Incidence and Risk Factors of Delayed Facial Palsy After Vestibular Schwannoma Resection

Delayed facial nerve palsy after vestibular schwannoma resection: risk factors, extent and prognosis

INTRODUCTION

Facial nerve palsies may develop during the postoperative period of microsurgical removal of vestibular schwannomas (VSs), even after normal facial function for days or weeks after surgery. The aim of this study was to identify the pathomechanism and predictive factors of delayed palsy.

MATERIAL AND METHOD

The clinical data of 193 patients who underwent vestibular schwannoma surgery between 2012 and 2021 were retrospectively analyzed. A total of 134 patients were included. The patients showed intact facial nerve function up to 24 h after surgery. All patients (n = 20) with palsy from postoperative day 4 were included and collectively referred to as delayed facial nerve palsy (DFNP). Various factors were checked using a binomial regression analysis.

RESULTS

The mean age of patients with DFNP was 57.8 years (55% female, 45% male). 70% had VS with KOOS ≥ 3, and 60% underwent surgery via a translabyrinthine approach Among the 16 patients with DFNP-related neurotropic pathogens, 25% were seropositive for herpes simplex virus. Most patients (n = 9/20) experienced onset of palsy between postoperative days 6 and 10. Of the four variables included in the significance test, three were significant: KOOS ≥ 3 (p < .04), ipsilateral vestibular organ failure (p < .05), and age group (p < .03). After therapy, 100% of patients recovered almost complete facial nerve function. The parameters mentioned above (KOOS classification and ipsilateral vestibular dysfunction) could be proven risk factors for the occurrence of DFNP.

Postoperative hematoma can be a risk factor in delayed facial palsy after vestibular schwannoma resection via a retrosigmoid approach: a retrospective single-center cohort study

PURPOSE

Delayed facial palsy (DFP) is a rare postoperative complication after vestibular schwannoma (VS) surgery. The exact mechanism of DFP remains uncertain and the risk factors for DFP are still controversial. The authors aimed to investigate the characteristics, risk factors, and etiology of DFP after VS resection retrospectively.

METHODS

Ninety-one consecutive surgeries with VS were analyzed. Patients with neurofibromatosis 2 in eight surgeries and postoperative facial palsy House-Brackmann (HB) grade more than 3 in two surgeries were excluded. Eighty-one surgeries were included in this research. Facial nerve function was evaluated using the HB grade. Delayed facial palsy was defined as deterioration in the facial function of at least 1 HB grade more than 1 day after undergoing VS resection. The characteristics of patients with VS and risk factors for DFP were analyzed.

RESULTS

All surgeries were performed via a retrosigmoid approach. DFP was observed in nine patients. There were no statistically significant differences between the DFP group and non-DFP group in terms of the following characteristics: sex, age, side, size, Koos grading system, postoperative facial palsy, or extent of resection. Postoperative hematoma in the cerebellopontine angle (CPA) cistern was significantly higher in the DFP group than in the non-DFP group (p = 0.0023), and was significantly associated with DFP after VS surgery (odds ratio 18.40, p < 0.001). DFP improved in seven patients, but two patients did not improve.

CONCLUSION

DFP occurred in 11.1% of patients after VS surgery. This study revealed that postoperative hematoma in the CPA cistern was significantly associated with DFP after VS surgery.

Facial nerve outcome score: a new score to predict long-term facial nerve function after vestibular schwannoma surgery

Introduction

Patients' quality of life (QoL), facial nerve (FN), and cochlear nerve (CN) (if conserved) functions should be pursued as final outcomes of vestibular schwannoma (VS) surgery. In regard to FN function, different morphologic and neurophysiological factors have been related to postoperative outcomes. The aim of the current retrospective study was to investigate the impact of these factors on the short- and long-term FN function after VS resection. The combination of preoperative and intraoperative factors resulted in designing and validating a multiparametric score to predict short- and long-term FN function.

Methods

A single-center retrospective analysis was performed for patients harboring non-syndromic VS who underwent surgical resection in the period 2015-2020. A minimum follow-up period of 12 months was considered among the inclusion criteria. Morphological tumor characteristics, intraoperative neurophysiological parameters, and postoperative clinical factors, namely, House-Brackmann (HB) scale, were retrieved in the study. A statistical analysis was conducted to investigate any relationships with FN outcome and to assess the reliability of the score.

Results

Seventy-two patients with solitary primary VS were treated in the period of the study. A total of 59.8% of patients showed an HB value < 3 in the immediate postoperative period (T1), reaching to 76.4% at the last follow-up evaluation. A multiparametric score, Facial Nerve Outcome Score (FNOS), was built. The totality of patients with FNOS grade A showed an HB value < 3 at 12 months, decreasing to 70% for those with FNOS grade B, whereas 100% of patients with FNOS grade C showed an HB value ≥ 3. The ordinal logistic regression showed three times increasing probability to see an HB value ≥ 3 at 3-month follow-up for each worsening point in FNOS score [Exp(B), 2,999; p < 0.001] that was even more probable [Exp(B), 5.486; p < 0.001] at 12 months.

Conclusion

The FNOS score resulted to be a reliable score, showing high associations with FN function both at short- and long-term follow-up. Although multicenter studies would be able to increase its reproducibility, it could be used to predict the FN damage after surgery and the potential of restoring its function on the long-term period.

