Biomechanical analysis of the clinical characteristics of enlarged vestibular aqueduct syndrome with Mondini malformation.

BACKGROUND: numerous researches on the pathological mechanism of Enlarged Vestibular Aqueduct (EVA) syndrome mainly focuses on the genetic characteristics of SLC26A4 gene and the function of its encoding protein, Pendrin. One of the limitations with these explanations is that it does not explain why cerebrospinal fluid pressure can affect clinical manifestations. OBJECTIVES: To establish a new approach to explain the clinical manifestations of EVA syndrome with biomechanical method. MATERIAL AND METHODS: 108 cases of EVA syndrome who received cochlear implantation were analyzed retrospectively. A cochlear model was built to reflect the differences of the structure in EVA syndrome with or without Mondini malformation. The CFD software was used to simulate and display the differences in mechanical pathogenic factors to which the model was subjected. RESULTS: EVA syndrome patients with Mondini malformation suffer more mechanical damage from the cerebrospinal fluid pressure due to their structural reason and their symptoms appear earlier and progress faster. CONCLUSIONS: Biomechanics is an important aspect of pathological mechanism of EVA syndrome, and it provides a new angle for clinical decision-making.

[Imaging characteristics of patients with large vestibular aqueduct syndrome and its relationship with the acoustically evoked short latency negative response].

Objective: To explore the imaging characteristics of large vestibular aqueduct syndrome (LVAS) patients and their relationship with the acoustically evoked short latency negative response (ANSR), so as to provide reference for the diagnosis of LVAS. Methods: Clinical data of 174 patients(334 ears) with LVAS diagnosed and treated by the Department of Otorhinolaryngology Head and Neck Surgery of the First Affiliated Hospital of Guangxi Medical University, from October 2009 to December 2017 were retrospectively analyzed, including 117 males and 57 females, aged from 5 months to 47 years old, with the median age of 4 years and 4 months. ABR and imaging data of patients were collected. Midpoint diameter and the outlet diameter of the vestibular aqueduct were measured on CT images, the midpoint diameter of the intraosseous parts and the extraosseous parts of enlarged endolymphatic sac(EES) were measured on MRI images. The correlation between the above measurements was analyzed by Pearson test using SPSS 17.0. According to whether ASNR was detected in ABR, the above data were divided into two groups, and the differences of the above imaging measurements were compared by the Independent-Sample Test. Results: The average midpoint diameter of the vestibular aqueduct was (1.87±0.58) mm (x±s, the following was the same), and the outlet diameter was (3.07±0.99) mm on CT; the average midpoint diameter of the intraosseous parts in enlarged endolymphatic sac(EES) was (2.39±1.37) mm, and the extraosseous parts was (2.50±2.18) mm on MRI. There was a correlation between the four measurements (P<0.05), among which the midpoint diameter of vestibular aqueduct was strongly positively correlated with the outlet diameter (r=0.760), and the remaining pairs were weakly correlated. ASNR was detected in 241 ears (72.16%,241/334) and undetected in 93 ears (27.84%, 93/334) of the 334 ears with LVAS. Midpoint diameter and the outlet diameter of the vestibular aqueduct in no ASNR group were smaller than the ASNR group, and the difference was statistically significant (t value was 2.814 and 2.754, P<0.05). There was no significant difference in the midpoint diameter of the intraosseous parts and the extraosseous parts of enlarged endolymphatic sac between the two groups, and the difference was no statistically significant(t value was 0.101 and 0.683, P>0.05). Conclusions: There is a strong positive correlation between the midpoint diameter of vestibular aqueduct and the outlet diameter in LVAS patients. There is a certain correlation between the size of vestibular aqueduct and the size of endolymphatic sac. The smaller the diameter of vestibular aqueduct, the lower the occurrence rate of ASNR.

Pathophysiologic Findings in the Human Endolymphatic Sac in Endolymphatic Hydrops: Functional and Molecular Evidence.

