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

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.

Ruptured Total Intrameatal Anterior Inferior Cerebellar Artery Aneurysm

Among the distal anterior inferior cerebellar artery (AICA) aneurysms, a unique aneurysm at the meatal loop inside the internal auditory meatus is extremely rare. The authors report a case of surgically treated total intrameatal AICA aneurysm. A 62-year-old female patient presenting with sudden bursting headache and neck pain was transferred to our department. Computed tomography and digital subtraction angiography showed subarachnoid hemorrhage at the basal, prepontine cistern and an aneurysm of the distal anterior inferior cerebellar artery inside the internal auditory meatus. Surgery was performed by retrosigmoid craniotomy with unroofing of the internal auditory meatus. The aneurysm was identified between the seventh and eighth cranial nerve in the meatus and was removed from the canal and clipped with a small straight Sugita clip. After operation the patient experienced transient facial paresis and tinnitus but improved during follow up.