Neurootological findings in facial nerve neurinomas of the internal auditory canal and cerebello-pontine angle

Eleven patients had facial nerve neurinomas, which involved the internal auditory canal (IAC), and were operated via a transtemporal approach. Six of these tumors, which were confined to the IAC and CPA, resembled acoustic neurinomas in their clinical and neuroradiological appearance and neurootological findings. Only tumors (n=5), which had grown into parts of the fallopian canal, caused facial nerve dysfunction and preoperatively pointed to the existence of a facial nerve tumor. In case of tumors of the IAC and CPA even extensive preoperative neurootological testing cannot differentiate between tumors originating from the vestibular nerve and tumors evolving from the facial nerve.