Retrolabyrinthine section of the vestibular nerve

When symptoms of dizziness and episodic vertigo cannot be controlled through medical management or drainage procedures such as endolymphatic subarachnoid shunt operations, selective vestibular nerve section may be necessary. In the 1920s eighth cranial nerve sections were performed by neurosurgeons through the suboccipital approach but were frequently associated with hearing loss and facial paralysis. The middle fossa approach has been popularized by Dr. William House and others as a method of selectively sectioning the vestibular nerve and preserving facial and cochlear function. More recently the suboccipital retrolabyrinthine approach has been described as a method of selectively sectioning the vestibular nerve. We have reviewed 42 cases of suboccipital retrolabyrinthine selective section of the vestibular nerve performed at the Otologic Medical Group over the past 2 years. The shortest follow-up on these patients has been 6 months. Thirty-two patients had preoperative diagnosis of Meniere's disease, and of these patients 25 had had previous endolymphatic subarachnoid shunt surgery. Eighty-five percent (27 patients) experienced complete relief of vertigo following surgery, while 6% (two patients) stated they were improved. Three patients reported no relief. There were 10 patients with dizziness who had a diagnosis other than Meniere's disease. In this diverse group three experienced complete relief of vertigo, five were improved, and two reported no improvement of vertigo following surgery. None of the patients lost his hearing as a result of the surgery and there was no facial weakness. One patient had postoperative CSF rhinorrhea and another had meningitis.     

Intratympanic gentamicin therapy for persistent vertigo after endolymphatic sac surgery.

OBJECTIVES: To evaluate the role of intratympanic gentamycin therapy (ITGM) in controlling vertigo in patients with refractory Meniere's who have recurrent or persistent vertigo after endolymphatic sac surgery. STUDY DESIGN AND SETTING: A retrospective review of 491 patients seen in a university balance clinic between July 1999 and July 2000. Of these, 68 patients had Meniere's disease; 4 patients had recurrent vertigo after endolymphatic sac surgery and were followed for at least 1 year. These 4 patients received a series of ITGM injections. Outcome measures included control of vertigo and audiometric results. RESULTS: Three of 4 (75%) patients had control of their vertigo with ITGM therapy. The 1 patient who failed ITGM therapy underwent a successful vestibular neurectomy with ultimate control of his vertigo. No patients had progression of their sensorineural hearing loss. CONCLUSION: ITGM therapy can be used to control vertigo in selected patients with Meniere's disease who have persistent vertigo after unsuccessful endolymphatic sac surgery. SIGNIFICANCE: ITGM therapy may reduce the need for vestibular neurectomy in patients with refractory Meniere's disease after endolymphatic sac surgery.     

MRI evaluation of the endolymphatic space in otosclerosis and correlation with clinical findings

PurposeThe purpose of this study was to investigate the clinical features of ears with otosclerosis and their correlation with endolymphatic hydrops and blood-labyrinth barrier (BLB) impairment on 3 T magnetic resonance imaging (MRI).Materials and methodsThis was a single-center retrospective imaging study. Thirty-nine ears from 29 patients (17 men, 12 women; mean age 52 ± 12 [SD] years; range 27–74 years) with non-operated otosclerosis were included. All patients underwent three-dimensional fluid attenuated inversion recovery (FLAIR) MRI sequences performed 4 hours after the intravenous administration of a single dose of gadolinium-based contrast material. MRI examinations were analyzed by two radiologists for the presence of saccular hydrops (SH) and BLB impairment. Results of MRI examinations were compared with clinical findings, hearing levels and extent of otosclerotic lesions based on high-resolution computed tomography findings. BLB impairment was evaluated using the signal intensity ratio, ratio of intensities between the basal turn of the cochlea and the medulla.ResultsSH was observed in 1/39 (3%) otosclerotic ears and BLB impairment in 8/39 (21%) while 8/29 patients with otosclerosis (28%) had vertigo. No significant associations were found between SH or BLB impairment on MRI, and the presence of vertigo or the degree of sensorineural hearing loss.ConclusionClinical manifestations of otosclerosis (sensorineural hearing loss and rotatory vertigo) were not significantly associated with MRI findings such as BLB impairment and endolymphatic hydrops. SH was only observed in one patient with obstruction of the vestibular aqueduct by an otosclerotic focus.     

