Sumiko Koyama

HLA Associations with Meniere's Disease

In order to investigate the genetic background of Menières disease, histocompatibility (HLA) antigens in Japanese patients were studied. HLA-class I: HLA-A, -B and -C were typed by the classical microcytotoxicity technique, and HLA-class II: HLA-DR, DQ, and DP were typed by PCR-DNA typing methods. Twenty patient samples tested were selected very strictly following clinical data and classical criteria. Most of the patients had been suffering from typical symptoms during a considerably long period of time (16 +/- 7 years). Normal controls were based on the gene frequency in the Japanese population. Compared with the normal controls, a higher frequency of the DRB1*1602 subtype of HLA-DR2 was found in the patient group (chi 2 = 9,21, p < 0.04). P-values were corrected by multiplying by the total number of antigens. Additionally, HLA-Cw4 was increased, although the p-value was not significant after multiple antigen correction. There was no obvious relationship between the HLA-DRB1*1602 patients and the clinical data that included severity, age at time of onset, etc.

Barotraumatic Perilymphatic Fistula and Tympanometry in Lateral Position.

The presence of a perilymphatic fistula has been difficult to determine because of the lack of efficient and reliable testing methods. The condition is suspected on the basis of the history alone and is confirmed by surgery.Our previous studies have shown that when a patient with mild dysfunction of the eustachian tube lies on his side, the lower middle ear cavity pressure becomes markedly positive.It is important to differentiate perilymphatic fistula (PLF) from other inner ear disease, and the purpose of this study was to clarify by positional tympanometry mild dysfunction of the eustachian tube with barotraumatic PLF.Using the peak values of the tympanogram in the lateral position (TLP), we analyzed the changes in pressure of the lower tympanomastoid cavity in ears with PLF and in patients with sudden deafness.In patients with PLF, there was a significant increase in the internal pressure of the affected lower cavity, which rose to 81.0±4.4 mmH2O after 10 min (Nor. 27.7±16.8 mmH2O). On the other hand, in patients with sudden deafness, middle ear pressure was 24.13±8.00mmH2O after 10 min.These results suggest that when there is a strong possibility of barotraumatic PLF, we can utilize TLP for the diagnosis of PLF. Once there is a marked elevation of the affected ear cavity pressure in TLP, exploratory tympanotomy must be done immediately.

Aeration of the tympanomastoid cavity and eustachian tube function.

The degree of opening and closing of the eustachian tube varied with changes in body position. However, neither the duration of auditory tube opening and closing nor the opening pressure varied.The physiological reason for such findings appears to involve the anatomic course of the pharyngeal orifice of the auditory tube and of the auditory tube itself, protecting the middle ear cavity from invasion by secretions and from infections. When a patient with mild dysfunction of the auditory tube lies on his side, the middle ear cavity pressure becomes markedly positive. Involvement of congestion in the venous plexus of the middle ear cavity and of gas emission is suggested in this shifting of tympanic compliance to the positive pressure side with change in head position or when lying on the side. These findings, show that the ventilation of the middle ear cavity under environmental pressure, keeping the internal pressure of the middle ear cavity equal or slightly higher than atmospheric pressure at all times, serves to maintain the conductive efficiency of the middle ear cavity through adjusting of the internal pressure of the middle ear cavity to atmospheric pressure by the opening and closing of the auditory tube.

Sonometric auditory tubal function test for evaluation of children with otitis media with effusion.

The present study investigated the eustachian tube function in children with otitis media with effusion (OME) and also evaluated the effectiveness of adenoidectomy in such patients. The subjects consisted of 32 children with OME, all of whom underwent tube insertion and adenoidectomy, resulting in an improved hearing level to a range of 0-10dB. Sonometric auditory function test was carried out on the patients whose tube was in place and the middle ear was well aerated. Normal transmission of sound was observed in 71.4% of these children. However, it was seen in only 2% of the children not surgically treated. Satisfactory tubal function was noted in patients whose ventilation tubes remained in place for a period of 250 days or longer. It is, therefor, suggested that the optimal timing of tube extraction should be approximately eight months post-operatively, at which time the eustachian tube appears to tart functioning well.Our second study measured intranasal pressure in children with OME when they performed Toynbees manuever. Some children were treated with adenoidectomy with tube insertion and the others were not surgically treated, and the results were 5.66±2.92mm H2O and 3.93±1.79mm H2O, respectively. A significantly high intranasal pressure seen in patients with OME who had undergone adenoidectomy seems to account for the effective nasopharyngeal closure that had occurred as a result of improved movement of the soft palate including the levator veli palatine muscle. From these findings, it was concluded that adenoidectomy facilitates opening the tubal lumen by the tensor veli palatine muscle.