scholarly journals Impact of Motor-Evoked Potential Monitoring on Facial Nerve Outcomes after Vestibular Schwannoma Resection

2018 ◽  
Vol 128 (1) ◽  
pp. 56-61 ◽  
Author(s):  
Kareem O. Tawfik ◽  
Zoe A. Walters ◽  
Gavriel D. Kohlberg ◽  
Noga Lipschitz ◽  
Joseph T. Breen ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Vestibular Schwannoma ◽  
Predictive Value ◽  
Evoked Potential ◽  
Amplitude Ratio ◽  
Motor Evoked Potential ◽  
Level Of Evidence ◽  
Facial Function

Objectives: Assess the utility of intraoperative transcranial facial motor-evoked potential (FMEP) monitoring in predicting and improving facial function after vestibular schwannoma (VS) resection. Study Design: Retrospective chart review. Methods: Data were obtained from 82 consecutive VS resections meeting inclusion criteria. Sixty-two cases were performed without FMEP and 20 with FMEP. Degradation of FMEP response was defined as a final-to-baseline amplitude ratio of 0.5 or less. House-Brackmann (HB) grade was assessed preoperatively, postoperatively, at follow-up assessments, and it was compared between pre- and post-FMEP cohorts. Positive predictive value (PPV) and negative predictive value (NPV), sensitivity, and specificity of FMEP degradation in predicting facial weakness were calculated. Results: In the pre-FMEP group, at length of follow-up (LOF) ⩾9 months, 83.9% (52/62) of patients exhibited HB 1-2 outcome. In the post-FMEP cohort, 75.0% (15/20) exhibited HB 1-2 function at LOF ⩾9 months. There was no difference in rates of HB 1-2 outcomes between groups in the immediate postoperative period ( P = .35) or at long-term follow-up ( P = 1.0). With respect to predicting immediate postoperative facial function, FMEP demonstrated high specificity (88.9%) and moderate sensitivity (54.5%). The PPV and NPV for immediate postoperative facial function were 85.7% and 61.5%, respectively. With respect to long-term (⩾9 months LOF) facial function, intraoperative FMEP was moderately sensitive (71.4%) and highly specific (84.6%); PPV was moderate (71.4%), and NPV was high (84.6%). Conclusions: Intraoperative FMEP is highly specific and moderately sensitive in predicting postoperative facial function for patients undergoing VS resection, but its use may not be associated with improved facial nerve outcomes. Level of Evidence: 4

scholarly journals Long-term facial nerve clinical evaluation following vestibular schwannoma surgery

2008 ◽  
Vol 66 (2a) ◽  
pp. 194-198 ◽  
Author(s):  
Rafaela Julia Batista Veronezi ◽  
Yvens Barbosa Fernandes ◽  
Guilherme Borges ◽  
Ricardo Ramina
Keyword(s):  
Facial Nerve ◽  
Vestibular Schwannoma ◽  
Tumor Size ◽  
Nerve Function ◽  
Facial Nerve Function ◽  
Significant Difference ◽  
Long Term Follow Up ◽  
Facial Function

BACKGROUND: Facial function is important in accompaniment of patients operated on vestibular schwannoma (VS). OBJETIVE: To evaluate long term facial nerve function in patients undergoing VS resection and to correlate tumor size and facial function in a long-term follow-up. METHOD: Transversal study of 20 patients with VS operated by the retrosigmoid approach. House-Brackmann Scale was used preoperatively, immediately after surgery and in a long-term follow-up. Student t test was applied for statistic analysis. RESULTS: In the immediate postoperative evaluation, 65% of patients presented FP of different grades. Improvement of facial nerve function (at least of one grade) occurred in 53% in the long-term follow-up. There was statistically significant difference in facial nerve outcome in long-term follow-up when tumor size was considered (p<0.05). Conclusion: The majority of patients had improvement of FP in a long-term follow-up and tumor size was detected to be a factor associated with the postoperative prognostic.

