Are Cochlear Implants a Viable Option Following Temporal Bone Fracture?

TRIO Best Practice articles are brief, structured reviews designed to provide the busy clinician with a handy outline and reference for day-to-day clinical decision making. The ENTtoday summary below includes the Background and Best Practice sections of the original article. To view the complete articles free of charge, visit Laryngoscope.

Background

Temporal bone fractures (TBFs) occur in up to 20% of patients who sustain a skull fracture, and they may result in a range of complications, including hearing loss, balance disturbance, facial nerve palsy, and cerebrospinal fluid leak. Unfortunately, sensorineural hearing loss (SNHL) is a common sequela following TBF, especially in individuals with otic-capsule violating fractures. For patients with severe to profound SNHL after TBF, cochlear implantation (CI) is the primary option for auditory rehabilitation. Known labyrinthine changes following TBF, such as intracochlear fibrosis and new bone formation, raise concerns regarding the feasibility of proper CI electrode insertion and postoperative audiometric outcomes. In this Triological Society Best Practice, we address the question: Are cochlear implants a viable option following a temporal bone fracture?

Best Practice

Studies examining CI following TBF consistently demonstrate successful auditory rehabilitation; however, outcomes may be variable. Patients who were implanted years after trauma appear to have worse outcomes than peers implanted earlier, following the general trend of CI outcomes. Additionally, although CI for single-sided deafness as a result of head injury has been performed, more research is needed to further assess outcomes. The current literature raises a host of anatomic features, such as cochlear ossification and testing, including promontory stimulation, that may help to predict outcomes; however, the majority of the studies were not primarily designed to address these questions. There are a host of limitations of the current studies, and several variables remain underinvestigated. The articles also utilized different speech discrimination testing, making comparisons challenging. In addition, the studies were not sufficiently designed to delineate how preoperative imaging, fracture location, promontory stimulation, and time to implantation may influence outcomes. These studies also tended to group together head injury patients, with and without fractures, limiting direct analysis of patients with TBF. In summary, as a best practice, there is sufficient evidence to advocate for CI after TBF. However, specific timing of implantation and patient selection criteria need to be further delineated in future studies.