Stahl N, Cohen D. Idiopathic Sudden Sensorineural Hearing Loss in the Only Hearing EarPatient Characteristics and Hearing Outcome. Arch Otolaryngol Head Neck Surg. 2006;132(2):193-195. doi:10.1001/archotol.132.2.193
To determine the otological outcome in patients with idiopathic sudden sensorineural hearing loss (ISSHL) in their only hearing ear.
Retrospective medical chart review study.
Tertiary care hospital.
Forty-five consecutive patients older than 18 years with sudden sensorineural hearing loss during a 10 year period (1985-1995), 9 of whom had ISSHL in their only hearing ear.
Daily audiometric tests, oral prednisolone (full available dose), and bed rest for at least a week.
Main Outcome Measure
The audiometric result 7 to 10 days following the start of treatment was used as the treatment outcome.
Demographic characteristics were not significantly different between patients with ISSHL whose contralateral ear is deaf and those whose contralateral ear hears well. A tendency to seek help sooner (2.8 ± 1.4 vs 7.1 ± 5.2 days [mean ± SD], respectively) was noted. The mean ± SD improvement of hearing in the 3 more affected frequencies was 13 ± 13.4 dB for the investigated group compared with 9 ± 8.7dB for the rest of the patients (not statistically significant). Of the 9 patients who previously had sensorineural hearing loss in the opposite ear, 5 showed end results of speech reception thresholds of 35 dB or better, as did 13 of the 36 patients in the other group.
Patients with ISSHL in their only hearing ear may be treated the same way as other patients because their outcome appears to be the same. About 50% of the patients will have a 10 dB or more hearing improvement, and about 60% of patients in the investigated group will regain useful hearing.
Sudden sensorineural hearing loss (SSHL) is considered an ear, nose, and throat (ENT) emergency. The definition of the hearing loss includes abrupt hearing deterioration of 30 dB or more in at least 3 consecutive frequencies that occur during no more than 3 days.1 In most cases, no known cause is found, and the patient's hearing loss is defined as idiopathic SSHL (ISSHL). There are several treatments advocated by different authors, but no one treatment is accepted by all. The diversity of treatment protocols is due to the lack of a fully understood ethiopathogenesis of the disease. The confusion is enhanced because there is also a spontaneous recovery rate of approximately 40% without any treatment.2 Few controlled studies regarding treatment have been published, and in a review of the literature, Stokroos and Albers2 concluded that steroid treatment of ISSHL is the only treatment available with a significant beneficial effect.
Patients with sudden deterioration in hearing are confused, worried, and anxious. The treatment should always include reassurance and alleviation of fears: fear of having a tumor and fear of permanent deafness. The small subpopulation of patients whose only hearing ear is affected requires special consideration. These patients become practically deaf by the hearing loss and quickly seek medical help. It seemed important to evaluate the prognosis in this specific group and to compare it with the rest of our patients in terms of hearing improvement and hearing results.
In the evaluation period (1985-1995), 50 patients were admitted to the ENT Department of Shaare Zedek Hospital, Jerusalem, Israel, because of SSHL. All patients were evaluated with a complete history review, physical examination, audiologic examination, and blood tests (ie, complete blood cell count, general chemistry screen, thyroid function test, erythrocyte sedimentation rate, and fluorescent treponemal antibody absorbance). There were no positive results in 45 of the patients, who were diagnosed as having ISSHL.
Among these 45 patients with ISSHL, 9 presented with previous sensorineural hearing loss in the opposite ear. The cause of hearing loss was idiopathic in all of them. Hospital documentation showing that the hearing loss in the opposite ear was also sudden was found in 3 of the 9 patients. Two younger patients had ISSHL in their only hearing ear repeatedly (Table 1>). Findings from extensive investigation including blood tests and magnetic resonance imaging were negative. These 2 younger patients eventually regained useful hearing and at present attend the outpatient clinic for follow-up.
A retrospective study was performed to evaluate the characteristics and prognosis of these patients with previous hearing loss in the opposite ear compared with the 36 patients who had a functional opposite ear. The data gathered included demographic characteristics, laboratory data, imaging data, and audiometric results.
The hospital treatment was identical for all—hydration, bed rest, and a full-dose oral corticosteroid treatment (prednisolone, 60-80 mg). All patients underwent daily audiometric follow-up.1
Hospitalization was for 1 week, and following that week, our patients continued to visit the outpatient clinic as necessary. The audiogram at the end of the week was used for evaluation. Yamamoto et al3 showed that the audiometric results after a week are representative for the final results following ISSHL.
