Endolymphatic Sac Decompression Research Articles

Quantitative Analysis of Psychiatric Disorders in Intractable Peripheral Vertiginous Patients

To investigate the correlation between psychological disorder and vestibular dysfunction in patients suffering from intractable peripheral vertigo. Prospective study. In-patients in a university hospital. Prospective design of 26 intractable peripheral vertiginous patients with peripheral vestibular dysfunction and 20 controls recruited from the EENT hospital. Hospital Anxiety and Depression scale, Self-rating Anxiety scale, Self-rating Depression scale, Symptom Checklist-90 were used in this study. All vertigo patients received intratympanic gentamicin/dexamethasone administration or endolymphatic sac decompression. Pre- and posttreatment scores were collected and compared. All the results were statistically analyzed using Stata 8.0. t test or rank-sum test and paired-sample t test or rank-sum test were performed. The outcomes of Hospital Anxiety and Depression scale, Self-rating Anxiety scale, Self-rating Depression scale, Symptom Checklist-90 were significantly greater in vertiginous group than that in normal controls (p < 0.05). The pretreatment scores of these four scales were greater than the posttreatment scores in vertiginous patients, especially in Class A and B groups (p < 0.05). The scores of more scales were demonstrated to be statistically different in patients with over 5 years of the disorder and among patient in stages 1 to 3 than in stage 4 (p < 0.05). No significant difference was noted between male and female participants in all the questionnaires used (p > 0.05). Increased anxiety/depression levels were noted in peripheral vertiginous patients compared with normal controls through psychiatric questionnaires, and then a significant decrease after the effective treatment of vertigo, suggesting that vertigo attack may contribute to psychological dysfunction. The intervention seemed to be more effective in lowering anxiety/depression levels among patients in earlier stage of Ménière's disease marked by pure-tone audiometry results.

Meniere's disease.

Meniere's disease (MD) is a disorder of the inner ear that causes vertigo attacks, fluctuating hearing loss, tinnitus and aural fullness. The aetiology of MD is multifactorial. A characteristic sign of MD is endolymphatic hydrops (EH), a disorder in which excessive endolymph accumulates in the inner ear and causes damage to the ganglion cells. In most patients, the clinical symptoms of MD present after considerable accumulation of endolymph has occurred. However, some patients develop symptoms in the early stages of EH. The reason for the variability in the symptomatology is unknown and the relationship between EH and the clinical symptoms of MD requires further study. The diagnosis of MD is based on clinical symptoms but can be complemented with functional inner ear tests, including audiometry, vestibular-evoked myogenic potential testing, caloric testing, electrocochleography or head impulse tests. MRI has been optimized to directly visualize EH in the cochlea, vestibule and semicircular canals, and its use is shifting from the research setting to the clinic. The management of MD is mainly aimed at the relief of acute attacks of vertigo and the prevention of recurrent attacks. Therapeutic options are based on empirical evidence and include the management of risk factors and a conservative approach as the first line of treatment. When medical treatment is unable to suppress vertigo attacks, intratympanic gentamicin therapy or endolymphatic sac decompression surgery is usually considered. This Primer covers the pathophysiology, symptomatology, diagnosis, management, quality of life and prevention of MD.

Comparison the results of two different vestibular system surgery in patients with persistent Meniere's disease.

