Predictive value of facial motor-evoked potential and electromyography for facial motor function in vestibular schwannoma surgery.

PURPOSE: Intraoperative neuromonitoring (IONM) aims to preserve facial nerve (FN) function during vestibular schwannoma (VS) surgery. However, current techniques such as facial nerve motor evoked potentials (FNMEP) or electromyography (fEMG) alone are limited in predicting postoperative facial palsy (FP). The objective of this study was to analyze a compound fEMG/FNMEP approach. METHODS: Intraoperative FNMEP amplitude and the occurrence of fEMG-based A-trains were prospectively determined for the orbicularis oris (ORI) and oculi (OCU) muscle in 322 VS patients. Sensitivity and specificity of techniques to predict postoperative FN function were calculated. Confounding factors as tumor size, volume of intracranial air, or IONM duration were analyzed. RESULTS: A relevant immediate postoperative FP was captured in 105/322 patients with a significant higher risk in large VS. While fEMG demonstrated a high sensitivity (77% and 86% immediately and 15 month postoperative, respectively) for identifying relevant FP, specificity was low. In contrast, FNMEP have a significantly higher specificity of 80.8% for predicting postoperative FP, whereas the sensitivity is low. A retrospective combination of techniques demonstrated still an incorrect prediction of FP in ~ 1/3 of patients. CONCLUSIONS: FNMEP and fEMG differ in sensitivity and specificity to predict postoperative FP. Although a combination of IONM techniques during VS surgery may improve prediction of FN function, current techniques are still inaccurate. Further development is necessary to improve IONM approaches for FP prediction.

Continuous intraoperative neuromonitoring of the facial nerve predicts postoperative facial palsy in parotid surgery: a prospective study.

PURPOSE: Facial palsy (FP) is the most significant complication of parotidectomy. Currently, the use of intermittent intraoperative neuromonitoring (iIONM) in parotid surgery facilitates nerve detection, which is paramount to nerve protection. Continuous IONM (cIONM), as applied in thyroid surgery, enables real-time information on electrophysiological nerve status through continuous nerve stimulation, thereby allowing consequent amplitude analysis. To date, the application of cIONM in parotid surgery has not been noted in literature. METHODS: We performed parotidectomies with anterograde facial nerve visualization using cIONM in 32 consecutive patients in a prospective study (German Register of clinical studies-DRKS 00011051) during the period October 2016 to January 2020. After the facial trunk had been exposed, an atraumatic stimulation electrode was placed and the nerve was stimulated at 3 Hz, at a low threshold (0.62 ± 0.06 mA), for the entire duration of the preparation. Selected electrophysiological parameters were collected and compared to postoperative facial nerve function, measured by the House-Brackmann grading system. RESULTS: In the post hoc analysis, a significant correlation between a drop in amplitude (< 50% of the "baseline" amplitude) and postoperative FP was recorded (p = 0.001). True positive prediction of FP was noted in 14 out of 16 patients and true negative in 10 out of 16. The sensitivity was 87.5% (AUC 0.75), with a high negative predictive value of 83.3%. CONCLUSION: cIONM has significant value in predicting postoperative FP in parotidectomy. Future development of an acoustic/optic warning system in IONM devices could prevent nerve injury in real time.

[Preservation, reconstruction, and rehabilitation of the facial nerve]. / Erhalt, Rekonstruktion und Rehabilitation des N. facialis.

Handling of the facial nerve during surgery for parotid cancer is relevant for the patient's long-term quality of life. In about two thirds of cases, the facial nerve is not affected by the tumor. In these cases, in addition to complete tumor resection, identification and preservation of the facial nerve are important components of a successful operation. If the nerve is infiltrated by the tumor, the affected part must be resected during radical parotidectomy. When possible, primary nerve reconstruction leads to the best long-term cosmetic and functional outcomes. Individual selection of the optimal treatment concept is based on clinical examination of facial muscle mobility, preoperative imaging to understand the positional relationship between tumor and nerve, and on the basis of an electrophysiological examination of nerve function. Intraoperatively, standardized dissection helps to identify and preserve the facial nerve. If radical parotidectomy is indicated, in addition to one-step reconstruction, preoperative diagnostic tests can help to plan postoperative adjuvant therapy. The aim of rehabilitation is restoration of facial tone, facial symmetry, and movement of the paralyzed face. Restoration of eye closure is of high importance. The surgical treatment of facial paralysis has seen many improvements in recent years. The present work provides an overview of the most recent advances in diagnostics, surgical techniques, and further possibilities for preventing damage to the normal facial nerve during parotid cancer treatment. Furthermore, the options for rehabilitation of the tumor-infiltrated facial nerve in the context of treatment of salivary gland malignancies are described.

