Significance of Arachnoid Dissection to Obtain Optimal Exposure of Lower Cranial Nerves and the Facial Nerve Root Exit Zone during Microvascular Decompression Surgery

Glossopharyngeal neuralgia (GPN) is an uncommon facial pain syndrome often misdiagnosed as trigeminal neuralgia. The rarity of this condition and its overlap with other cranial nerve hyperactivity syndromes often leads to a significant delay in diagnosis. The surgical procedures with the highest rates of pain relief for GPN are rhizotomy and microvascular decompression (MVD) of cranial nerves IX and X. Neurovascular conflict at the level of the root exit zone of these cranial nerves is believed to be the cause of this pain syndrome in most cases. Vagus nerve rhizotomy is usually reserved for cases in which vascular conflict is not evident. A review of the literature reveals that although the addition of cranial nerve X rhizotomy may improve the chances of long-term pain control, this maneuver also increases the risk of permanent dysphagia and vocal cord paralysis. The risks of this procedure have to be carefully weighed against its benefits. Based on the authors' experience, careful patient selection with a thorough exploratory operation most often leads to identification of the site of vascular conflict, obviating the need for cranial nerve X rhizotomy.

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Interventional Neuroradiology in Hemifacial Spasm

Interventional Neuroradiology ◽

10.1177/15910199970030s204 ◽

1997 ◽

Vol 3 (2_suppl) ◽

pp. 32-36 ◽

Cited By ~ 1

Author(s):

K. Yamashita ◽

S. Okamoto ◽

K. Hosotani ◽

S. Nakatsu ◽

M. Hojo ◽

...

Keyword(s):

Facial Nerve ◽

Hemifacial Spasm ◽

Microvascular Decompression ◽

Contrast Material ◽

Interventional Neuroradiology ◽

Decompression Surgery ◽

Neurovascular Compression ◽

Root Exit Zone ◽

Functional Investigation ◽

Microvascular Decompression Surgery

There have never been functional studies in the diagnosis of hemifacial spasm caused by neurovascular compression. We used neurointerventional techniques to conduct a functional investigation of the artery responsible for hemifacial spasm in seven patients. A microcatheter was inserted into the various arteries of the posterior circulation under systemic heparinization, and its effect on the spasm was evaluated clinically and electromyographically. In six patients who underwent microvascular decompression surgery, the vessels compressing the root exit zone of the facial nerve were surgically determined, and compared with the result of the procedure. The catheter was inserted into twelve arteries. The spasms were stopped immediately and completely by the insertion of the catheter into seven arteries. Six of them were surgically proven to compress the root exit zone of the facial nerve. The spasm was changed in frequency or in type by the insertion into two arteries. These arteries were also compressing the root exit zone. One artery was located at a more peripheral part of it and the other was running over another artery compressing the root exit zone. The spasms were not affected at all by the insertion into three arteries. These arteries were not observed in the operative field and had no contact with the nerve. Superselective ‘angiograms showedpositional qnd configurational changes of the arteries. There was no arterial spasm and tight catheterization leading to stasis of contrast material within the arteries. There were no complications related to the procedures. Functional relationship between the artery and the spasms was established in all the patients, and one patient refused surgery because the frequency of the spasm was reduced by the procedure. The result of this study may suggest that a functional investigation of hemifacial spasm is feasible and seems useful for selecting good candidates for microvascular decompression surgery.

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Hemifacial spasm

Journal of Neurosurgery ◽

10.3171/jns.1982.57.6.0753 ◽

1982 ◽

Vol 57 (6) ◽

pp. 753-756 ◽

Cited By ~ 77

Author(s):

Tsutomu Iwakuma ◽

Akihisa Matsumoto ◽

Nishio Nakamura

Keyword(s):