The hearing outcome was calculated from a comparison of the average of hearing thresholds before treatment in the 3 most affected frequencies with the average of pure tone hearing in the same 3 frequencies after a week of treatment.4 Other audiologic components that were checked were the speech reception thresholds and the discrimination. The improvement in speech reception threshold and discrimination were assessed owing to their functional aspects. The Mann-Whitney test was used to assess the statistical significance of the treatment result comparisons between the 2 groups of patients.
There were 4 women and 5 men aged 21 to 72 years with ISSHL in 1 ear with previous hearing loss in the opposite ear. No cause for the hearing loss was found despite meticulous investigation that included magnetic resonance imaging to exclude acoustic neuroma. Of the 9 patients, 6 were otherwise healthy without any chronic illness. Only the 72-year-old man had diabetes mellitus, cancer of the bladder, and gout, but he did not have these conditions when his hearing loss occurred 30 years prior. Patient characteristics and clinical details are given in Table 1>.
Our patients with hearing loss in their only hearing ear tended to search for help sooner (2.8 ± 1.4 vs 7.1 ± 5.2 [mean ± SD] days) than the other patients. The initial hearing loss in the affected ear was as follows: 2 patients had mild hearing loss, 5 had moderate hearing loss, and 2 had severe hearing loss (Table 2>). The discrimination scores were less than 85% in 4 patients.
Following treatment, similar results were achieved in the observed patients compared with the rest of our patients. The mean ± SD improvement of hearing in the 3 more affected frequencies was 13 ± 13.4 dB for those patients with the contralateral normal hearing ear and 9 ± 8.7 dB for those patients with the contralateral deaf ear (this difference did not reach statistical significance [P = .30]). The mean ± SD discrimination scores were 56% ± 34% for those patients with an opposite normal hearing ear and 68% ± 33% for those patients with an opposite deaf ear; posttreatment improvement was 16% ± 27% and 12% ± 6%, respectively. Improvement of more than 10 dB in the 3 affected frequencies was obtained in 4 of 9 patients compared with 19 of the other 36 patients. Of the 9 patients with ISSHL in the only hearing ear, 5 showed end results of speech reception threshold of 35 dB or better compared with 13 of the other 36 patients. Similarly, the discrimination scores were close. Table 3> presents the hearing results according to patient characteristics. The status of the opposite ear, the presence of tinnitus, and the presence of vertigo at the beginning of disease were not found to influence significantly the outcome of ISSHL.
In reviewing the literature, we could not find any description of patients with ISSHL of 1 ear with previous hearing loss in the opposite ear that was nonfunctional at presentation. Hirayama et al5 described 20 cases of idiopathic bilateral sensorineural hearing loss. These patients had been treated with the same therapeutic regimen used in ISSHL. Improvement of hearing loss after treatment was generally less effective in the cases with rapidly progressed bilateral sensorineural hearing loss than in the cases with ISSHL. Fetterman et al6 found that 14 (1.7%) of 823 patients with ISSHL had bilateral ISSHL. By audiological criteria, they reported that 67% of bilateral ISSHL cases improved, whereas the improvement rate in unilateral ISSHL was 52% (this difference was not statistically significant). In the present series of 45 adults with ISSHL, the influence of patient's sex, age, vertigo, tinnitus, delay in treatment, and type of initial audiograms on hearing improvement and outcome was evaluated. Small differences were found in the improvement and speech reception threshold outcome between men and women and according to the time of starting treatment, but the differences were not statistically significance. We found that hearing following treatment was not influenced by the status of the opposite ear and that most of our patients gained functional hearing even though 1 ear was unusable for a long time.
In conclusion, patients with ISSHL in their only hearing ear may be given the same treatment as other patients. The audiologic end results seem to be similar to the rest of patients. About 50% of the patients will have a 10 dB or more hearing improvement, and about 60% of those patients with hearing loss in their only hearing ear will regain functional hearing. This information may be useful in relieving anxiety and fears while treating those patients.
Correspondence: Nador Stahl, MD, Zydkiyahu 6, Beer-Sheva 84468, Israel (Nadorstahl@hotmail.com).
Submitted for Publication: May 3, 2005; final revision received September 1, 2005; accepted September 9, 2005.
Financial Disclosure: None.