Long-term results of vestibular nerve section

Regression of Endolymphatic Hydrops in Patient With Meniere's Disease Treated With Vestibular Neurectomy: A Case Report

Vestibular neurectomy is an effective method eliminating vertigo attacks in patients suffering from disabling Meniere's disease with no clinical improvement despite conservative and intratympanic therapy. Magnetic resonance imaging allows in vivo evaluation of changes manifesting in the inner ear after treatment; however, downgrading of the endolymphatic hydrops after vestibular neurectomy had not been previously described in the literature. In the present article, a case of a patient with unilateral severe Meniere's disease treated with selective vestibular nerve section from middle fossa approach was described. Clinical symptoms and audiovestibular tests were evaluated before and 13 months after the surgery. Complete resolution of vertigo episodes and hearing preservation was achieved. Magnetic resonance imaging was performed before and after the surgery using a 3 Tesla scanner with dedicated protocol after intravenous administration of gadolinium contrast agent. In the follow-up examination, regression of the cochlear and vestibular endolymphatic hydrops was visualized, which may suggest processes occurring in the labyrinth as a result of the vestibular efferent fibers section.

Changes in endolymphatic hydrops after vestibular neurectomy observed in magnetic resonance imaging - A pilot study

OBJECTIVES

The aim was to evaluate endolymphatic hydrops in patients with Ménière's disease before and after vestibular neurectomy to verify if the endolymphatic space dilatation, observed in magnetic resonance imaging, regressed within several months after surgery.

METHODS

Magnetic resonance imaging was performed after intravenous gadolinium injection in four patients with unilateral definite Ménière's disease before and eight months after vestibular neurectomy. Clinical symptoms, audiovestibular tests, and endolymphatic hydrops in magnetic resonance imaging were evaluated.

RESULTS

Endolymphatic hydrops was visualized in preoperative magnetic resonance imaging in three out of four analyzed patients. In the remaining one, an asymmetrical contrast enhancement in the affected ear was found. After the vestibular neurectomy, all four patients presented a complete resolution of vertigo episodes and improved functional level. Significant postoperative hearing deterioration was found in two patients. In the follow-up magnetic resonance imaging, no reduction of the endolymphatic hydrops was visualized. A reduction of asymmetrical contrast enhancement in one patient was found.

CONCLUSIONS

Magnetic resonance imaging of the inner ear is a helpful diagnostic tool for Menière's disease. Vestibular neurectomy is an effective treatment for intractable vertigo; however, there is no endolymphatic hydrops regression evidence within several months after the surgery. Therefore, further studies with a long follow-up period and repeated magnetic resonance imaging are needed to assess the vestibular neurectomy's impact on endolymphatic hydrops. Nevertheless, magnetic resonance imaging supports the clinical diagnosis of Ménière's disease and may help understand its pathophysiology.

Comparison of Enhancement of the Vestibular Perilymph between Variable and Constant Flip Angle-Delayed 3D-FLAIR Sequences in Menière Disease

BACKGROUND AND PURPOSE

Endolymphatic hydrops in patients with Menière disease relies on delayed postcontrast 3D-FLAIR sequences. The purpose of this study was to compare the degree of perilymphatic enhancement and the detection rate of endolymphatic hydrops using constant and variable flip angles sequences.

MATERIALS AND METHODS

This was a retrospective study performed in 16 patients with Menière disease who underwent 3T MR imaging 4 hours after gadolinium injection using two 3D-FLAIR sequences with a constant flip angle at 140° for the first and a heavily-T2 variable flip angle for the second. The signal intensity ratio was measured using the ROI method. We graded endolymphatic hydrops and evaluated the cochlear blood-labyrinth barrier impairment.

RESULTS

Both for symptomatic and asymptomatic ears, the median signal intensity ratio was significantly higher with the constant flip angle than with the heavily-T2 variable flip angle (7.16 versus 1.54 and 7.00 versus 1.45, P < .001). Cochlear blood-labyrinth barrier impairment was observed in 4/18 symptomatic ears with the heavily-T2 variable flip angle versus 8/19 with constant flip angle sequences. With heavily-T2 variable flip angle sequences, endolymphatic hydrops was observed in 7-10/19 symptomatic ears versus 12/19 ears with constant flip angle sequences. We found a significant association between the clinical symptomatology and the presence of endolymphatic hydrops with constant flip angle but not with heavily-T2 variable flip angle sequences. Interreader agreement was always perfect with constant flip angle sequences while it was fair-to-moderate with heavily-T2 variable flip angle sequences.

