The influence of epidural anesthesia on the hearing system after normal labor.

OBJECTIVE: The purpose of our study was to evaluate the influence of epidural anesthesia on the hearing system in women undergoing normal labor. DESIGN: We examined two groups of patients: women with epidural anesthesia underwent four tests of distortion product otoacoustic emissions(DPOAEs): on admission, and fifteen minutes, one hour, and three hours after the last epidural bolus of local anesthetic. Auditory brainstem response (ABR) tests were performed on admission, and one hour, and three hours after the last epidural bolus. Women who gave birth without epidural anesthesia underwent DPOAEs tests on admission, during a uterine contraction, during active delivery, and three hours after labor. ABR tests were performed on admission, during a uterine contraction, and three hours after labor. STUDY SAMPLE: twenty patients participated in the study. Twelve gave birth with epidural anesthesia and eight without anesthesia. RESULTS: No significant changes in DPOAEs and ABR recordings were found between the two groups. CONCLUSIONS: Epidural anesthesia does not impair the sensory or the neural elements of the hearing system and therefore does not influence hearing.

The role of tinnitus evaluation tests in differentiating functional versus organic tinnitus.

OBJECTIVE: To evaluate the usefulness of tinnitus tests in differentiating patients with functional tinnitus from patients with organic tinnitus. DESIGN: One hundred ninety-six patients with tinnitus were divided into 2 groups. Forty-three patients, group 1, were not exposed to noise and had sensorineural hearing loss. One hundred fifty-three patients, group 2, were exposed to noise and claimed disability. All the patients underwent 4 tinnitus evaluation tests: pitch matching, intensity matching, residual inhibition, and tinnitus masking. We compared the results of the tinnitus tests between the 2 groups. RESULTS: Group 1 patients had a high-frequency, low-intensity tinnitus that tended to be more inhibited by narrow-band noise, was usually consistent with type I Feldman masking curve, and could be effectively masked. Group 2 patients had tinnitus that could not be characterized. The results of the tinnitus tests were significantly different between the groups. CONCLUSION: Tinnitus tests may help us differentiate functional tinnitus that is not of cochlear origin from genuine tinnitus.

Asymmetric hearing loss in a random population of patients with mild to moderate sensorineural hearing loss.

OBJECTIVES: We evaluated the correlation of asymmetric hearing loss, in a random population of patients with mild to moderate sensorineural hearing loss, to several clinical factors such as age, sex, handedness, and noise exposure. METHODS: We randomly selected, from 8 hearing institutes in Israel, 429 patients with sensorineural hearing loss of at least 30 dB at one frequency and a speech reception threshold not exceeding 30 dB. Patients with middle ear disease or retrocochlear disorders were excluded. The results of audiometric examinations were compared binaurally and in relation to the selected factors. RESULTS: The left ear's hearing threshold level was significantly higher than that of the right ear at all frequencies except 1.0 kHz (p < .05). One hundred fifty patients (35%) had asymmetric hearing loss (more than 10 dB difference between ears). In most of the patients (85%) the binaural difference in hearing threshold level, at any frequency, was less than 20 dB. CONCLUSIONS: Age, handedness, and sex were not found to be correlated to asymmetric hearing loss. Noise exposure was found to be correlated to asymmetric hearing loss.