Objective: The aim of the study was to provide a clinical review of the middle fossa approach for hearing preservation in patients with neurofibromatosis type 2 (NF2).
Study design: The study design was a prospective case review.
Setting: The study was conducted at a private practice tertiary neurotologic referral center.
Patients: Eighteen patients diagnosed with NF2 underwent 23 middle fossa procedures between 1992 and 1996 for removal of an acoustic neuroma. The nine males and nine females ranged in age from 11-73 years with a mean age of 28 years. Tumor size ranged from 0.5-2.5 cm with a mean of 1.1 cm.
Main outcome measures: House-Brackmann facial nerve grade was measured. In addition, hearing level was classified both by the American Academy of Otolaryngology-Head and Neck Surgery criteria for reporting results of hearing preservation surgery and by comparison with preoperative level (15 dB/15%).
Results: Measurable hearing was preserved in 65%, 48% within 15 dB of preoperative pure-tone average (PTA) and within 15% of preoperative speech discrimination. Bilateral hearing preservation occurred in five patients. Excellent facial nerve function (House-Brackmann grades I-II) was obtained in all patients with normal preoperative facial nerve function.
Conclusions: In this series of patients with NF2, outcomes in hearing and preservation of preoperative facial nerve function are similar to results seen in patients suffering a sporadic unilateral acoustic neuroma. However, early intervention is crucial in obtaining such favorable outcomes.