Traumatic Facial and Vestibulocochlear Nerve Injury in The Internal Acoustic Canal in The Absence of A Temporal Bone Fracture.

ABSTRACT

We present a rare case of traumatic facial and vestibulocochlear nerve injury in the internal acoustic canal in the absence of a temporal bone fracture. A 2.5-year-old female presented with sudden-onset left-sided facial paralysis and ipsilateral total hearing loss after being hit by a falling television. High-resolution computed tomography revealed an occipital fracture line that spared the temporal bone and otic capsule. Diagnostic auditory brainstem response testing showed that wave V at 90-db normal hearing level was absent in the left ear. Needle electromyography revealed severe axonal injury. Facial paralysis regressed to House-Brackmann grade IV 9 months after the trauma, and no surgical intervention was scheduled. Traumatic facial and vestibulocochlear nerve injury can occur in the absence of a temporal bone fracture. Thus, careful evaluation of the internal acoustic canal is mandatory if concurrent 7th and 8th cranial nerve paralyses exist with no visible fracture line.