Could ionic regulation disorders explain the overlap between meniere's disease and migraine?

Sensational site: the sodium pump ouabain-binding site and its ligands

Cardiotonic steroids (CTS), used by certain insects, toads, and rats for protection from predators, became, thanks to Withering's trailblazing 1785 monograph, the mainstay of heart failure (HF) therapy. In the 1950s and 1960s, we learned that the CTS receptor was part of the sodium pump (NKA) and that the Na+/Ca2+ exchanger was critical for the acute cardiotonic effect of digoxin- and ouabain-related CTS. This "settled" view was upended by seven revolutionary observations. First, subnanomolar ouabain sometimes stimulates NKA while higher concentrations are invariably inhibitory. Second, endogenous ouabain (EO) was discovered in the human circulation. Third, in the DIG clinical trial, digoxin only marginally improved outcomes in patients with HF. Fourth, cloning of NKA in 1985 revealed multiple NKA α and β subunit isoforms that, in the rodent, differ in their sensitivities to CTS. Fifth, the NKA is a cation pump and a hormone receptor/signal transducer. EO binding to NKA activates, in a ligand- and cell-specific manner, several protein kinase and Ca2+-dependent signaling cascades that have widespread physiological effects and can contribute to hypertension and HF pathogenesis. Sixth, all CTS are not equivalent, e.g., ouabain induces hypertension in rodents while digoxin is antihypertensinogenic ("biased signaling"). Seventh, most common rodent hypertension models require a highly ouabain-sensitive α2 NKA and the elevated blood pressure is alleviated by EO immunoneutralization. These numerous phenomena are enabled by NKA's intricate structure. We have just begun to understand the endocrine role of the endogenous ligands and the broad impact of the ouabain-binding site on physiology and pathophysiology.

Outcomes of Endolymphatic Sac Surgery for Meniere's Disease with and without Comorbid Migraine

Purpose

To explore outcomes of endolymphatic sac surgery for patients with Meniere's disease with and without the comorbid condition of migraine.

Materials and Methods

A retrospective chart review of adult patients undergoing endolymphatic sac surgery at a single tertiary care center from 1987 to 2019 was performed. All adult patients who failed medical therapy and underwent primary endolymphatic sac surgery were included. The main outcome measures were vertigo control and functional level scale (FLS) score. Patient characteristics, comorbidities, and audiometric outcomes were tracked as well.

Results

Patients with Meniere's disease and migraine had a stronger association with psychiatric comorbidities (64.29% vs. 25.80%, p=0.01), shorter duration of vertigo episodes (143 vs. 393 min, p=0.02), and younger age (36.6 vs. 50.8 yr, p=0.005) at the time of endolymphatic sac surgery. Postoperative pure tone averages and word recognition scores were nearly identical to preoperative baselines. Class A vertigo control (47.92%) was most common, followed by class B vertigo control (31.25%). The FLS score improved from 4.2 to 2.8 (p < 0.001). Both patients with and without migraine had classes A-B vertigo control (66.67% vs. 80.95%) without any statistically significant difference (p=0.59). Of the patients who required secondary treatment (10.42%), none had migraine.

Conclusions

Endolymphatic sac surgery is an effective surgical intervention for Meniere's disease with and without migraine. Patients with comorbid migraine tend to be younger and present with psychiatric comorbidities.

A Family with a High Incidence of Migraine and Vestibular Migraine and a Case of Menière's Disease

Vestibular migraine (VM) and Menière's disease (MD) are common neurotological disorders causing episodic vertigo. Sometimes, VM is accompanied by cochlear symptoms suggestive for MD. Therefore, in those cases, the differential diagnosis between the two disorders can be difficult. Moreover, a comorbidity with migraine in MD patients is widely reported, up to the hypothesis of a possible MD-VM overlapping syndrome. In this brief case report, we consider the clinical history of a family presenting high incidence of subjects fulfilling the diagnostic criteria of VM and single case fulfilling criteria for definite MD. The relationship between VM and MD is still under debate; anyway, it can be speculated that commonly shared genetic mutations could play a role as predisposing factors in both disorders. A congenital nystagmus in the family was present too, but its correlation with the other conditions is still not clear. Future goal of our work will be to assess genetics in this family.