The Pure Tone Audiometry and Auditory Brainstem Response in Patients with Small Acoustic Neuroma's / 听力学及言语疾病杂志

ABSTRACT

Objective To understand the characteristics of the hearing loss in patients with small acoustic neuroma .Methods A retrospective analysis was used to analyze the results of pure tone audiometry (PTA) and au-ditory brainstem response (ABR) in 35 patients (35 ears) diagnosed with small acoustic neuroma .The types of au-diometric curves ,degrees and frequencies of hearing loss and latent periods of ABR were analyzed .Results Moder-ate deafness was the most common type in this study ,with a total of 13 ears (37 .14％ ,13/35) .In addition ,8 ears were profound deafness (22 .86％ ,8/35) ,7 ears of binaural severe deafness (20 .00％ ,7/35) ,6 ears of mild deafness (17 .14％ ,6/35) ,and 1 normal ear (2 .86％ .1/35) ,respectively .The types of audiometric curves were mainly U -shaped and sloping .15 audiometric curves were U -shaped (42 .86％ ,15/35) ,15 sloping (42 .86％ ,15/35) ,3 flat (8 .57％ ,3/35) ,and 1 tent-shaped (2 .86％ .1/35％ ) .The main frequencies of hearing loss were 1 kHz ,2 kHz ,4 kHz ,and 8 kHz .The mean thresholds had statistically significant differences (P<0 .05) compared with the other frequencies by S -N -K test .ABR was abnormal in 32 ears(91 .43％ ,32/35) .20 of the ears'I - V waves were prolonged or the inter-aural latency difference of V wave was>0 .4 ms .Five ears failed to show any ABR wave , but their 4 kHz pure tone threshold was < 80 dB HL .25 (71 .43％ ,25/35)ears'ABR results indicated a retroco-chlear nature of ear disease .Conclusion Moderate deafness is the most common type of hearing loss in small acous-tic neuroma patients ,but only 71 .43％ of the patients'ABR indicate a retrocochlear disease ,so an analysis of PTA together with ABR will help to diagnose .