiometry, evaluation of facial function and CT and MR imaging. All patients having (1) a hearing loss of more than 50 dB, (2) an average tumor size of 2.7 cm (range 0.5–5.0 cm) and (3) signs of a contracted mastoid (high jugular bulb, anteriorly located sigmoid sinus, low middle cranial fossa, or reduced pneumatization) were selected. The tumor was totally removed in 34 and near-totally removed in 2 patients. The facial nerve was preserved in all patients. The postoperative facial function after 6 weeks was House–Brackmann grade I in 7, grade II in 27, and grade III in 2 patients. All patients presented postoperatively with unilateral total deafness. Seven patients experienced transitory postoperative imbalance. There were two patients who required revision surgery, one with intracranial hemorrhage and another with a CSF leak. There were no deaths and no severe complications such as hemiplegia or intracranial infections. The transotic approach has proven to be of value for the removal of vestibular schwannomas up to 5.0 cm in the presence of temporal bone contraction. Hearing was not preserved; however, other clinical outcomes were very favorable, including high rates of total tumor removal and facial nerve preservation, and low rates of complications.

Facial nerve reconstruction and facial disfigurement after radical parotidectomy.

The importance of facial contouring with facial nerve reconstruction following total and radical parotidectomy is often overlooked. The goal of this study was to quantify the level of facial disfigurement and nerve dysfunction following reconstruction of the facial nerve, with or without reconstruction of the contours, using free tissue transfer. A total of 26 patients with radical parotidectomy and facial nerve reconstruction were included in this retrospective study. Of the 26 patients, 15 underwent follow-up interviews and evaluation of facial nerve function and disfigurement using three different scales: the regional House-Brackmann (H-B) scale, the Facial Clinimetric Evaluation (FaCE) Scale, and the observer-rated disfigurement scale. Of the 15 evaluated patients, 8 patients underwent free tissue transfer. Mean follow-up time was 39 months (median, 35; range, 11-65 months). Of the 15 patients, 10 patients had good or moderate function according to the H-B mouth scale (median score, 4; range, 2-5), and satisfactory eye closure was observed in 10 patients (median score, 3; range, 2-5). The mean disfigurement value rated by the physician was 5 (scale, 1-9), with a mean patient rating of 4. Subjective total FaCE score varied significantly (mean, 52; range, 13-93). Facial nerve and soft tissue reconstruction are highly beneficial to patients undergoing radical parotidectomy.

Protection of Facial Nerves During Acoustic Neuroma Surgery.

The objective of this study was to summarize the experience about the protection of the facial nerve in surgery for acoustic neuroma surgery with the aim to improve the retention of facial nerve function and the quality of life. Forty-two patients with acoustic neuroma were recruited from the year 2010 to 2013. Using microsurgical techniques, the tumors were resected through the suboccipital approach over the posterior edge of the sigmoid sinus, and intraoperative electrophysiological monitoring of the facial nerve function was performed. The House-Brackmann (H-B) grading was used to evaluate the facial nerve function evaluation postoperatively. Total tumor resection was achieved in 32 cases, and partial resection in 10 cases, without any intraoperative deaths. Also facial nerves were retained in 35 of 42 cases (83.33 %). One week after surgery, the facial nerve H-B grading was grade I in 8 cases, grade II in 15 cases, grade III in 12 cases, grade IV in 6 cases, and grade V in 1 case. The key to improved protection of the facial nerve during acoustic neuroma surgery includes a complete understanding of the anatomy of the cerebellopontine angle, proper use of microsurgical techniques, and intraoperative electrophysiological monitoring of the status of facial nerve functions to avoid damage to the nerves.

Reversal of moderate and intense neuromuscular block induced by rocuronium with low doses of sugammadex for intraoperative facial nerve monitoring

We report two cases in which moderate and intense rocuronium-induced neuromuscular block was reversed intraoperatively with low sugammadex doses in order to facilitate electromyographic evaluation of facial nerve function during surgery of the parotid gland and the middle ear. Acceleromyography was used to assess reversal of neuromuscular block before starting electromyography monitoring. Rocuronium-induced neuromuscular block was reversed with sugammadex 0.22mgkg−1 when the TOF ratio was 0.14 in the first patient, and with sugammadex 2mgkg−1 during intense block (PTC 0) in the second patient. In each case, appropriate neuromuscular function (TOF ratio≥0.9) was established soon after sugammadex administration, and electromyographic evaluation of facial nerve was successfully conducted. The use of rocuronium and sugammadex, coupled with objective neuromuscular monitoring with acceleromyography, assured complete restoration of neuromuscular function and created the optimal conditions for the surgical team.