CONCLUSIONS

3D-FLAIR constant flip angle sequences provide a higher signal intensity ratio and are superior to heavily-T2 variable flip angle sequences in reliably evaluating the cochlear blood-labyrinth barrier impairment and the endolymphatic space.

Fully Endoscopic Retrosigmoid Vestibular Nerve Section for Refractory Meniere Disease

OBJECTIVE

This study aims to report our results and technical details of fully endoscopic retrosigmoid vestibular nerve section.

DESIGN

A prospective observational study was conducted.

SETTING

A single academic, tertiary institution involving neurosurgery and neurotology.

PARTICIPANTS

Previously diagnosed patients with Meniere disease, refractory to medical therapy, who underwent fully endoscopic vestibular nerve section.

MAIN OUTCOME MEASURES

Postoperative improvement in vertiginous symptoms as well as hearing preservation, based on the American Association of Otolaryngology-Head and Neck Surgeons score and the Gardener and Robertson-Modified Hearing Classification. Facial nerve preservation based on the House-Brackman (HB) score.

RESULTS

Symptoms improved or resolved in 38 of 41 (92.2%) patients with only 1 of 41 (2.4%) reporting worsening symptoms. All 41 patients (100%) had a postoperative HB score of 1/6, demonstrating full facial nerve preservation. Hearing was stable or improved in 34 of 41 (82.9%) patients. Three complications took place for a rate of 7.3%, one cerebrospinal fluid leak, and two wound infections.

CONCLUSION

The fully endoscopic approach to vestibular nerve sections is a safe and effective technique for the treatment of medically refractory Meniere disease. This technique also utilizes smaller incisions, minimal cranial openings, and no cerebellar retraction with improved visualization of the cerebellopontine angle neurovascular structures.

Two-handed endoscopic-directed vestibular nerve sectioning: case series and review of the literature

OBJECT

Vestibular nerve sectioning is an accepted surgical treatment option for patients with medically refractory Ménière disease. In this paper the authors introduce and evaluate a 2-handed endoscopic-directed technique for vestibular nerve section.

METHODS

Eleven patients underwent a retrosigmoid craniectomy for endoscopic-directed vestibular nerve sectioning as treatment for intractable vertigo associated with Ménière disease. In all patients, identification and dissection of the cranial nerve VII/VIII complex was performed entirely under endoscopic guidance. The authors used the specially designed Frazee II neuroendoscope, consisting of a traditional endoscope lens with a microsuction attachment.

RESULTS

Vestibular nerve sectioning was completed in all 11 patients. Postoperative improvement in vertiginous episodes was achieved in 10 patients (91%). Auditory function was noted to be worse postoperatively in only 1 patient (9%). The same patient also developed a House-Brackmann Grade III facial nerve palsy, which improved gradually over time. There were no further complications, including no delayed CSF leaks.

CONCLUSIONS

The endoscopic-directed approach represents a safe and effective method for performing vestibular nerve sectioning. Until now, the endoscope has been used primarily as an adjunct to the operating microscope in surgery at the cerebellopontine angle. In addition, previous endoscopic techniques typically require a third hand to manipulate the endoscope. With the 2-handed endoscopic-directed technique, however, the endoscope is used as the primary means of visualization, and the unique design of this endoscope allows for a bimanual procedure without the requirement of a cosurgeon. Advantages of using this technique compared with the microscope include superior brightness at close distances, greater depth of field, increased maneuverability within small regions, and an improved ability to visualize objects not in a direct line of sight. Among other things, this allows for minimally invasive openings, decreased cerebellar retraction, and better identification of nerve cleavage planes and vascular anatomy.

Revision Surgery for Vertigo

When confronted with vertigo after an otologic procedure, a surgeon first must identify the functional status of the inner ear by performing auditory and vestibular testing. Using this information in conjunction with knowledge of the primary disease process for which the initial procedure was performed, the surgeon can make a rational selection of the procedure required to eliminate vertigo. This article outlines a systematic approach to the selection of the appropriate revision procedure and discusses the specific advantages and disadvantages of these procedures used to control vertigo.

Combined retrosigmoid retrolabyrinthine vestibular nerve section: results of our experience over 10 years

OBJECTIVE

We aimed to evaluate the results of our experience in vestibular nerve sectioning (VN), which was performed using combined retrosigmoid-retrolabyrinthine approach.

STUDY DESIGN

Medical records of 280 patients who were consecutively operated on for incapacitating peripheral vertigo were retrospectively evaluated, and 210 patients who completed 2 years follow-up and had adequate follow-up data were found to be suitable for inclusion in the study.

