The Offprint of an Abnormal Pre-Parotidectomy Electrodiagnostic Finding in a Normally Functioning Facial Nerve: Correlation with Intraoperative Findings, Histology and Postoperative Facial Nerve Function

The aim of this study was to search for associations between an electrodiagnostically abnormal but clinically normal facial nerve before parotidectomy and the intraoperative findings, as well as the postoperative facial nerve function. The records of all patients treated for parotid tumors between 2002 and 2021 with a preoperative House–Brackmann score of grade I but an abnormal electrophysiologic finding were studied retrospectively. A total of 285 patients were included in this study, and 222 patients had a benign lesion (77.9%), whereas 63 cases had a malignant tumor (22.1%). Electroneurographic facial nerve involvement was associated with nerve displacement in 185 cases (64.9%) and infiltration in 17 cases (6%). In 83 cases (29.1%), no tumor–nerve interface could be detected intraoperatively. An electroneurographic signal was absent despite supramaximal stimulation in 6/17 cases with nerve infiltration and in 17/268 cases without nerve infiltration (p < 0.001). The electrophysiologic involvement of a normal facial nerve is not pathognomonic for a malignancy (22%), but it presents a rather rare (~6%) sign of a “true” nerve infiltration and could also appear in tumors without any contact with the facial nerve (~29%). Of our cases, two thirds of those with an anatomic nerve preservation and facial palsy had already directly and postoperatively recovered to a major extent in the midterm.

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Causes of Facial Nerve Paresis after Translabyrinthine Surgery for Acoustic Neuroma

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348949210101004 ◽

1992 ◽

Vol 101 (10) ◽

pp. 821-826 ◽

Cited By ~ 18

Author(s):

Mirko Tos ◽

Jens Thomsen ◽

Mahmoud Youssef ◽

Suat Turgut

Keyword(s):

Facial Nerve ◽

Brain Stem ◽

Acoustic Neuroma ◽

Facial Palsy ◽

Cerebellopontine Angle ◽

Patient Records ◽

Nerve Function ◽

Facial Nerve Function ◽

Common Site ◽

Nerve Paresis

Forty-six consecutive video-recorded translabyrinthine operations at Gentofte Hospital, for tumors of 5 to 25 mm, were investigated for possible damage to the facial nerve from cauterization, suction, stretching, pushing, and other instrumental trauma at the following regions: fundus, internal meatus, porus, cerebellopontine angle, and brain stem. House-Brackmann grading of the postoperative facial nerve function was determined from the patient records for the 1st, 3rd, and 10th days and 3 months and 6 months postoperatively, as well as the final status. Suction on the nerve seems to be the most important factor for perioperative facial nerve damage. The most common site of damage was the porus region. This investigation shows thermic drilling lesions to be very relevant. There was no correlation between the degree and character of damage and the postoperative facial nerve function. In eight patients we cannot explain the postoperative facial palsy.

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Retrosigmoid Transmeatal Approach for Resection of Acoustic Neuroma: Operative Video and Technical Nuances of Subperineural Dissection for Facial Nerve Preservation

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0039-1688488 ◽

2019 ◽

Vol 80 (S 03) ◽

pp. S269-S270

Author(s):

James K. Liu ◽

Vincent N. Dodson ◽

Robert W. Jyung

Keyword(s):

Facial Nerve ◽

Acoustic Neuroma ◽

Protective Layer ◽

Nerve Function ◽

Facial Nerve Function ◽

Tumor Removal ◽

Nerve Preservation ◽

Tumor Capsule ◽

Acoustic Neuromas ◽

Dissection Technique

The retrosigmoid (suboccipital) approach is the workhorse for most acoustic neuromas in the cerebellopontine angle. In this operative video atlas manuscript, the authors demonstrate the nuances of the subperineural dissection technique for microsurgical resection of an acoustic neuroma via the retrosigmoid transmeatal approach. The plane is developed by separating the perineurium of the vestibular nerve away from the tumor capsule. This perineurium provides a protective layer between the tumor capsule and the facial nerve which serves as a buffer to avoid direct dissection and potential trauma to the facial nerve. Using this technique during extracapsular tumor dissection helps to maximize the extent of tumor removal while preserving facial nerve function. A gross total resection of the tumor was achieved, and the patient exhibited normal facial nerve function (Fig. 1). In summary, the retrosigmoid transmeatal approach with the use of subperineural dissection are important strategies in the armamentarium for surgical management of acoustic neuromas with the goal of maximizing tumor removal and preserving facial nerve function (Fig. 2).The link to the video can be found at: https://youtu.be/L3lPtSvJt60.

