[Analysis on the correlation of auditory brain/stem response and 40 Hz auditory event related potential by pure tone audiometry in adult patients with sudden deafness].

Objective

To study the value of auditory brainstem response（ABR） and 40 Hz auditory evoked potential（40Hz AERP） in adult patients with sudden deafness.

Methods

Pure tone audiometry, ABR and 40 Hz AERP were performed in 184 adult patients with sudden deafness before treatment. According to the frequency and severity of hearing loss revealed by pure tone audiometry, the patients were divided into low-frequency decline type（86 cases）, high-frequency decline type（60 cases）, flat type（32 cases） and total deafness type（6 cases, statistical analysis were not conducted in this group due to the incomplete elicitation of reaction threshold）. Data from 178 ears were collected for statistical results. After treatment, pure tone audiometry, ABR and 40 Hz AERP were performed.

Results

As for ABR threshold, its correlation with 500 Hz threshold of subjective pure tone test was poor（r=0.233, P=0.706）, and was worse with 1000 Hz threshold（r=0.472, P=0.345）. ABR threshold was closely correlated with 2000 Hz threshold（r=0.878, P=0.021） and 4000 Hz threshold（r=0.800, P=0.010） of subjective pure tone test. As for 40 Hz AERP threshold, its correlation with 500 Hz threshold of subjective pure tone audiometry was good（r=0.992, P=0）, and was better with 1000 Hz threshold（r=0.912, P=0.110）. 40 Hz AERP threshold was poorly correlated with 2000 Hz threshold（r=0.210, P=0.690） and 4000 Hz threshold（r=0.370, P=0.945） of subjective pure tone audiometry. ABR and subjective pure tone audiometry have high correlation at high frequency, while 40 Hz AERP and subjective pure tone audiometry have high correlation at low frequency.

Conclusion

ABR and 40 Hz AERP can comprehensively reflect the severity of hearing loss in adult patients with sudden deafness.