Background:Incidence rates of Meniere's disease vary considerably from 157/100,000 in the United Kingdom to 15/100,000 in the United States. Furthermore, in Iran prevalence of Meniere's disease is high, whereas we have not a reliable statistical study on it. A wide range of treatments are used for the treatment of the condition with no consensus on the most effective intervention. The aim of the present study, which involved 37 patients treated because of severe vertigo due to persistent Meniere's disease from 1996 to 2011, was to compare the effectiveness of two surgical methods cochleosacculotomy and endolymphatic sac decompression on vertigo and tinnitus.Materials and Methods:In a cross-sectional study, we compared two surgical approaches in patients with Meniere's disease who did not respond to usual medical treatment. Twenty-three patients underwent cochleosacculotomy surgery and 14 patients endolymphatic sac decompression surgery. We compared all the patients for resolving of vertigo, tinnitus.Results:After surgery, in patients of both group vertigo was improved significantly (P < 0.0001), tinnitus was improved, but it was not significant (P > 0.05) and hearing level was worse than before (especially in patients who had undergone cochleosacculotomy) (P < 0.0001).Conclusion:Based on the data of the current study, cochleosacculotomy and endolymphatic sac decompression improved vertigo in patients with persistent Meniere's disease.

めまいの外科的治療

For the management of patients complaining of vertigo, less-invasive treatments should initially be selected. However, failure of conservative treatment necessitates consideration of more invasive procedures. These managements sometimes include surgical measures, which could be associated with some complications.For benign paroxysmal positional vertigo, canal plugging surgery may be a valid treatment option. In the case of Meniere’s disease, ventilation tube insertion, endolymphatic sac decompression, intratympanic gentamicin injection, vestibular neurectomy and vestibulotomy can be used for critical cases. In cases with superior canal dehiscence, surgical treatment (re-surfacing of middle cranial fossa and anterior semi-circular canal plugging) is the only treatment option that offers the opportunity for resolution of symptoms. Recently, surgery for small tumors of the cerebellopontine cistern have tended to be avoided, although certain cases do need surgery. Devices to compensate for vestibular deficit, some of which need surgical device insertion, are also under research and development. It is necessary for physicians to be aware about the treatment options, including surgical procedures, with their benefits and risks, for appropriate treatment of vertigo. At the same time, we should be cautious about the selection, evaluation and establishment of surgical treatment procedures.

A Case of Endolymphatic Sac Decompression of Intractable Meniere's Disease in Children

Meniere’s disease in children is characterised with a hard and long-term diagnostic course, for which there is no accurate classification and treatment plan. A patient may undergo severe dis comfort and long-term contraction of the disease. We experienced a 13-year-old female suffering from recurrent dizziness, and found that she had hearing loss, and tinnitus on her right ear. We diagnosed it as possible meniere’s disease, but the disease progressed despite a trial of medication. The patient then underwent an endolymphatic sac decompression. During 6 months after the operation, she has shown only mild, intermittent dizzy symptoms, without severe vertigo. We report this clinical experience with a brief review of literature.

Endolymphatic duct blockage: a randomized controlled trial of a novel surgical technique for Ménière's disease treatment.

To compare the effectiveness of the endolymphatic duct blockage (EDB) and the endolymphatic sac decompression (ESD) to control Ménière's disease symptoms and to evaluate their effect on hearing level. Prospective nonblinded randomized study. Tertiary medical center. Fifty-seven patients affected by a refractory Ménière's disease were included out of which 22 underwent an ESD and 35 underwent an EDB. Five periods of follow-up were considered: 0 to 1 week, 1 week to 6 months, 6 to 12 months, 12 to 18 months, and 18 to 24 months. Mean outcome measurements consisted of vertigo control, tinnitus, aural fullness, instability, and hearing level. Hearing level was evaluated using pure-tone average (PTA) and speech discrimination score (SDS). There was no significant difference between the 2 groups in the number of vertigo spells per months preoperatively (P = .153). Twenty-four months postoperatively, 96.5% of the EDB group had achieved a complete control of vertigo spells against 37.5% of the ESD group with a statistically significant difference (P = .002). There was a better control of tinnitus and aural fullness with EDB (P = .021 and P = .014, respectively). There was no statistically significant difference in hearing level preoperatively (P = .976) and 24 months postoperatively (P = .287) between the 2 groups. Hearing level was preserved in each group with no significant difference between the preoperative and the postoperative levels (P > .05). EDB is more effective than the traditional ESD in controlling the symptoms of Ménière's disease. It is a novel surgical technique with promising results for a complete treatment of Ménière's disease. There are no significant complications or adverse effect.