ECoG results in perilymphatic fistula: clinical and experimental studies

Patients with perilymphatic fistula have been described as having symptoms similar to Meniere's disease and endolymphatic hydrops. Direct clinical or experimental evidence linking the two inner ear disorders has been lacking. An enhancement of the summating potential observed with electrocochleography suggests a diagnosis of ELH in both of these inner ear disorders. In this study, ECoG results of 27 patients with surgically confirmed PLF are reported. Fourteen patients with surgically confirmed spontaneous PLF had abnormal ECoG. Six of these 14 patients had normal hearing. The ECoG changes in patients with Meniere's disease and those with surgically confirmed PLF are identical, indicating the underlying pathologic change in both is hydrops. But there is no specific diagnostic abnormality on ECoG that differentiates these two inner ear disorders. Also, an experimental model of PLF was developed and studied in guinea pigs. "Inactive" PLF is defined as "an opening was made into the cochlea, but if no perilymph moved out through the fistula, it was defined as inactive" An "active" PLF occurs when perilymph actually moves from the inner ear out to the middle ear. ECoGs were recorded before and after creation of an "active" PLF. ECoG abnormalities were seen in "active" PLF and correlated with histologic data demonstrating ELH. An abnormally enhanced summating potential was demonstrated after active removal of perilymph through the experimentally created fistula. Cochlear duct histology showed hydropic distention of Reissner's membrane in the experimental ears and no changes in the membranous labyrinths of the unoperated, control ears.(ABSTRACT TRUNCATED AT 250 WORDS)     

The Prevalence of High-Riding Jugular Bulb in Patients with Suspected Endolymphatic Hydrops

Background To determine the prevalence of a high-riding jugular bulb (HRJB) in the endolymphatic hydrops population. Methods This was a retrospective chart and radiology review of patients seen at a tertiary care medical center. Patients were identified using the International Classification of Diseases, 9th edition, code 386.xx (Meniere disease–unspecified), and were required to have undergone an imaging study that included views of the jugular bulb that were available for review. A radiologist then evaluated all of the imaging studies for evidence of HRJB or inner ear dehiscence with a jugular bulb abnormality. Results The prevalence of a HRJB in all endolymphatic hydrops patients was 9.0% (7 of 78), and it was 4.5% (7 of 156) in all ears. The prevalence of HRJB ipsilateral to an ear with endolymphatic hydrops was 4.6% (4 of 88 ears); it was 4.4% (3 of 68 ears) in ears without endolymphatic hydrops. The incidence of inner ear dehiscence with a HRJB was 1.3% (1 of 78). Electrocochleography results were not correlated with jugular bulb volume. Discussion The results of this study indicate that a small subset of patients treated for endolymphatic hydrops patients have a HRJB. Overall, these results suggest that HRJB does not play a major role in endolymphatic hydrops, although it may play a role in a few isolated patients.     

Endolymphatic mastoid shunt: a reevaluation of efficacy.

OBJECTIVES: The main goal of this paper was to statistically reevaluate the efficacy of the endolymphatic shunt procedure for Meniere's disease. METHODS: Thomsen et al (Arch Otolaryngol 1981;107:271-7) reported on the placebo effect in surgery for Meniere's disease in a controlled double-blind study. Thirty patients with typical Meniere's disease in whom medical treatment failed participated in the study. A placebo-controlled blinded surgical study has not since been replicated. We performed a retrospective statistical analysis using data extracted from the published report and reanalyzed it using both the original and new statistical measures and techniques. RESULTS: The original conclusions drawn by Thomsen et al differed considerably from ours in 5 key areas, including postoperative vertigo, nausea and vomiting, tinnitus, and combined score. CONCLUSIONS: This analysis strongly supports the effectiveness of the endolymphatic shunt in the management of Meniere's disease and refutes the placebo effect previously proposed.     