Patient Perception of Education, Care Coordination, and Psychological Distress After Developing Facial Paralysis: A Qualitative Study

Importance

The management of vestibular schwannoma may include observation, microsurgical resection, or radiation of a tumor near the facial nerve. Injury to the facial nerve can result in facial paralysis with major functional, social, and psychological sequelae, and the experiences of patients after paralysis are not well studied.

Objective

To (1) identify patient preparedness for developing facial paralysis and how well their care is coordinated following its development and (2) present in their own words outcomes of facial paralysis in terms of physical health, emotional health, self-perception, and social interactions.

Design, Setting, and Participants

A qualitative observational study was performed using semistructured interviews at a tertiary care academic medical center. Semistructured interviews were conducted between January 1, 2018, and June 30, 2019, with adults aged 25 to 70 years who developed facial paralysis after treatment for vestibular schwannoma. Data were analyzed from July 2019 to June 2020.

Main Outcomes and Measures

Perceptions of the educational and emotional experiences of individuals who developed complete facial paralysis after surgical treatment of vestibular schwannoma.

Results

Overall, 12 participants were interviewed (median age, 54 years [range, 25-70 years]; 11 were female). Saturation was achieved after 12 interviews, indicating that no further information could be elicited from additional interviews. Four major themes were identified: (1) lack of sufficient patient education about the diagnosis of facial paralysis; (2) lack of appropriate care coordination related to facial paralysis; (3) changes in physical and emotional health following facial paralysis; and (4) changes in social interactions and external support following facial paralysis.

Conclusions and Relevance

It is well-known that patients with facial paralysis have reduced quality of life, severe psychological and emotional sequelae. However, little is currently done to help prepare patients for this undesirable outcome. In this qualitative study of facial paralysis, patients express, in their own words, their feeling that the education and management of facial paralysis by their clinicians was inadequate. Before patients undergo surgery, and certainly after injury to the facial nerve, clinicians should consider the patient's goals, preferences, and values to ensure that a comprehensive educational program and psychosocial support system are implemented. Facial reanimation research has not adequately captured these key patient factors associated with the quality of communication.

Pre- and intra-operative prognostic factors of facial nerve function in cerebellopontine angle surgery

PURPOSE

The study assesses whether pre- and intraoperative factors linked to electromyography and direct electrical stimulation (DES) of facial nerve can predict facial nerve function in the short- (12 days) and long-term (1 year) after cerebellopontine angle (CPA) tumor resection.

METHODS

157 patients who underwent surgical resection of CPA tumors with facial nerve monitoring. Pre-operative factors (age, tumor size, pure tone average), surgical time and intra-operative parameters regarding facial function, minimum stimulation threshold (MST), compound muscle action potential (CMAP) and the difference between proximal and distal CMAP (DPDC) were evaluated.

RESULTS

A correlation between tumor size, MST, CMAP and facial function in both short and long term was found. A higher grade of immediate facial paralysis corresponded to a higher risk of poor outcome after one year. A postoperative House-Brackmann (HB) score of V or VI was correlated with poor outcome in 88.8% and 93.8% of cases. A risk of HB 3 or more, in the long term, was correlated with a tumor size of 20.2 mm. Using an MST of 0.1 mA, for long-term predictions, sensitivity and specificity were 0.62 (95% CI 0.46-0.75) and 0.73 (95% CI 0.61-0.82), respectively. With a CMAP cut-off < 200 µV, for long-term prediction, sensitivity was 0.73 (95% CI 0.53-0.87) and specificity 0.73 (95% CI 0.55-0.85).

CONCLUSION

The assessment based on the cut-offs described increases the ability to predict facial function. Improving predictive accuracy enables surgeons to address patients' expectations and to establish an intervention timeline for planning facial reanimation.

Delayed Facial Nerve Paralysis After Vestibular Schwannoma Resection

OBJECTIVE

To report the long-term outcome of delayed facial nerve paralysis (DFNP) after surgical resection of vestibular schwannoma and evaluate the influence of various factors on the prognosis of facial nerve function.

METHODS

Of 265 patients who underwent surgical excision of VS through a retrosigmoid approach between April 2019 and October 2021, 15 (5.7%) developed DFNP and were retrospectively studied. Preoperative and postoperative data were collected and analyzed.

RESULTS

The mean age of patients with DFNP was 42.6 years (range, 27-63 years), and 11 (73.3%) were male. Tumor size ranged from 12 to 37 mm (mean 24 mm) in largest dimension. All patients had normal (House-Brackmann [HB] I) facial nerve function preoperatively. Immediate postoperative facial nerve function was HB I in 12 patients (80%) and HB II in 3 patients (20%). The mean severity of DFNP onset was HB 4.7 (range, HB III-V). The average day of onset was postoperative day 12.6 (range, day 5-28). At 1-year follow-up, 12 patients (80%) were HB I, 1 patient (6.7%) was HB III, and 2 patients (13.3%) were HB IV. All patients who were HB III and IV at the last follow-up had immediate postoperative facial nerve function of HB II.

CONCLUSIONS

Most patients who develop DFNP have a favorable prognosis. However, a small proportion of patients with deteriorated facial nerve function immediately after surgery have poor long-term outcomes, despite confirmation of their facial nerve integrity anatomically and by electrical stimulation.