Does Endolymphatic Sac Decompression Surgery with Local Steroids Prevent Bilateral Development of Ménière's Disease?

Objectives: Elucidate whether endolymphatic sac decompression surgery (ESDS) has the potential to prevent unilateral Ménière’s disease (MD) from becoming bilateral. Methods: Prospective case-control study. Between 1996 and 2008, we performed a glycerol test (G-test) and electrocochleography (ECoG) on 237 patients with intractable MD at a tertiary referral center. We performed ESDS on 179 patients (144 without endolymphatic hydrops and 35 with silent endolymphatic hydrops in the contralateral ear). The other 58 patients (40 without endolymphatic hydrops and 18 with silent endolymphatic hydrops in the contralateral ear) were given available medical treatments. All underwent regular follow-up for at least 5 years. Results: Altogether, 22.4% (53/237) of patients with clinically diagnosed unilateral intractable MD had silent endolymphatic hydrops in the contralateral ear using G-test and ECoG. In the nonsurgical group, 6 of 40 patients with unilateral MD without endolymphatic hydops in the contralateral ear developed bilateral disease, whereas in the surgical group, 12 of 144 patients did so ( P &gt; .05). In the nonsurgical group, 9 of 18 patients with unilateral MD and silent endolymphatic hydrops developed the disease in the contralateral ear, whereas in the surgical group, 6 of 35 patients developed bilateral disease ( P &lt; .05). Conclusions: The present findings suggest that ESDS may decrease the incidence of developing MD in silent endolymphatic hydronic contra lateral ears diagnosed with G-test and ECoG within the first 5 postoperative years.

Comparative Study of Endolymphatic Sac Decompression and Vestibular Neurectomy in Intractable Meniere's Disease.

To comparative study the clinical effect of endolymphatic sac decompression (ELSD) and vestibular neurectomy (VN) in intractable Meniere's disease (MD). The study included 30 MD intractable patients, 21 of which underwent ELSD and nine of which were treated by VN via retrosigmoid approach. Follow-up period ranged from 3 to 6years. In 21 patients by ELSD, excellent vertigo control and good control were noted in 11 patients (52.4%) and 4 patients (19.0%), partial control in 4 and no control in 2 patients. All the 9 patients by VN, vertigo was excellent control. ELSD can improve hearing and tinnitus, but VN not. VN can achieve much better effect in improving vertigo in intractable MD patients. But relative to ELSD, it has much more disadvantages.

Management of Meneere's Disease—the Beijing Tiantan Hospital Experience

ObjectiveTo report outcomes of nonsurgical and surgical management of Menière's disease at Beijing Tiantan Hospital. MethodsPatients with Menière's disease were categorized into groups based on hearing and quality of life. Individualized management was provided, including life style modification, drug therapies, endolymphatic sac decompression and labyrinthectomy. Treatment outcomes were evaluated during up to 24 months follow up. ResultsEighty seven patients underwent life style modification and drug therapies. The vertigo control rate of Grade A and B was 76.9% and 83.8% respectively. Six patients received surgical management, including endolymphatic sac decompression (n = 5) and labyrinthectomy (n = 1). For these patients, the vertigo control rate of Grade A and B was 80% and 100%, respectively. ConclusionsManagement of Menière's disease depends on several factors, i.e. severities of vertigo and hearing loss, quality of life, surgical contraindications and patient subjective desire. The treatment is drug therapies for the majority of patients, as well as life style modification. Surgical indications are rare and the least invasive procedures should be considered first. The results of surgery are generally satisfying.