Evaluation of facial nerve function following surgical approaches for maxillofacial trauma

Purpose:The aim of this study was to report facial nerve injury following extraoral surgical approaches for the treatment of maxillofacial trauma, using the House–Brackmann facial nerve grading system (HBFNGS) as a means of classifying and measuring the degree and type of injury.Materials and Methods:The sample comprised 100 consecutive cases of various maxillofacial trauma in which extraoral surgical approaches were used. Variety of surgical approaches such as coronal, preauricular, endaural, retromandibular, and submandibular approach and its modifications were used based on the anatomic location of the fracture and the accessibility required for its reduction and fixation. Facial nerve function of all patients was evaluated preoperatively and 24 hours after surgery. Patients who presented postoperative facial nerve injury were likewise examined using the HBFNGS at 24 hours, 1 week, 1 month, 3 months, and 6 months.Results:Of the 100 patients, temporofacial branch involvement was seen in 11 cases, whereas cervicofacial branch involvement was seen in 6 cases. Complete recovery of the temporofacial branches was seen in a period of 3–4 months; whereas cervicofacial branches recovered in 5–6 months postoperatively.Conclusion:The frequency of facial nerve injury was related to various surgical approaches in maxillofacial trauma. Facial nerve impairment was found to be temporary in all cases, although the recovery of cervicofacial branches took a longer time. Moreover, there is a need to standardize the reporting of facial nerve recovery.

Evaluation of Facial Nerve Function by Yanagihara's 40 Points Grading System and House and Brackmann's Facial Nerve Grading System

Evaluation of Facial Nerve Function by Yanagihara's 40 Points Grading System and House and Brackmann's Facial Nerve Grading System

Long-term facial nerve function evaluation following surgery for large acoustic neuromas via retrosigmoid transmeatal approach

By evaluating the postoperative facial nerve function of large acoustic neuromas, the purpose of this study was to analyze the factors that influence the facial nerve function outcome and to explore the surgical strategy for large acoustic neuromas. A retrospective study of surgical outcome was performed on 89 patients with large acoustic neuromas. All operations were performed via the retrosigmoid transmeatal approach using the intraoperative electrophysiological monitoring. Gross total resection was performed in 38 (42.7%) of the 89 patients, near total resection in 35 (39.3%), and subtotal resection in 16 (18.0%). The facial nerve was anatomically intact at the end of surgery in 83 (93.3%) patients. At 1year after surgery, 48 (53.9%) patients had good facial nerve function (House-Brackmann (HB) Grades I-II), 23 (25.8%) patients had regular facial nerve function (HB Grades III-IV), and 18 (20.2%) patients had poor facial nerve function (HB Grades V-VI). For large acoustic neuromas, the goal of complete tumor resection and preservation of acceptable facial nerve function can be attained via the retrosigmoid transmeatal approach, using the intraoperative facial nerve monitoring. The surgical strategy of near total resection is indicated for the large acoustic neuromas with severe adherence or inclusion in order to preserve facial nerve function.

Can You Hear Me Now? Long-Term Hearing Preservation in Intracanalicular Vestibular Schwannoma