Role of Facial Nerve Motor-Evoked Potential Ratio in Predicting Facial Nerve Function in Vestibular Schwannoma Surgery Both Immediate and at 1 Year

2016 ◽  
Vol 37 (8) ◽  
pp. 1162-1167 ◽  
Author(s):  
Sanjiv K. Bhimrao ◽  
Trung N. Le ◽  
Charles C. Dong ◽  
Serge Makarenko ◽  
Sarin Wongprasartsuk ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Vestibular Schwannoma ◽  
Evoked Potential ◽  
Motor Evoked Potential ◽  
Nerve Function ◽  
Facial Nerve Function

Hearing Preservation Using the Middle Fossa Approach for the Treatment of Vestibular Schwannoma

Neurosurgery ◽  
2011 ◽  
Vol 70 (2) ◽  
pp. 334-341 ◽  
Author(s):  
Joe Walter Kutz ◽  
Tyler Scoresby ◽  
Brandon Isaacson ◽  
Bruce E. Mickey ◽  
Christopher J. Madden ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Vestibular Schwannoma ◽  
Academic Medical Center ◽  
Hearing Preservation ◽  
Middle Fossa ◽  
Middle Fossa Approach ◽  
Class A ◽  
Facial Function ◽  
Grade Iii

Abstract BACKGROUND: The incidence of small vestibular schwannomas in patients with serviceable hearing is increasing because of the widespread use of MRI. The middle fossa approach provides the patient with an opportunity for tumor removal with hearing preservation. OBJECTIVE: To determine the rate of hearing preservation and facial nerve outcomes after removal of a vestibular schwannoma with the use of the middle fossa approach. METHODS: A retrospective case review at a tertiary, academic medical center was performed identifying patients from 1998 through 2008 that underwent removal of a vestibular schwannoma by the middle fossa approach. Preoperative and postoperative audiograms were compared to determine hearing preservation rates. In addition, facial nerve outcomes at last follow-up were recorded. RESULTS: Forty-six patients underwent a middle fossa craniotomy for the removal of a vestibular schwannoma. Of the 38 patients that had class A or class B hearing preoperatively, 24 (63.2%) retained class A or B hearing and 29 (76.3%) retained class A, B, or C hearing. When tumors were 10 mm or less in patients with class A or B preoperative hearing, 22 of 30 patients (73.3%) retained class A or B hearing. When the tumor size was greater than 10 mm in patients with class A or B preoperative hearing, 2 of 8 patients (25%) retained class A or B hearing. At most recent follow-up, 76.1% of patients had House-Brackmann grade I facial function, 13.0% had House-Brackmann grade II facial function, and 10.9% had House-Brackmann grade III facial function. CONCLUSION: Hearing preservation rates are excellent using the middle fossa approach, especially for smaller tumors. No patient experienced long-term facial nerve function worse than House-Brackmann grade III.

Transcranial Electrocortical Stimulation to Monitor the Facial Nerve Motor Function During Cerebellopontine Angle Surgery

2010 ◽  
Vol 66 (suppl_2) ◽  
pp. ons354-ons362 ◽  
Author(s):  
Marcus André Acioly ◽  
Marina Liebsch ◽  
Carlos Henrique Carvalho ◽  
Alireza Gharabaghi ◽  
Marcos Tatagiba
Keyword(s):  
Facial Nerve ◽  
Cerebellopontine Angle ◽  
Amplitude Ratio ◽  
Motor Evoked Potential ◽  
Postoperative Outcome ◽  
Abductor Pollicis Brevis ◽  
Orbicularis Oculi ◽  
Control Response ◽  
Orbicularis Oris Muscle ◽  
Facial Function

Abstract OBJECTIVE This study was conducted to investigate the success rate of using the facial motor evoked potential (FMEP) of orbicularis oculi and oris muscles for facial nerve function monitoring with use of a stepwise protocol, and its usefulness in predicting facial nerve outcome during cerebellopontine angle (CPA) surgeries. METHODS FMEPs were recorded intraoperatively from 60 patients undergoing CPA surgeries. Transcranial electrocortical stimulation (TES) was performed using corkscrew electrodes positioned at hemispheric montage (C3/C4 and CZ). The contralateral abductor pollicis brevis muscle was used as the control response. Stimulation was always applied contralaterally to the affected side using 1, 3, or 5 rectangular pulses ranging from 200 to 600 V with 50 μs of pulse duration and an interstimulus interval of 2 ms. Facial potentials were recorded from needles placed in the orbicularis oculi and oris muscles. RESULTS FMEP from the orbicularis oris and oculi muscles could be reliably monitored in 86.7% and 85% of the patients, respectively. The immediate postoperative facial function correlated significantly with the FMEP ratio in the orbicularis oculi muscle at 80% amplitude ratio (P = .037) and orbicularis oris muscle at 35% ratio (P = .000). FMEP loss was always related to postoperative facial paresis, although in different degrees. CONCLUSION FMEPs can be obtained reliably by using TES with 3 to 5 train pulses. Stable intraoperative FMEPs can predict a good postoperative outcome of facial function. However, further refinements of this technique are necessary to minimize artifacts and to make this method more reliable.