Noninvasive evaluation of the effect of endolymphatic sac decompression in Ménière's disease using magnetic resonance imaging

Conclusions: This study is the first to demonstrate noninvasive evaluation of the effect of endolymphatic sac decompression (ESD) in Ménière's disease using magnetic resonance imaging (MRI). Objective: To evaluate the effect of ESD for the treatment of Ménière's disease by applying noninvasive intratympanic gadolinium (Gd) perfusion through the eustachian tube and three-dimensional fluid-attenuated inversion MRI (3D-FLAIR MRI). Methods: This was a prospective study. 3D-FLAIR MRI was performed with a 3 Tesla unit 24 h after intratympanic administration of Gd through the eustachian tube in five patients with intractable Ménière's disease before and 3 months after ESD, with a 2-year follow-up on the effect of ESD. Results: Gd was present in the perilymph of the inner ear in all the patients, which clearly displayed the endolymphatic space on 3D-FLAIR MRI with a visible borderline between the perilymph and the endolymph. According to the normal values for the endolymphatic space, four of five patients had a ratio of more than 26% in the cochlea, and three of five patients had a ratio of more than 41% in the vestibule preoperatively. All the patients had a ratio of less than 26% in the cochlea and 41% in the vestibule postoperatively. ESD was effective in reducing the incidence and severity of vertigo attacks with significant improvement in 60% of patients.

Does endolymphatic sac decompression surgery prevent bilateral development of unilateral Ménière disease?

The aim of the study was to elucidate whether endolymphatic sac decompression surgery (ESDS) has the potential to prevent unilateral Ménière disease (MD) from becoming bilateral. Prospective case-control study at tertiary referral center. Between 1996 and 2008, we performed a glycerol test (G-test) and electrocochleography (ECoG) on 237 patients with intractable unilateral MD. We performed ESDS on 179 patients (144 with no endolymphatic hydrops and 35 with silent endolymphatic hydrops in the contralateral ear). The other 58 patients (40 without endolymphatic hydrops and 18 with silent endolymphatic hydrops in the contralateral ear) were given available medical treatments. All underwent regular follow-up for at least 5 years. Altogether, 22.4% (53 of 237) of patients with clinically diagnosed unilateral intractable MD had silent endolymphatic hydrops in the contralateral ear using G-test and ECoG. In the nonsurgical group, six of 40 patients with unilateral MD with no endolymphatic hydrops in the contralateral ear developed bilateral disease, whereas in the surgical group 12 of 144 patients did so (P = .231, Fisher test). In the nonsurgical group, nine of 18 patients with unilateral MD and silent endolymphatic hydrops developed the disease in the contralateral ear, whereas in the surgical group six of 35 patients developed bilateral disease (P = .022, Fisher test). The present findings suggest that ESDS may decrease the incidence of developing MD in silent endolymphatic hydronic contralateral ears diagnosed with G-test and ECoG within the first 5 postoperative years.

Effects of endolymphatic sac decompression surgery on endolymphatic hydrops

Conclusions: The present findings suggest that complete control of vertigo after endolymphatic sac decompression surgery (ESDS) does not always depend on improved vestibular function or reduced endolymphatic hydrops. Vertigo control is, however, associated with hearing stability.Objective: Among surgical treatments for intractable Meniere’s disease, ESDS is performed to preserve and improve inner ear function. We examined the correlation between changes in vertigo frequency and neuro-otologic function to understand the condition of the inner ear in patients whose vertigo was completely controlled after undergoing ESDS.Methods: This was a retrospective cross-tabulation study. Between 1997 and 2001, we treated 52 patients with intractable vertigo using ESDS and followed the patients regularly for 2 years. Postoperatively we evaluated and recorded changes in vertigo attack frequency, maximum slow phase eye velocity, worst hearing level, and glycerol test results according to modified American Academy of Otolaryngology–Head and Neck Surgery 1995 criteria.Results: We found no correlation between vertigo control and vestibular function. There was also no correlation between vertigo control and negative conversion of the glycerol test. There was a significant correlation between vertigo control and hearing control .