Bilateral electrocochleographic findings in unilateral Menière's disease.

At present, electrocochleography is the only proven investigation that can demonstrate objectively the presence of endolymphatic hydrops. The electrophysiologic recordings in response to sound stimuli show an enhancement of the negative summating potential in these cases. It is well established that patients with unilateral Meniere's disease have a high likelihood of development of the disease bilaterally in the fullness of time. Using transtympanic electrocochleography in 40 patients who manifested unilateral clinical Meniere's disease, we have recorded bilateral abnormalities indicative of endolymphatic hydrops in 35% of cases. The early recognition of incipient Meniere's disease in the asymptomatic contralateral ear of a patient with known unilateral disease has obvious profound implications for patient management.     

Endolymphatic sac-vein decompression for intractable Meniere's disease: long term treatment results.

OBJECTIVES: We sought to determine the long-term efficacy of endolymphatic sac-vein decompression surgery on patients with classic Meniere's disease. STUDY DESIGN AND SETTING: Using the 1995 American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium criteria, starting stage, functional level, vertigo class, and hearing results were addressed. We studied 68 patients with classic Meniere's disease from a tertiary, private otology-neurotology practice. Patient data were gathered by retrospective chart review, questionnaire, and patient interview. All patients underwent endolymphatic sac-vein decompression with an average follow-up period of 55 months. RESULTS: Median functional level before surgery was level 4, improving to level 2 after surgery. Eighty-one percent of patients showed improvement in functional level, 12% remained stable, and 7% declined. Long-term vertigo control was 47% in class A, 25% in class B, 9% in class C, 3% in class D, and 16% in class F. Twenty percent of patients were in hearing stage I Meniere's disease; 31%, stage II; 44%, stage III; and 5%, stage IV. Eighteen percent of patients showed improvement in hearing class, 64% were stable, and 18% declined. CONCLUSION: Endolymphatic sac-vein decompression surgery is a safe, nondestructive surgical option for Meniere's disease that offers durable control of vertigo and stabilization of hearing for the majority of symptomatic patients. SIGNIFICANCE: The beneficial long-term outcome of the endolymphatic sac-vein decompression supports its continued use as a first-line treatment option in intractable Meniere's disease.     

Otosclerosis involving the vestibular aqueduct and Menière's disease

The coexistence of otosclerosis and endolymphatic hydrops in the temporal bone have been described; however, the mechanism for the development of endolymphatic hydrops in otosclerosis remains unknown. Among 128 temporal bones with otosclerosis, involvement of the vestibular aqueduct by otosclerosis was observed in four temporal bones from two patients. In all four, the vestibular aqueduct was filled with active otosclerotic foci; the lumen of the endolymphatic duct and sac was narrowed as a result of fibrosis, and endolymphatic hydrops, more severe in the pars inferior than the pars superior, was observed. Collapse of the ductus reuniens and dilated saccule was seen in three temporal bones. Our study indicates that otosclerotic obstruction of the vestibular aqueduct may create a disturbance of the outflow and/or absorption of endolymph, leading to the development of endolymphatic hydrops and Meniere's disease, thus supporting the theory of longitudinal flow of endolymph.     

Cellular changes of Reissner's membrane in Meniere's disease: human temporal bone study.