BACKGROUND: The endolymphatic sac (ES) is a cystic structure situated on the posterior fossa dura and is connected to the luminal space of the vestibular organ through the endolymphatic duct, which branches into the utricular and saccular ducts. Unlike the cochlea and vestibule, the ES does not contain sensory epithelium in its luminal space, and a single layer of epithelial cells line the luminal surface area. The ES in the inner ear is thought to play a role in the regulation of inner ear homeostasis, fluid volume, and immune reaction. If these functions of the ES are disrupted, dysfunction of the inner ear may develop. The most well-known pathology arising from dysfunction of the ES is endolymphatic hydrops, characterized by an enlarged endolymphatic space due to the accumulation of excessive endolymphatic fluid. Although, molecular identities and functional evidence for the roles were identified in animal studies, basic studies of the human ES are relatively uncommon compared with those using animal tissues, because of limited opportunity to harvest the human ES. METHODS: In this study, molecular and functional evidence for the role of the human ES in the development of endolymphatic hydrops are reviewed. RESULTS AND CONCLUSIONS: Although evidence is insufficient, studies using the human ES have mostly produced findings similar to those of animal studies. This review may provide a basis for planning further studies to investigate the pathophysiology of disorders with the finding of endolymphatic hydrops.

Gentamicin delivery to the inner ear: Does endolymphatic hydrops matter?

INTRODUCTION: Middle ear application of gentamicin is a common medical treatment for uncontrolled Ménière's disease. The objective of the study was to evaluate the impact of endolymphatic hydrops on inner ear delivery. METHODS: Perilymph gentamicin concentrations and correlation with endolymphatic hydrops in an animal model were assessed. A group of 24 guinea pigs was submitted to surgical obstruction of the endolymphatic sac and duct of the right ear. Gentamicin was applied either to the right ear's round window niche or through a transtympanic injection. Perilymph specimens were collected at different times. Histologic morphometry was used to evaluate both turn-specific and overall hydrops degree. RESULTS: In animals with endolymphatic hydrops, lower concentrations of gentamicin were observed after 20 or 120 minutes of exposure and in both types of administration, when compared to controls. This difference reached statistical significance in the round window niche application group (Mann-Whitney, p = 0,007). A negative correlation between perilymphatic gentamicin concentration and hydrops degree could be observed in both groups, after 120 minutes of exposure (Spearman correlation, round window niche p<0,001; TT p = 0,005). CONCLUSIONS: The study indicates that the endolymphatic hydrops degree has a negative interference on the delivery of gentamicin into the inner ear following middle ear application.

Dehydration effects of a V2 antagonist on endolymphatic hydrops in guinea pigs.

We investigated the influence of vasopressin type 2 receptor antagonist (OPC-41061; Tolvaptan) on experimentally induced endolymphatic hydrops (EH) in guinea pigs. In the first series, the endolymphatic sac (ES) of the left ear of all animals was electrocauterized. Four weeks after surgery, the animals were allocated to four groups: three systemic applications groups (saline, OPC 10 and 100 mg/kg) and a local round window (RW) OPC 1 mg/body application group. We examined the histopathology of the temporal bones and assessed volumetric changes of the endolymphatic space in the cochlea and saccule. In the second series, we investigated the effects of systemic and topical applications of OPC on plasma vasopressin (p-VP) concentrations and plasma osmolality (p-OSM). In the first series, we found that EH was reduced in the OPC 10 mg/kg systemic and OPC RW application groups. In contrast, EH increased in the OPC 100 mg/kg systemic application group. In the second series, neither p-VP levels nor p-OSM were significantly different among the non-OPC, OPC 10 mg/kg systemic, and OPC RW application groups. However, in the OPC 100 mg/kg systemic application group, the p-VP level was significantly higher than that in other groups, and p-OSM was higher than that in the non-OPC group. The systemic application of a low dose of OPC and topical application of OPC resulted in reduced EH in the face of minimal systemic effects (p-VP and p-OSM). These findings suggest that OPC-41061 may be one useful treatment option for EH.

