Acute Low-tone Sensorineural Hearing Loss Research Articles

Clinical Evaluation of an Acute low-tone Sensorineural Hearing loss Based on subjective complaints

Clinical Evaluation of an Acute low-tone Sensorineural Hearing loss Based on subjective complaints

Prognosis of acute low-tone sensorineural hearing loss

We studied 50 patients with acute low-tone sensorineural hearing loss (ALHL) who were examined at the Department of Otolaryngology, University of Tokyo, and followed up for 18 months or more. We investigated the prognosis of hearing loss within 3 months after onset, rate of recurrence during long-term follow-up, interval between the first and the second episodes of hearing loss or between onset and the time when the diagnosis of Meniere's disease was made, and factors affecting prognosis. The results were as follows. 1. Within the initial 3 months of follow-up, hearing loss continued to fluctuate in 5 patients. In the remaining 45, hearing returned to normal in 34, improved without returning to normal in 6, showed no marked change in 4, and became worse in one. 2. In long-term follow-up, the recurrence of hearing loss without vertigo occurred in 16 patients, and 5 others were eventually diagnosed as having Meniere's disease. The average interval between the first and second episodes of hearing loss was 9.2 months, and the diagnosis of Meniere's disease was made an average of 27 months after onset. 3. Recurrence was not significantly related to the initial prognosis of hearing loss. 4. Within the initial 3 months of follow-up, the prognosis of hearing loss was significantly better in patients whose hearing loss at 1 kHz was within 20 dB, and tended to be better in females and in patients attending within one week of onset. Long-term follow-up showed that the rate of recurrence was significantly lower in patients aged 40 years or more, and tended to be lower in patients who visited the hospital within one week of onset or whose hearing loss at 1 kHz was within 20 dB. 5. There were no significant differences between patients with single and recurrent attacks with respect to sex, subjective symptoms, and results of the glycerol test and electrocochleography. ALHL tends to recur without any relationship to the initial prognosis of hearing loss. Since it is still difficult to predict whether or not hearing loss will recur, long-term follow-up is necessary even in patients with good initial prognosis.

急性低音障害型感音難聴について

急性低音障害型感音難聴について

か牛水腫の示唆される急性低音障害型感音難聴の臨床的観察

Acute low-tone sensorineural hearing loss (ALHL) has the following three criteria; obscure origin, acute onset and sensorineural hearing loss limited to low frequencies. Sixteen cases of ALHL which were considered as cochlear hydrops using glycerol test and electrocochleogram were studied. All patients visited our department within two weeks after onset and were followed up for one year or more after initial examination. The subjective symptoms, the character of vestibular and hearing impairment and prognosis of 16 cases with ALHL were also investigated. The results were as follows. 1. Patients complained of ear fullness rather than hearing impairment. Four patients were unaware of hearing loss. 2. Recruitment phenomenon was found in all of 15 cases examined. Vestibular findings were mostly normal, except that spontaneous nystagmus was found in two cases and head-shaking nystagmus in one. 3. Recurrence and fluctuation of hearing impairment occurred in 14 cases. Three cases had an attack of rotatory vertigo once and two has diagnosed as Meniere's disease later. 4. During three months prior to last examination, hearing was stabilized in nine cases and continued to fluctuate in seven cases. In the former, hearing was improved in four cases, unchanged in three, and worsened in two. 5. Two patients underwent an endolymphatic sac operation and have had a good prognosis. 6. The authors suggest that most of ALHL should be considered as transient cochlear hydrops because the subjective symptom and audiological and vestibular findings of our cases are similar to those of cases which were reported as ALHL by other investigators. According to the findings of glycerol test and electrocochleogram, endolymphatic hydrops in ALHL is considered to exist in all turns of cochlea.