Facial Nerve ◽

Hemifacial Spasm ◽

Microvascular Decompression ◽

Nerve Root ◽

Posterior Inferior Cerebellar Artery ◽

Content Type ◽

Stylomastoid Foramen ◽

Root Exit Zone ◽

Selective Neurectomy ◽

Fine Print

✓ Patients with hemifacial spasm were treated by three different surgical procedures: 1) partial sectioning of the facial nerve just distal to the stylomastoid foramen; 2) selective neurectomy of facial nerve branches; and 3) microvascular decompression. A retromastoid craniectomy with microvascular decompression was most effective in relieving hemifacial spasm and synkinesis. In a postmorten examination on one patient, microscopic examination of the facial nerve, which was compressed by an arterial loop of the posterior inferior cerebellar artery at the cerebellopontine angle, revealed fascicular demyelination in the nerve root. On the basis of surgical treatment, electromyography, and neuropathological findings, the authors conclude that compression of the facial nerve root exit zone by vascular structures is the main cause of hemifacial spasm and synkinesis.

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Importance of awareness of the rhomboid lip in microvascular decompression surgery for hemifacial spasm

Journal of Neurosurgery ◽

10.3171/2013.4.jns121546 ◽

2013 ◽

Vol 119 (4) ◽

pp. 1038-1042 ◽

Cited By ~ 10

Author(s):

Yukiko Nakahara ◽

Toshio Matsushima ◽

Tetsuya Hiraishi ◽

Tetsuro Takao ◽

Takeshi Funaki ◽

...

Keyword(s):

Hemifacial Spasm ◽

Microvascular Decompression ◽

Fourth Ventricle ◽

Ventral Side ◽

Preoperative Imaging ◽

Decompression Surgery ◽

Mr Images ◽

Root Exit Zone ◽

Inferior Portion ◽

Microvascular Decompression Surgery

Object The authors adopted the infrafloccular approach for microvascular decompression (MVD) surgery to treat hemifacial spasm (HFS). The inferior portion of the flocculus is retracted to observe the root exit zone of cranial nerve (CN) VII between CN IX and the flocculus. During the procedure, the rhomboid lip, a sheetlike layer of neural tissue forming the lateral recess of the fourth ventricle, is sometimes encountered. The existence of the rhomboid lip in cases of HFS was reviewed to determine the importance of the structure during MVD surgery. Methods Preoperative imaging and intraoperative observations in 34 consecutive cases of HFS treated in the period from October 2008 through September 2011 were used to assess the frequency of encountering the rhomboid lip. Results The rhomboid lip was observed during MVD surgery in 9 (26.5%) of the 34 cases but had been demonstrated on preoperative MR images in only 3 cases (8.8%). On T2-weighted images, it appeared as a high-intensity nonstructural area on the ventral side of the flocculus and continued into the fourth ventricle via the foramen of Luschka. Conclusions A large rhomboid lip presents an impediment to MVD surgery in a significant minority of patients with HFS. It is seldom observed on preoperative MR images. Proper dissection of the rhomboid lip away from the arachnoid membrane and/or the lower CNs during MVD surgery provides good visualization of the root exit zone of CN VII and reduces injury of CNs IX and X, avoiding postoperative deficits like dysphagia.

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Failed microvascular decompression surgery for hemifacial spasm due to persistent neurovascular compression: an analysis of reoperations

Journal of Neurosurgery ◽

10.3171/2015.1.jns142714 ◽

2016 ◽

Vol 124 (1) ◽

pp. 90-95 ◽

Cited By ~ 18

Author(s):

Mark Gregory Bigder ◽

Anthony M. Kaufmann

Keyword(s):

