Satisfactory Facial Nerve Function Research Articles

Analysis of the influencing factors of short-term and long-term facial nerve function after vestibular schwannoma resection via suboccipital retrosigmoid approach

Objective: To summarize the experience of facial nerve(FN) preservation in microsurgical treatment of vestibular schwannoma (VS) resection via suboccipital retrosigmoid approach and to analyze the influencing factors of facial function prognosis in short-term and long-term period. Methods: Patients with VS who underwent microsurgery via suboccipital retrosigmoid approach by the skull base surgery team in Huashan Hospital from January 2013 to February 2018 were enrolled. A total of 308 patients were included in this study, including 132 males and 176 females. The average age was 47.9 year-old (Range: 17-79 year-old). The patient's clinical data and FN function prognosis were recorded. Univariate and multivariate analysis by SPSS 23.0 statistical software were performed to evaluate the factors affecting facial function prognosis and its recovery. Results: Gross total resection was achieved in 304 cases, and subtotal resection was in 4 cases. The facial nerve preservation rate anatomically was 99.4%. The facial nerve of 2 cases was thin due to large tumor compression and severed, and a one-stage reconstruction was performed during surgery.Of the 308 patients, 300 cases were successfully followed up, and 8 cases were lost to follow-up. The mean follow-up time was 52 months. In short-term (2 weeks after surgery), satisfactory facial nerve function (House-Brackmann (H-B) grade Ⅰ-Ⅱ) was achieved in 96 cases, and 212 cases were unsatisfactory function (H-B grade Ⅲ-Ⅵ). After 1 year, 198 were satisfactory function and 97 were unsatisfactory. After 3 years, 219 were satisfactory function and 75 were unsatisfactory. Five years later, 155 were satisfactory function and 34 were unsatisfactory. According to the results of logistic regression analysis, the impact factors of FN function in short-term were tumor size (P=0.011) and stimulation threshold (ST) of EMG monitoring (P<0.001). The impact factors in long-term were tumor size (P=0.005), ST of EMG monitoring (P=0.005) and FN rehabilitation training. Conclusions: Tumor diameter is an independent factor related to FN function, and the larger the tumor, the worse the postoperative FN function. The ST of EMG (ST≤0.05 mA) can predict short-term and long-term FN function. The systematic facial rehabilitation training can effectively promote the recovery of FN after surgery.

Large Intratemporal Facial Nerve Schwannoma without Facial Palsy: Surgical Strategy of Tumor Removal and Functional Reconstruction

Three patients with large intratemporal facial schwannomas underwent tumor removal and facial nerve reconstruction with hypoglossal anastomosis. The surgical strategy for the cases was tailored to the location of the mass and its extension along the facial nerve. To provide data on the different clinical aspects of facial nerve schwannoma, the appropriate planning for management, and the predictive outcomes of facial function. Three patients with facial schwannomas (two men and one woman, ages 45, 36, and 52 years, respectively) who presented to the clinic between 2009 and 2015 were reviewed. They all had hearing loss but normal facial function. All patients were operated on with radical tumor removal via mastoidectomy and subtotal petrosectomy and simultaneous cranial nerve (CN) 7- CN 12 anastomosis. Multiple segments of the facial nerve were involved ranging in size from 3 to 7 cm. In the follow-up period of 9 to 24 months, there was no tumor recurrence. Facial function was scored House-Brackmann grades II and III, but two patients are still in the process of functional recovery. Conservative treatment with sparing of the nerve is considered in patients with small tumors. Excision of a large facial schwannoma with immediate hypoglossal nerve grafting as a primary procedure can provide satisfactory facial nerve function. One of the disadvantages of performing anastomosis is that there is not enough neural tissue just before the bifurcation of the main stump to provide neural suturing without tension because middle fossa extension of the facial schwannoma frequently involves the main facial nerve at the stylomastoid foramen. Reanimation should be processed with extensive backward mobilization of the hypoglossal nerve.