[Complications in the surgery of the parotid salivary glands. Causes, mechanisms of development, methods of prevention]. / Oslozhneniya v khirurgii okoloushnykh slyunnykh zhelez. Prichiny, mekhanizmy razvitiya, sposoby profilaktiki.

Operations for neoplasms of the parotid salivary gland require from the surgeon a deep knowledge of the anatomical and topographic features of this area and technical skill, which puts it in a number of «jewelry¼ operations that require patience and concentration. The review is devoted to the topic of specific postoperative complications after parotidectomy or subtotal resection of the gland. These include relapses of tumors, paralysis or paresis of facial muscles, Frey syndrome, salivary fistulas or sialocele, violation of skin sensitivity, soft tissue deformity. The review presents the frequency and causes of complications, mechanisms of their development, methods of prevention and elimination.

Facial nerve monitoring during parotid gland surgery: a systematic review and meta-analysis.

INTRODUCTION: Facial nerve injury remains the most severe complication of parotid gland surgery. However, the use of intraoperative facial nerve monitoring (IFNM) during parotid gland surgery among Otolaryngologist-Head and Neck Surgeons continues to be a matter of debate. MATERIALS AND METHODS: A systematic review and meta-analysis of the literature was conducted including articles from 1970 to 2019 to try to determine the effectiveness of intraoperative facial nerve monitoring in preventing immediate and permanent postoperative facial nerve weakness in patients undergoing primary parotidectomy. Acceptable studies included controlled series that evaluated facial nerve function following primary parotidectomy with or without intraoperative facial nerve monitoring. RESULTS: Ten articles met inclusion criteria, with a total of 1069 patients included in the final meta-analysis. The incidence of immediate and permanent postoperative weakness following parotidectomy was significantly lower in the IFNM group compared to the unmonitored group (23.4% vs. 38.4%; p = 0.001) and (5.7% vs. 13.6%; p = 0.001) when all studies were included. However, when we analyze just prospective data, we are not able to find any significant difference. CONCLUSION: Our study suggests that IFNM may decrease the risk of immediate post-operative and permanent facial nerve weakness in primary parotid gland surgery. However, due to the low evidence level, additional prospective-randomized trials are needed to determine if these results can be translated into improved surgical safety and improved patient satisfaction.

Continuous dynamic mapping to avoid accidental injury of the facial nerve during surgery for large vestibular schwannomas.

In vestibular schwannoma (VS) surgery postoperative facial nerve (CN VII) palsy is reducing quality of life. Recently, we have introduced a surgical suction device for continuous dynamic mapping to provide feedback during tumor resection without switching to a separate stimulation probe. The objective was to evaluate the reliability of this method to avoid CN VII injury. Continuous mapping for CN VII was performed in large VS (08/2014 to 11/2017) additionally to standard neurophysiological techniques. A surgical suction-and-mapping probe was used for surgical dissection and continuous monopolar stimulation. Stimulation was performed with 0.05-2 mA intensities (0.3 msec pulse duration, 2.0 Hz). Postoperative CNVII outcome was assessed by the House-Brackmann-Score (HBS) after 1 week and 3 months following surgery. Twenty patients with Koos III (n = 2; 10%) and Koos IV (n = 18; 90%) VS were included. Preoperative HBS was 1 in 19 patients and 2 in 1 patient. Dynamic mapping reliably indicated the facial nerve when resection was close to 5-10 mm. One week after surgery, 7 patients presented with worsening in HBS. At 3 months, 4 patients' facial weakness had resolved and 3 patients (15%) had an impairment of CN VII (HBS 3 and 4). Of the 3 patients, near-total removal was attempted in 2. The continuous dynamic mapping method using an electrified surgical suction device might be a valuable additional tool in surgery of large VS. It provides real-time feedback indicating the presence of the facial nerve within 5-10 mm depending on stimulation intensity and may help in avoiding accidental injury to the nerve.