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Translabyrinthine Approach for Resection of Large Cystic Acoustic Neuroma: Operative Video and Technical Nuances of Subperineural Dissection for Facial Nerve Preservation

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0039-1685534 ◽

2019 ◽

Vol 80 (S 03) ◽

pp. S267-S268

Author(s):

James K. Liu ◽

Vincent N. Dodson ◽

Robert W. Jyung

Keyword(s):

Hearing Loss ◽

Facial Nerve ◽

Acoustic Neuroma ◽

Nerve Function ◽

Facial Nerve Function ◽

Nerve Preservation ◽

Translabyrinthine Approach ◽

Acoustic Neuromas ◽

Extracapsular Dissection ◽

Cerebellar Retraction

The translabyrinthine approach is advantageous for the resection of large acoustic neuromas compressing the brainstem when hearing loss is nonserviceable. This approach provides wide access through the presigmoid corridor without prolonged cerebellar retraction. Early identification of the facial nerve at the fundus is also achieved. In this operative video atlas manuscript, the authors demonstrate a step-by-step technique for microsurgical resection of a large cystic acoustic neuroma via a translabyrinthine approach. The nuances of microsurgical and skull base technique are illustrated including performing extracapsular dissection of the tumor while maintaining a subperineural plane of dissection to preserve the facial nerve. This strategy maximizes the extent of removal while preserving facial nerve function. A microscopic remnant of tumor was left adherent to the perineurium. A near-total resection of the tumor was achieved and the facial nerve stimulated briskly at low thresholds. Other than preexisting hearing loss, the patient was neurologically intact with normal facial nerve function postoperatively. In summary, the translabyrinthine approach and the use of subperineural dissection are important strategies in the armamentarium for surgical management of large acoustic neuromas while preserving facial nerve function.The link to the video can be found at: https://youtu.be/zld2cSP8fb8.

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Congenital facial nerve agenesis

The Journal of Laryngology & Otology ◽

10.1258/0022215011906795 ◽

2001 ◽

Vol 115 (1) ◽

pp. 53-54 ◽

Cited By ~ 6

Author(s):

P. N. Jervis ◽

P. D. Bull

Keyword(s):

Surgical Treatment ◽

Parotid Gland ◽

Facial Nerve ◽

Facial Paralysis ◽

Facial Palsy ◽

Surgical Procedure ◽

Nerve Function ◽

Facial Nerve Function ◽

Stylomastoid Foramen ◽

Unrelated Condition

We present a case of a seven-year-old child with a congenital facial palsy, diagnosed at birth, who subsequently developed a non-tuberculous mycobacterial (NTM) infection of the ipsilateral parotid gland. This required parotid exploration to treat the NTM disease with the intention of identifying and protecting the facial nerve to preserve any residual facial nerve function. At operation, thorough exploration revealed the complete absence of the nerve both at the stylomastoid foramen and more peripherally within the substance of the parotid gland. Exploration of the facial nerve for congenital facial paralysis is not normally indicated. Surgical treatment, if required, tends to involve the use of techniques such as cross facial nerve and free vascularized muscle grafting. To our knowledge this is the first reported case of complete congenital facial nerve agenesis, diagnosed incidentally during a surgical procedure for an unrelated condition.

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Role of electrophysiology in guiding near-total resection for preservation of facial nerve function in the surgical treatment of large vestibular schwannomas

Journal of Neurosurgery ◽

10.3171/2016.11.jns161737 ◽

2018 ◽

Vol 128 (3) ◽

pp. 903-910 ◽

Cited By ~ 11

Author(s):

Daniele Bernardeschi ◽

Nadya Pyatigorskaya ◽

Antoine Vanier ◽

Franck Bielle ◽

Mustapha Smail ◽

...