Delayed motor weakness following peripheral nerve schwannoma resection: illustrative cases

BACKGROUND

Delayed facial palsy (DFP) after vestibular schwannoma resection is a well-documented, yet poorly understood condition. The exact pathophysiological mechanisms of DFP are unknown, although diminished intraoperative nerve response has been shown to be a prognostic factor. To date, no such condition has been described in regard to peripheral nerve schwannomas.

OBSERVATIONS

Here the authors present the first reported cases of delayed motor weakness (DMW) after peripheral schwannoma resection of the ulnar nerve at the elbow and peroneal nerve in the popliteal fossa. Both patients presented with a mass lesion and radiating paresthesias and had normal motor function preoperatively. Immediately after surgical resection, the patients had full strength. Within 24 hours, both patients exhibited marked weakness that gradually resolved over the course of several weeks.

LESSONS

DMW after peripheral schwannoma resection is a rare condition likely akin to delayed facial nerve palsy after VS resection. The mechanism of this phenomenon remains unknown, although symptoms appear to self-resolve with time. A better understanding of the processes driving this condition may allow for therapies that can expedite and improve long-term outcomes.

Applicability of contemporary quality indicators in vestibular surgery-do they accurately measure tumor inherent postoperative complications of vestibular schwannomas?

Background

Due to rising costs in health care delivery, reimbursement decisions have progressively been based on quality measures. Such quality indicators have been developed for neurosurgical procedures, collectively. We aimed to evaluate their applicability in patients that underwent surgery for vestibular schwannoma and to identify potential new disease-specific quality indicators.

Methods

One hundred and three patients operated due to vestibular schwannoma were subject to analysis. The primary outcomes of interest were 30-day and 90-day reoperation, readmission, mortality, nosocomial infection and surgical site infection (SSI) rates, postoperative cerebral spinal fluid (CSF) leak, facial, and hearing function. The secondary aim was the identification of prognostic factors for the mentioned primary outcomes.

Results

Thirty-day (90-days) outcomes in terms of reoperation were 10.7% (14.6%), readmission 9.7% (13.6%), mortality 1% (1%), nosocomial infection 5.8%, and SSI 1% (1%). A 30- versus 90-day outcome in terms of CSF leak were 6.8% vs. 10.7%, new facial nerve palsy 16.5% vs. 6.1%. Hearing impairment from serviceable to non-serviceable hearing was 6.8% at both 30- and 90-day outcome. The degree of tumor extension has a significant impact on reoperation (p < 0.001), infection (p = 0.015), postoperative hemorrhage (p < 0.001), and postoperative hearing loss (p = 0.026).

Conclusions

Our data demonstrate the importance of entity-specific quality measurements being applied even after 30 days. We identified the occurrence of a CSF leak within 90 days postoperatively, new persistent facial nerve palsy still present 90 days postoperatively, and persisting postoperative hearing impairment to non-serviceable hearing as potential new quality measurement variables for patients undergoing surgery for vestibular schwannoma.

Delayed Facial Nerve Palsy Following Resection of Vestibular Schwannoma: Clinical and Surgical Characteristics

OBJECTIVE

Analyze delayed facial nerve palsy (DFNP) following resection of vestibular schwannoma (VS) to describe distinct characteristics and facial nerve (FN) functional course.

STUDY DESIGN

Prospective cohort with retrospective review.

SETTING

Academic medical center.

PATIENTS

Consecutive patients undergoing VS resection 11/2017 to 08/2020. Exclusion criteria: preoperative House-Brackmann (HB) ≥ III, postoperative HB ≥ III without delayed palsy, <30 days follow-up.

INTERVENTIONS

VS resection with intraoperative electromyographic monitoring.

MAIN OUTCOME MEASURES

FN outcomes utilizing the HB scale; comparison between patients with DFNP (deterioration greater than one HB grade 24 hours to 30 days postoperatively) vs. those with HBI-II throughout.

RESULTS

Two hundred eighty-eight patients met criteria: mean age 47.6 years, 36.1% male; 24.0% middle cranial fossa, 28.5% retrosigmoid, 47.6% translabyrinthine. DFNP occurred in 31 (10.8%) patients with average time to onset of 8.1 days. Of these, 22 (71.0%) recovered HBI-II and 3 (9.7%) recovered HBIII. Patients who experienced DFNP, on average, had larger maximum tumor diameter (23.4 vs. 18.7 mm, p = 0.014), lower rate of gross-total resection (54.8% vs. 75.5%, p = 0.014), and lower rate of ≥100 μV FN response to 0.05 mA stimulus intraoperatively (80.6% vs. 94.9%, p = 0.002). Compared to overall incidence of DFNP, translabyrinthine approach demonstrated higher incidence (15.3%, p = 0.017) while retrosigmoid lower (3.7%, p = 0.014). In multivariable logistic regression, patients with FN response ≥100 μV to 0.05 mA stimulus were 72.0% less likely to develop DFNP (p = 0.021).

CONCLUSIONS

Intraoperative electromyographic facial nerve response, tumor size, surgical approach, and extent of resection may play a role in development of DFNP following resection of VS. Most patients who develop DFNP recover near-normal function.

The Influence of Extent of Resection and Tumor Morphology on Facial Nerve Outcomes Following Vestibular Schwannoma Surgery

OBJECTIVE

To determine the influence extent of resection and tumor characteristics on facial nerve (FN) outcomes following microsurgical resection of vestibular schwannoma (VS).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

Three hundred eighty-five patients who underwent VS microsurgical resection.