Interfascial approach for pterional craniotomy: technique and adjustments to prevent cosmetic complications.

BACKGROUND: Interfascial dissection for pterional craniotomy is one of the main techniques to expose the pterional region. METHOD: A step-by-step optimized method of interfascial dissection to avoid three main esthetic complications of the pterional approach-upper facial nerve palsy, temporal muscle atrophy, and retro-orbital depression. A video of the interfascial dissection and three artistic drawings are provided in support of this technique. CONCLUSION: A safe method of interfascial dissection, respecting anatomy, and avoiding cosmetic complications has been proposed.

[Current trends in surgery for benign parotid lesions]. / Gutartige Parotistumore: moderne Therapiekonzepte.

Parotidectomy is the standard procedure for treatment of benign parotid tumors. Nowadays, one of the main objectives of surgery is to minimize morbidity. However, the debate about the appropriate surgical technique in parotid surgery is still ongoing. There is a high level of evidence, that limited parotidectomy techniques are associated with fewer complications and especially with lower prevalence of permanent facial nerve palsy and Frey´s syndrome. However, limited parotidectomy requires an accurate pre-selection of patients and a precise preoperative diagnostic work-up. This manuscript describes the current trends in surgery for benign parotid lesions and illustrates the treatment options for major post-parotidectomy complications.

Efficacy of the red blood cell distribution width for predicting the prognosis of Bell palsy: a pilot study.

The aim of this study was to investigate the association between RDW values and the prognosis of patients with Bell palsy in an effort to find a prognostic biomarker that predicts recovery from Bell palsy. We measured RDW and evaluated facial movement in 61 patients with Bell palsy aged 50 years and less. All patients were treated with a steroid plus an antiviral agent. Seven patients underwent surgery for facial nerve decompression. During the post-treatment period, patients with a Yanagihara grading score of 36 or more were regarded as having a satisfactory recovery. Patients were divided into two groups (recovered and unrecovered) according to their response to treatment, and several parameters, including the RDW, were measured for further analysis. RDW values were significantly higher in the unrecovered group than in the recovered group (13.5 ± 1.7 vs. 12.7 ± 0.7%, p = 0.046). In the multiple logistic regression model, RDW was the only factor associated with recovery from Bell palsy (odds ratio 1.93, 95% confidence interval 1.02-4.65, p = 0.042). Our preliminary study provides the first evidence that the red cell distribution width (RDW) can predict recovery from Bell palsy in patients aged 50 years and less. Further studies are necessary to elucidate the potential pathophysiological mechanisms for our findings.

The Retroauricular Approach to the Facial Nerve Trunk.

BACKGROUND: Exposure of the common trunk of the facial nerve has traditionally been approached based on principles of parotidectomy, which is associated with high rates of facial nerve palsy and landmarks that may be unreliable. On the basis of experience gained with vascularized composite allotransplantation of the face, the authors propose a retroauricular approach that may be more time-effective and safe. METHODS: In the proposed retroauricular facial nerve approach, an incision is made posterior to the ear in the retroauricular sulcus, and dissection proceeds anteriorly to the mastoid fascia to the base of the conchal bowl. The anteroinferior edge of the external auditory canal is followed as a reference structure to locate the facial nerve trunk (FNT), coursing between the stylomastoid foramen (posteromedially) and entering the parotid gland (anteriorly). Twelve unilateral FNT dissections were performed in 6 fresh human cadaver heads. Six dissections were performed for illustration and proof of concept using full facial transplant, conventional, and limited retroauricular exposures; 6 additional dissections were performed by trainees to assess reliability and replicability of technique. RESULTS: The FNT was successfully identified in all 12 dissections. Trainees tended toward being more time efficient in exploring the anatomy when using the limited retroauricular technique than with the conventional approach, 7.8 ±â€Š0.78 minutes versus 13.0 ±â€Š3.3 minutes (P = 0.089). No intraoperative injury to any critical structure was noted with either technique. CONCLUSION: A retroauricular approach to the FNT based on liberating anterior tissues from the auditory canal provides expedient and aesthetic exposure of the FNT.

