Hearing preservation in bilateral acoustic neurinomas.

Bilateral acoustic neurinomas are found in almost all patients with neurofibromatosis 2 (NF2). With better knowledge of the disease and development of diagnostic procedures, an increasing number of patients have been detected at an early stage of the disease. Preservation of hearing in these cases has become more feasible. Between 1979 and 1992, 110 acoustic neurinomas in 74 NF2 patients have been resected in this department. All tumours but 11 were completely removed. In 11 cases deliberate subtotal tumour removal was performed: bilaterally in one deaf patient for brainstem decompression, and unilaterally in nine patients with the aim of hearing preservation. In seven of these nine cases hearing was preserved. The total rate of hearing preservation was 36%. Considering only those patients with good preoperative hearing and small tumours, the rate of hearing preservation was 58%. Facial nerve preservation was 92%. Nerve reconstructions were performed in cases of facial nerve damage, with good results in most of the cases. The importance of early detection of the disease and early removal of tumours is stressed. Surgical decision making based on the author's personal experience in dealing with these cases is discussed, and some cases are illustrated.