Auto-inflammatory challenge of the endolymphatic sac--Cochlear damage measured by distortion product oto-acoustic emissions.

CONCLUSION: Twenty-five rats were challenged by an immunologic attack of the endolymphatic sac. After 6 months, distortion product oto-acoustic emissions (DPOAE) revealed a dysfunction of the outer hair cells and immunological active cells were observed in the endolymphatic sac. This information could contribute to the understanding of Ménière's disease. OBJECTIVES: This study investigated if an autoimmune challenge of the endolymphatic sac could affect DPOAE output measurements in rats. Also, a potential autoimmune cell infiltration of the endolymphatic sac was investigated. METHODS: Eighteen Lewis rats were immunized with a crude endolymphatic sac extract in complete Freund's adjuvant. Seven control animals were injected with Freund's adjuvant in saline. Cochlear damage was estimated by DPOAE dynamics 3 weeks and 6 months after the immunization. Infiltrative cells in the endolymphatic sac were investigated with transmission electron microscopy. RESULTS: The hearing assessment 6 months after immunization revealed a reduction of the DPOAE, on the full range of frequencies (2-63 kHz) in an average of the mean, of 2 dB ± 1.1 in the immunized group compared to the controls (p < 0.05). The same test showed a 2.5 dB decrease from 2 to 5 kHz (p < 0.01). Immunological active cells were observed in the endolymphatic sac in most of the immunized rats.

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 .

Experimental hyperactivity of the endolymphatic sac.

Injury to the endolymphatic sac may play an important role in the pathogenesis of Ménière's disease, an inner ear disorder characterized by hearing loss, tinnitus and attacks of vertigo. Isoimmunization of 16 inbred Lewis rats with a crude endolymphatic sac extract and complete Freund's adjuvant induced hyperactivity of the endolymphatic sac. One group of rats was immunized by a single dose whereas a second group was immunized twice. Control animals were injected with Freund's adjuvant in saline only. Serum was collected from all rats by the end of the study and harvested autoantibodies were tested by immunohistochemistry. The endolymphatic sacs were investigated by transmission electron microscopy. Endolymphatic sac stimulation was observed in all immunized rats. Based on detailed ultrastructural observations, the degree of reactivity seemed proportional to the number of injections and the extent of immunization. Moreover, the ribosome-rich cells seemed hyperactive with an extravagant content of intracellular components: numerous rough endoplasmic reticulum and free ribosomes, morphological signs of extensive endo- and exocytosis, vesicles of material with a density similar to the homogeneous substance of which many were observed to fuse with primary lysozymes. Basolateral foldings were numerous and in the subepithelial capillaries formation of multiple and apposing fenestrations were observed. No endolymphatic sac stimulation was observed in the control animals. Specific ribosome-rich cell alterations identical to those present in the endolymphatic sac of Ménière's disease were observed 21 days after the first immunization. The observations suggest that either an autoantigen or a trophic factor, capable of inducing a hyperactivity of the ribosome-rich cells and an imbalance of the homogeneous substance metabolism, exists in the endolymphatic sac of the rat.

Mice deficient in H+-ATPase a4 subunit have severe hearing impairment associated with enlarged endolymphatic compartments within the inner ear.

Mutations in the ATP6V0A4 gene lead to autosomal recessive distal renal tubular acidosis in patients, who often show sensorineural hearing impairment. A first Atp6v0a4 knockout mouse model that recapitulates the loss of H(+)-ATPase function seen in humans has been generated and recently reported (Norgett et al., 2012). Here, we present the first detailed analysis of the structure and function of the auditory system in Atp6v0a4(-/-) knockout mice. Measurements of the auditory brainstem response (ABR) showed significantly elevated thresholds in homozygous mutant mice, which indicate severe hearing impairment. Heterozygote thresholds were normal. Analysis of paint-filled inner ears and sections from E16.5 embryos revealed a marked expansion of cochlear and endolymphatic ducts in Atp6v0a4(-/-) mice. A regulatory link between Atp6v0a4, Foxi1 and Pds has been reported and we found that the endolymphatic sac of Atp6v0a4(-/-) mice expresses both Foxi1 and Pds, which suggests a downstream position of Atp6v0a4. These mutants also showed a lack of endocochlear potential, suggesting a functional defect of the stria vascularis on the lateral wall of the cochlear duct. However, the main K(+) channels involved in the generation of endocochlear potential, Kcnj10 and Kcnq1, are strongly expressed in Atp6v0a4(-/-) mice. Our results lead to a better understanding of the role of this proton pump in hearing function.