Hemifacial Spasm ◽

Microvascular Decompression ◽

Senior Author ◽

Decompression Surgery ◽

Neurovascular Compression ◽

Exit Point ◽

Root Exit Zone ◽

Prior Surgery ◽

Microvascular Decompression Surgery

OBJECT Microvascular decompression (MVD) surgery for hemifacial spasm (HFS) is potentially curative. The findings at repeat MVD in patients with persistent or recurrent HFS were analyzed with the aim to identify factors that may improve surgical outcomes. METHODS Intraoperative findings were determined from review of dictated operative reports and operative diagrams for patients who underwent repeat MVD after prior surgery elsewhere. Clinical follow-up was obtained from the hospital and clinic records, as well as telephone questionnaires. RESULTS Among 845 patients who underwent MVD performed by the senior author, 12 had been referred after prior MVD for HFS performed elsewhere. Following repeat MVD, all patients improved and complete spasm resolution was described by 11 of 12 patients after a mean follow-up of 91 ± 55 months (range 28–193). Complications were limited to 1 patient with aggravation of preexisting hearing loss and mild facial weakness and 1 patient with aseptic meningitis without sequelae. Significant factors that may have contributed to the failure of the first surgery included retromastoid craniectomies that did not extend laterally to the sigmoid sinus or inferiorly to the posterior fossa floor in 11 of 12 patients and a prior surgical approach that focused on the cisternal portion of the facial nerve in 9 of 12 patients. In all cases, significant persistent neurovascular compression (NVC) was evident and alleviated more proximally on the facial root exit zone (fREZ). CONCLUSIONS Most HFS patients will achieve spasm relief with thorough alleviation of NVC of the fREZ, which extends from the pontomedullary sulcus root exit point to the Obersteiner-Redlich transition zone.

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219 A Clinical Analysis on Microvascular Decompression Surgery for Treatment of Hemifacial Spasm: 2500 Cases Review in a Single Institute

Neurosurgery ◽

10.1093/neuros/nyx417.219 ◽

2017 ◽

Vol 64 (CN_suppl_1) ◽

pp. 259-260

Author(s):

Myeongki Yeo ◽

Bong Jin Park ◽

Hridayesh Pratap Malla ◽

Bong Arm Rhee ◽

Young Jin Lim

Keyword(s):

Hemifacial Spasm ◽

Microvascular Decompression ◽

Clinical Analysis ◽

Postoperative Outcomes ◽

Cerebrospinal Fluid Leakage ◽

Subdural Hemorrhage ◽

Decompression Surgery ◽

Vascular Compression ◽

Root Exit Zone ◽

Microvascular Decompression Surgery

Abstract INTRODUCTION Hemifacial spasm (HFS) is caused by vascular compression of the facial nerve at its root exit zone from the brainstem. Microvascular decompression (MVD) is the only treatment option that offers the prospect of a definitive cure for HFS. However, this surgery can be risky and the postoperative outcomes might not be good enough sometimes. In order to refine that, we investigated our result of MVDs. METHODS Among 2500 consecutive cases of MVDs have been performed in our institute between January 2000 and December 2015, 2196 patients were enrolled in the current study. They were retrospectively analyzed with emphasis on postoperative outcomes and complications. RESULTS >Postoperatively, the spasm complete cease occurred immediately in 73.4%. The symptoms improved at some degree in 22.7%. The spasm not improved at all in 3.9%. However, the symptom free rate was 88.3% at 6 months after surgery. Eventually, the successful rate was increased by 93.1% at 1 year after MVD. Major complications included permanent hearing disturbance (1.13%), permanent facial palsy (0.4%), vertebral artery injury (0.2%), subdural hemorrhage (0.2%), and epidural hemorrhage (0.1%). Minor complications included transient cerebrospinal fluid leakage (1.3%), infection (0.6%). CONCLUSION MVD is a safe and effective treatment for HFS. A precise recognition of the neurovascular conflict site lead to a successful MVD.

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Microanatomy Around the Facial Nerve Pathway for Microvascular Decompression Surgery Investigated with Correlative Light Microscopy and Block-Face Imaging

World Neurosurgery ◽

10.1016/j.wneu.2018.06.228 ◽

2018 ◽

Vol 118 ◽

pp. e526-e533 ◽

Cited By ~ 1

Author(s):

Keiya Iijima ◽

Yuki Tajika ◽

Yukitaka Tanaka ◽

Hiroshi Yorifuji ◽

Yuhei Yoshimoto

Keyword(s):

Facial Nerve ◽

Light Microscopy ◽

Microvascular Decompression ◽

Decompression Surgery ◽

Block Face ◽

Microvascular Decompression Surgery

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Crocodile tear syndrome post microvascular decompression of the trigeminal nerve: a case report and literature review

