Diuretics in Meniere disease: a therapy or a potential cause of harm. Med Hypotheses. 2011;77:869-871. [PMID: 21864986 DOI: 10.1016/j.mehy.2011.07.060]

Meniere's disease: Pathogenesis, treatments, and emerging approaches for an idiopathic bioenvironmental disorder

Meniere's disease (MD) is a severe inner ear condition known by debilitating symptoms, including spontaneous vertigo, fluctuating and progressive hearing loss, tinnitus, and aural fullness or pressure within the affected ear. Prosper Meniere first described the origins of MD in the 1860s, but its underlying mechanisms remain largely elusive today. Nevertheless, researchers have identified a key histopathological feature called Endolymphatic Hydrops (ELH), which refers to the excessive buildup of endolymph fluid in the membranous labyrinth of the inner ear. The exact root of ELH is not fully understood. Still, it is believed to involve several biological and bioenvironmental etiological factors such as genetics, autoimmunity, infection, trauma, allergy, and new theories, such as saccular otoconia blocking the endolymphatic duct and sac. Regarding treatment, there are no reliable and definitive cures for MD. Most therapies focus on managing symptoms and improving the overall quality of patients' life. To make significant advancements in addressing MD, it is crucial to gain a fundamental understanding of the disease process, laying the groundwork for more effective therapeutic approaches. This paper provides a comprehensive review of the pathophysiology of MD with a focus on old and recent theories. Current treatment strategies and future translational approaches (with low-level evidence but promising results) related to MD are also discussed, including patents, drug delivery, and nanotechnology, that may provide future benefits to patients suffering from MD.

Hearing Preservation and Speech Outcomes After Cochlear Implantation in Meniere's Disease

OBJECTIVES/HYPOTHESIS

To evaluate speech perception outcomes and hearing preservation after cochlear implantation in patients with Meniere's disease (MD).

STUDY DESIGN

Retrospective chart review.

METHODS

Fifty-one adult patients, accounting for a total of 63 implants, with MD treated at a tertiary care center were included in the study. Patients with unaided preoperative air-conduction thresholds ≤80 dB at 250 Hz were included in hearing preservation analyses. The primary outcome measure was Consonant-Nucleus-Consonant (CNC) score. Hearing preservation was assessed as follows: 1) maintenance of functional hearing, defined as a postoperative unaided air-conduction threshold ≤80 dB at 250 Hz and 2) low-frequency pure-tone average (LFPTA) shift.

RESULTS

Speech perception scores improved significantly postimplantation; specifically, the CNC mean score was 9% preoperatively and increased to 57% by 1 year postoperatively (P < .001). Eighteen ears were included in hearing preservation analysis; the mean preoperative LFPTA was 65 dB (standard deviation [SD] = 10). The mean postoperative LFPTA at activation was 93 dB (SD = 21), and at 1 year was 102 dB (SD = 11). Twenty-seven percent of patients achieved short-term functional hearing preservation, whereas the longer-term outcomes were less favorable (11%).

CONCLUSIONS

Speech perception scores improve after implantation in patients with MD. Hearing preservation is possible in patients with MD, albeit at lower rates than reported non-MD populations. Our data suggest that there can be degradation in acoustic hearing over time.

LEVEL OF EVIDENCE

4 Laryngoscope, 2019.

It is 2015: What are the best diagnostic and treatment options for Ménière’s disease?

Ménière’s disease (MD) is a common cause of recurrent vertigo. Its pathophysiology is still unclear and controversial. The most common histological finding in postmortem temporal bone studies of patients is endolymphatic hydrops (EH). However, not all cases of hydrops are associated with MD and it may represent the end point of various etiologies. The diagnostic criteria for MD have undergone changes during the past few decades. A recent collaboration among specialty societies in United States, Europe and Japan has given rise to a new set of guidelines for the diagnosis and classification of MD. The aim is to develop international consensus criteria for MD that would help improve the quality of data collected from patients. The diagnosis of MD can be difficult in some cases as there is no gold standard for testing. Previous use of audiometric data and electrocochleography are poorly sensitive as screening tools. Recently magnetic resonance imaging as a diagnostic tool for identifying EH has gained popularity in Asia and Europe. Vestibular evoked myogenic potentials are also used but lack specificity. Finally, the treatment for MD has improved with the introduction of intratympanic treatments with steroids and gentamicin as well as less invasive treatment with the Meniett device.

Does the intravenous administration of frusemide reduce endolymphatic hydrops?

Objective:

To verify the hypothesis that intravenous frusemide reduces endolymphatic hydrops, as evaluated by three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging following intratympanic gadolinium administration.

Methods:

The study comprised 12 patients (7 females and 5 males, aged 19–74 years) with Ménière's disease. Disease duration ranged from 0.5 to 8 years, with a frequency of 0.5 to 6 vertigo spells per month, as calculated in the last 6 months. Three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging was performed 24 hours after intratympanic injection of gadobutrol diluted eight-fold. Frusemide 20 mg was given intravenously immediately after imaging. Magnetic resonance imaging was repeated after 1 hour, using the same parameters and sequence.

Results:

All patients showed enhancement defects, indicating endolymphatic hydrops of variable degrees. No modifications occurred at the second magnetic resonance imaging performed 1 hour after frusemide administration.

Conclusion:

There was no evidence of endolymphatic hydrops modification 1 hour after intravenously administered frusemide. Therefore, loop diuretics in Ménière's disease, which are today used on an empirical basis, must be reconsidered. Implications of these outcomes are discussed and related to the role of endolymphatic hydrops in the development of Ménière's disease.

Primary vascular dysregulation syndrome: Possible implications for inner ear acute diseases?

Primary vascular dysregulation syndrome has been reported as a possible cause for different eye diseases. Signs or symptoms of this syndrome not only may consist in a series of ocular disorders, as they possibly concern or are associated to various systemic conditions; even the damage of another terminal sensory organ as the inner ear is reported among the possible associations. Herein, the analogies between eye and inner ear are outlined, analyzing the PVD profile that well corresponds to our widely described model of subject without organic cardiovascular impairment but prone to inner ear acute disturbances. Actually, in absence of a recognized cause the latter can be due to a systemic dysregulation like the described one concerning ocular disorders.

Vasopressin Proves Es-sense-tial: Vasopressin and the Modulation of Sensory Processing in Mammals

As mammals develop, they encounter increasing social complexity in the surrounding world. In order to survive, mammals must show appropriate behaviors toward their mates, offspring, and same-sex conspecifics. Although the behavioral effects of the neuropeptide arginine vasopressin (AVP) have been studied in a variety of social contexts, the effects of this neuropeptide on multimodal sensory processing have received less attention. AVP is widely distributed through sensory regions of the brain and has been demonstrated to modulate olfactory, auditory, gustatory, and visual processing. Here, we review the evidence linking AVP to the processing of social stimuli in sensory regions of the brain and explore how sensory processing can shape behavioral responses to these stimuli. In addition, we address the interplay between hormonal and neural AVP in regulating sensory processing of social cues. Because AVP pathways show plasticity during development, early life experiences may shape life-long processing of sensory information. Furthermore, disorders of social behavior such as autism and schizophrenia that have been linked with AVP also have been linked with dysfunctions in sensory processing. Together, these studies suggest that AVP's diversity of effects on social behavior across a variety of mammalian species may result from the effects of this neuropeptide on sensory processing.