Posterior semicircular canal dehiscence following endolymphatic sac surgery.

Posterior semicircular canal dehiscence is a rare otologic entity that presents with third window signs and symptoms. Petrous apex cholesteatoma, fibrous dysplasia, high riding jugular bulb, and eosinophilic granuloma have been reported to be associated with posterior semicircular canal dehiscence. Here we report a case of development of posterior semicircular canal dehiscence following an endolymphatic sac surgery for the first time.

von Hippel-Lindau disease: surveillance strategy for endolymphatic sac tumors.

PURPOSE: : Up to 16% of patients with the hereditary von Hippel-Lindau disease develop endolymphatic sac tumors of the inner ear. Early diagnosis and treatment of endolymphatic sac tumors can prevent audiovestibular morbidity, but optimal endolymphatic sac tumor surveillance strategy has yet to be determined. We aimed to evaluate endolymphatic sac tumor surveillance to determine the best surveillance strategy. METHODS: : In a national prospective study, 40 VHL mutation carriers were interviewed about audiovestibular symptoms and had audiological examinations and magnetic resonance imaging of the inner ear. Further, we performed a meta-analysis including all reported endolymphatic sac tumor von Hippel-Lindau disease cases in the literature (N = 140 with 156 endolymphatic sac tumors). RESULTS: : In the prospective study, endolymphatic sac tumors were suspected based on audiovestibular symptoms, audiometry, and magnetic resonance imaging in 34%, 30%, and 12.5% of subjects, respectively. In total, more than 90% of radiologically diagnosed endolymphatic sac tumors were associated with abnormal audiometric findings. No endolymphatic sac tumor genotype-phenotype correlations were found. CONCLUSION: : We recommend annual audiometry as a first-line endolymphatic sac tumor screening tool, and in countries where periodic surveillance magnetic resonance imaging of the central nervous system is performed, specific images of the inner ear should be included. Audiometric abnormalities in patients with von Hippel-Lindau disease without magnetic resonance imaging-visible endolymphatic sac tumors could be due to microscopic endolymphatic sac tumors. Determination of audiometric endolymphatic sac tumor characteristics could further target screening and improve endolymphatic sac tumor diagnosis.

Management of von Hippel-Lindau disease-associated CNS lesions.

Patients with von Hippel-Lindau disease (VHL) often harbor significant disease burden within the CNS, specifically craniospinal-axis hemangioblastomas and endolymphatic sac tumors (ELSTs). The majority (60-80%) of patients with VHL harbor hemangioblastomas, and 10-15% will develop ELSTs. Advances in the understanding of the natural history and outcomes associated with the surgical management of VHL-associated tumors have led to improved management of patients with VHL. Optimizing indications for surgical intervention and refining of surgical techniques for these lesions can reduce patient morbidity associated with the management of this syndrome. In this article, we review the various aspects of perioperative management of patients with VHL, surgical indications and general operative principles for the management of hemangioblastomas and ELSTs, and outcomes associated with the surgical treatment of these tumors.

Visualization of endolymphatic hydrops after administration of a standard dose of an intravenous gadolinium-based contrast agent.

