Facial Nerve Deficit and Cochlear Implantation

Objective Since Facial Nerve (FN) deficit after surgery for cochlear implantation can be ascribed to different causes, this study aimed to identify possible correlation with pathological or surgically-related issues. Study design A retrospective study was carried out on 100 consecutive cases of cochlear implantation. Setting The Institute of Otorhinolaryngology of University Hospital of Rome “La Sapienza.” Patients One hundred consecutive patients who underwent cochlear implant surgery were enrolled for the study; 35 of them were children, and 65 were adult (30 females, 35 males). Intervention(s) A standard surgical approach was used for implanting 85 Clarion®, 14 Med-El® and 1 All-Hear®. For the former implant device, a larger posterior tympanotomy as well as cochleostomy was carried out in order to insert the positioner in the latter 35 Clarion® implantees. All surgeries were performed by monitoring facial nerve function with electromyography and/or videomonitoring. Main outcome measure(s) FN function was assessed postoperatively and classified according to the House-Brackmann grading system. Primary cause of deafness was correlated with postoperative FN deficit. A further correlation regarded FN deficit and extension of posterior tympanotomy and cochleostomy in the last generation Clarion® implantees. Results Eight patients presented a FN deficit of different degree in relation to cochlear implantation: 3 had a grade V immediately after surgery; 3 had a FN deficit of delayed onset (2 grade V, 1 grade IV); 2 presented FN stimulation 1 and 4 years after surgery, respectively. Steroids and an immediate postoperative physical rehabilitation (Kabat’s method) allowed to reach normality in 4 of them, whilst the other 2 patients hesitated in a Grade II and Grade III FN deficit. Conclusions Although rare, a FN deficit can be observed after cochlear implantation. Such a deficit usually recovers to normality, such as it was the case in all but one of our patients. The possibility of a delayed FN deficit or a delayed FN stimulation should also be considered.