In 70 cases of sudden deafness (SD) treated in our hospital, the prognostic factors were analyzed by t-test using recovery rate. The factors including ages, days before therapy, vertigo, hearing levels, the difference between high- and low-frequency hearing level (H-L difference), were estimated. H-L difference was calculated by (8000Hz+4000Hz)/2-(250Hz+500Hz)/2. The poor prognostic factors were 1) over 40 years old, 2) first visit after 8 days from onset, 3) initial hearing level was less than 60dB or more than 80dB HL, 4) H-L difference was zero or more. Vertigo had no relation to prognosis. The group of patients who had more than two factors had poor prognosis without preference for hearing level. The number of poor prognostic factors is thought to be a good index for prognosis of SD.
Multiple logistic regression analysis was used to determine which factors are most strongly related to outcome in patients with sudden sensorineural hearing loss. The study group comprised 177 patients (177 ears). The sudden sensorineural hearing loss was cured in 35, prominently recovered in 54, recovered in 58, and no change in 30. The following factors were studied: age, sex, affected side, the days before start of treatment, vestibular symptom, mean hearing level at 0.25Hz, 0.5kHz, 1kHz, 2kHz, and 4kHz, inpatient/outpatient status, smoking, treatment (adrenocortical hormones, low molecular weight dextrans, vitamin B12, satellite ganglion block therapy). The first analysis was underwent between the group without change of hearing and the recovered group. The factor most strongly related to outcome was the days before the start of treatment. The second analysis was underwent between the group with no change and the prominently recovered groups. The days before the start of treatment, age, vestibular symptom, and the mean hearing level at 0.25kHz, 0.5kHz, 1kHz, 2kHz, and 4kHz were significantly related to outcome. The third analysis was undergone between the group with no change and the cured groups. The days before the start of treatment, age, vestibular symptom, and satellite ganglion block therapy were most strongly related to outcome. There was no significant relation to outcome for other factors.
The Research Committee on Acute Profound Deafness, the Ministry of Health and Welfare in Japan established a grading system based on the severity of hearing loss regarding sudden deafness. We evaluated the results of nationwide epidemiological surveys on sudden deafness using the grading system. The grading system will be useful for evaluation of the outcome of sudden deafness.
The potentials evoked by acoustic stimuli in the cervical muscle are called vestibular evoked myogenic potentials (VEMP). Study results suggested that VEMP reflect the vestibular function, particularly that of the saccule and inferior vestibular nerve. In the present study we measured VEMP in the cases of sudden deafness and studied its relation with hearing at the first clinic visit, vestibular findings and hearing prognosis. The subjects included 49 cases who were diagnosed as sudden deafness at our department between April, 1998 and June, 1999, in whom VEMP were measured. According to the hearing level at the first presentation and the results of VEMP measurements, the more profound the hearing impairment was, the higher was the percetage of abnormal VEMP cases. This result suggested that the vestibular system close to the cochlea might be impaired in the profoundly deaf cases. From this result the authors postulated that the vestibular lesion in sudden deafness could be evaluated. The presence or absence of the vestibular findings (subjective dizziness, nystagmus and CP on the caloric test) is well correlated with the results of VEMP measurement in that both reflect the vestibular impairment. Many cases of good prognosis were found in the normal VEMP cases, while many cases of poor prognosis were noted in the abnormal VEMP cases. These results suggested that examination of VEMP can serve as a useful factor in estimating the hearing prognosis in sudden deafness.
Evoked otoacoustic emissions were examined in the ears with idiopathic sudden deafness or low tone type acute sensorineural hearing loss. Detection thresholds elevated and saturation levels changed to two patterns, truncation or parallel shift. The truncation was seen mainly in the ears of idiopathic sudden deafness with high and middle tone hearing loss, and the parallel shift was in the ears with low tone hearing loss. Most of recovery cases of those ears revealed the parallel shift. It is, however, difficult to conclude that the two patterns in input-output curves are valuable indicators for prognosis. As the saturation level expresses the active basilar membrane vibration linked with outer hair cell function, the observation of input-output curves is useful for precise diagnosis of intracochlear impairments.
Patients with bilateral acute deafness or acute deafness occurred in an only-hearing ear face the catastrophic consequences. The purpose of this study was to analyze the incidence, etiology of deafness and performance of cochlear implantees who had lost their hearing from acute profound sensorineural hearing loss. We found 13 cases, in which implanted ears had been acutely deafened, among 75 postlingual-deaf adults. The causes of deafness included idiopathic sudden deafness in 4 cases, mumps, meningitis, bromate poisoning in 2 cases respectively and other reasons, such as acute renal failure and head injury. Postoperative performance on word recognition tests in these cases were generally high compared to the average performance for progressively deafened patients. In particular, 4 cases of idiopathic sudden deafness showed excellent performance regardless of duration of deafness. Our results indicated that retrocochlear function tended to be maintained in ears with acute deafness, regardless of the cause. Some protective mechanisms might exist against spiral ganglion cell death secondary to extensive damages to organ of corti and/or stria vascularis.
We analyzed statistically the prognosis of hearing impairment in patients with idiopathic sudden sensory neural hearing loss. 119 patients (SGB group) were treated with the combination therapy with hyperbaric oxygenation (HBO) and stellate ganglion block (SGB) as well as oral administration of vasodilator and vitamins. 39 patients (PG group) were treated with HBO and intravenous drip infusion of prostaglandin E1 (PGE1). As conclusion, the therapeutic results in PG group was worse than SGB group, but there was no statistical significance.