Initial Exploration on Temporal Branch of Facial Nerve Function Preservation in Plexiform Neurofibroma Resection.

BACKGROUND: Large temporal plexiform neurofibroma (PNF) is an irritating problem that causes facial disfigurement. Surgical resection of PNF is the only effective way to remove the tumor as well as to improve the patient's facial appearance. However, temporal branch of the facial nerve (TBFN) in the tumor is prone to be destroyed during PNF removal. Thus, TBFN palsy is the inevitable complication after surgery and might induce other malformation and dysfunction. Therefore, the aim of this study is to reconstruct a nearly normal face contour while preserving the facial nerve function. PURPOSE: Selective PNF removal technique was designed to protect TBFN during PNF lesions resection in our patients. METHODS: From May 2011 to June 2015, the authors had 10 patients who suffered from PNF in the temporal region with facial disfigurement and underwent selective PNF removal to correct the facial disfigurement while preserving TBFN as well. RESULT: All patients obtained the improvement of facial appearance after surgery. The temporal PNF was removed and the TBFN function successfully maintained. Plexiform neurofibroma recurrence has not been relapsed during 6 to 49 months' follow-up. CONCLUSIONS: In our initial exploration, TBFN function maintenance and facial appearance improvement can be achieved simultaneously by using PNF-selective removal surgery technique.

Effect of corticosteroids on facial function after cerebellopontine angle tumor removal: a double-blind study versus placebo.

The aim of this study was to assess the effect of corticosteroids administered intra- and postoperatively on the occurrence of facial palsy after a cerebellopontine angle (CPA) tumor resection, and to investigate pre- and intraoperative prognostic factors. A multicenter, prospective, randomized, double-blind and versus-placebo study was conducted between 2006 and 2010. Three hundred and ten patients operated on for a CPA tumor (96% vestibular schwannomas, 4% miscellaneous) were included by five participating centers. The population was stratified into patients with small (≤15 mm CPA on axial MRI views) and large tumors. In each group, patients were randomized to receive corticosteroid (1 mg/kg/day i.v. methylprednisolone intraoperatively and at postoperative days 1-5) or placebo. Steroids did not affect the facial function at postoperative days 1, 8 and 30 in patients with small or large tumors as evaluated by House and Brackmann grading.

Recurrent facial palsy in Melkersson Rosenthal syndrome: total facial nerve decompression is effective to prevent further recurrence.

OBJECTIVE: To study the role of total facial nerve decompression in preventing further recurrence of facial palsy in Melkersson Rosenthal syndrome (MRS). METHODS: Total facial nerve decompression was performed on nine patients with recurrent facial palsy in MRS, and prednisolone treatment was given to 6 cases who declined surgery. They were incorporated into surgery group and control group, respectively. Patients in surgery group and control group were followed up for 5.4 ± 1.4 years (range, 4 to 8 years) and 6.0 ± 1.4 years (range, 4 to 8 years), respectively. RESULTS: Further episodes of facial palsy affected none of 9 cases (0.0%) in surgery group, while they affected 3 of 6 cases (50.0%) in control group, with significant difference (p<0.05). CONCLUSIONS: Total facial nerve decompression was effective to prevent further episodes of facial palsy in MRS.

Stripping surgery in intratemporal facial nerve schwannomas with poor facial nerve function.

UNLABELLED: To report stripping surgery in intratemporal facial nerve schwannomas (FNS) with poor facial nerve function. METHODS: We attempted stripping surgery to completely remove intratemporal FNS with nerve intact in 17 patients, and succeeded in 12 cases. Clinical features of the tumors and the surgical approach were discussed. RESULTS: Multi-segment involvement was present in 10 cases (58.8%). The tumors were completely removed in all cases, and facial nerve integrity was preserved in 12 patients (70.6%). Six of 12 cases (50.0%) with nerve intact obtained acceptable facial nerve recovery, two of which recovered to Grade II, compared to 2 of 5 cases (40%) with nerve grafting. CONCLUSIONS: Multi-segment involvement was more common in FNS. Stripping surgery could remove tumor completely with nerve intact in majority patients, and it seemed to obtain better outcomes of facial nerve.