CONCLUSION: Even after the administration of a standard dose of an intravenous gadolinium-based contrast agent (GBCA), visualization of endolymphatic hydrops (ELH) became possible in patients with Meniere's disease. The next step would be to consistently visualize ELH in the upper part of the cochlea. OBJECTIVE: To visualize ELH after routine administration of an intravenous GBCA. METHODS: An intravenous GBCA (gadodiamide; 0.2 ml/kg) was administered to three patients with unilateral Meniere's disease and two healthy volunteers. Three-dimensional fluid attenuated inversion recovery (3D-FLAIR) magnetic resonance imaging (MRI) was performed with a 3 T MRI scanner 4 h later. RESULTS: In all three patients, ELH was observed in the affected vestibules. In contrast, the endolymphatic space of both vestibules was the same size in healthy volunteers. ELH of the cochlea was not observed in any of the subjects. Gadolinium enhancement was insufficient in the upper turns of both cochleae in patients 1 and 3.

Large vestibular aqueduct syndrome: anatomic and functional parameters.

OBJECTIVES/HYPOTHESIS: To correlate imaging and audiologic findings in patients with large vestibular aqueduct syndrome (LVAS). STUDY DESIGN: Retrospective analysis. METHODS: Thirty-eight patients with LVAS evident on magnetic resonance imaging with available clinical and audiometric data were selected from the databases of the study institution. Images were analyzed for endolymphatic sac and duct size, evidence of incomplete cochlear partitioning, and endolymphatic sac signal heterogeneity. The endolymphatic duct was measured in two different locations: near the vestibular aperture (ED(VA)) and at the midpoint between the common crus and the operculum (ED(MID)). Imaging data were correlated with audiologic variables. RESULTS: There was significant correlation between ears for the audiologic and anatomic variables collected. Twenty-one (62%) patients had a fluctuating or progressive hearing loss, and 13 (38%) remained stable (four were not evaluable). At the time of the analysis, 41% of ears had a profound loss. Significant correlation was identified between the presence of endolymphatic signal heterogeneity and worse pure tone average (PTA). ED(VA) measures were significantly larger among ears with a progressive pattern of hearing loss when compared to those that were stable. Also, ED(VA) correlated with PTA and the presence of progressive hearing loss, but ED(MID) had no such a relationship. CONCLUSIONS: Evidence of endolymphatic sac signal heterogeneity and larger measures of endolymphatic width when measured near the vestibule (ED(VA)) are markers of poorer hearing in these patients. By contrast, midpoint measures of the endolymphatic duct (ED(MID)) have no correlation with audiometric parameters.

Induced endolymphatic flow from the endolymphatic sac to the cochlea in Ménière's disease.

OBJECTIVE: The aim of the present study was to verify whether drugs injected into the endolymphatic sac (ES) can reach the cochlea and possibly treat inner ear disorders. STUDY DESIGN: Prospective cohort study. SETTING: Tertiary referral center, Otolaryngology Department, University of Verona. SUBJECTS AND METHODS: Patients with Ménière's disease (MD) who were candidates for ES decompression were selected. Nineteen subjects received dexamethasone (DEX) via injection into the ES. To objectively define whether substances administered into the ES could reach the cochlea, we added gadolinium (GD) in three patients. All subjects had intraoperative electrocorticogram recordings and an audiologic follow-up. The three subjects who underwent injection of the DEX-GD solution were followed-up with magnetic resonance imaging. The audiological data are presented during a follow-up period of 12 months. RESULTS: Intraoperative electrocochleography recordings revealed no changes in two patients and summating potentials and compound action potential latency and wave-form modifications in all the other subjects. GD distribution was observed from 48 hours to one week after ES injection into the cochlea of the three subjects injected with DEX-GD. GD-related enhancement of inner ear structures lasted more than two weeks in all subjects. Pure tone average results showed hearing improvement of at least 20 dB HL in 42 percent of patients (8 of 19) at the 12-month follow-up. Statistically significant differences emerged between the mean pure tone average of the ES procedure subjects at one and 12 months after surgery (P = 0.0096). CONCLUSION: This novel approach might reveal new prospects for treating viral, metabolic, autoimmune, and genetic disorders of the cochlea.