Facial reanimation with end-to-end hypoglossofacial anastomosis: 20 years’ experience

2009 ◽  
Vol 124 (1) ◽  
pp. 23-25 ◽  
Author(s):  
T Catli ◽  
Y A Bayazit ◽  
O Gokdogan ◽  
N Goksu
Keyword(s):  
Facial Nerve ◽  
Acoustic Neuroma ◽  
Cranial Nerves ◽  
Significant Difference ◽  
Facial Reanimation ◽  
Short And Long Term ◽  
End To End ◽  
Facial Function

AbstractObjective:This study aimed to evaluate retrospectively the results of experience with end-to-end anastomosis of cranial nerves VII and XII, performed due to transection of the facial nerve during acoustic neuroma removal.Methods:We assessed the facial reanimation results of 33 patients whose facial nerves had been transected during acoustic neuroma excision via a retrosigmoid approach, between 1985 and 2006, and who underwent end-to-end hypoglossofacial anastomosis. We compared the facial nerve functions of patients receiving short term (two to three years) and long term (more than three years) follow up, and we assessed any complications of the anastomosis.Results:A House–Brackmann grade III facial function was achieved in 46.2 and 86.4 per cent of the patients in the short and long term, respectively. House–Brackmann grade IV facial function was achieved in 53.8 and 13.6 per cent of the patients in the short and long term, respectively. There was a statistically significant difference between the facial recovery results, comparing the short and long term follow-up periods (p = 0.03). Disarticulation was the most common complication, seen in 19 (57.6 per cent) patients; numbness of the tongue was the next commonest (10 (30.3 per cent) patients). None of the patients developed dysphagia.Conclusion:Despite such morbidities as disarticulation and tongue numbness, end-to-end hypoglossofacial anastomosis is still an effective procedure for the surgical rehabilitation of static and dynamic facial nerve functions. Significant improvement in facial nerve function can occur more than three years post-operatively.

Pre-operative and per-operative factors conditioning long-term facial nerve function in vestibular schwannoma surgery through translabyrinthine approach

1998 ◽  
Vol 112 (5) ◽  
pp. 441-445 ◽  
Author(s):  
Olivier Deguine ◽  
André Maillard ◽  
Alain Bonafe ◽  
Hassan El Adouli ◽  
Michel Tremoulet ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Vestibular Schwannoma ◽  
Internal Auditory Canal ◽  
Stage Iv ◽  
Nerve Function ◽  
Facial Nerve Function ◽  
Stimulation Threshold ◽  
Translabyrinthine Approach ◽  
Facial Function

AbstractFacial nerve function was evaluated in 103 patients, after vestibular schwannoma removal through the translabyrinthine approach. The mean follow-up was 43 months (minimum six months). Grade I facial function was achieved in 100 per cent of stage I schwannomata compared with 36 per cent of stage IV schwannomata. Grade I or II facial function was found in 78 per cent of homogeneous schwannomata, compared with 48 per cent of heterogeneous schwannomata. Facial function was preserved in 89 per cent of cases, if the angle between the internal auditory canal and the schwannoma was >66°, compared with 54 per cent if the angle was <66°. There was 82 per cent of normal facial function when the nerve appeared normal after tumour removal, compared with 18 per cent when the nerve was traumatized. When the ratio (stimulation threshold at the internal auditory canal/stimulation threshold at brainstem) was <2, postoperative facial function was preserved in 87 per cent of cases, compared with 13 per cent when the ratio was >2.

Quantitative parameters of facial motor evoked potential during vestibular schwannoma surgery predict postoperative facial nerve function

2011 ◽  
Vol 153 (6) ◽  
pp. 1169-1179 ◽  
Author(s):  
Marcus André Acioly ◽  
Alireza Gharabaghi ◽  
Marina Liebsch ◽  
Carlos Henrique Carvalho ◽  
Paulo Henrique Aguiar ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Vestibular Schwannoma ◽  
Evoked Potential ◽  
Motor Evoked Potential ◽  
Nerve Function ◽  
Facial Nerve Function ◽  
Quantitative Parameters

Long-Term Outcomes of the Electrically Unresponsive, Anatomically Intact Facial Nerve Following Vestibular Schwannoma Surgery