OBJECTIVE: To study the cellular characteristics of Reissner's membrane (RM) in temporal bones (TBs) from patients with endolymphatic hydrops with symptoms of Meniere's disease (EH/+MD) and TBs with endolymphatic hydrops without symptoms of Meniere's disease (EH/-MD) in an effort to understand the role of endolymphatic hydrops in MD symptoms. STUDY DESIGN: Comparative study of human TB histopathology. METHODS AND MATERIALS: Epithelial and mesothelial cellularity of RM from control TBs, TBs from patients with EH/+MD, and TBs from patients with EH/-MD were compared. The cellularity of epithelial and mesothelial cell nuclei (defined as number of cells/100 microm width of RM) were counted along the width of RM. The width of RM was measured from the vestibular crest of the spiral ligament to the limbus spiralis. RESULTS: The cellular densities of epithelial cells in the basal and middle turns of RM were significantly higher in the EH/+MD and EH/-MD groups compared with "controls." There was no difference in epithelial cellularity between EH/+MD and EH/-MD. There was a decrease in the number of mesothelial cells of RM in the basal turn in EH/+MD and EH/-MD groups (statistically significant only in EH/+MD group) when compared with controls. The number of mesothelial cells of RM in the middle turn in EH/+MD and EH/-MD groups were significantly decreased compared with normals. DISCUSSION: Similar findings in cellularity of RM in temporal bones with EH/+MD and EH/-MD suggest that pathophysiologic mechanisms other than hydrops may be responsible for symptoms in Meniere's disease.     

Selective microsurgical vestibular neurectomy: an option in the treatment of intractable vertigo and related microsurgical landmarks.

Selective microsurgical vestibular neurectomy (SMVN) is an accepted and effective means of treating patients with intractable vertigo, a resistant component of Meniere's syndrome. Meniere's syndrome is a condition characterized by fluctuating hearing loss, tinnitus and serious vertigo attacks. Vertigo is the most disabling symptom of the disease. There may be permanent hearing loss in untreated cases and vertigo may continue after deafness. Selective microsurgical vestibular neurectomy is an elite surgical procedure providing exact relief from vertigo while protecting the preoperative hearing level. In this report, clinical results of nine patients with intractable vertigo operated in the University of Ankara Medical Faculty, Department of Neurosurgery between 1999 and 2001 are discussed. Accordingly, we aimed to represent the landmarks often required for microsurgical exposure. From this study we conclude that SMVN is an effective neurosurgical procedure for those patients who are resistant for medical treatment and require hearing preservation.     

Investigations into the cause of vertigo in sudden sensorineural hearing loss

In this light microscopic study of the temporal bone, an attempt has been made to find a morphologic correlate of vertigo associated with idiopathic sudden sensori-neural hearing loss (ISSHL). Hair cell densities of the three cristae and both maculae, as well as vestibular ganglion cell (neuronal) count estimation, was done in nine ears that had documented histories of ISSHL. There were five ears with vertigo and four without. These quantitative data--i.e., hair cell densities and neuronal counts, of the vertiginous ears (group I) and nonvertiginous ears (group II)--was compared by histograms and statistically. Additionally, in each of the two groups, the data from three opposite normal hearing ears were taken as a control and used for comparison with the ISSHL ears. The differences between the vertiginous, nonvertiginous, and control ears were not significant at the 0.01 level, indicating that the vertigo was not caused by hair cell or neuronal degeneration. Gross morphologic alterations in the vestibular system, such as membrane ruptures, endolymphatic hydrops, etc., were also assessed, but no clear-cut pathology was identified in the vertiginous and nonvertiginous ears. The absence of a light microscopic morphologic correlate for vestibular disturbances associated with ISSHL suggests that the symptoms could result from ultrastructural changes in the hair cells and their synapses or from biochemical alterations in their environment.     

Endolymphatic mastoid shunt surgery using the Denver inner ear shunt

This study, merging data from two different clinics, was undertaken to evaluate the efficacy of endolymphatic mastoid shunt surgery using the Denver Inner Ear Shunt operation for Meniere's disease. This surgery was performed by the senior authors (C.G.J., J.R.E.D., and M.E.G.) between May 1984 and October 1986, after we attended the Colorado Otologic Research Center (CORC) instructional course. Sixty-six and thirty-four cases, respectively, were performed. Follow-up questionnaires were sent to this total of 100 patients. Fifty-six patients returned completed questionnaires, which formed the basis of this report. A retrospective chart study was also carried out. The results of surgery and questionnaires are reported as statistical data, and, where applicable, the 1985 AAO-HNS criteria for reporting vertigo and hearing results in the treatment of Meniere's disease are used. Preliminary analysis of these data is reported because of its profound effect upon our treatment protocol for patients with Meniere's disease. Results on use of the Denver valve do not appear to be significantly different than the results of other shunt surgery not using the valve.     