Keyword(s):

Surgical Treatment ◽

Facial Nerve ◽

Residual Tumor ◽

Incomplete Resection ◽

Nerve Function ◽

Inclusion Criteria ◽

Facial Nerve Function ◽

Total Resection ◽

Supramaximal Stimulation ◽

Stimulation Of

OBJECTIVEIn large vestibular schwannoma (VS) surgery, the facial nerve (FN) is at high risk of injury. Near-total resection has been advocated in the case of difficult facial nerve dissection, but the amount of residual tumor that should be left and when dissection should be stopped remain controversial factors. The objective of this study was to report FN outcome and radiological results in patients undergoing near-total VS resection guided by electromyographic supramaximal stimulation of the FN at the brainstem.METHODSThis study was a retrospective analysis of a prospectively maintained database. Inclusion criteria were surgical treatment of a large VS during 2014, normal preoperative FN function, and an incomplete resection due to the strong adherence of the tumor to the FN and the loss of around 50% of the response of supramaximal stimulation of the proximal FN at 2 mA. Facial nerve function and the amount and evolution of the residual tumor were evaluated by clinical examination and by MRI at a mean of 5 days postoperatively and at 1 year postoperatively.RESULTSTwenty-five patients met the inclusion criteria and were included in the study. Good FN function (Grade I or II) was observed in 16 (64%) and 21 (84%) of the 25 patients at Day 8 and at 1 year postoperatively, respectively. At the 1-year follow-up evaluation (n = 23), 15 patients (65%) did not show growth of the residual tumor, 6 patients (26%) had regression of the residual tumor, and only 2 patients (9%) presented with tumor progression.CONCLUSIONSNear-total resection guided by electrophysiology represents a safe option in cases of difficult dissection of the facial nerve from the tumor. This seems to offer a good compromise between the goals of preserving facial nerve function and achieving maximum safe resection.

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Extra-Arachnoidal Dissection for Excision of Giant Vestibular Schwannomas: Improved Facial Nerve Preservation

Neurosurgery ◽

10.1093/neuros/nyz310_429 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Author(s):

Sunil K Gupta

Keyword(s):

Facial Nerve ◽

Vestibular Schwannomas ◽

Nerve Function ◽

Total Excision ◽

Facial Nerve Function ◽

Nerve Preservation ◽

Group A ◽

Grade 3 ◽

Group B

Abstract INTRODUCTION Surgical excision of giant vestibular schwannomas with preservation of facial nerve function remains a challenge. A modified surgical technique using an extra-arachnoid plane of dissection and limited meatal drilling is described here with the goal of improving the rated of functional preservation of facial nerve. METHODS The clinical material was analyzed for two groups: Group A patients of giant vestibular schwannomas operated between 2002 and 2009 with the “standard” surgical technique, Group B- patients of giant vestibular schwannomas operated between 2009 and 2015 using the new technique of pure extra-arachnoid dissection and limited meatal drilling. RESULTS Group A: Of the 115 patients in this group, total excision was possible in 103 (89.5%), near total excision in 7 (6%) and partial excision in 5 (4.3%) patients. Anatomical preservation of 7th nerve was achieved in 87.8% of patients. House and Brackman grade 1 and grade 2 facial nerve function was present in 68 (59.1%) patients, grade 3 in 10 (8.7%), grades 4 and 5 in 11 (9.6%), and 26 (22.6%) had grade 6 facial nerve involvement. Group B: Of the 127 patients operated by this technique, details and long term follow-up was available for 98 patients. Total excision was achieved in 70 (71.4%) patients, near total excision in 9 (9.2%), and subtotal excision in 19 (19.4%) cases. Four patients had repeat surgery and 14 patients underwent gamma knife radiosurgery. At follow-up, 78 (79.5%) patients had grade 1 and 2 facial nerve involvement, while 20 (20.4%) patients continued to have a poor function (grade 3-5). CONCLUSION Extra-arachnoid dissection and limited meatal drilling resulted in an improved rate of functional facial nerve preservation.