Intraoperative Transcranial Motor-Evoked Potential Monitoring of the Facial Nerve during Cerebellopontine Angle Tumor Resection

Objective To determine whether transcranial motor-evoked potential (TCMEP) monitoring of the facial nerve (FN) during cerebellopontine angle (CPA) tumor resection can predict both immediate and long-term postoperative FN function. Design Retrospective review. Setting Tertiary referral center. Main Outcome Measures DeltaTCMEP (final-initial) and immediate and long-term facial nerve function using House Brackmann (HB) rating scale. Results Intraoperative TCMEP data and immediate and follow-up FN outcome are reported for 52 patients undergoing CPA tumor resection. Patients with unsatisfactory facial outcome (HB >2) at follow-up had an average deltaTCMEP of 57 V, whereas those with HB I or II had a mean deltaTCMEP of 0.04 V (t = -2.6, p < 0.05.) Intraoperative deltaTCMEP did not differ significantly between groups with satisfactory (HB I, II) and unsatisfactory (HB > 2) facial function in the immediate postoperative period. Conclusion Intraoperative TCMEP of the facial nerve can be a valuable adjunct to conventional facial nerve electromyography during resection of tumors at the CPA. Intraoperative deltaTCMEP >57 V may be worrisome for long-term recovery of satisfactory facial nerve function.

Intraoperative facial nerve motor evoked potential monitoring during skull base surgery predicts long-term facial nerve function outcomes

Objectives: This study was designed to clarify whether facial nerve motor evoked potentials (FNMEPs) elicited by transcranial electrical stimulation during skull base surgery are useful for predicting long-term facial nerve function.Methods: We analyzed FNMEP findings in 35 patients with skull base tumors. Mean follow-up was 24·4 months. Corkscrew electrodes positioned at C3 or C4 and Cz were used to deliver supramaximal stimuli. FNMEPs were recorded from the orbicularis oculi and oris muscles.Results: The correlation between the final-to-baseline FNMEP ratio and initial or long-term facial nerve function was examined. Initial post-operative facial nerve function correlated significantly with the FNMEP ratios in the orbicularis oculi (r=−0·53, P<0·005) and orbicularis oris (r=−0·80, P<0·001) muscles. The correlations between FNMEP ratios and facial nerve function remained significant during long-term follow-up (orbicularis oculi muscle: r=−0·43, P<0·05; orbicularis oris muscle: r=−0·71, P<0·001). All patients in whom the FNMEP ratio in the orbicularis oculi muscles remained above 50% were assigned to the satisfactory facial nerve function (House-Brackmann Grades i and ii) group at the final examination.Discussion: FNMEP monitoring can predict facial nerve function not only immediately after surgery but also long-term.

Facial nerve motor-evoked potential monitoring during skull base surgery predicts facial nerve outcome

Objective: To determine whether monitoring facial nerve motor-evoked potentials (FNMEPs) elicited by transcranial electrical stimulation during skull base tumour surgery is useful for predicting facial nerve outcome. Methods: This study...

Management of facial paralysis in temporal bone fractures: a prospective study analyzing 11 operated fractures

Objective This study was instituted to evaluate patients operated on for traumatic facial paralysis. Study design A prospective study and literature review. Materials and methods Between 1996 and 2001, 10 patients with 11 temporal bone fractures resulting in facial paralysis, who were treated by surgical exploration, were handled. One patient had bilateral facial paralysis because of a bilateral temporal bone fracture. All patients had immediate facial paralysis after trauma. The sample included 7 males and 3 females, aged between 8 and 43 years. Results Of the 11 fractures, 7 (63%) were longitudinal and 4 (37%) were mixed type. There were no transverse fractures. The longitudinal fractures were operated on by the middle cranial fossa (MCF) approach, whereas the mixed fractures were operated on by using a combined approach, consisting of both MCF and transmastoid approaches. The first neurotologic examination and electrophysiological evaluation of the patients were carried out at the earliest 5 days and at the latest 50 days (mean, 25.6 days). The decision for surgery based mainly on electroneurography (ENoG) was possible only in one fracture. In the remaining 10 fractures, the decision for surgery was based mainly on the high-resolution computed tomography (HRCT), taking into account that electromyography (EMG) showed no regeneration potentials. The timing of the surgical intervention ranged from 14 to 75 days (mean, 37.9 days). During the operation, fibrosis at the geniculate ganglion was seen in 5 fractures, impingement of the facial nerve by bone spicules at the geniculate ganglion in 2 fractures, disruption or laceration at the origin of major superficial petrosal nerve also in 2 fractures, and edema around the geniculate ganglion, which is considered a mild form of injury, seen in only 2 fractures. Five fractures showed House-Brackmann (HB) grade 1, 4 patients showed HB grade 2, and 2 patients showed HB grade 3 facial recovery. There were no hearing deterioration or permanent complications related with the procedures. Conclusions It is rarely possible to see the patients with traumatic facial paralysis in the early period and thus to perform ENoG in the critical 6 days after facial paralysis. HRCT, with the contribution of EMG and clinical judgment, has the greatest impact in decision making in patients seen late. On the basis of the facial outcomes observed in the present prospective surgical series, the recovery of satisfactory facial nerve function could be achieved, regardless of timing of surgery performed, within the first 3 months after the onset of paralysis. This study demonstrates that unless there is a disruption of the main trunk, necessitating primary end-to-end anastomosis or grafting, the type of injury does not have any clear effect on the facial outcome, as long as appropriate surgical management is applied.