Facial and lower cranial nerve function preservation in lateral approach for craniocervical schwannomas.

The purpose of this study was to discuss surgical approach selection, surgical procedures, and treatment strategy for preservation of the facial and lower cranial nerve function in craniocervical schwannomas surgery. Between 2002 and 2011, 44 craniocervical schwannomas were operated in Xinhua hospital of Shanghai, China by the same surgical team. The records were reviewed retrospectively regarding clinical presentation, radiographic assessment, surgical approaches selection, surgical procedures and facial and lower cranial nerve follow-up outcomes. Headache or neck pain was present in 30 patients (68.2 %) and cervical mass in 9 patients (20.5 %). Cranial nerve impairments, mainly involving the vagus nerve, were present in 19 patients (43.2 %) and hypoglossal nerve in five patients (11.4 %). 22 tumors were intra- and extracranial, 10 were intra-cranial and 12 were extra-cranial. According to the tumor region, infratemporal fossa type A approach, petrous occipital transsigmoid approach and transcervial approach were selected for tumor removal. Gross-total resection was achieved in 40 patients (90.9 %). Adjunctive radiosurgery was used in the management of residual tumor in two patients; tumor control was ultimately obtained in all cases. During follow-up period, good facial function was obtained in 42 patients (95.5 %) and complete compensation of lower cranial nerve function was achieved in all patients. The preoperative estimation of tumor in nature is of great importance in the determination of proper surgical planning of craniaocervical schwannomas. Facial nerve and lower cranial nerve function can be preserved in maximal degree by proper surgical approaches and careful operative manipulation. Initial surgical resection followed by radiosurgery may be an effective option for some special patients.

Results of anterior facial nerve rerouting procedures for removing skull base tumors.

OBJECTIVES: The purpose of this study was to estimate the rates of functional recovery of the facial nerve and of total tumor resection in patients who undergo short anterior rerouting and long anterior rerouting of the facial nerve in removal of skull base tumors. METHODS: We retrospectively collected data on 37 patients with skull base tumors who underwent facial nerve rerouting during the procedure for tumor removal. Information on the rerouting technique, the completeness of tumor resection, and changes in facial nerve function were obtained from the medical records. Rerouting techniques were classified as short anterior rerouting or long anterior rerouting. RESULTS: Ten of 16 patients (62.5%) in the group with short anterior rerouting showed postoperative facial palsy, and all completely recovered within 1 year. In the group with long anterior rerouting, 18 of 21 patients (85.7%) showed postoperative facial palsy, and recovery to a preoperative level of facial function was found in 10 patients at 1 year of follow-up. Total tumor resection was possible in 94% and 81% of patients with short rerouting and long rerouting, respectively. The mean operation time was not significantly related to the postoperative recovery of facial function. CONCLUSIONS: Short rerouting techniques, when appropriately chosen on the basis of tumor and patient characteristics, offer excellent preservation of facial function and tumor resection, comparable to those of long rerouting techniques.

Using coronary computerized tomographic images to predict the bulging second genu of the facial nerve in mastoidectomy.

