Auditory brainstem response and otoacoustic emissions in Duane retraction syndrome

Abstract

We aimed to investigate the origin of hearing loss with relevance to auditory brainstem responses and otoacoustic emissions in patients with Duane's retraction syndrome (DRS). 17 patients with DRS were included in the study. 14 patients were diagnosed as DRS type 1 and the remaining three as type 3. The control group consisted of nine healthy subjects. Pure tone audiogram, auditory brainstem response, as well as distortion product otoacoustic emissions were recorded in all the patients and the controls. Among the 17 patients with DRS, 15 demonstrated normal hearing according to pure tone audiogram. One patient with DRS had profound sensorineural hearing loss with a pure tone average of 110 dB, and one patient had moderate sensorineural hearing loss with a pure tone average of 60 dB. Auditory brainstem response latencies of the waves I, III and V, and interwave latencies were calculated in 15 patients with DRS and were compared with the control group. There was statistically significant increase in wave I latency of left ear in the DRS group compared to the controls (P<0.05). Amplitudes of distortion product otoacoustic emissions were also recorded at frequencies of 2, 3, 4, 6, and 8 kHz in both groups and the comparison of the DRS patients and controls revealed no statistically significant difference. We recommend auditory examinations be undertaken in patients with DRS by auditory brainstem response tests, as well as distortion product otoacoustic emissions, whereas all patients with normal results should be followed-up for future hearing loss.