The Difference of Clinical Symptoms and Audiovestibular Function between Intrameatal and Extrameatal Acoustic Neuroma

Lee, Jeong Yeop; Lee, Se A; Lee, Sang Kuk; Kim, Jeong Tae; Park, Seung Bum; Kim, Bo Gyung; Lee, Jong Dae

Abstract

BACKGROUND AND OBJECTIVES
Various hearing tests and vestibular function tests are used to diagnose acoustic neuroma. We analyzed the clinical characteristics and the results of audiovestibular function tests between patients of intrameatal and extrameatal acoustic neuroma.
SUBJECTS AND METHOD
Reviewing the medical records for 64 patients with acoustic neuroma between March 2007 and February 2014, we divided the patients into two groups, intrameatal (31 patients) and extrameatal acoustic neuroma (33 patients) according to the involvement of cerebropontine angle. We compared the clinical characteristics, pure tone audiograms, speech audiometry, caloric test, and vestibular evoked myogenic potential (VEMP) between the two groups.
RESULTS
While hearing loss was the most frequent presenting symptom in patients with intrameatal acoustic neuroma, dizziness was the most common symptom in patients with extrameatal acoustic neuroma. Hearing thresholds measured by pure tone audiometry and speech discrimination scores were significantly worse for patients with extrameatal acoustic neuroma. Abnormal unilateral canal paresis of caloric test was significantly higher for extrameatal acoustic neuroma than for intrameatal acoustic neuroma. Most patients with acoustic neuroma showed abnormal findings in the VEMP test, but the number of patients between intrameatal and extrameatal acoustic neuroma did not differ significantly.
CONCLUSION
Clinical symptoms and the results of audiovestibular function tests differed according to the tumor size of acoustic neuroma. Physicians should counsel patients presenting with audiovestibular symptoms of the possibility of acoustic neuroma.