INTERVENTIONS

Microsurgical VS resection.

MAIN OUTCOME MEASURES

House-Brackmann (HB) scores postoperatively. Good FN function was defined as HB grade I and II and poor FN function was defined as HB grade III and VI. Gross total resection (GTR) versus subtotal resection (STR). Propensity-score matching was used in subset analysis to balance tumor volume between the surgical cohorts, followed by multivariable analysis.

RESULTS

Seventy-one patients (18%) underwent STR and 314 patients (82%) underwent GTR. Two hundred fourteen patients (63%) had good FN function at 2 to 3 weeks postoperatively, and 80% had good FN function at 1 year. In single predictor analysis, STR did not influence FN function at 2 to 3 weeks (p = 0.65). In propensity-score matched subset analysis (N = 178), patients with STR were less likely to have poor FN function at 2 to 3 weeks (p = 0.02) independent of tumor volume (p = 0.004), but there was no correlation between STR and FN function at 1 year (p = 0.09). Ventral extension of tumor relative to the internal auditory canal plane was associated with poor FN outcomes at 2 to 3 weeks (p = 0.0001) and 1-year postop (p = 0.002).

CONCLUSIONS

When accounting for tumor volume, STR is protective in immediate postoperative FN function compared to GTR. Ventral extension of the tumor is a clinical predictor of long-term FN outcomes.

Botulinum Toxin a Treatment of Delayed Facial Palsy in a Randomized Trial

Introduction: Delayed facial palsy (DFP) is a common complication appearing ≥3 days after neurosurgery. In cases where glucocorticoids are contraindicated, other treatments are needed. Methods: The efficacy of BoNT-A injections was evaluated in patients with DFP after vestibular schwannoma resection. Patients received: Group I, BoNT-A (40–50 IU); Group II, prednisolone (1 mg/kg per day, 5–7 days); Group III, glucocorticoids with BoNT-A; Group IV, refused treatment. Functional efficacy was assessed. Results: Among 75 patients, pretreatment facial nerve dysfunction was mild, moderate, and moderate-to-severe in 48.0%, 33.3%, and 18.7%, respectively. One month post-treatment initiation, Group III had a significantly higher rate of facial symmetry normalization versus Groups II and IV (P < 0.05). After 3 months, complete recovery of facial nerve function was significantly higher in Groups I–III versus Group IV (P < 0.05). Conclusion: BoNT-A injections may be recommended for DFP treatment to attenuate facial asymmetry and improve functional recovery.

Delayed Facial Palsy After Resection of Vestibular Schwannoma: An Analysis of Long-term Facial Nerve Outcomes

OBJECTIVES

1) Identify clinical factors associated with delayed facial palsy (DFP) after microsurgical resection of vestibular schwannoma. 2) Determine whether DFP predicts worse facial nerve (FN) outcomes.

METHODS

Adult patients (≥18 yrs) who underwent vestibular schwannoma resection between February 2008 and December 2017 were retrospectively reviewed. Postoperative House-Brackmann (HB) FN function was assessed on the day of surgery, daily during patients' inpatient admissions, and at postoperative clinic visits. Follow-up exceeded ≥12 months for all patients. DFP was defined as a decline (≥1 HB grade) in FN function (relative to the preoperative state) occurring between postoperative days 1 and 30.

RESULTS

Two hundred ninety-one patients were analyzed. Mean age was 51.5 years (±12.3) and mean tumor size 20.6 mm (±10.8). Immediate FP occurred in 61 (21%) patients, and DFP occurred in 112 (38%) patients. Tumor size was largest in patients with immediate FP (p < 0.0001). On univariate analysis, DFP was associated with better final FN outcomes (OR 0.447, p = 0.0101) compared with immediate FP. Multivariate analysis, however, showed that timing of FP was no longer significant, whereas larger tumor size and preoperative HB2 function predicted worse FN outcomes (OR 2.718, p < 0.0001 and OR 9.196, p = 0.0039, respectively). In patients with DFP, longer time to onset of palsy predicted more favorable FN outcomes.

CONCLUSIONS

When accounting for tumor size, the timing of onset of postoperative facial palsy does not predict final FN outcomes. In patients who develop DFP, the longer the interval between surgery and onset of weakness, the better the chances of good long-term FN function.

Clinical Studies and Pre-clinical Animal Models on Facial Nerve Preservation, Reconstruction, and Regeneration Following Cerebellopontine Angle Tumor Surgery-A Systematic Review and Future Perspectives

Background and purpose: Tumorous lesions developing in the cerebellopontine angle (CPA) get into close contact with the 1st (cisternal) and 2nd (meatal) intra-arachnoidal portion of the facial nerve (FN). When surgical damage occurs, commonly known reconstruction strategies are often associated with poor functional recovery. This article aims to provide a systematic overview for translational research by establishing the current evidence on available clinical studies and experimental models reporting on intracranial FN injury.

Methods: A systematic literature search of several databases (PubMed, EMBASE, Medline) was performed prior to July 2020. Suitable articles were selected based on predefined eligibility criteria following the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines. Included clinical studies were reviewed and categorized according to the pathology and surgical resection strategy, and experimental studies according to the animal. For anatomical study purposes, perfusion-fixed adult New Zealand white rabbits were used for radiological high-resolution imaging and anatomical dissection of the CPA and periotic skull base.

