Effect of tinnitus masking on auditory brainstem response wave amplitude in patients with tinnitus

Shufang LIU; Wei ZHU; Yuting WEN

ABSTRACT

BACKGROUND:

Research shows that the auditory brainstem response (ABR) wave amplitude of tinnitus patients often act as big Ⅲ small Ⅴ.Tinnitus masking is a therapy of tinnitus, then how dose the ABR change in the process of tinnitus masking?

OBJECTIVE:

To observe the changing characteristics of ABR in patients with tinnitus as well as the changing rules of ABR after tinnitus masking.

DESIGN:

Case-control and self-control.

SETTING:

Department of Otorhinolaryngology, First Hospital of Jilin University.

PARTICIPANTS:

Continuous tinnitus group 63 cases (68 ears) were selected from the Clinic of First Hospital of Jilin University from March 1999to October 2001. Control group 10 cases (20 ears) of normal hearing youth (20-23 years old). All subjects received the examination and treatment voluntarily.

METHODS:

The ABR was firstly detected in tinnitus patients (foreheadmastoid conducting method was adopted), and examination of tinnitus as well as tinnitus masking test (masking for 5 minutes) were respectively conducted, immediately after that, the ABR was detected to do control-observation with the control group.MAIN OUTCOME

MEASURES:

①The characteristics of ABR in patients with tinnitus. ②Effects of tinnitus masking on the amplitude wave of ABR, which was divided into positive group in residual inhibition test and negative group in residual inhibition test for analyzing.

RESULTS:

A total of 83 subjects were involved in the analysis of results.①The amplitude wave of ABR in youth of normal hearing were small Ⅲ big Ⅴ, whereas that in 22 ears (32.4％) out of 63 subjects (68 ears) were big Ⅲ smallⅤ, in which 17 ears were of patients positive residual inhibition test, and 5 were of negative.②After tinnitus masking therapy, 10 ears out of 17 ears of patients positive in residual inhibition test turned from big Ⅲ small Ⅴ to small Ⅲ big Ⅴ, and the wave amplitude of Ⅲ wasre duced in 3 ears, while the ABR in 2 ears out of 5 ears of negative patients turned to small Ⅲ bigⅤ, and there were no changes in other 3 ears.

CONCLUSION:

Tinnitus masking therapy can convert the abnormal ABR wave amplitude in patients with tinnitus to normal, which will be taken as the objective index in judging whether it is positive in residual inhibition test.