2021 ◽  
Author(s):  
Alireza Shoakazemi ◽  
Alejandro Feria ◽  
Constantine E. Kanakis ◽  
Emma Stapleton ◽  
Omar N. Pathmanaban ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Vestibular Schwannoma ◽  
Tumor Size ◽  
Conduction Block ◽  
Extent Of Resection ◽  
Nerve Grafting ◽  
Long Term Outcomes ◽  
Operative Notes

Abstract Objective The study aimed to determine long-term outcomes in patients with intraoperative electrical conduction block in an anatomically intact facial nerve (FN). Patients and Methods Single center retrospective review of prospectively collected database of all vestibular schwannoma surgeries between January 1, 2008 and August 25, 2015. Operative notes were reviewed and patients with anatomically intact FNs, but complete conduction block at the end of surgery were included for analysis. Results In total, 371 patients had vestibular schwannoma surgery of which 18 met inclusion criteria. Mean follow-up was 34.28 months and average tumor size was 28.00 mm. Seventeen patients had House-Brackmann Grade VI facial palsy immediately postoperatively and one patient was grade V. At 1 year, three patients remained grade VI (17%), two improved to grade V (11%), seven to grade IV (39%), six to grade III (33%), and one patient to grade II (6%). On extended follow-up, five patients (28%) had additional 1 to 2 score improvement in facial function. Subset analysis revealed no correlation of tumor size, vascularity, adherence to nerve, operative approach, extent of resection, splaying of FN, and recurrent tumor or sporadic tumors to the extent of FN recovery. Conclusion Intraoperative conduction block does not condemn a patient to permanent FN palsy. There is potential for a degree of recovery comparable with those undergoing nerve grafting. Our data do not clearly support a policy of same-surgery or early-postoperative primary nerve grafting in the event of a complete conduction block, and instead we favor monitoring for recovery in an anatomically intact nerve.

Use of supramaximal stimulation to predict facial nerve outcomes following vestibular schwannoma microsurgery: results from a decade of experience

2013 ◽  
Vol 118 (1) ◽  
pp. 206-212 ◽  
Author(s):  
William R. Schmitt ◽  
Jasper R. Daube ◽  
Matthew L. Carlson ◽  
Jayawant N. Mandrekar ◽  
Charles W. Beatty ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Vestibular Schwannoma ◽  
Tumor Resection ◽  
Constant Current ◽  
Tumor Diameter ◽  
Facial Weakness ◽  
Tumor Removal ◽  
Supramaximal Stimulation ◽  
Facial Function

Object The goal of vestibular schwannoma surgery is tumor removal and preservation of neural function. Intraoperative facial nerve (FN) monitoring has emerged as the standard of care, but its role in predicting long-term facial function remains a matter of debate. The present report seeks to describe and critically assess the value of applying current at supramaximal levels in an effort to identify patients destined for permanent facial paralysis. Methods Over more than a decade, the protocol for stimulating and assessing the FN during vestibular schwannoma surgery at the authors' institution has consisted of applying pulsed constant-current stimulation at supramaximal levels proximally and distally following tumor resection to generate an amplitude ratio, which subtracted from 100% yields the degree to which the functional integrity of the FN “dropped off” intraoperatively. These data were prospectively collected and additional variables that might impact postoperative FN function were retrospectively reviewed from the medical record. Only patients with anatomically intact FNs and > 12 months of follow-up data were analyzed. Results There were 267 patients available for review. The average posterior fossa tumor diameter was 24 mm and the rate of long-term good (House-Brackmann Grade I–II) FN function was 84%. Univariate logistic regression analysis revealed that prior treatment, neurofibromatosis Type 2 status, tumor size, cerebellopontine angle extension, subjectively thinned FN at the time of operation, minimal stimulation threshold, percent dropoff by supramaximal stimulation (SMS), and postoperative FN function all correlated statistically (p < 0.05) with long-term FN function. When evaluating patients with significant FN weakness at the time of hospital discharge, only the percent dropoff by SMS remained a significant predictor of long-term FN function. However, the positive predictive value of SMS for long-term weakness is low, at 46%. Conclusions In a large cohort of patients, the authors found that interrogating intraoperative FN function with SMS is safe and technically simple. It is useful for predicting which patients will ultimately have good facial function, but is very limited in identifying patients destined for long-term facial weakness. This test may prove helpful in the future in tailoring less than gross-total tumor removal to limit postoperative facial weakness.

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