Clinical Analysis of 25 Cases of Acoustic Neuroma for the Last Five Yers

Abstract

Background and Objectives : For the past 10 years with the development of imaging techinques, acoustic tumors(AT) have been detected before significant symptoms could develop. The development of MRI scan and improved awareness by otolaryngologists of the changign clinical presentation of AT have increased the relative incidence of small AT. The objective of this study is to review symptomatology, diagnostic approach and surgical treatment of AT which were experienced for the last 5 years, and to make an effective diagnostic work-up with management. Patients and Methods : From March 1995 through March 2000, 25 patients with AT (including 4 patients with neurofibromatosis type Ⅱ) were diagnosed and treated at Ajou University Hospital. We analysed tumor size, chief complaints, pure tone audiogram(PTA), speech discrimination score (SDS), auditory evoked response(ABR), caloric test, surgical approach, hearing preservation, and facial nerve preservation. Patients were groups by tumor size, which was recommended from AANR(Americal Acoustic Neuroma Registry) in 1996. Results : The most common symptom of AT was progressive unilateral hearing loss. But sudden hearing loss and dizziness were chief complaints in the cases with small tumors (group IC, 0). Hearing was relatively well preserved with small tumors, but was impaired in large tumors. ABR showed normal response in 3 cases with small tumors. In caloric test, 3 cases didn't show unilateral vestibular weakness, and 2 of these cases were confirmed as AT from inferior vestibular nerve during operation. Hearing presrvation was done in 4 of 10 cases with hearing conservation surgeries. Facial nerve was well preserved with small tumors, especially less than 2cm, but its ostoperative function was not good with large tumors. Conclusion : These data provide patients with small tumor showed good hearing and facial nerver functions. So it is very important to detect small AT earlier with systematized diagnostic approach.