Use of Image‐Guidance to Access the Endolymphatic Sac

Objective: One of the challenges in endolymphatic sac (ELS) decompression is the reliable identification of the ELS with minimal injury to surrounding structures. Here we propose to: 1) Demonstrate the feasibility of using imaging technology to identify the ELS. 2) Define a direct pathway from the lateral skull to the ELS. Method: The location of the ELS was approximated in a CT scan using its anatomic relationship to nearby structures, and a linear path was manually selected from the mastoid cortex to the predicted ELS. The path was visually verified to determine its relationship to the actual location of the ELS. Results: CT scans of 6 cadaveric temporal bones with bone-implanted fiducial markers were analyzed. The location of the ELS was predicted using traditional surgical landmarks. A custom Microtable (microstereotactic frame) was manufactured for each bone to target the ELS via a linear path (selected manually by CT). The bone was drilled to decompress the ELS. The Microtable was then mounted on the fiducial markers and the drill bit passed through its target hole to determine the actual targeted path. The drill bit coincided with the ELS in all specimens and did not transect any critical structures along its pathway. Conclusion: Current imaging technology allows for reliable identification of the ELS and generation of linear trajectories to reach the ELS without injury to adjacent structures. This work is the first step in the development of minimally invasive image-guided techniques to safely access the ELS in the treatment of Ménière’s disease.

Short-Term Efficacy of Semicircular Canal Occlusion in the Treatment of Intractable Ménière's Disease

Objective To investigate the short-term efficacy and safety of triple semicircular canal occlusion （TSCO） in the treatment of intractable Meniere's disease （MD）, so as to provide an alternative surgical procedure for treating MD. Methods Seventeen patients, who had received standardized conservative treatment for at least one year with poor effect, underwent TSCO were retrospectively analyzed. Vertigo control and auditory function were evaluated. Pure tone audiometry, caloric test, and vestibular evoked myogenic potential （VEMP） were performed for evaluation of audiological and vestibular function. Postoperative follow-up period was 6-13 months, with an average of ten months. Results According to the preoperative staging of hearing, among the 17 patients, there were 2 cases in stage Ⅱ （with an average hearing threshold of 25-40 dBHL） and 15 in stage Ⅲ （41-70 dBHL）. No vertigo was found during the follow-up period, with 100% control rate of vertigo. During the same period, we had performed endolymphatic sac decompression operation in 25 MD patients. The control rate of vertigo was 72.0%. The vertigo control rate of TSCO was significantly higher than that of endolymphatic sac decompression operation （X2 = 3.87, P < 0.05）. Three months after surgery, 12 patients showed no significant change in comparison to primary status, 5 patients presented with an mild increase in the average hearing threshold of less than 20 dBHL, with 29.4% of hearing loss rate. Post-operatively, all patients suffered from temporary vertigo and balance disorders. Vertigo was disappeared in all patients within 3 days, while, balance disorders were disappeared in 10 patients within 1-2 weeks after surgery, and in another 7 patients within 2 months, with an average recovery time of 12.6 days. Three months after treatment, loss of semicircular canal function by caloric test was found in the operation side of all patients and no change in VEMP test was noted. All patients had no facial paralysis, cerebrospinal fluid leakage, and other complications. Conclusions TSCO, which can reduce vertiginous symptoms in patients with intractable MD, represents an effective and safe therapy for this disorder. TSCO is expected to be used as an alternative procedure for the treatment of MD in selected patients suffering from moderate to severe hearing loss. Key words: Meniere's disease; Semicircular canals; Otologic surgical procedures; Treatment outcome

Lateral semicircular canal plugging with endolymphatic sac decompression as new surgical treatment for intractable Meniere's disease