Effects of endolymphatic-perilymphatic fistula on endolymphatic hydrops in guinea pig.

The endolymphatic-perilymphatic shunt operation between the scala media and scala tympani was performed in 22 guinea pigs with endolymphatic hydrops induced by the silver nitrate injection method 2 months before the operation. Two (n = 10), 7 (n = 6), and 28 (n = 6) days after the operation, the condition of the fistula and the inner ear pathology were studied histopathologically. In half of the animals, the fistula was open, whereas in the other half, the fistula was closed. In the group examined after 2 postoperative days, the animals with open fistulas showed a slight collapse of Reissner's membrane, which might indicate that excess endolymph escaped through the fistula into the scala tympani. In the groups examined later, especially in the group examined after 28 postoperative days, the animals showed distention of hydrops despite preservation of the fistula. Moderate-to-severe degenerative changes of the organ of Corti, macula sacculi, and stria vascularis were observed in the vicinity of the fistula. We conclude from this study that the endolymphatic-perilymphatic fistula created inside the cochlea apparently was not sufficient to reduce the hydrops. Rather, it caused degenerative changes of the inner ear structure. This type of surgery is not suitable for Meniere's disease.     

Vestibular Neurectomy and Microvascular Decompression of the Cochlear Nerve in Meniere's Disease

Vestibular neurectomy (VN) results in a high success rate in the control of vertigo in Meniere's disease, although the subsequent fate of auditory function is fairly unpredictable. The present investigation reports the postoperative results obtained in a group of 30 subjects with a clinical diagnosis of Meniere's disease and vascular cross-compression of cranial nerve VIII. All subjects underwent VN using a retrosigmoid approach, and in half of them microvascular decompression (MVD) of the cochlear nerve with interposition of autogenous muscle was performed at the same time. All patients had complete relief from vertigo. Hearing was significantly improved in the VN-MVD group (46.7% of subjects). In this group tinnitus and aural fullness also improved significantly, with values of 62.6% and 66.6%, respectively.     

Vestibular Neurectomy and Microvascular Decompression of the Cochlear Nerve in Meniere's Disease

Vestibular neurectomy (VN) results in a high success rate in the control of vertigo in Meniere's disease, although the subsequent fate of auditory function is fairly unpredictable. The present investigation reports the postoperative results obtained in a group of 30 subjects with a clinical diagnosis of Meniere's disease and vascular cross-compression of cranial nerve VIII. All subjects underwent VN using a retrosigmoid approach, and in half of them microvascular decompression (MVD) of the cochlear nerve with interposition of autogenous muscle was performed at the same time. All patients had complete relief from vertigo. Hearing was significantly improved in the VN-MVD group (46.7% of subjects). In this group tinnitus and aural fullness also improved significantly, with values of 62.6% and 66.6%, respectively.     

Reflexogenic vertigo treated by tensor tympani transection

Two patients complained of severe vertigo following eructation or hiccup. One patient was poststapedectomy; the other had idiopathic cochlear degeneration. The symptoms were reproduced by Hennebert's test in the pathologic ear. The tensor tympani was transected in both patients. An endolymphatic sac procedure was performed concomitantly in the second patient. Both patients had immediate relief of symptoms. It is hypothesized that these reflex phenomena, which elicited vertigo, were accompanied by tensor tympani contraction, which resulted in medial movement of the stapes or prosthesis, and that this movement was transmitted via adhesions to vestibular endorgans to produce the described symptoms.     