There are many reports in efficiency of hyperbaric oxygen therapy (HBO) for sudden deafness. However, special devices are necessary for HBO, This paper is to study that the inhalation of low-pressure oxygen via nasal cannula could take effect as same as HBO. From July of 1998 to June of 1999, 18 hospitalized patients with sudden deafness were treated with transnasal oxygen inhalation therapy and intravenous drip therapy. They were compared with previous 26 cases who were undergone the intravenous drip therapy, but, without the transnasal oxygen inhalation therapy. The results showed that the % recuperation of transnasal oxygen inhalation therapy was 72.2%, and it was better than the % recuperation of previous therapy (42.3%).
This study was performed as a part of comprehensive study to determine the incidence of hearing impaired children in Kitakyushu-city. The number of elementary school pupils with severe hearing loss for each grade was approximately eight, which corresponded to 0.08-0.09% of total pulils of the grade. More than a half of them attended regular class and received speech training for a few hours in a week. Seventy-nine children with hearing level exceeding 80dB were referred to Kitakyushu Rehabilitation Center for Children with Disabilities during the period from 1988 to 1997. Twenty-five (32%) of the 79 visited the Center after the second birthday. Auditory screening was considered to be necessary at the age of one a half or less.
For 30 years (1968-1997), we have investigated the changes in the prevalence of hearing impairment in primary school children in Sendai City and have obtained the following results: 1) The number of subjects increased gradually until 1981, and then decreased from 1982 in response to a remarkable population reduction of 0-14 years old children in Japan. 2) The prevalence of hearing impaired children rapidly decreased yearly from a peak of 1.94% in 1972. Subsequently, it was less than 1.0% in 1979, less than 0.5% in 1991, and was a little over 0.4% since 1994. This reduction is mainly attributed to the eminent decrease of a conductive hearing loss produced by secretory otitis media and chronic otitis media. Sensorineural hearing loss also had decreased slowly from 0.6% in 1972 and was 0.22-0.26% after 1989. 3) Sensorineural and conductive hearing losses were more frequently found among boys than girls, and were more commonly unilateral than bilateral. 4) The percentage of children suffering from severe unilateral sensorineural hearing loss had been decreasing gradually from 0.1% before 1988 to 0.04%. 5) The prevalence of impaired hearing due to secretory otitis media has decreased, but it still remains the leading cause accounting for 50-60% of all conductive hearing losses.
The aim of this study was to investigate the progression in contralateral ears of 400 children in whom 28 had total deafness or others sensorineural hearing loss (30dB or more in at least one audiometric frequency). We analyzed 372 children with total deafness in one ear and the other had normal hearing. The results obtained were as follows; 1) The longest observation period of 28 cases was 21 years, with the average period of 8.5 years. It was found that 10 cases of 28 (35.7%) showed progression, 1case (3.6%) showed fluctuation and 2 cases (7.1%) showed fluctuation and progression. 2) It was found that 6 cases of 372 (1.6%) showed progression and 2 cases (0.5%) showed fluctuation and progression in the longer observation period with the average of 7.5 years. 3) In progressive and fluctuated cases, there might be some cases with delayed endolymphatic hydrops.
117 cases of unilateral hearing loss in children who visited in our clinic from 1985 to 1994 and were observed for over five years were studied. The patient group included 72 (62%) males and 45 (38%) females. The age range was 2 to 15 years old, and there was a peak of incidence at the 6-8 years old group. The hearing level of 8 ears (7%) were ranged in 0-30dB, 10 ears (9%) in 31-60dB, 21 ears (18%) in 61-90dB and 78 ears (67%) in over 91dB in average pure tone audiogram. There were 15 cases (13%) complaining of tinnitus, 4 cases (3%) of dizziness, 3 cases (3%) of functional hearing loss in the contralateral ear and 2 cases (2%) of another cochlear symptoms without alter the hearing level. There were 2 cases whose hearing loss were improved, 2 cases whose hearing loss were fluctuated with tinnitus or dizziness and 3 cases whose contralateral hearing level were changed with or without cochlear sympton. The long term follow up for unilateral hearing loss in children is necessary.
Nine cases (18 ears) of juvenile sensorineural hearing loss were followed up for a period from 6 to 18 years (average 13.2 years). Hearing (average of 1-4kHz) was deteriorated in 13 ears. Sever deterioration (pure tone threshold elevation≥30dB) was seen in 8 ears. Mild deterioration (30dB≤pure tone threshold elevation>15dB) was seen in 5 ears. The rest of 5 ears had no remarkable threshold shift. There were two major patterns of the threshold evevation in the pure tone threshold. One was that the pure tone threshold elevated rapidly and largely following gradual and small threshold elevation. Another was that the pure tone threshold elevation was small and occurred gradually. These differences of threshold change may cause the differences of damage and/or vulnerability in their ears.
Fourteen cases (28 ears; female-to-male ratio 1:1) of hearing loss with the large vestibular aqueducts were followed for more than 3 years. After follow-up of 3 to 16 years (mean: 8.7 years), progressive hearing loss more than 10dB was observed in only 6 ears (21%) and the rate of hearing loss progression was 0.6dB per year, but 25 ears (85%) demonstrated acute hearing drops. The hearing in 11 ears (39%) fluctuated (more than 4 episodes of hearing drop) but almost all drops recovered after conservative therapy including administration of corticosteroids and/or prostagrandin E1 and/or hyperbaric oxygen therapy. The ears with progressive or fluctuating hearing loss were frequently associated with vestibular symptoms at hearing drop, and developed these attacks without triggers such as minor head trauma. We suggest that the large vestibular aqueduct includes some subcategories such as stable or fragile inner ear. Acute hearing drop with vertigo without trigger in a patient with the large vestibular aqueducts should be treated carefully.