Initial Audiogram Research Articles

突発性難聴に対する高気圧酸素療法の効果

Patients with sudden deafness who were treated either in our department or in our branch hospital between January 1984 and December 1994 were divided into two groups. Group A consisted of 69 patients who were treated with steroids, vasodilators, and stellate ganglion block but without hyperbaric oxygen therapy. Group B consisted of the other 85 patients who were treated with not only steroids, vasodilators, and stellate ganglion block but also with hyperbaric oxygen therapy. Patients in the two groups showed no significant difference in age, or number of patients with vertigo, but the initial audiogram was worse and time from onset to consultation were significantly greater in group B than those in group A. The prognoses of the two groups were analyzed by several issues, such as initial audiogram, time from onset to consult and there was no significant difference.

Changes in hearing features according to days from onset of sudden deafness

We analyzed 746 patients with idiopathic sudden hearing loss who visited our clinic within 16 days after the onset. Patients were divided into 10 groups according to the number of days between the initial visit and the onset. Initial hearing levels, audiometric types and hearing recoveries were investigated in these groups to estimate the natural history of sudden deafness. The results were as follows: 1) There were no significant differences among the 10 groups regarding the averaged five-frequency hearing levels of initial audiograms. 2) Regarding the audiometric types of the initial audiograms, flat and upward slope types were frequently seen in the groups who visited us within 6 days. In contrast, the population of down slope types gradually increased in the groups presenting after 7 days. In the ultimate audiograms, flat and down slope types were frequently seen in all groups. 3) There were significant differences among the 10 groups regarding the averaged five-frequency improvement (one-way analysis of variance, p < 0.01). After 9 days, hearing recovery became less likely.

Investigation of Pure-Tone Hearing Levels at a Single Frequency in Sudden Deafness

Hearing levels in patients with sudden deafness are commonly discussed in terms of average thresholds at 3 or 5 frequencies, but an investigation of hearing levels at a single frequency is also important. In this paper, pure tone thresholds at 500 Hz and 4,000 Hz were investigated in patients with sudden deafness who came to our clinic within 4 days of onset. Particular attention was paid to the relationship between audiometric types according to the contour of the initial loss and degree of hearing recovery at each frequency. In the group of patients whose initial hearing level at 500 Hz was between 55 and 70 dB, the hearing recovery at 500 Hz in the upward slope type was significantly greater than that in the downward slope type, but in other groups no significant differences in hearing recovery were observed among the different types of initial audiograms. We considered that the hearing recovery at a single frequency was not related to the audiometric type except in the patients with the upward slope type with moderate hearing loss.

Clinical Study of Inner Ear Barotrauma

We reviewed the records of 24 patients with inner ear barotrauma (IEBT) who were treated at our hospital between January 1981 and December 1991. Nose-blowing was the most common cause of IEBT. Hearing loss occurred in 23 patients, and 8 patients experienced vertigo in addition to cochlear symptoms. There were various types of initial audiograms such as profound hearing loss, high-tone hearing loss, low-tone hearing loss, dip type and flat type. Conservative therapy including intravenous drip infusion of vitamin B complex and ATP etc was performed in all 24 patients. Four patients out of 11 patients who received exploratory tympanotomy had round window membrane rupture. Patients with low-tone or dip type hearing loss on their initial audiograms experienced complete recovery, while the patients who began treatment more than two weeks after the onset of barotrauma did not experience full hearing recovery.

Sudden hearing loss: Eight years' experience and suggested prognostic table

The etiology, incidence, acute and late prognosis, and treatment of sudden hearing loss (SHL) are described variously in the literature. In an 8-year prospective study of 225 SHL patients, initiated in July 1973, overall, normal, or complete recovery occurred in 45% of patients and late otologic complications in 28%. Important prognostic indicators were severity of initial hearing loss and vertigo, time to initial audiogram, and elevated erythrocyte sedimentation rate; other indicators were age greater than 60 and less than 15 years, midfrequency audiogram configuration, and hearing status of the opposite ear. A common inflammatory cause is suggested for all degrees of severity in SHL, and a prognostic table is provided to aid the practitioner in predicting recovery. There is still no evidence that treatment achieves a result better than expected with spontaneous recovery.

Natural history of sudden sensorineural hearing loss.

This is a prospective in-depth study of patients with sudden idiopathic sensorineural hearing loss. We found that 65% recover completely to functional hearing levels spontaneously and independent of any type of medical treatment. The majority do so within 14 days and many within the first few days. Prognosis can be predicted according to the slope of the initial audiogram (low-frequency losses do better than high-frequency losses), hearing at 8 kHz, erythrocyte sedimentation rates, in some select instances spatial disorientation symptoms, and speech discrimination scores. There was a very poor correlation between hearing and vestibular test abnormalities, except hypoactive calories. There were no correlations with age (excepting the very elderly), with antecedent respiratory infections, hypertension, diabetes, or other chronic diseases. We conclude that there is a fundamental difference in the behavior of apical and basal cochlea losses, that hearing recovery is always better at low than at high frequencies, that because of the high spontaneous recovery rates, tympanotomies seeking peri-lymph fistulas should be delayed ten days unless there is a progressive hearing loss, and that none of the current recommended treatments, especially histamine, have any effect on the outcome.

Long Term Variation in the Threshold Audiorgramm of Sensori-neural Deafness

Statistical observations are made in 529 ears on the long term variations in the threshold of sensorineural deafness. These cases are all retested audiometrically more than 6 months later. And the differences between the initial audiogram and the last one are statistically examined.A remarkable shift to recovery was shown in cases of so-called sudden deafness and cochlear neuronitis. On the other hand slight progression of hearing loss was observed in deafness due to SM, KM and KDM injection. Little changes were found in other cases.

On the Prognosis of Sudden Deafness

15 cases with sudden deafness were treatad by conservative therapies, and fair improvement of hearing was obtained in 2 cases, and slight improvement in one case. All of improved 3 cases were adequately administrated at least within 10 days after the attack of sudden deafness. The initial audiogram showed flat type in 2 cases and deaf type in one. In 2 cases with fair improvement of hearing, their prognosis were followed up during 2.5 or 1.5 years respectively. The improvement of hearing of both cases was lapid in initial stage, and then gradual. In one case, Bekesy audiograms revealed the transit from Jerger's type II to type I along with the fair improvement of hearing at 2.5 years after the onset of hearing loss. In other case, although initial fair improvement, Bekesy audiograms still showed Jerger's type II and standard audiometry revealed progressive deterioration on high frequencies, at 1.5 years after the onset of hearing loss.

Deterioration of the residual hearing of children with sensorineural deafness.

Deterioration in the residual hearing of the aided and unaided ears of children with sensorineural deafness was investigated by comparing the mean Average Hearing Losses of their initial audiograms with the mean Average Hearing Losses of recent audiograms, and relating the changes to various variables. The results of the investigation confirm previous findings that the use of high-powered hearing aids tends to cause deterioration of the hearing of the aided ear, that this effect of aid use is about the same in degree in endogenous and exogenous deafnesses and that small amounts of deterioration of unknown origin tend to occur in the unaided ears of children with sensorineural deafness, and tend to be greater in ears with less initial hearing loss. It was also found that the general deterioration of hearing tends to be bilateral and greater in exogenous than in endogenous deafnesses.