P100 Pilot Studies

The P100-For Ménière´s Disease delivers pressure pulses which are far below the pressures that the inner ear can tolerate. Von Bekesy in his experiments in hearing has estimated and measured that the round window membrane can withstand pressures up to three to four atmospheres
(von Bekesy: Experiments in hearing. New York. Mc Grawe-Hill. 102: 433-434, 1960; Kringlebotn M: Rupture pressures of membranes in the inner ear, Ann Otol Rhinol Laryngol 109: 940-944, 2000).
Side effects have not been currently observed with the use of the P100-For Ménière´s Disease or the more expensive electronic device.

A general comment from patients that have used the P100-For Ménière´s Disease was that it was very user friendly.
It was easy to store in ones handbag, and quickly at hand whenever needed.

How the pressure pulse therapy operates is still open to speculation.

However, there is the possibility of an ion shift, particularly potassium. It has been known for some time that a gradual potassium shift from the scala vestibuli towards the scala tympani occurs in Ménière’s disease.

The potassium concentration gradually increases from the base towards the apex in the scala vestibuli, and decreases from the apex towards the base in the scala tympani. When an ion shift occurs in direction of the scala tympani an increased concentration of potassium will be observed at the apical end of the scala tympani. Potassium is toxic to neurons.

As neurons are bathed in perilymph and thus exposed to potassium in the scala tympani, it will intoxicate these neurons.

The consequence is a low frequency hearing loss.

The forerunner of Ménière’s disease, the COO-Syndrome, typically shows a reverse of this intoxication following the insertion of a middle ear ventilation tube.
It can be demonstrated electrophysiologically by an improved SP/AP ratio in the electrocochleogram.

The improvement is caused by a larger AP voltage, a consequence of detoxication
(Franz et al.: The Cervicogenic Otoocular Syndrome: A Suspected Forerunner of Ménière’s Disease, International Tinnitus J 5: 125-130, 1999).

This might be one of the reasons that positive pressure pulses might also be helpful in the treatment of tinnitus.
The mechanism of intoxication is facilitated with a particularly mild Eustachian tube disorder which results in a mild suction on the round window membrane.
The naturally existing flow of perilymph towards the round window is thus increased causing the ion shift towards the scala tympani.

Positive pressure pulses will simply reverse this intoxicating ion shift.

The response of patients treated was excellent. Not all patients suffering from Ménière’s disease were willing to have a ventilation tube inserted which is a prerequisite for the treatment with the electronic device and the P100-For Ménière´s Disease.

There was hardly a patient that failed to respond. This might be due to a careful selection of patients.

Patients were not given a ventilation tube simply because they suffered from Ménière’s disease.

The demonstration of a mild Eustachian tube disorder was regarded as a very important test that justified the procedure.

However, it is very rare that patients with Ménière’s disease have normal Eustachian tube function.
This is a feature which is often overlooked by ENT surgeons. We found that the modified Holmquist test is well suited to demonstrate the unbalanced relationship between the middle ear and the inner ear.

We recommend that it is employed in every patient that is suspected to have Ménière’s disease.

The results will give the treating physician the confidence that more options for treatment are available.

Electro-cochleogram following insertion of a ventilation tube in a patient with early stages of Ménière’s disease.
Electro-physiological improvement is due to an AP effect.