Facial and Vestibulocochlear Nerve Avulsion at the Fundus of the Internal Auditory Canal in a Child Without a Temporal Bone Fracture

Abstract

To describe a case of facial, vestibular, and cochlear nerve avulsion secondary to blunt trauma without an associated temporal bone fracture. Clinical capsule report. University hospital. A 3.5-year-old girl presented with immediate facial nerve paralysis and complete deafness after being struck by an automobile. High-resolution computed tomography demonstrated a depressed occipital bone fracture with no visible fracture of the temporal bone. Magnetic resonance imaging sequence raised the question of VIIth nerve bundle discontinuity at the distal end of the internal auditory canal. The patient underwent a posterior fossa craniotomy via a translabyrinthine approach 9 months after the initial injury, and facial and auditory nerve avulsion at the fundus was confirmed at the time of surgery. The proximal segment of the facial nerve had formed a traumatic neuroma, which was resected, and primarily anastomosed to the rerouted distal segment. Facial nerve function. Patient has regained facial function to Grade III/VI House-Brackmann with no asymmetry at rest. An unusual pattern of injury is described. We suggest that in patients presenting with facial nerve paralysis secondary to blunt trauma, without an associated temporal bone fracture, high-resolution magnetic resonance imaging is recommended to evaluate internal auditory canal discontinuity of the VIIth and VIIIth nerve complexes. A potential mechanism of avulsion is explained.