Results: One hundred forty four out of 166 included publications were clinical studies reporting on FN outcomes after CPA-tumor surgery in 19,136 patients. During CPA-tumor surgery, the specific vulnerability of the intracranial FN to stretching and compression more likely leads to neurapraxia or axonotmesis than neurotmesis. Severe FN palsy was reported in 7 to 15 % after vestibular schwannoma surgery, and 6% following the resection of CPA-meningioma. Twenty-two papers reported on experimental studies, out of which only 6 specifically used intracranial FN injury in a rodent (n = 4) or non-rodent model (n = 2). Rats and rabbits offer a feasible model for manipulation of the FN in the CPA, the latter was further confirmed in our study covering the radiological and anatomical analysis of perfusion fixed periotic bones.

Conclusion: The particular anatomical and physiological features of the intracranial FN warrant a distinguishment of experimental models for intracranial FN injuries. New Zealand White rabbits might be a very cost-effective and valuable option to test new experimental approaches for intracranial FN regeneration. Flexible and bioactive biomaterials, commonly used in skull base surgery, endowed with trophic and topographical functions, should address the specific needs of intracranial FN injuries.

Facial palsy after temporal lobectomy for epilepsy: illustrative cases

BACKGROUND

Facial palsy is a rare, unexpected complication of temporal lobectomy (TL) for intractable epilepsy. Even without direct manipulation, the facial nerve fibers may be at risk of injury during supratentorial surgery, including TL.

OBSERVATIONS

The authors presented two cases of facial palsy after unremarkable TL. In the first case, the palsy appeared in a delayed fashion and completely resolved within weeks. In the second case, facial nerve dysfunction was observed immediately after surgery, followed by progressive recovery over 2 years. The second patient had a dehiscence of the roof of the petrous bone overlying the geniculate ganglion, which put the facial nerve at risk of bipolar coagulation thermal injury.

LESSONS

Two major mechanisms could explain the loss of facial nerve function after TL: surgery-related indirect inflammation of the nerve resulting in herpesvirus reactivation and delayed dysfunction (Bell's palsy) or indirect thermal damage to the geniculate ganglion through a dehiscent petrous roof.

Probability assessment of facial nerve injury in children and adolescents during the elective maxillofacial surgery

Relevance. Various factors can cause facial neuropathy. Iatrogenic facial nerve injury in childhood and adolescence is a complicated medical, psychological and legal problem. Risk assessment of the facial nerve injury during the elective maxillofacial surgeries is required depending on the localization of the procedure. The statistical assessment is very important for the evaluation of the possible iatrogenic facial neuropathy in children and adolescents during the elective maxillofacial surgeries.Materials and methods. 715 medical records for 2017 from the Department of Pediatric Maxillofacial Surgery of the MSUMD Clinical Center for Maxillofacial, Reconstructive and Plastic Surgery were analyzed.Results. There was a risk of injury to the trunk or branches of the facial nerve during surgery in 121 cases (16,9%) for the technical complexity of the surgical approach and the pathology location.Conclusions. There is a high risk of the facial nerve injury during the elective maxillofacial surgery in children and adolescents due to the complex anatomy of the area. Intraoperative neuromonitoring is recommended to prevent iatrogenic neuropathy of the facial nerve.

Facial Nerve Outcomes Following Total Excision of Vestibular Schwannoma by the Enlarged Translabyrinthine Approach

OBJECTIVE

To study the early and late facial nerve (FN) outcomes in different tumor classes in addition to determining the predictive factors for the same.

STUDY DESIGN

A retrospective clinical study.

SETTING

A quaternary referral otology and skull base center.

PATIENTS AND METHODS

A retrospective study of 1983 cases of vestibular schwannomas (VSs) with preoperative normal FN function, undergoing total excision with anatomical preservation of the nerve by enlarged translabyrinthine approach (ETLA) were included. FN status was recorded postoperatively at day 1, at discharge, and at 1-year follow-up and were analyzed in different tumor sizes.

RESULTS

At 1 year, 988 patients with House-Brackmann (H-B) grade I and II FN at day 1 after surgery, 958 (96.9%) maintained their status up-to 1 year. Of the 216 patients with H-B grade III at day 1 after surgery, 113 (52.3%) improved to H-B grade I and II. Similarly, of the 779 patients with H-B grade IV and VI FN function at day 1 after surgery, improvement to H-B III and H-B I and II were noted in 442 (56.7%) and 80 (10.3%) of patients, respectively. Intrameatal and extrameatal tumors upto 2 cm showed better recovery from H-B grade III to H-B I and II and from H-B grade IV and VI to H-B I and III when compared with extrameatal tumors >2 cm (p = 0.001).

CONCLUSION

Tumors of smaller sizes have good immediate postoperative FN results and recover well at the end of 1 year while more than 3 cm have poor outcomes and recover poorly at the end of 1 year. When the VSs reaches more than 1 cm, the HB I and II outcomes drop significantly.

Prognostic factors of facial nerve function after vestibular schwannoma removal via translabyrinthine approach

BACKGROUND

Prediction of facial function is a major concern when proposing surgery for patients with vestibular schwannoma (VS).