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Viral Titers and Delayed Facial Palsy after Acoustic Neuroma Surgery

Otolaryngology ◽

10.1067/mhn.2002.129817 ◽

2002 ◽

Vol 127 (5) ◽

pp. 427-431 ◽

Cited By ~ 25

Author(s):

Gerard J. Gianoli

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Facial Nerve ◽

Acoustic Neuroma ◽

Facial Palsy ◽

Nerve Function ◽

Facial Nerve Function ◽

Acoustic Neuroma Surgery ◽

Simplex Virus ◽

Viral Titers

OBJECTIVE: Delayed facial palsy (DFP) after acoustic neuroma surgery has been reported to occur in up to one third of cases. Reactivation of latent virus has been proposed as an etiology for DFP. However, only retrospective case reports and case series have offered data to support this theory. The objective of this study was to correlate DFP with change in viral titers. PATIENTS AND METHODS: Twenty consecutive patients who underwent acoustic neuroma surgery were prospectively evaluated for viral titers immediately preoperatively and at 3 weeks postoperatively. Viral titers measured included herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2), and varicella zoster virus (VZV) and included both IgG and IgM titers. The status of facial nerve function was documented preoperatively and throughout the postoperative period. Patients were categorized according to the presence or absence of DFP. RESULTS: Seven patients developed DFP after acoustic neuroma surgery, while the remaining 13 patients did not. There was no difference in preoperative and 3-week postoperative IgG titers for any of the 3 viruses tested. However, IgM titers were much higher postoperatively in DFP patients for all 3 viruses tested. The average HSV-1 IgM titer rose 92% in DFP patients compared with only 4.5% in the patients who did not develop DFP. Average HSV-2 IgM titers rose 70% compared with a decline of 8.5% in non-DFP patients. Most strikingly, VZV IgM titers rose an average 495% postoperatively among DFP patients compared with a decline of 14% in the non-DFP patients. CONCLUSION: Elevation of the IgM titers of the viruses measured in this study implies that recrudescence of the virus has occurred. The absence of this rise among patients who did not develop DFP implies that viral recrudescence plays a role in the etiology of DFP. These findings support treatment or prophylaxis of DFP with antiviral therapy. Although the finding of normal facial nerve function immediately after acoustic neuroma surgery is an excellent prognostic indicator for the ultimate outcome of facial nerve function, it is not uncommon for the patient to exhibit deterioration of facial nerve function in the first few days to weeks after surgery. When facial palsy is not complete, the prognosis remains excellent. However, when there is total loss of facial nerve function, the final outcome is more variable. Delayed facial palsy (DFP) after acoustic neuroma surgery has been defined as initially normal facial nerve function noted immediately postoperative with subsequent deterioration of facial nerve function. 1 This phenomenon has been noted to occur in up to one third of cases. Numerous causes for this entity have been proposed, including neural devascularization, vasospasm, edema, immune reactions, and viral reactivation. Varicella zoster virus (VZV) and herpes simplex virus (HSV) are ubiquitous, with more than 90% of the adult population demonstrating evidence of prior infection. 2 Reactivation of latent VZV has been implicated as the cause of Ramsay Hunt syndrome. 3 There is mounting evidence that HSV reactivation is the cause of Bell's palsy. 4 In the present study, viral titers for VZV and HSV were assessed before and after acoustic neuroma surgery. DFP and non-DFP patients were compared in an attempt to determine whether there was any correlation between viral recrudescence and DFP.