10.21203/rs.3.rs-961587/v1 ◽

2021 ◽

Author(s):

Mohammad H Abul

Keyword(s):

Facial Nerve ◽

Trigeminal Nerve ◽

Microvascular Decompression ◽

Botulinum Toxin Injection ◽

Csf Leak ◽

Decompression Surgery ◽

First Case ◽

Initial Surgery ◽

Long Term Follow Up ◽

Microvascular Decompression Surgery

Abstract Background Crocodile tear syndrome (CTS) is a condition characterised by excessive tear secretion in response to eating, drinking, or smelling foods. Traditionally, acquired cases are most commonly reported following facial nerve trauma or paralysis, or in slow-growing facial nerve tumours. More recently, it has been reported following vestibular Schwannoma surgery. We report the first case of crocodile tear syndrome following microvascular decompression of the trigeminal nerve. Case presentation A 61-year-old lady presented with excessive lacrimation and clear rhinorrhoea one month post-operatively from a re-do trigeminal microvascular decompression surgery. The patient experienced similar symptoms following her initial surgery two years prior, which had resolved spontaneously. CT and MRI head, and comprehensive clinical examination showed no evidence of CSF rhinorrhoea or cause of her symptoms. An ENT opinion was sought, and the patient was diagnosed with post-operative crocodile tear syndrome.Literature review revealed no reported cases of CTS following microvascular decompression of the trigeminal nerve. Surgical technique and relevant imaging were reviewed for any possible explanation for the condition. Considering the accepted pathogenesis of CTS, we discuss the aetio-pathogenesis for the development of the condition following this procedure. Conclusions We conclude CTS should be considered in patients presenting with rhinorrhoea following microvascular decompression of the trigeminal nerve. In patients presenting with post-operative rhinorrhoea after MVD, after excluding CSF leak, CTS should be considered as a potential differential diagnosis. Treatment for CTS in this context may pose a challenge. The patient has undergone botulinum toxin injection of the lacrimal gland and will need long term follow up. This is the first documented case of CTS post microvascular decompression of the trigeminal nerve.

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Penetrating Offending Vessel, The Most Surgically Demanding Type during Microvascular Decompression Surgery in Hemifacial Spasm

Neurosurgery ◽

10.1093/neuros/nyz310_455 ◽

2019 ◽

Vol 66 (Supplement_1) ◽

Author(s):

Seunghoon Lee ◽

Kwan Park

Keyword(s):

Facial Nerve ◽

Hemifacial Spasm ◽

Microvascular Decompression ◽

Decompression Surgery ◽

Neurovascular Compression ◽

Extent Of Surgery ◽

Free Running ◽

The One ◽

Microvascular Decompression Surgery

Abstract INTRODUCTION Microvascular decompression (MVD) is the most effective and curative treatment option for neurovascular compression syndrome and it is increasingly performed around the world. This study aimed to identify and describe the most technically difficult cases, which were the patients with penetrating offending vessel through the facial nerve, from our experiences and to give surgical tips for the successful MVD. METHODS Surgical records and intraoperative video of hemifacial spasm patients with penetrating offending vessels were reviewed. Interposition of Teflon felt between nerve and vessel was pursued, and neurectomy was avoided as much as possible. RESULTS Five patients with hemifacial spasm were identified as having a penetrating offending vessel through the facial nerve during the last 5 yr of MVD surgery in our institution. Four AICAs and one PICA were the causative vessels. Partial neurectomy was required in 1 patient. During the median follow-up of 6 mo (range, 1-26), all patients were spasm-free. No patients including the one with partial neurectomy were involved in facial palsy or hearing loss. CONCLUSION MVD in HFS patients with penetrating offending vessel through the facial nerve is the most surgically challenging and demands a high surgical skill. Interposition with Teflon felt is effective and neurectomy should be avoided. Intraoperative monitoring of free-running EMG and abnormal muscle response are helpful to decide the extent of surgery.

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