AIMS/OBJECTIVES

To evaluate postoperative facial function of patients who underwent operation of VS via a translabyrinthine approach (TL), and to analyze factors that influence facial functions.

MATERIAL AND METHODS

A total of 91 VS patients, who were operated via a TL approach, between March 1997 and December 2016, were analyzed. Demographics, tumor-related factors, and operative findings were collected. Facial function was assessed according to the House-Brackmann (HB) grading system before surgery, immediately after surgery, and 1-, 3-, 6-months, and 1 year after surgery.

RESULTS

In cases of patients that had a tumor that extended to the CPA, an unsatisfactory facial outcome was noted in 12 (30.0%) patients. FN outcomes after tumor removal depend on tumor size (p = .040). Among FN-related factors, only the FN recovery timing was correlated with facial outcomes (p = .030). Univariable and multivariable analysis revealed that tumor size and the timing of FN recovery were significant as favorable prognostic factors for good facial outcomes.

CONCLUSIONS AND SIGNIFICANCE

Tumor size and the FN recovery timing are significant prognostic factors of facial outcome in VS patients who underwent operations via a TL approach.

[Update on diagnostics and microsurgical treatment of vestibular schwannoma]

Vestibular schwannomas are primary benign tumors of the cerebellopontine angle originating either from the superior or the inferior vestibular nerve. Hearing deterioration is the leading symptom, which is why the widespread name for this tumor is acoustic neuroma. Due to the widespread availability of magnetic resonance imaging (MRI), the diagnosis of vestibular schwannoma is frequently made in an early stage of the disease. In these cases a wait and scan policy is recommended. If the tumor grows, the therapeutic options are stereotactic radiotherapy or microsurgical tumor operation. Young patient age, functional hearing ability, persistent dizziness, cystic tumor consistence and large space-occupying tumor size are in favor of surgery via the retrosigmoid, transmeatal approach. In experienced hands excellent results in terms of functional preservation of the facial nerve and the cochlear nerve and radical tumor resection can be obtained.

Differential Recovery in Early- and Late-Onset Delayed Facial Palsy Following Vestibular Schwannoma Resection

BACKGROUND

Delayed facial palsy (DFP) after resection of vestibular schwannomas (VS) is worsening of facial nerve function after an initially normal postoperative result.

OBJECTIVE

To characterize different types of DFP, compare recovery rates, and review of series of outcomes in patients following resection of VS.

METHODS

Between 2001 and 2017, 434 patients (51% female) with VS underwent resection. We categorized the patients who developed facial palsy into groups based on timing of onset after surgery, immediate facial palsy (IFP), early-onset DFP (within 48 h), and late-onset DFP (after 48 h). Introduction of facial nerve motor-evoked potentials (fMEP) in 2002 and a change of practice utilizing perioperative minocycline in 2005 allowed for historical analysis of these interventions.

RESULTS

Mean age of study cohort was 49.1 yr (range 13-81 yr), with 19.8% developing facial palsy. The late-onset DFP group demonstrated a significantly faster recovery than the early-onset DFP group (2.8 ± 0.5 vs 47 ± 8 wk, P &lt; .0001), had prolonged latency to palsy onset after initiating perioperative minocycline (7.3 vs 12.5 d, P = .001), and had a nonsignificant trend towards faster recovery from facial palsy with use of minocycline (2.6 vs 3.4 wk, P = .11).

CONCLUSION

Given the timings, it is likely axonal degeneration is responsible for early-onset DFP, while demyelination and remyelination lead to faster facial nerve recovery in late-onset DFP. Reported anti-apoptotic properties of minocycline could account for the further delay in onset of DFP, and possibly reduce the rate and duration of DFP in the surgical cohort.

Intentional Subtotal Resection of Vestibular Schwannoma: A Reexamination

Background  Treatment of vestibular schwannomas (VS) remains controversial. Historical surgical series prioritized gross total resections (GTR); however, near total resections (NTR) and intentional subtotal resections (STR) aiming at improving cranial nerve outcomes are becoming more popular. Objective  The main purpose of this article is to assess the tumor control and facial nerve outcomes in VS patients treated with STR or NTR. Methods  VS patients undergoing STR or NTR at our institution between 1984 and 2016 were retrospectively reviewed. Patient demographics, extent of tumor resection, facial nerve injury, tumor recurrence, and need for Gamma Knife radiosurgery were analyzed. Facial nerve outcomes were quantified using House-Brackmann (HB) scores. Tumor regrowth was defined by the San Francisco criteria. Results  Four-hundred fifty-seven VS resections were performed in a 32-year period. Sixty cases met inclusion criteria. The mean (range) follow-up duration was 30.9 (12-103) months. The STR cohort ( n  = 33) demonstrated regrowth in 12 patients (36.3%) at an average of 23.6 months. The NTR cohort ( n  = 27) did not experience tumor recurrence. Risk of tumor recurrence was positively correlated with preoperative tumor size ( p  = 0.002), size of residual tumor ( p  < 0.001), and STR ( p  < 0.001). Facial nerve outcomes of HB1-2 were observed in the majority of patients in both cohorts (74.1% NTR, 56% STR), though NTR was associated with a higher likelihood of facial nerve recovery ( p  = 0.003). Conclusion  GTR remains the gold standard as long as facial nerve outcomes remain acceptable. NTR achieved superior tumor control and higher likelihood of facial nerve recovery compared with STR.