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Improved preservation of hearing and facial nerve function in vestibular schwannoma surgery via the retrosigmoid approach in a series of 200 patients

Journal of Neurosurgery ◽

10.3171/jns.2006.105.4.527 ◽

2006 ◽

Vol 105 (4) ◽

pp. 527-535 ◽

Cited By ~ 221

Author(s):

Madjid Samii ◽

Venelin Gerganov ◽

Amir Samii

Keyword(s):

Facial Nerve ◽

Hearing Preservation ◽

Neurological Status ◽

Retrosigmoid Approach ◽

Cerebrospinal Fluid Leakage ◽

Nerve Function ◽

Facial Nerve Function ◽

Nerve Preservation ◽

Permanent Morbidity

Object The aim of this study was to evaluate and present the results of current surgical treatment of vestibular schwannomas (VSs) and to report the refinements in the operative technique. Methods The authors performed a retrospective study of 200 consecutive patients who had undergone VS surgery over a 3-year period. Patient records, operative reports, follow-up data, and neuroradiological findings were analyzed. The main outcome measures were magnetic resonance imaging, neurological status, patient complaints, and surgical complications. Complete tumor removal was achieved in 98% of patients. Anatomical preservation of the facial nerve was possible in 98.5% of patients. In patients treated for tumors with extension Classes T1, T2, and T3, the rate of facial nerve preservation was 100%. By the last follow-up examination, excellent or good facial nerve function had been achieved in 81% of the cases. By at least 1 year postsurgery, no patients had total facial palsy. In the patients with preserved hearing, the rate of anatomical preservation of the cochlear nerve was 84%. The overall rate of functional hearing preservation was 51%. There was no surgery-related permanent morbidity in this series of patients. Cerebrospinal fluid leakage was diagnosed in 2% of the patients. The mortality rate was 0%. Conclusions The goal of VS treatment should be total removal in one stage and preservation of neurological function, as they determine a patient’s quality of life. This goal can be safely and successfully achieved using the retrosigmoid approach.

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Prophylactic nimodipine treatment for cochlear and facial nerve preservation after vestibular schwannoma surgery: a randomized multicenter Phase III trial

Journal of Neurosurgery ◽

10.3171/2015.1.jns142001 ◽

2016 ◽

Vol 124 (3) ◽

pp. 657-664 ◽

Cited By ~ 20

Author(s):

Christian Scheller ◽

Andreas Wienke ◽

Marcos Tatagiba ◽

Alireza Gharabaghi ◽

Kristofer F. Ramina ◽

...

Keyword(s):

Treatment Group ◽

Facial Nerve ◽

Hydroxyethyl Starch ◽

Phase Iii ◽

Control Group ◽

Nerve Function ◽

Facial Nerve Function ◽

Phase Iii Trial ◽

Nerve Preservation ◽

Multicenter Phase

OBJECT A pilot study of prophylactic nimodipine and hydroxyethyl starch treatment showed a beneficial effect on facial and cochlear nerve preservation following vestibular schwannoma (VS) surgery. A prospective Phase III trial was undertaken to confirm these results. METHODS An open-label, 2-arm, randomized parallel group and multicenter Phase III trial with blinded expert review was performed and included 112 patients who underwent VS surgery between January 2010 and February 2013 at 7 departments of neurosurgery to investigate the efficacy and safety of the prophylaxis. The surgery was performed after the patients were randomly assigned to one of 2 groups using online randomization. The treatment group (n = 56) received parenteral nimodipine (1–2 mg/hr) and hydroxyethyl starch (hematocrit 30%–35%) from the day before surgery until the 7th postoperative day. The control group (n = 56) was not treated prophylactically. RESULTS Intent-to-treat analysis showed no statistically significant effects of the treatment on either preservation of facial nerve function (35 [67.3%] of 52 [treatment group] compared with 34 [72.3%] of 47 [control group]) (p = 0.745) or hearing preservation (11 [23.4%] of 47 [treatment group] compared with 15 [31.2%] of 48 [control group]) (p = 0.530) 12 months after surgery. Since tumor sizes were significantly larger in the treatment group than in the control group, logistic regression analysis was required. The risk for deterioration of facial nerve function was adjusted nearly the same in both groups (OR 1.07 [95% CI 0.34–3.43], p = 0.91). In contrast, the risk for postoperative hearing loss was adjusted 2 times lower in the treatment group compared with the control group (OR 0.49 [95% CI 0.18–1.30], p = 0.15). Apart from dose-dependent hypotension (p < 0.001), no clinically relevant adverse reactions were observed. CONCLUSIONS There were no statistically significant effects of the treatment. Despite the width of the confidence intervals, the odds ratios may suggest but do not prove a clinically relevant effect of the safe study medication on the preservation of cochlear nerve function after VS surgery. Further study is needed before prophylactic nimodipine can be recommended in VS surgery.