Conclusion: Lateral canal plugging with endolymphatic sac decompression (LCPESD) is a new therapeutic approach to intractable Meniere's disease. Further clinical data will be required. Objective: The objective of this paper is to present a new surgical procedure, i.e. lateral canal plugging (LCP) with endolymphatic sac decompression (ESD), which we defined as LCPESD. Two cases of intractable Meniere's disease, a 48-year-old male and a 48-year-old female, were successfully treated by this method. Methods: LCPESD was performed under general anesthesia. First ESD was undertaken followed by LCP. The bone was drilled up to the ‘blue line' in the central portion of the bony lateral canal; then a 2 mm segment of canal was skeletonized to create a fenestra. A plug comprising temporalis fascia, bone pate, and fibrinogen glue was inserted through the fenestra to compress the endosteum and membranous labyrinth. Results: The attack of Meniere's disease was completely controlled and the hearing threshold did not change after the surgery for 2 years. Obliteration of the horizontal canal was confirmed by MRI.

Clinical analysis of benign paroxysmal positional vertigo secondary to Menieres disease

In the present study, the clinical characteristics of 15 cases of benign paroxysmal positional vertigo (BPPV) secondary to Meniere’s disease (MD) were retrospectively analyzed, in order to improve the diagnosis and therapeutic efficacy. Patients clinically characterized as positional paroxysmal vertigo were diagnosed as MD by electrocochleography (ECochG) and glycerol test and were confirmed as BPPV associated with MD by Dix-Hallpike test and roll test. They were treated with Epley maneuver or Barbecue roll maneuver according to the type of BPPV, and the efficacy was evaluated. BPPV occurred after MD in all of the cases, of which 13 cases were posterior semicircular canal lithiasis and 2 cases were horizontal semicircular canal lithiasis. In this study, 10 patients were cured after 3 to 4 times of posture treatment (66.7%), 4 patients were cured after no less than 5 times and 1 patient received endolymphatic sac decompression because of recurrent vertigo. BPPV can result from MD, and a possible mechanism may be the hydrolabyrinth that lead to otolith falling off. BPPV occurred in the ipsilateral posterior semicircular canal in majority of cases, with an obvious sexual bias to female. Otolith reposition is an effective method to treat BPPV secondary to MD, while it is refractory compared to simple BPPV and requires multiple times of treatments. This may be related to the recurrence of hydrolabyrinth. Key words: Meniere’s disease, benign paroxysmal positional vertigo.

Low-tone air-bone gaps after endolymphatic sac surgery

Objectives We detected chronic low-tone air-bone gaps (LTABGs) in some patients with Meniere's disease after endolymphatic sac surgery. The aim of the present study was to elucidate the mechanism of LTABGs after endolymphatic sac surgery. Methods We investigated 50 patients with Meniere's disease, who underwent surgery more than two years prior. LTABGs were defined as the three-tone-average = 20 dB formulated by ( a + b + c)/3, where a, b, and c are ABGs at 0.25, 0.5, and 1 kHz, respectively (ABG ±). The intra-operative finding was focused on identifying operculum (OPC ±). Results The ratio of post-operative ABG(+) was 50.0% (25/50). The ratio of intra-operative OPC(+) was 72.0% (36/50). The surgery results were as follows: the ratio of complete vertigo suppression (VS(+)) was 84.0% (42/50), air-conduction hearing gain (aHG(+)) was 40% (20/50), bone-conduction hearing gain (bHG(+)) was 64% (32/50), and speech discrimination gain (SDG(+)) was 28% (14/50). The post-operative ABG(+) was commonly observed in patients with intra-operative OPC(+) (chi-square test, p = 0.013). aHG(+) and SDG(+) results were related to the post-operative ABG(+) (chi-square test, p = 0.021 and p = 0.0018, respectively). Conclusions These data suggest that intra-operative OPC(+) may be causative for post-operative ABG(+), resulting in post-operative aHG(+) and SDG(+). Thus, as enlarged vestibular aqueduct syndrome and superior semicircular canal deficiency syndrome exhibit LTABGs due to the third mobile inner ear window, endolymphatic sac surgery with adequate endolymphatic sac decompression and exposure to high doses of steroids, might induce LTABGs and the beneficial results of endolymphatic sac surgery.

