Eustachian tube disorders
A new nasal medication
by J.R. DI BARTOLOMEO, D.F. HENRY, and M. DI BARTOLOMEO
The Ear Foundation, Santa Barbara, CA (USA)
The diagnosis of an abnormally patent Eustachian tube may elude even the most astute physician. The symptoms common to most Eustachian tube disorders include a “plugged ear,” stuffiness, or dullness of sound tone. The patient with a patent Eustachian tube is quite disturbed by autophony and/or the appreciation of amphoric sounds. The presence of a patent Eustachian tube may occur continuously (patulous) or intermittently (semi-patulous).
Under normal physiologic conditions the Eustachian tube is closed and only opens intermittently during swallowing or yawning and sneezing; permitting the air pressure in the middle ear to equalize with atmospheric pressure. According to the observations of Armstrong, he concluded that a positive 15 mm of mercury in the middle ear is needed to open the tube. Then it remains open until the pressure is reduced to 3.6 mm, when it closes again, leaving an excess of pressure of 3.6 mm in the middle ear (1). This phenomenon is confirmed when the physician observes rhythmic lateral and medial displacement of the eardrum in harmony with the respiratory cycle. In mild cases the amplitude of movement of the eardrum is increased during forced inspiration and expiration through one nostril while the contralateral nostril is occluded.
In the normal state, the closed Eustachian tube prevents the fluctuating intranasal pressure changes, which occur during respiration, from being transmitted to the middle ear cavity. In the patulous state, the Eustachian tube orifice fails to close, allowing respiratory and vocal sounds to be transmitted through the isthmus of the tube to the sound conducting structures of the middle ear.
The Eustachian tube serves as a physiologic mechanism of eliminating middle ear fluid and equalizing atmospheric pressure on both sides of the tympanic membrane.
The middle ear cavity usually contains a mild negative pressure as a result of constant gas flow across the walls of the middle ear and mastoid mucosa. This pressure is normally 0.5 to 4.0 mm of mercury pressure. Opening of the tube by muscular activity usually occurs when the pressure differential is 20 to 40 mm of mercury.
In 1563 the anatomist, Bartolomeo Eustachio, was the first to provide a complete description of the narrow tube connecting the tympanic cavity with the nasopharynx (2). Until 1853, the majority of anatomists believed that the Eustachian tube was normally open, but Toynbee declared that the natural state of the Eustachian tube was “closed.” This was documented in 1861 by Politzer3 using a manometer in the external ear canal during Toynbee’s maneuver while recording the displacement of the tympanic membrane due to pressure changes within the Eustachian tube during swallowing. In 1864 Schwartze (4) published the first clinical description of the tympanic membrane moving in harmony with respiration.
Objective recording of tympanic membrane displacement in PET disorders was first used by Metz (5) in 1953. Today otoadmittance tympanometry is able to both identify the Eustachian tube disorder, and quantify and record the degree of displacement of tympanic membrane displacement.
Various reports estimate that the incidence of patulous Eustachian tube disorders is increasing, but this is most likely due to increased awareness of the condition and improved diagnostic techniques, including the operating microscope and tympanometry.
Since most patients with patulous Eustachian tube symptoms are disturbed by the autophony, various forms of treatment have been attempted in the past. These have included Eustachian tube catheterization with instillation of salicylic/boric acid powder, nitric acid and phenol, and 20% silver nitrate. Diathermy has been used. Surgical attempts to narrow the lumen using paraffin, Teflon or gelatin sponge injections have been inconsistent. Insertion of middle ear ventilation tubes have treated only the symptoms, and not the cause. In severe cases rerouting of palatal muscles, with or without pterygoid hamulotomy has been performed.
Under a recent pilot study, the patients were treated with a new nasal medication which proved to be effective in eliminating the symptoms of patulous Eustachian tube disorders (6). In this pilot study several compositions of medication in the form of nose drops were evaluated to determine their ability to produce congestion of the Eustachian tube mucosa sufficient enough to close the orifice. A nasal solution developed by the author resulted in congestion of the peritubal mucosa and closure of the Eustachian tube orifice. The patients accepted in the study included only those who had a diagnosis of patulous Eustachian tube exceeding three months in duration and not influenced by weight fluctuations. The patients in the study were instructed to record the beneficial effect and any associated nasal irritation during the clinical trial. Eighty percent of the patients achieved closure of the Eustachian tube and relief of symptoms with little or no side effects. The beneficial effect of the medication persisted for one to two weeks after taking the medication for two to three days.
The results of this pilot study look promising. The study is being expanded, including additional co-investigators, to determine if the same results are possible in a larger series of patients.
(1) Armstrong, H.G. and Heim, J.W.; Effect of Flight on the Middle Ear, J.A.M.A. 109; 417 (Aug 7) 1937
(2) Eustachio, B. (1563), OPUSCLA ANATOMICA – DEAUDITUS ORGANIS
(3) Politzer, A; Wurzburg. Naturwissensch. Ztschr., 1861, 2:92
(4) Schwartze, H.: Respiratorische Bewegung Des Trommelfelles, ARCH OHRENHEILKD, 1864, 1:139
(5) Metz, O., Influence of the patulous Eustachian tube on the acoustic impedance of the ear, ACTA OTOLARYNGOLOGICA, 1953, (STOCKHOLM) Suppl. 109, 105
(6) A New Medication to Control Patulous Eustachian Tube Disorders; Joseph DiBartolomeo, M.D., David F. Henry, Ph.D. THE AMERICAN JOURNAL OF OTOLOGY; Vol 13, 1992.
From the 2nd European Congress of Oto-Rhino-Laryngology
THE NEW FRONTIERS OF OTORHINOLOGYLARYNGOLOGY IN EUROPE
Sorronto, Italy, June 6 - 10, 1992
© 1992 by Monduzzi Editore S.p.A. - Bologna (Italy)