Pressure Treatment

The direct effect of external pressure on inner ear hydrodynamics has been studied for over 30 years. In 1965, Lundgren published his findings on the influence of changes in atmospheric pressure on divers.¹⁶ This was followed by Tjernström's work with pilots.¹⁷ The clinical observation that changes in ambient pressure, as with increasing altitude, affects Ménière's symptoms suggested a new approach to therapy.

The first attempts to control the symptoms in Ménière's disease by ambient pressure changes were made when patients with acute symptoms were treated in a hypobaric pressure chamber.¹⁸ Symptoms improved in response to a relative over-pressure created in the middle ear and deteriorated when a relative under-pressure was induced. Since then, pressure chamber therapy has been used with some success for acute attacks¹⁹ but is cumbersome, expensive, and not widely available.

Investigations through animal studies began in the early 1980s in an effort to understand the mechanisms responsible for resolution of endolymphatic hydrops and the effects of pressure treatments on the inner ear fluids.^19-24 The studies demonstrated the response of the inner ear fluids to positive and negative pressures, and they demonstrated the presence of a fluid stabilization time pattern. Figure 4 The effects of complex waveforms on the inner ear fluids was investigated and demonstrated.²³ Figure 5 These data provided pressure parameters and laid the groundwork for the development of a patented waveform algorithm for reducing inner ear fluid pressures.
In spite of all the efforts to date, the exact mechanism of endolymphatic fluid reduction remains unresolved and highly debated. Currently, the most popular theories for reduction of endolymph fluid are flow of fluid through the endolymphatic duct into the sac and/or interaction of the fluid with the stria vascularis. Regardless of the exact mechanism, externally applied pressure in the middle ear has been demonstrated to be effective in modulating the inner ear fluids.²⁴ 

Figure 4.  Inner ear fluid response to square wave stimulating pressure. Click on image to view larger.
Figure 5.  Inner ear fluid response to complex pressure wave stimulating pressure. Click on image to view larger.

Based on the animal and clinical studies, the Meniett, a low-pressure, air-pulse delivery device, was developed to deliver specific wave forms of energy to the middle ear and subsequently the inner ear fluids to cause relief of endolymphatic hydrops and the symptoms of Ménière's Disease. 

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