Facial and acoustic nerve preservation during excision of extracanalicular acoustic neuromas using the suboccipital approach.

The results are presented from a consecutive operative series of 62 acoustic neuromas in 60 patients following the introduction of improved neurophysiological monitoring techniques. Twenty-two patients had usable preoperative hearing. Thirty tumours were less than 2.5 cm diameter and 32 greater in size. Operation was via a 3-4-cm diameter retromastoid craniectomy. The internal auditory meatus was opened by an ENT surgeon (RM) using a drill and the facial nerve identified by stimulation. The tumour was then centrally evacuated by a neurosurgeon (MT/HC) using an ultrasonic aspirator, and the thin exterior part of the tumour carefully dissected off the nerves in or around the capsule with constant stimulation and monitoring of facial EMG, BSAEP and electrocochleography. A new type of stimulation probe has been designed and coupled to a stimulator/integrator/tone burst generator (SB) so that continuous immediate direct feedback to the surgeon is possible. A variable amplitude discriminator rejects baseline EMG (> 50 microV) and a gating circuit prevents stimulus artefact (during monopolar stimulation) from causing interference. By these means the VII nerve could be identified even when translucent and undefinable as a nerve bundle. Anatomical preservation was possible in 98% of VII nerves. Full facial function was present in 20 cases immediately postoperatively. Full delayed recovery occurred in 23 cases giving an eventual total in House Grade I of 69%. Seven other cases recovered to House Grade II. There was therefore 81% satisfactory facial nerve function. This percentage is exactly the same for larger and for smaller tumours. Anatomical preservation of the VIII nerve was achieved in 24/62 (39%) of the whole series and 11/16 (69%) of those with a hearing loss of < 50 dB. Functional preservation of hearing described as usable by the patient (< 65 dB) was achieved in 7/22 cases (32%), 3/13 (23%) in tumours < 2.5 cm and 4/9 (44%) in those > 2.5 cm diameter. Hearing preservation of < 50 dB in patients with preoperative hearing threshold < 50 dB and tumours of < 2.5 cm was 3/11 (27%). Monitoring by BSAEP and ECochG was technically unsatisfactory because the responses were affected by drilling and stimulation. Acoustic nerve preservation should be attempted in all cases with measurable hearing, regardless of tumour size.

Technical and instrumental improvements in the surgical treatment of acoustic neurinomas.

Microsurgical removal of large acoustic neurinomas, more than 3 cm in diameter, has been performed by the lateral suboccipital transmeatal approach with the patient in the lateral position in 68 cases in the past 5 years. sixty-two patients (92%) returned to their former occupations and two died: one in the immediate postoperative period and the other 16 months later. The postoperative follow-up examination showed satisfactory facial nerve function in 70% of the patients. Hearing was preserved in six of 14 patients who had preoperatively retained their auditory function. The authors emphasize the usefulness of bipolar forceps for intraoperative stimulation of the facial nerve and for facial muscle monitoring. The value of the four-pronged hook and the multipurpose head-frame in this procedure is also discussed.