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Efficacy and outcomes of facial nerve–sparing treatment approach to cerebellopontine angle meningiomas

Journal of Neurosurgery ◽

10.3171/2016.10.jns161982 ◽

2017 ◽

Vol 127 (6) ◽

pp. 1231-1241 ◽

Cited By ~ 5

Author(s):

Randy S. D'Amico ◽

Matei A. Banu ◽

Petros Petridis ◽

Alexandra S. Bercow ◽

Hani Malone ◽

...

Keyword(s):

Facial Nerve ◽

Extent Of Resection ◽

Nerve Sparing ◽

Nerve Function ◽

Facial Nerve Function ◽

Anatomical Features ◽

Nerve Preservation ◽

Facial Nerve Preservation ◽

Tumor Origin ◽

Microsurgical Resection

OBJECTIVEAdvanced microsurgical techniques contribute to reduced morbidity and improved surgical management of meningiomas arising within the cerebellopontine angle (CPA). However, the goal of surgery has evolved to preserve the quality of the patient's life, even if it means leaving residual tumor. Concurrently, Gamma Knife radiosurgery (GKRS) has become an acceptable and effective treatment modality for newly diagnosed, recurrent, or progressive meningiomas of the CPA. The authors review their institutional experience with CPA meningiomas treated with GKRS, surgery, or a combination of surgery and GKRS. They specifically focus on rates of facial nerve preservation and characterize specific anatomical features of tumor location with respect to the internal auditory canal (IAC).METHODSMedical records of 76 patients with radiographic evidence or a postoperative diagnosis of CPA meningioma, treated by a single surgeon between 1992 and 2016, were retrospectively reviewed. Patients with CPA meningiomas smaller than 2.5 cm in greatest dimension were treated with GKRS, while patients with tumors 2.5 cm or larger underwent facial nerve–sparing microsurgical resection where appropriate. Various patient, clinical, and tumor data were gathered. Anatomical features of the tumor origin as seen on preoperative imaging confirmed by intraoperative investigation were evaluated for prognostic significance. Facial nerve preservation rates were evaluated.RESULTSAccording to our treatment paradigm, 51 (67.1%) patients underwent microsurgical resection and 25 (32.9%) patients underwent GKRS. Gross-total resection (GTR) was achieved in 34 (66.7%) patients, and subtotal resection (STR) in 17 (33.3%) patients. Tumors recurred in 12 (23.5%) patients initially treated surgically, requiring additional surgery and/or GKRS. Facial nerve function was unchanged or improved in 68 (89.5%) patients. Worsening facial nerve function occurred in 8 (10.5%) patients, all of whom had undergone microsurgical resection. Upfront treatment with GKRS for CPA meningiomas smaller than 2.5 cm was associated with preservation of facial nerve function in all patients over a median follow-up of 46 months, regardless of IAC invasion and tumor origin. Anatomical origin was associated with extent of resection but did not correlate with postoperative facial nerve function. Tumor size, extent of resection, and the presence of an arachnoid plane separating the tumor and the contents of the IAC were associated with postoperative facial nerve outcomes.CONCLUSIONSCPA meningiomas remain challenging lesions to treat, given their proximity to critical neurovascular structures. GKRS is a safe and effective option for managing CPA meningiomas smaller than 2.5 cm without associated mass effect or acute neurological symptoms. Maximal safe resection with preservation of neurological function can be performed for tumors 2.5 cm or larger without significant risk of facial nerve dysfunction, and, when combined with GKRS for recurrence and/or progression, provides excellent disease control. Anatomical features of the tumor origin offer critical insights for optimizing facial nerve preservation in this cohort.

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