Section 3: Adult

Ménière's Disease: A Challenging and Relentless Disorder

MD is considered a rare disease. An adequate model that explains MD's pathophysiology is not well established. Recently, the vascular theory of the disease has been revived.

To characterize a MD population according to its cardiovascular risk and correlate it to the MD clinical course.

In this retrospective chart study the data of 31 MD patients observed between January 2017 and April 2018 in a tertiary university hospital were reviewed. Patients included in the study were diagnosed according to the Bárány Society criteria. Lost follow-ups, patients with autoimmune disease, atopy or allergy, major psychiatric disease and migraine were excluded. Age, gender, cardiovascular risk factors, audiometric and vestibular parameters, occurrence of MD attacks in the previous 6 months, vestibular medication in course and time course of MD were recorded and compared between groups (with and without cardiovascular risk factors).

31 patients (61.3% females) mean aged 60.3 years (±9.7) were studied. 74% of the population had at least one risk factor and 51.6% of patients had attacks in the last 6 months. There was a statistically significant difference in the occurrence of MD attacks in the last 6 months (p = 0.014) between MD patients with and without risk factors. Mean PTA thresholds were higher and speech discrimination was lower in individuals with more cardiovascular risk factors.

Treatment of MD focusing on vascular risk factors may allow a better control of symptoms and result in a decreased need for ablative procedures in this disorder.

To evaluate the long-term efficacy of endolymphatic sac shunt techniques with and without local steroid administration.

Retrospective case series and patient survey.

Tertiary university hospital.

Meniere's disease (MD) patients that failed medical therapy and subsequently underwent an endolymphatic sac shunt procedure. All patients had definitive or probable MD and at least 18-months of follow-up.

Three variations on endolymphatic sac decompression with shunt placement were performed: Group A received no local steroids, Group B received intratympanic dexamethasone prior to incision, and Group C received dexamethasone via both intratympanic injection and direct endolymphatic sac instillation.

Vertigo control, hearing results, and survey responses.

Between 2002 and 2013, 124 patients with MD underwent endolymphatic sac decompression with shunt placement. 53 patients met inclusion criteria. Groups A, B, and C had 6 patients, 20 patients, and 27 patients, respectively. Mean follow-up was 56 months. Vertigo control improved in 66%, 83%, and 93% of Groups A, B, and C. Functional level improved for Group B (− 2.0) and Group C (− 2.2) but was unchanged in Group A. Pure-tone average and speech discrimination scores changed by + 22 dB and − 30%, + 6 dB and − 13%, and + 6 dB and − 5% in Groups A, B, and C. The long-term hearing results were significantly better with steroids (Groups B and C) according to the AAO-HNS 1995 criteria but did not meet significance on non-parametric testing.

Endolymphatic sac shunt procedures may benefit from steroid instillation at the time of shunt placement.

Phosphorus and vitamin D (calcitriol) supplementation in the Phex mouse, a murine model for endolymphatic hydrops (ELH), will improve otic capsule mineralization and secondarily ameliorate the postnatal development of ELH and sensorineural hearing loss (SNHL).

Male Phex mice have X-linked hypophosphatemic rickets (XLH), which includes osteomalacia of the otic capsule. The treatment for XLH is supplementation with phosphorus and calcitriol. The effect of this treatment has never been studied on otic capsule bone and it is unclear if improving the otic capsule bone could impact the mice's postnatal development of ELH and SNHL.

Four cohorts were studied: 1) wild-type control, 2) Phex control, 3) Phex prevention, and 4) Phex rescue. The control groups were not given any dietary supplementation. The Phex prevention group was supplemented with phosphorus added to its drinking water and intraperitoneal calcitriol from postnatal day (P) 7–P40. The Phex rescue group was also supplemented with phosphorus and calcium but only from P20 to P40. At P40, all mice underwent auditory brainstem response (ABR) testing, serum analysis, and temporal bone histologic analysis. Primary outcome was otic capsule mineralization. Secondary outcomes were degree of SNHL and presence ELH.

Both treatment groups had markedly improved otic capsule mineralization with less osteoid deposition. The improved otic capsule mineralized did not prevent the development of ELH or SNHL.

Supplementation with phosphorus and calcitriol improves otic capsule bone morphology in the Phex male mouse but does not alter development of ELH or SNHL.

From histopathological specimens, endolymphatic hydrops has been demonstrated in association with inner ear disorders. Recent studies have observed findings suggestive of hydrops using MRI in humans. Previous studies suggest that vasopressin may play a critical role in endolymph homeostasis and may be involved in the development of Ménière's disease. In this study we evaluate the effect of vasopressin administration in vivo in longitudinal studies using two mouse strains. High resolution MRI at 9.4 T in combination with intraperitoneally delivered Gadolinium contrast, was performed before and after chronic subcutaneous administration of vasopressin via mini-osmotic pumps in the same mouse. A development of endolymphatic hydrops over time could be demonstrated in C57BL6 mice (5 mice, 2 and 4 weeks of administration) as well as in CBA/J mice (4 mice, 2 weeks of administration; 6 mice, 3 and 4 weeks of administration). In most C57BL6 mice hydrops developed first after more than 2 weeks while CBA/J mice had an earlier response. These results may suggest an in vivo model for studying endolymphatic hydrops and corroborates the future use of MRI as a tool in the diagnosis and treatment of inner ear diseases, such as Ménière's disease. MRI may also be developed as a critical tool in evaluating inner ear homeostasis in genetically modified mice, to augment the understanding of human disease.

This article is part of a Special Issue entitled <IEB Kyoto>.