Kimiko Teramura

Sonotubometric Measurement of the Eustachian Tube Function by Means of Band Noise

The Eustachian tube is well known as an organ serving the ventilation and drainage of the tympanic cavity and mastoid. Ventilation is carried out by the opening and closing of the Eustachian tube accompanying swallowing movements. Until now there has been no instrument to quantify these motor activities of the tube necessary for its function as a ventilator. The author developed a generally applicable sonotubometer Model WIO-01 with the help of Siemens Hearing Institute K.K. for automatic measurement of the aforesaid tubal function with the use of 7 kHz full-octave band noise. In a sonotubometric trial with 32 adult female subjects, the duration of patency of the Eustachian tube was 288.5 +/- 1.38.5 ms, and the amplitude eliciting response was 16.4 +/- 8.3 dB. The positive response rate was 89.1%. In 89 children aged 4-12 years, a positive response was detected in 117 ears (61.9%). The mean duration of patency was 337.7 +/- 154.4 ms, and the amplitude 16.3 +/- 7.2 dB. It is physiological to have tubal opening and closing during natural swallowing. It is therefore important to understand the tubal function when dealing with tympanoplasty and diseases caused by tubal dysfunction.

Surgical Approach to Tumors Arising from the Posterior Two Thirds of the Nasal Septum

A surgical approach to tumors of the septum is discussed. Two patients who had tumors in the posterior two thirds of the septum are shown in this paper. One had a benign mixed tumor and the other had an extramedullary plasmacytoma in the posterior two thirds of the septum. They underwent resection of the tumors with the septum by lateral rhinotomy. The first case additionally underwent an oval-shape resection of the palate. The postoperative profiles of the nose are good.

Factors influencing middle ear pressure variations under normal and hyper and hypo baric conditions.

The author investigated the effect of changing posture and blood flow on the middle ear pressure of humans. First, a sudden change of posture, from sitting to the head down position was induced in 38 normal persons (65 ears) in normal and hyper and hypobaric environments. Then blood flow was changed by SGB or excercise. The SGB procedure was applied to 3 normal persons and 3 patients with sudden deafness, and 9 normal persons were tested during exercise. PO2 in the middle ear was measured simultaneously with the measurement of the middle ear pressure. The change of pressure was estimated by tympanometry, and the PO2 value was measured by a sensor introduced into the middle ear via the Eustachian tube.At both normal and abnormal atmospheric pressures, the middle ear pressure increased when the posture was changed from the sitting to the head down position. Pressure change caused by posture change was 2.4 times greater in a relatively hypobaric than in a relatively hyperbaric environment. When blood flow was raised by SGB or excercise, PO2 in the middle ear increased, but the pressure decreased.It was concluded that middle ear pressure is increased by a rise of venous pressure and also by adiminution of middle ear volume caused by temporary swelling of mucous membranes. Middle ear pressure changes due to variations of blood flow may also be related to changes in gas metabolism, especially the production and influence of CO2.

Hyperbaric therapy of otitis media in children.

Secretory otitis media occurs most frequently in infancy. Since the Eustachian tube functions differently in children and adults, it is considered unlikely that secretory otitis media in the two age groups is due to the same cause. Since the infantile Eustachian tube is a kind of pressure open type, we preffered high-pressure therapy in the treatment of secretory otitis media in children.We used high-pressure therapy for 111 children aged 3 to 12 years 188 ears) with secretory otitis media. As a result, 129 ears(68.6%)showed improved average hearing levels within 10 dB in the low, medium, and high tone ranges. No patient experienced earache or other trouble when exposed to high-pressures. In the highpressure therapy, air escapes through the Eustachian tube when the middle ear pressure is regulated. In this case, the fluid can be excreted together with the air. Since the partial pressure of oxgen rises with the pressure, it is estimated that the highpressure therapy favorably affects ciliary movement and restores the mucous menbranes in the tympanic cavity and the Eustachian tube.