Incidence of Prolonged Systemic Steroid Treatment after Surgery for Acoustic Neuroma and Its Implications

Objectives  To determine the incidence of prolonged postoperative systemic corticosteroid therapy after surgery for acoustic neuroma as well as the indications and associated risk factors that could lead to prolonged steroid administration, and the incidence of steroid-related adverse effects. Study Designs  Retrospective chart review. Methods  Retrospective chart review of patients undergoing resection of acoustic neuroma between 2010 and 2017 at two tertiary care medical centers. Patient and tumor characteristics, operative approach, hospital length of stay, initial postoperative taper length, number of discrete postoperative steroid courses, and postoperative complications were analyzed. Results  There were 220 patients (99 male, 121 female) with an average age of 49.4 (range 16-78). There were 124 left-sided tumors and 96 right-sided tumors. Within the group, 191 tumors were operated through a retrosigmoid approach, 25 tumors through a translabyrinthine approach, and 4 tumors with a combined retrosigmoid-translabyrinthine approach under the same anesthetic. In total, 35 (15.9%) patients received an extended initial course of postoperative systemic steroids, defined as a taper longer than 18 days. Twenty six (11.8%) patients received additional courses of systemic steroids after the initial postoperative taper. There were 5 (2.3%) patients who required an extended initial taper as well as additional courses of steroids. Aseptic meningitis, often manifested as headache, was the most common indication for additional steroids (14 cases of prolonged taper and 17 cases of additional courses). None of the patient or tumor factors including age, gender, side, size, and approach were statistically significantly associated with either a prolonged initial steroid taper or additional courses of steroids. An extended hospital length of stay was associated with a prolonged initial steroid taper ( p  = 0.03), though the initial taper length was not predictive of additional courses of steroids. The cumulative number of days on steroids was associated with need for additional procedures ( p  < 0.01) as well as steroid-related side effects ( p  = 0.05). The administration of steroids was not found to significantly improve outcomes in postoperative facial paresis. Steroid-related complications were uncommon, seen in 9.26% of patients receiving steroids, with the most common being psychiatric side effects such as agitation, anxiety, and mood lability. Conclusions Systemic corticosteroids are routinely administered postoperatively for patients undergoing craniotomy for the resection of acoustic neuromas. In a review of 220 patients operated by a single neurotologist, no patient or tumor factors were predictive of requiring prolonged initial steroid taper or additional courses of steroids. The cumulative number of days on systemic steroids was associated with undergoing additional procedures and steroid-related side effects. The most common indications for prolonged or additional steroids were aseptic meningitis, cerebrospinal fluid leak, and facial paresis. Additional steroids for postoperative facial paresis did not significantly improve outcomes. Patient-reported steroid-related complications were infrequent and were most commonly psychiatric including agitation, anxiety, and mood lability.

[The efficacy of botulinum therapy in treatment of delayed facial palsy after resection of vestibular schwannoma]

Delayed facial palsy is a complication developing 3 or more days after surgery. The etiology and pathogenesis of this condition has not been fully explored, and there are no treatment standards for it. As in the case of Bell's paralysis, glucocorticosteroids (GCSs) are currently used to treat delayed facial palsy. However, patients with contraindications to GCSs need new therapy modalities.

AIM

We aimed to evaluate the efficacy and safety of botulinum therapy in patients with delayed facial palsy after neurosurgical interventions.

MATERIAL AND METHODS

We examined 33 patients with delayed facial palsy developed 3 or more days after resection of vestibular schwannoma. The main group included 18 patients with contraindications to GCSs who received injections of botulinum toxin A (BTA) into the facial muscles of the healthy side for muscle relaxation. The comparison group consisted of 15 patients who received a course of prednisolone (1 mg/kg/day) for 5-7 days. The efficacy of treatment was assessed using the House-Brackmann scale and Clinical Global Impression Scale. The follow-up period after therapy was 3 months.

RESULTS

Delayed facial palsy was more common in the following cases: the facial nerve was located near the antero-inferior tumor pole; the tumor was adherent to the facial nerve; the tumor extended in the oral direction; the tumor had with unclear borders and was 11 to 30 mm in size. In most patients of both groups, facial muscle palsy developed more than 11 days after surgery. Treatment both in the main and control groups resulted in a significant improvement: complete regression of the facial asymmetry in patients of the main group and comparison groups 3 months after treatment onset was 83.3 and 93.3% (House-Brackmann scale), respectively.

CONCLUSION

Botulinum therapy may be recommended for patients with delayed facial palsy developed after vestibular schwannoma resection, who have contraindications to GCSs.

