Prevalence of Acoustic Neuroma Associated with Each Configuration of Pure Tone Audiogram in Patients with Asymmetric Sensorineural Hearing Loss

Objectives The criteria have not yet been established for identifying the configuration of a pure tone audiogram constituting abnormal results that warrant further investigation. The purpose of this study was to determine the prevalence of acoustic neuroma associated with each configuration of the pure tone audiogram in patients with asymmetric sensorineural hearing loss (SNHL). Methods We performed a retrospective chart review of 500 patients 15 years of age or older who had asymmetric SNHL and had undergone magnetic resonance imaging. Results The prevalence of acoustic neuroma in these patients was 2.6% (13 of 500). The prevalence of acoustic neuroma in each audiometric configuration was as follows: 7.1% (3 of 42) for a basin-shaped loss (odds ratio [OR] versus overall prevalence, 2.88; p =0.23; 95% confidence interval [CI], 0.79 to 10.54),4.7% (5 of 107) for a flat loss, 3.4% (2 of 58) for total deafness, 2.9% (l of 34) for a high-frequency sloping audiogram, and 2.5% (2 of 81) for a high-frequency steep audiogram. The prevalence in patients with nonimproving idiopathic sudden deafness was 8.1% (OR, 3.29; p = 0.06; 95% CI, 1.13 to 9.55). Conclusions In conclusion, 2.9% to 8.1% of patients with a characteristic configuration of the pure tone audiogram and symptoms of nonimproving or progressive idiopathic sudden deafness may have acoustic neuroma.