The aim of the present study is to determine whether coronary CT images of the temporal bone are useful to predict a bulging second genu of the facial nerve (SGFN) in mastoidectomy by measuring and comparing the heights of the SGFN above the prominence of the lateral semicircular canal (PLSC) in medial-to-lateral dimension on coronary CT images and in mastoidectomy. The relationship between the SGFN and the PLSC in medial-to-lateral dimension, which may have big variability, can be evaluated on the coronary CT images of the temporal bone. The heights of the SGFN above the PLSC in medial-to-lateral dimension were measured on coronary CT images and in mastoidectomy in 184 patients. If the SGFN is above the PLSC in medial-to-lateral dimension, we called the SGFN a bulging SGFN. The data measured on CT images and in surgery were described in histograms and compared. The sensitivity and the specificity in the diagnosis of a bulging SGFN on CT images were calculated by comparison with surgical measurement. Cohen's kappa coefficient was calculated. The heights of the SGFN above the PLSC measured in medial-to-lateral dimension varied from -2.9 to 2.9 mm on coronary CT images and varied from -3.0 to 3.0 mm in surgery. The data measured in surgery showed that the SGFN was above the PLSC in medial-to-lateral dimension in 27.7% (51/184) patients, at least 1 mm above the PLSC in 15.8% (29/184) patients and at least 2 mm above the PLSC in 6.0% (13/184) patients. The sensitivity and the specificity for CT diagnosis of a bulging SGFN were 100% (51/51) and 91.0% (121/133), respectively. Bulging SGFN can be predicted by measuring the height of the SGFN above the PLSC on coronary CT images of the temporal bone.

[Multiple erythema migrans and facial nerve paralysis: clinical manifestations of early disseminated Lyme borreliosis]. / Multilokuläre Erythemata migrantia und Fazialisparese : Klinische Manifestationsformen der disseminierten Frühinfektion der Lyme-Borreliose.

Lyme borreliosis is a common vector-borne disease in Europe. The infection follows different stages with a broad variability of clinical symptoms and manifestations in different organs. A 49-year-old man presented with flu-like symptoms, facial nerve paralysis and multiple erythematous macular on his trunk and extremities. We diagnosed Lyme disease (stage II) with facial nerve paralysis and multiple erythema migrans. Intravenous ceftriaxone led to complete healing of hissymptoms within 2 weeks.

End-to-Side interposed donor grafting as a facial nerve reinforcement technique after vestibular schwannoma surgery.

OBJECTIVES: This retrospective case review was performed to determine the facial function outcome of an end-to-side interposed donor grafting technique in patients who had a nonresponsive and partially injured facial nerve during a translabyrinthine approach for vestibular schwannoma resection. METHODS: The study included patients with silent electrophysiological tests after partial injury of the facial nerve during translabyrinthine schwannoma resection surgery in a tertiary referral hospital. The patients underwent end-to-side interposed donor grafting as a facial nerve reinforcement technique, and we evaluated their facial function after 1 year of follow-up. RESULTS: Four cases with intact preoperative facial function were included (3 men and 1 woman). All patients had a lack of electrical response from the facial nerve and partial anatomic injury after a translabyrinthine approach. An end-to-side interposed donor grafting technique was performed. The donor grafts used were the sural nerve (2 patients), superior vestibular nerve (1 patient), and greater auricular nerve (1 patient). All patients achieved a good House-Brackmann grade. Ocular adjuvant procedures were performed in all patients. CONCLUSIONS: Immediate repair of the facial nerve with an interposed donor graft may provide better facial function in patients who have no electrical response from a partially injured facial nerve after vestibular schwannoma surgery.

Applying Tumescent solution for preserving the facial nerve in parotidectomy.

BACKGROUND: Facial nerve palsy is one of the most common complications in parotid gland surgery. This report evaluates the effectiveness of applying Tumescent solution for preserving the facial nerve in parotidectomy. MATERIAL AND METHODS: Prospective and descriptive clinical study on 34 patients undergoing parotidectomy with facial nerve preservation. Before skin incision, 5-10 min, we injected 100-200 ml of the Tumescent solution into the surgical area. We recorded the surgical method, tumor size, length of surgery, pathological results and facial nerve dysfunction. All patients were followed for a period ranging from 6 to 24 months. RESULTS: There were 14 patients with malignant tumors and 20 patients with benign tumors. The length of surgery lasted from 90 to 180 min, with an average of 126.8 min. The number of patients having temporary facial paralysis was 22 cases (64.7%), recovery time ranged from 1 week to 6 months, and no permanent facial paralysis cases were recorded. The clinical occurrence of Frey's syndrome was five cases (14.7%). CONCLUSIONS: The application of Tumescent solution for preserving facial nerves in parotidectomy could minimize nerve injury and shorten the length of surgery.