Seven adult cases (3 male and 4 female) of functional deafness are reported. Subjects ranged in age from 16 to 59 years old. All subjects were complaining progressive hearing loss. Four patients had a history of organic hearing loss bilaterally. Conflicts in school, occupation or family were thought to be causes for functional deafness. Pure tone audiometry revealed severe sensorineural hearing loss in 6 subjects and moderate loss in 1 subject. Speech discrimination, stapedial reflex, Bekesy audiometry and ABR were performed. In addition to these examinations, pure tone audiometry using continuous pure tone was performed on 5 subjects. This method was found useful to determine functional hearing loss. Three subjects showed improvement with counseling and medications. Four subjects with organic hearing loss did not show improvement.
The effects of iontophoresis by dexamethasone and lidocain for tinnitus were evaluated with distortion product otoacoustic emissions (DPOAE). Volunteers with normal hearing and patients with tinnitus were treated by iontophoresis with a mixture of 0.1% dexamethasone and 4% lidocain solution (4:1). The positive ear pole was used, and a direct current flow of 0.5mA was applied for 10 minutes. Experimental studies with physiological saline were performed in normal subjects. After the treatments, average DP levels were significantly increased at 1001Hz (F2) in the effective cases (especially acute tinnitus with low-tone hearing loss), slightly decreased in the non-effective cases, and unchanged in the normal subjects. The average DP change values between effective and non-effective cases were significantly different at 1001Hz (F2). The average DP levels for all the groups treated with iontophoresis, significantly decreased at high tone. The author suggested that the increase of the DP levels at middle tone for the effective cases were due to the therapeutic effects of dexamethasone and the decrease at high tone for all the treated cases were due to the effects of electrical current. The auther speculated that dexamethasone negative ions infiltrate into the ear drum with lidocain positive ions and water by electroosmosis, infiltrate into the cochlea through the round window, and improve cochlear function. These treatments were painless without side effect.
Thirty-six ears of 24 patients with otosclerosis who underwent stapes surgery were investigated by questionnaire regarding preoperative and postoperative tinnitus. In these 36 ears, tinnitus was improved in 22 ears, unchanged in 11 ears, or worsened in 3 ears. Tinnitus significantly improved postoperatively in the ears with multiple tinnitus, in those with the preoperative bone threshold within 30dBHL at 4kHz, in those with the mean postoperative air threshold at speech frequencies within 30dBHL, and the mean postoperative air threshold within 40dBHL at 4kHz and 8kHz. On the other hand, subjective estimtion of pitch of tinnitus and postoperative airbone gap at speech frequencies did not contribute to the improvement of tinnitus following surgery. The subjective expression by onomatopoeias before surgery was the same as that of the patients with ordinary perceptive and conductive hearing impairment. After surgery, almost all kinds of tinnitus expression totally decreased.
56 patients with the acute acoustic sensorineural hearing loss were analysed in retrospective study. Most hearing losses were occurred during their military service. The following factors were examined: age, affected side, days to the first consultation after accident, ear protection, therapy, pure tone average (PTA), high tone average (HTA), 1000Hz hearing level and 4000Hz hearing level. Logistic regression was used to evaluate the adjusted odds ratios for these factors and the prognosis of the acute acoustic sensorineural hearing loss. No influence of age, affected side, ear protection, therapy, high tone average (HTA), 1000Hz hearing level on prognosis of hearing loss was detected. The days to the first consultation, 4000Hz hearing level and PTA had a significant prognostic releavance.