Permanent sensorineural hearing loss following spinal anesthesia

A 25-year-old female developed permanent, fluctuating sensorineural hearing loss (SNHL), disabling vertigo, and tinnitus following an uneventful spinal anesthesia for cesarean section. At her first visit to the ear-nose-throat (ENT) department approximately 2 months postoperatively, pure-tone thresholds revealed profound SNHL on the right side whereas thresholds were within normal limits on the left side. The recruitment score (SISI) was 95% at 2000 Hz on the right side. Directional preponderance towards the right and the right canal paresis were evidenced by bithermal caloric testing. At follow ups the pure tone thresholds have shown some improvement, but fluctuating SNHL, disabling vertigo attacks, and tinnitus have remained. These findings imply a cochlear pathology causing endolymphatic hydrops possibly induced by lumbar puncture for spinal anesthesia.     

Autoimmune endolymphatic hydrops: five-year review

This article reviews the authors' experience with autoimmune endolymphatic hydrops over the past 5 years. Twenty-seven of 52 patients with diagnosed autoimmune inner ear disease (52%) manifested endolymphatic hydrops, usually bilateral. Treatment consisted of low salt diet, diuretic, vestibular suppressant, and usually prednisone. Cytotoxic drugs and lymphocytoplasmapheresis were reserved for refractory cases. Audiometric followup (average, 23 months) was available in 12 patients. Using American Academy of Otolaryngology--Head and Neck Surgery guidelines, hearing improved or stabilized in at least one ear in nine patients and deteriorated bilaterally in three patients. Vestibular treatment results paralleled auditory treatment results. Autoimmune endolymphatic hydrops should be considered in the differential diagnosis when symptoms are bilateral and do not respond to conventional therapy or when immune laboratory tests are positive. In suspect patients, medical therapy with prednisone, and rarely cytotoxic drugs and lymphocytoplasmapheresis, should be recommended. Further research is needed to determine whether surgery should be performed in medically unresponsive cases.     

Re-evaluation of the role of the human endolymphatic sac in Menière's disease

The role of endolymphatic sac (ES) dysfunction in the etiopathogenesis of Meniere's disease has remained controversial since the early 1900s. The first reports of the ultrastructural (transmission electron microscopy, TEM) pathology of the human ES in Meniere's disease have been published only in the last decade. These studies have been based on biopsies of the extraosseous (intradural) ES and in no cases has the TEM appearance of the intraosseous ES been described. Likewise the control material used has been from biopsies of extraosseous ES taken from patients with acoustic schwannomas. To date, no reports have compared the ultrastructure of the intrasosseous ES from normal control patients to patients with Meniere's disease. Since the intraosseous ES is believed to be the most active portion of the entire ES, studies were made of the ultrastructure of ten normal interosseous human ESs fixed immediately after death and obtained at autopsy (control material). Fourteen patients undergoing translabyrinthine (TL) neurotologic procedures (10, TL resection of acoustic schwannoma; 4, TL eighth cranial nerve section for Meniere's disease) had the entire vestibular aqueduct, containing the endolymphatic duct and the intraosseous ES, removed and processed for TEM. The roles of the epithelium, subepithelial space, and vasculature were morphologically studied to evaluate possible ES pathology in Meniere's disease and in patients with acoustic schwannoma. Wide anatomic variation in the distribution and density of the subepithelial connective tissue was observed in all groups. There was no difference in the TEM appearance of the intraosseous ES from normal controls and patients with eighth nerve schwannoma, nor was there any difference in the ES collagen deposition in patients with Meniere's disease. The ESs from two patients with Meniere's disease showed evidence of abnormal glycoprotein metabolism; one with possible hypersecretion and one with possible alteration of degradation of resorbed glycoprotein. The results of this preliminary study suggest that "perisaccular fibrosis" of the intraosseous ES was not a pathologic feature in these four cases of Meniere's disease and that alteration of ES glycoprotein secretion/resorption may be of etiopathologic significance.