METHODS

Hearing results, vertigo control rates, and complications of the retrosigmoid-retrolabyrinthine VN were evaluated.

RESULTS

The patients were suffering from vertigo for a mean period of 32.2 months. Bilateral Meniere's disease occurred in 5.7% of the patients in the follow-up period. A complete or substantial vertigo control could be achieved in 94.4% of the patients (191 [90.1%] in Class A and 9 [4.3%] in Class B). Preoperative speech reception threshold, pure-tone average, and speech discrimination score of the patients were 56.5 dB, 47.4 dB, and 73.6%, respectively. Postoperative corresponding values were 62.2 dB, 43.4 dB, and 68.5%, respectively (p > 0.05). The complication rate was low (2.5%). Most common complication was abdominal hematoma, which was seen in 4.5%.

CONCLUSION

VN performed using retrosigmoid-retrolabyrinthine approach has low complication and high vertigo control and hearing preservation rates. It can be applied as an initial surgery or reserved as the last step when the other surgical treatments have failed to control vertigo.

Surgical treatment of Ménièreʼs disease

PURPOSE OF REVIEW

This review comprises new insights from and discusses the impact of recent medical publications on the surgical treatment of Meniere's disease.

RECENT FINDINGS

Refining surgical indications through recognition of clinical conditions with similar symptoms and through a more precise estimation of the degree of disability will improve the process of decision making for surgery. Further high-level evidence-based medical data supporting the effectiveness of intratympanic gentamycin has become available. Physiopathological progress, based on animal experiments, towards surgically applied intracochlear drug delivery is addressed.

SUMMARY

Studies using level 1 or 2 evidence-based medicine must be conducted to enable better decision making, such as in the application of intratympanic gentamycin or micropressure Meniett therapy at an earlier stage of Meniere's disease. If the results of such studies are conclusive for surgery, this will lead to a shorter duration of discomfort for patients before being offered the possibility of surgery.

Hearing outcome after concurrent endolymphatic shunt and vestibular nerve section

OBJECTIVE

To determine if endolymphatic shunt surgery concurrent with vestibular nerve section improves hearing outcome compared with vestibular nerve section alone.

STUDY DESIGN

Retrospective observational study with cross-sectional survey.

SETTING

Tertiary otologic private practice.

PATIENTS

Thirty-five patients who underwent vestibular nerve section and endolymphatic shunt surgery and 17 patients who had vestibular nerve section alone between 1985 and 2000.

METHODS

Chart review and correspondence for audiogram results and survey.

MAIN OUTCOME MEASURES

Hearing at last follow-up. Hearing Handicap Inventory, Dizziness Handicap Inventory, Tinnitus Handicap Inventory, and SF-36.

RESULTS

Eight patients in the vestibular nerve section and 15 in the vestibular nerve section and endolymphatic shunt surgery group had an audiogram at more than 16 months after surgery available for review. In the vestibular nerve section group, three patients had same hearing whereas five were worse. In the vestibular nerve section and endolymphatic shunt surgery group, 2 patients showed improvement, 2 were the same, and 11 were worse. There was no significant difference in the change from preoperative pure tone average or Word Discrimination Score to postoperative levels between the surgical groups. Eighteen patients had serviceable hearing preoperatively. Five of 8 in the vestibular nerve section and 4 of 10 in the vestibular nerve section and endolymphatic shunt surgery groups maintained serviceable hearing postoperatively. Of the 52 patients, 33 responded to the survey (63%). There were no significant differences between the groups for Dizziness Handicap Inventory, Hearing Handicap Inventory, Tinnitus Handicap Inventory, or SF-36, suggesting that patient-oriented outcomes are the same in both groups.

CONCLUSIONS

Concurrent endolymphatic shunt surgery and vestibular nerve section does not improve hearing or tinnitus outcome over vestibular nerve section alone.