A 13-year-old boy complained of progressive bilateral hearing impairment with a three-month history of recurrent fever. At first, he was treated with bethamethasone 3mg daily as sudden deafness, but his hearing loss was not improved. He developed high fever associated with hearing loss and abdominal pain one month later. Then he was diagnosed with systemic lupus erythematosus (SLE) on the basis of clinical findings and laboratory data. His hearing loss was bilateral moderate hearing loss, which was greater in the high frequency tones with positive recruitment phenomenon. He was treated with predonisolone 60mg daily, and then his hearing impairment was gradually improved. Four weeks later, when predonisolone was reduced to 40mg daily, he developed hearing impairment again. Then he was treated by 6 series of plasma exchange, immmunosuppressive therapy and hyperbolic oxygen therapy in addition to predonisolone 40mg daily. His hearing impairment was gradually improved. Immune-mediated sensorineural hearing loss could occur due to various causes, so the clinical feature should be different in each case. In this case hearing impairment was immune-mediated and one of symptoms which occurred in the very early stage of SLE responsive to the treatments including steroids.
162 cases who received hearing test in our clinic for the past one and half years were analized. The results obtained were as follows: 1. The half of them had hearing impairment, and 21 had OME. In 89 children with hearing impairment, 82 had bilateral sensorineral hearing loss (bil SNH). About 77% of bil SNH cases were found severe or profound hearing loss. 2. Cases were mainly referred from pediatric or otologic clinicians. 3. Ages of detection of their hearing loss were averaged 1 year and 6 months for severe or profound bil SNH, and 4 years and 2 months for mild or moderate bil SNH. The age for diagnosis of hearing impairment was correlated to the hearing level (R=-0.54). High-risk children were found earlier than those with mild hearing impairment, but some cases were found later for their lack of symptom. 4. Children with suspicion of hearing impairment should be examined in early childhood and to be followed. Coopolation with medical care, welfeare and education is important.
Transiently Evoked Otoacoustic Emissions (TEOAEs) are believed to be attributed to the presence of impedance discontinuities on the basilar membrane in the cochlea. However, the generation mechanism of TEOAEs has not been clarified. In this study, using the mathematical model of a cochlea, which has the impedance discontinuities on the basilar membrane, TEOAEs were simulated. The results reveal that TEOAEs are produced by not only the active process associated with the outer hair cells, but also the presence of impedance discontinuities at a site of the basilar membrane whose characteristic frequency is equal to the stimulus frequency. Therefore it may be said that TEOAEs in response to a tone burst stimulus reflect the condition at the specific point of the cochlea.
The etiology of idiopathic sudden deafness has not been clearified. A low reccurence rate in sudden deafness has been known to be one of characteristic features of this disease. The aim of this study was to present electrocochleographic findings in a patient with recurrent sudden deafness. Repeated tympanic electrocochleography was performed in the 60-year-old male who developed sudden sensorineural hearing loss 6 years after complete recovery from the initial episode of sudden deafness on the same ear. The summating potential (SP) and the action potential (AP) evoked by alternating polarity clicks and 1kHz tone bursts were measured. Positive SP was found at the acute stage, followed by increased-SP/AP ratio at the convalescent stage and normal-SP/AP ratio after complete recovery from deafness. The patterns of SP and AP changes during the recovery process of sudden deafness was compatible with those in a guinea pig model of the temporal stria dysfunction owing to intravenous furosemide injection. Thus, dysfunction of the stria vascularis seems to be involved in the mechanism of sensorineural hearing loss in the present case.
The purpose of this investigation was to compare the intelligibility of speech mixed with impact noises for digital hearing aid compressing the signals in the time domain (TD-1) and conventional analog hearing aids equipped with peak clipping (PC) or automatic gain control (AGC). Seven subjects with moderate sensorineural hearing loss were participated in this experiment. The sentences were mixed with impact noises every 500ms and presented to subjects wearing TD-1 or the conventional hearing aid. The results were that the intelligibility score of speech mixed with impact noises was decreased in four subjects (three with PC and one with AGC) when they wore the conventional hearing aid. On the other hand all subjects wearing TD-1 showed the good intelligibility score regardless of noises. This result indicates that TD-1 is beneficial to sensorineural hearing losses even under the circumstances with the impact noises.