Temporal bone fracture requiring facial nerve decompression or repair

Abstract

Facial nerve paralysis is one of the complications with temporal bone fractures. Although most are treated medically with observation and steroids, we review the indications and surgical approaches to the facial nerve along its course within the temporal bone. It is important to get an examination as early as possible to determine immediate vs delayed, and complete vs incomplete paralysis. Patients with immediate onset, complete facial nerve paralysis should receive electrodiagnostic testing 3-7 days after onset, to allow for Wallerian degeneration. If there is >90% electroneuronography degeneration within 6 days or >95% degeneration within 14 days, surgical exploration is recommended. Exact surgical timing for decompression is controversial and definitive data is lacking but some authors have had success even beyond 2 months postinjury and the risks and benefits should always be discussed with each patient. The approach for surgical decompression of the facial nerve should be based on the site of injury, if discernible, but most commonly involves transmastoid, middle fossa craniotomy, or a combination of these approaches. The perigeniculate region is the most commonly injured portion of the facial nerve with temporal bone fractures. If a transection is encountered, the nerve should be repaired by either primary nerve repair if tension free, otherwise a secondary repair with a cable graft should be performed.