The effect of vestibular nerve section upon tinnitus

This paper reviews the published evidence regarding the effect of vestibular nerve section upon tinnitus. This is of relevance not only for those performing and undergoing this procedure, but also for those considering the hypothesis that auditory efferent system dysfunction may be influential in tinnitus perception. The auditory medial efferent fibres within the internal auditory canal run within the inferior vestibular nerve, only joining the cochlear nerve at the anastomosis of Oort, a bundle of 1300 fibres running from the saccular branch of the inferior vestibular nerve to the cochlear nerve. Vestibular nerve section procedures therefore section this efferent olivocochlear pathway, and ablate efferent influence upon that cochlear. If auditory efferent dysfunction is involved in tinnitus perception, this ablation might influence the tinnitus status of that patient. A literature search identified 18 papers mentioning tinnitus status after vestibular nerve section, describing the experiences of a total of 1318 patients. The proportion of patients in whom tinnitus was said to be exacerbated postoperatively ranged from 0% to 60%, with a mean of 16.4% (standard deviation 14.0). The proportion of patients in whom tinnitus was unchanged was 17% to 72% (mean 38.5%, standard deviation 15.6), and in whom tinnitus was said to be improved was 6% to 61% (mean 37.2%, standard deviation 15.2). In the majority of patients undergoing this procedure, ablation of auditory efferent input (and thus total efferent dysfunction) to the cochlea was not associated with an exacerbation of tinnitus. The finding of this review is that efferent dysfunction after vestibular nerve section does not consistently worsen tinnitus.

Vestibular nerve section in a child with intractable Menière's disease

Clinical presentation of Menière's disease in children is not as typical as in adults. The triad of vertigo, tinnitus and deafness are not usually elicited, diagnosis often being made after years of follow up and batteries of investigation. A case of Menière's disease in a 3-year-old boy is presented. The diagnosis was only obvious at the age of 8 when the triad of vertigo, deafness and tinnitus were present. His disease progressed despite a trial of intratympanic gentamicin injections and endolymphatic sac decompression. Vestibular nerve section was subsequently performed for his intractable disease. Following the procedure he was asymptomatic and able to attend school.

Adjunctive use of endoscopy during posterior fossa surgery to treat cranial neuropathies

OBJECTIVE

The objective of this study was to determine the utility and safety of rigid endoscopy as an adjunct during posterior fossa surgery to treat cranial neuropathies.

METHODS

A suboccipital craniotomy was performed for 19 patients with non-neoplastic processes involving the Vth, VIIth, and/or VIIIth cranial nerves. Ten patients with trigeminal neuralgia (n = 8), hemifacial spasm (n = 1), or intractable tinnitus (n = 1) underwent primarily microvascular decompression procedures. One patient with geniculate neuralgia underwent nervus intermedius sectioning combined with microvascular decompression. Eight patients underwent unilateral vestibular nerve neurectomies for treatment of Meniere's disease. A 0- or 30-degree rigid endoscope was used in conjunction with the standard microscopic approach for all procedures.

RESULTS

All patients experienced resolution or significant improvement of their preoperative symptoms after posterior fossa surgery. The endoscope allowed improved definition of anatomic neurovascular relationships without the need for significant cerebellar or brainstem retraction. Cleavage planes between the cochlear and vestibular nerves entering the internal auditory canal and sites of vascular compression could not be microscopically observed for several patients; however, endoscopic identification was possible for all patients. There were no complications related to the use of the endoscope.

CONCLUSION

The rigid endoscope can be used safely during posterior fossa surgery to treat cranial neuropathies, and it allows improved observation of the cranial nerves, nerve cleavage planes, and vascular anatomic features without significant cerebellar or brainstem retraction.

Vestibular neurectomy

A brief history of the vestibular neurectomy is given. This treatment modality was introduced in Denmark by us, using the experiences obtained by the use of translabyrinthine treatment modality for vestibular schwannoma surgery. This paper presents our experiences with this type of surgery (translabyrinthine, retrolabyrinthine and retrosigmoid vestibular nerve section) from 1980 to 1996, including 43 operations in 42 patients. The patients had all been treated with conventional methods without success and were all severely handicapped by their attacks of vertigo. The mean age was 51 years, postoperative observation time between 2 and 15 years, with a mean of 6.4 years. The vertigo was controlled in 88% of the patients, while postoperative imbalance occurred in 14 patients, mainly due to the ablation of the vestibular labyrinth and not by episodic vertigo. A total of 39 patients indicated that they were satisfied with the operation. Six patients were deaf before surgery and 92% of the remaining patients retained their preoperative hearing. Postoperative complications were few, including two re-operations for CSF leaks, one patient with a slight transient facial nerve paresis and one transient VI nerve paresis. The results compare favorably with results from other authors. Retrosigmoid vestibular nerve section is an effective treatment modality to be offered to patients in whom other modalities have failed. Information about the efficacy and leniency of the treatment should be given to the patient's organization in order to diminish the fear of an intracranial intervention. Surgical experience is necessary in order obtain good results, the number of patients needing the operation is small and centralization of the treatment is mandatory.