Abducens Nerve Avulsion and Facial Nerve Palsy After Temporal Bone Fracture: A Rare Concomitance of Injuries.

BACKGROUND

Avulsion of the abducens nerve in the setting of geniculate ganglion injury after temporal bone fracture is unreported previously. We discuss clinical assessment and management of a patient with traumatic avulsion of cranial nerve (CN) VI in the setting of an ipsilateral CN VII injury after temporal bone fracture and call attention to this unusual injury.

CASE DESCRIPTION

A 26-year-old man suffered a temporal bone fracture after a motor vehicle accident and developed diplopia and right-sided facial droop. Six weeks after the accident, the patient was readmitted with worsening diplopia and ipsilateral facial weakness. He demonstrated absent lateral gaze on the right suggestive of either restrictive movement or right.

CN VI DEFICIT

In addition, he had right-sided facial palsy graded as 6/6 House-Brackmann. High-resolution computed tomography demonstrated a right-sided longitudinal otic capsule-sparing temporal bone fracture that propagated into the facial nerve canal and geniculate fossa. Magnetic resonance imaging revealed discontinuity of the right CN VI between the pons and the Dorello canal, as well as injury to the ipsilateral geniculate ganglion. CN VII was intact proximally, from the pons through the internal auditory canal. Consensus was reached to proceed with conservative management. At 13 months after injury, the patient reported 1/6 House-Brackmann with no improvement in CN VI function.

CONCLUSIONS

This case illustrates 2 subtle findings on imaging with potential therapeutic implications, notably the role of surgical intervention for facial nerve palsy.