The clinical characteristics of the benign paroxysmal positional vertigo associated with Meniere's disease

To explore the clinical characteristics of the benign paroxysmal positional vertigo (BPPV) associated with Meniere's disease (MD) in retrospect in an effort to improve the diagnosis and efficacy of treatment. Fifteen cases (1 male and 14 female, aged 46 to 68 years old) of BPPV associated with MD from July 2007 to June 2009 were retrospectively analyzed. Patient clinically characterized with positional paroxysmal vertigo were diagnosed as MD by ECochG and glycerol test and were confirmed as BPPV associated with MD by Dix Hallpike test or roll test. They were treated with Epley maneuver or Barbecue rol maneuver according to the type of BPPV, and the efficacy was evaluated. (1) Most cases involved female patients in this study; (2) BPPV occurred after MD in al of the cases, of which 13 cases were posterior semicircular canal lithiasis (9 cases in the same ear, 2 in the other and 2 in both) and 2 cases were horizontal semicircular canal lithiasis (cupula lithiasis in the same ear); (3) in this study, 10 patients were cured after 3-4 times of posture treatment (66.7%), 4 patients were cured after 5 times and 1 patient received endolymphatic sac decompression because of recurrent vertigo. (1) BPPV can result from MD, for which a possible mechanism may be the hydrolabyrinth that lead to eardust falling off. (2) Most cases of BPPV occurred in the posterior semicircular canal in the same ear. Most cases in incidence rate have obvious sexual bias in female. (3) Eardust reposition is an effective treatment for BPPV caused by MD; while it is refractory compared to ordinary BPPV and require multiple treatments, which may be related to the recurrence of hydrolabyrinth.

Evidence of Gadolinium Distribution from the Endolymphatic Sac to the Endolymphatic Compartments of the Human Inner Ear

To verify whether injection of substances into the endolymphatic sac (ES) diffuses into the endolymphatic compartments of the human inner ear and in particular to the endolymphatic space of the scala media (ESp-SM), as demonstrated in animals, an exploratory investigation with magnetic resonance imaging (MRI) and intraoperative electrocochleographic recordings (ECoG) was conducted in patients with Ménière’s disease (MD) treated with ES decompression. A mixture of dexamethasone and gadolinium (GD) in solution was injected into the ES of 4 patients. The results of the ES injection procedure were compared with administration of the same solution intratympanically (IT, 1 patient) and via a platinotomy in 2 patients. The study was conducted retrospectively at a tertiary referral center. Main outcomes measures were pre- and postintervention complete audiological and neuro-otological evaluation; intraoperative ECoG investigation with evaluation of the morphology of acoustically elicited compound action potentials (CAPs) and 1.5 T MRI evaluations at different follow-up times. Distribution of GD from the ES injection procedure was observed first in the ES, after 24 h in the vestibule and semicircular canals, and after 24–48 h in the ESp-SM in all patients. High signal was detected within the inner ear for 1 week or more (mean: 10 days; range: 7–16 days). Changes in morphology and latency of CAPs were observed within 30 min of the dilatory injection into the ES in all patients. Administration of GD into the vestibule and the IT approach did not distribute the contrast in the ES and GD was observed in the perilymphatic space of the vestibule, cochlea and semicircular canals. No side effects relating to administration of GD into the ES, IT or into the vestibule were observed. To the best of our knowledge this is the first demonstration in humans that drugs injected into the endolymphatic structure of the ES diffuse to the cochlea, presumably into the ESp-SM. The possibility of injecting substances into the endolymphatic space might open up new prospects in the treatment of inner ear disorders. Further studies will be needed to define the limitations of this approach.

SP329 – Can ECOG predict post-op hearing in endolymphatic sac decompression

SP329 – Can ECOG predict post-op hearing in endolymphatic sac decompression