Initial UK experience of patient satisfaction with the Meniett® device for Ménière's disease treatment.

OBJECTIVES: To evaluate patient satisfaction and symptom improvement following treatment of Ménière's disease with the Meniett® device. METHODS: Retrospective, questionnaire-based audit and analysis of unilateral Ménière's disease patients' records, following on from a previous study from our departments on intra-tympanic gentamicin for Ménière's disease, using the Vertigo Symptom Scale and Glasgow Benefit Inventory as outcome measures. RESULTS: Of 33 consecutive patients treated with the Meniett® device for four to six weeks, 30 responded to the questionnaires (90.9 per cent). Respondents' mean Vertigo Symptom Scale score was 0.7 (range 0-2.1), and their mean Glasgow Benefit Inventory general subscale score was 24.1. Nineteen (63.3 per cent) patients felt that the device had alleviated their vertigo and tinnitus. CONCLUSIONS: This is the first UK study of the effectiveness of the Meniett® device in treating Ménière's disease. It shows that the Meniett® device is a well tolerated, useful and minimally invasive means of treating Ménière's disease after medical treatment has failed, and before more potentially cochleo- and vestibulo-toxic therapies and invasive procedures are utilised.

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.

Analysis of hearing preservation after endolymphatic mastoid sac surgery for Meniere's disease.

OBJECTIVES/HYPOTHESIS: Comparison of audiometric outcomes between patients with definite Meniere's disease who underwent endolymphatic mastoid sac surgery (EMSS) following failed medical therapy and patients who underwent medical therapy only. STUDY DESIGN: Retrospective chart review of 456 consecutive patients between 1997 and 2006. METHODS: Outcome measures were changes in pure-tone average (PTA), word recognition score (WRS), and speech reception threshold (SRT). RESULTS: Of 58 qualified patients, 29 who underwent EMSS after failing medical therapy showed a 4 dB decrease in PTA, a 2% increase in WRS, and a 2 dB decrease in SRT. Twenty-nine patients treated with medical therapy only demonstrated a 1 dB PTA increase, 2% WRS improvement, and 2 dB SRT improvement. No significant difference was noted between the medically and surgically managed patients in terms of changes in PTA (P = .34) or WRS (P = .95) after treatment. Of all patients in the study, 60% had no clinically significant change in hearing, whereas 24% improved and 16% worsened. The distribution of post-treatment hearing changes between the medical and surgical groups was statistically insignificant (P = .17). CONCLUSIONS: The changes in PTA and WRS among patients with Meniere's disease managed with medical therapy or EMSS were not statistically significant. Although performing EMSS to treat the vertigo of Meniere's disease does not appear to be associated with an increased risk of deteriorating auditory function after treatment, surgery also does not confer an increased likelihood of stabilizing or improving hearing.

Antisecretory factor-inducing therapy improves the clinical outcome in patients with Ménière's disease.

CONCLUSION: Intake of antisecretory factor (AF)-inducing SPC-flakes significantly reduced vertigo in patients suffering from Ménière's disease (MD). The positive effect may be due to a modulation of the transport of water and ions in the endolymphatic space. OBJECTIVE: To evaluate the effects of a 3-month treatment period with SPC-flakes in patients suffering from MD. PATIENTS AND METHODS: A prospective, double-blind, placebo-controlled study was performed. A total of 51 adult patients with MD were included in the study: 27 subjects treated with SPC-flakes and 24 subjects with control cereals. The patients received SPC-flakes or control cereals (1 g per kg body weight per 24 h in two servings) for 3 months. Otoneurological examinations were carried out before and after this period. RESULTS: The severity of MD was classified according to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) grading system. Fourteen of the 27 patients randomized to intake of the AF-inducing SPC-flakes reported decreased vertigo, compared with 2 of 24 in the control group (p < 0.001). No consistent change in the otoneurological examinations could be demonstrated in any of the groups of patients.