Introduction: The primary goal of treating intracanalicular vestibular schwannomas (IVS) is often hearing preservation. There are three viable approaches to this goal: watchful waiting, stereotactic radiosurgery, and microsurgical resection. We have favored microsurgical excision via the middle fossa route when hearing preservation is the patient's primary goal, but we have also utilized stereotactic radiosurgery and watchful waiting in appropriate circumstances. We review our experience in achieving the goal of hearing preservation in patients with intracanalicular vestibular schwannoma in whom a minimum of 8 years' follow-up is available. Methods: Consecutive patients evaluated with intracanalicular vestibular schwannoma at our institution were identified from clinic and hospital records and a prospectively managed data base. Pre- and serial postoperative audiometry, clinical evaluation of facial nerve function, and post-treatment complications were extracted from medical records. Serial postoperative contrast enhanced MRI were reviewed for evidence of tumor recurrence. Results: Data collection is ongoing and will be updated for the meeting. Between 1987 and 1997 we performed 36 middle fossa operations for vestibular schwannoma. Hearing preservation was attempted in 35 who had Gardner-Robertson class I or II hearing preoperatively, one of whom is lost to follow-up. Of the 34 patients, serviceable hearing was preserved in 20 (59%). In those with preserved hearing the median word recognition score is 96% and median pure tone average 33 dB. At 36 months of follow-up these values are statistically unchanged, suggesting that hearing, once preserved, is well maintained. Conclusion: When hearing is preserved after microsurgical excision of IVS it appears to be well maintained. Hearing progressively declines in untreated and radiosurgically treated patients followed up to 3 years after treatment or diagnosis. Longer follow-up of surgically treated patients, which will be presented at the meeting, will clarify the relative value of these approaches.

The facial nerve in medial acoustic neuromas.

Functional results after surgery for acoustic neuromas that have little or no growth within the internal auditory canal are controversial, because these medial tumors can grow to a considerable size within the cerebellopontine angle (CPA) before symptoms occur. A prospective study was designed to evaluate the surgical implications of the course of the facial nerve within the CPA on medial acoustic neuromas. This study included a consecutive series of 22 patients with medial acoustic neuromas (mean size 32 mm, range 17-52 mm) who underwent surgery via a suboccipitolateral approach between 1997 and 2001. All patients underwent pre- and postoperative magnetic resonance imaging and preoperative electromyography (EMG). Evaluation was based on continuous intraoperative EMG monitoring and video recordings of the procedure. All patients were reevaluated at a mean of 19 months (6-50 months) postsurgery. Preoperative evaluation of facial nerve function revealed House-Brackmann Grade I in six, Grade II in 14, and Grade III in two patients. During surgery a distinct splitting of the nerve at the root exit zone through its intracisternal course was seen in eight patients and documented by selective electrical stimulation. The facial nerve was separated into a smaller portion that ran cranially and parallel to the trigeminal nerve, and a larger portion on the anterior tumor surface. Both components joined anterior to the porus without major spreading of the nerve bundle. In two cases the nerve was found on the posterior surface of the cranial tumor. In one case the facial nerve entered the porus of the canal at its lower part, obtaining the expected anatomical position proximally within the middle portion of the canal. An anterior cranial, middle (five cases each), or caudal course (two cases) was seen in the remaining patients. After surgery, facial nerve function deteriorated in most cases; on follow-up evaluation House-Brackmann Grade I was found in 11, Grades II and III in 10, and Grade V in one patient. The facial nerve requires special attention in surgery for medial acoustic neuromas, because an atypical course of the nerve can be expected in the majority of cases. A split course of the nerve was found in 36% of the cases presented. Meticulous use of intraoperative facial nerve stimulation and continuous monitoring ensures facial nerve integrity and offers good functional results in patients with medial acoustic neuromas.

ＥＮｏＧによる耳下腺腫ようの術前顔面神経評価

Parotid gland tumor are often associated with carcinomatous infiltration into facial nerves without overt manifestations of facial nerve palsy, which makes preoperative predictions of carcinomatous infiltration difficult. ENoG has been shown to be a useful approach to evaluate facial nerve degeneration. Here, we measured facial nerve function by performing ENoG preoperatively on patients with parotid gland tumors prior to investigate the usefulness of ENoG in preoperative examination of these tumors.Subjects: Twenty healthy individuals without any history of facial nerve palsy and 18 patients with parotid gland tumors (13 with benign tumors and 5 with malignant tumors) but no overt facial nerve palsy.Results: Mean ENoG values obtained for each groups were 103.5% (control), 82.2% (benign) and 48.1% (malignant). The mean ENoG values for the malignant group was significantly different compared to the other two groups (p<0.05). Differences in sizes or regions of tumors did not affect ENoG values significantly.Conclusion: ENoG was useful for the preoperative evaluation of facial nerve function. We suggest that a 50% reduction or more in ENoG values may predict the malignancy of tumor and a high risk for carcinomatous infiltration into facial nerves without any manifestations of facial nerve palsy.