Delayed Facial Nerve Paralysis after Vestibular Schwannoma Resection

Objective  To describe the incidence and clinical course of patients who develop delayed facial nerve paralysis (DFNP) after surgical resection of vestibular schwannoma. Setting  Tertiary skull base center. Methods  Retrospective chart review. Results  Two hundred and forty six consecutive patients, who underwent surgical resection for vestibular schwannoma at a single center between 2010 and 2015, were analyzed. Of these patients, 22 (8.9%) developed DFNP, defined here as deterioration of function by at least 2 House-Brackmann (HB) grades within 30 days in patients with immediate postoperative HB ≤ 3. The mean age of DFNP patients was 47.2 years (range: 17-67) and 16 (73%) were female. The mean tumor size in greatest dimension was 2.1 cm (range: 0.7-3.5 cm). At the conclusion of each case, the facial nerve stimulated at the brainstem. Mean immediate postoperative facial nerve function was HB 1.8 (range: 1-3). Average facial nerve function at the 3-week-postoperative visit was 4.4 (range: 2-6). In 1-year, 8 patients (36%) recovered HB 1 function, 10 patients (46%) recovered to HB 2, and 2 patients (9%) were HB 3. The remaining 2 patients did not recover function and were HB 6 at last follow-up. Initial postoperative facial nerve function (HB 1 or HB 2) was associated with improved recovery to normal (HB 1) function ( p  = 0.018). Conclusion  A majority of patients that develop delayed paralysis will recover excellent facial nerve function. Patients should be counseled; however, a small percentage of patients will not recover function long-term, despite having a previously functioning and anatomically intact nerve.

"Wait and scan" management of patients with vestibular schwannoma and the relevance of non-contrast MRI in the follow-up

Vestibular schwannoma (VS) is a slow-growing benign neoplasm. There has been an evolution in the management of VS from active treatments (microsurgery and stereotactic radiotherapy) to conservative management (wait and scan). Regular MRI scanning is necessary to monitor tumor progression. Conservative management causes significantly less complications and offers a higher quality of life compared with active treatments. The mean growth rate of VS varies from 0.4 to 2.9 mm/year, and spontaneous shrinkage is observed in 3.8 percent of tumors during observation. If significant growth occurs, active treatment is considered. Significant growth is defined as an increase of at least 3 mm in the largest extrameatal diameter in any plane between the first and last available scans. The vestibulocochlear nerve is surrounded by cerebrospinal fluid, which provides natural contrast for MRI; thus, gadolinium may not be needed to detect VS. Specific sequences have high sensitivity, specificity, and accuracy for detection of progression. Hypointense signal in the ipsilateral inner ear fluid might be a useful sign to distinguish VS from meningioma. In this paper, we summarize the current status of research on conservative management and non-contrast MRI for the detection of VS.

Multivariate Analysis of Factors Influencing Facial Nerve Outcome following Microsurgical Resection of Vestibular Schwannoma

Objective To assess through multivariate analysis the clinical pre- and intraoperative factors of facial nerve outcomes at day 8 and 1-year recovery of facial palsy, as compared with day 8 status among patients who underwent total resection of unilateral vestibular schwannoma. Study Design Case series with chart review. Setting Tertiary referral center. Subjects and Methods This study included 229 patients with preoperative normal facial function and anatomic preservation of the facial nerve. Clinical, radiologic, and intraoperative factors were assessed according to facial nerve function at day 8 and 1 year. Results We observed that 74% and 84% of patients had good facial function (House-Brackmann [HB] I-II) at day 8 and 1 year, respectively. Of 60 patients, 26 (43%) who had impaired facial function (HB III-VI) at day 8 recovered good facial function (HB I-II) 1 year after surgery. A structured equation model showed that advanced tumor stage and strong facial nerve adhesion were independently associated with facial nerve conduction block at day 8. No predictive factor of impaired facial function recovery was seen at 1 year. In terms of the extracanalicular diameter of the tumor, the cutoff point to minimize the risk of impaired facial function was 16 mm. Conclusion At day 8 after vestibular schwannoma resection, facial function was impaired in the case of large tumors or strong facial nerve adhesion to the tumor. After 1 year, less than half of the patients recovered good facial function, and no predictive factor was found to be associated with this possible recovery.

Functional Outcome of the Facial Nerve After Surgery for Vestibular Schwannoma: Prediction of Acceptable Long-Term Facial Nerve Function Based on Immediate Postoperative Facial Palsy

OBJECTIVE

To examine the relationship between immediate postoperative facial palsy and long-term facial palsy and identify a treatment strategy for vestibular schwannoma considering long-term outcomes of facial nerve function and tumor control.

METHODS

Patients (N = 385) who underwent surgery in a single institution were reviewed retrospectively; 12 patients with neurofibromatosis, 6 with preoperative radiosurgery, and 14 with multiple surgeries were excluded. The generalized estimating equation method was used to show the correlation between immediate and later postoperative facial palsy and to identify the cutoff grade of immediate postoperative facial palsy.

RESULTS

The tumor control rates for 1 year, 3 years, and 5 years were 88.7%, 83.9%, and 80.0%. Preservation of facial function above House-Brackmann (H-B) grades 1 and 2 was achieved in 47.9% of patients immediately postoperatively, in 50.1% after 1 month, and in 74.5% after >2 years. The immediate postoperative facial palsy grade showed a statistically significant relationship with the facial palsy grade on long-term follow-up (P < 0.001). H-B grade 3 immediate postoperative facial palsy was identified as the cutoff grade that showed the most significant relationship between the grade of immediate postoperative facial palsy and the grades above the cutoff (H-B grade 1-3) on long-term follow-up (P < 0.001).

CONCLUSIONS

H-B grade of immediate postoperative facial palsy can predict facial palsy at long-term follow-up. H-B grade 3 immediate postoperative facial palsy is the lowest tolerable grade that guarantees functional improvement on long-term follow-up. Planned facial nerve preservation surgery followed by radiosurgery is thought to be optimal treatment in patients with vestibular schwannoma for both tumor control and facial nerve function.