Facial nerve injury in cochlear implantation.

We present eight cases of FN dysfunction after cochlear implantation. Four mechanisms of injury are proposed. The most common injury occurs from the heat of a bur shaft rotating over the FN in the facial recess. Several suggestions are made to help prevent the type of injuries we have seen. Preoperative imaging and intraoperative FN monitoring may be of general assistance in avoiding injuries to the FN, especially in cases of revision surgery and congenital malformations.