A case of Mobius syndrome--radiological and electrophysiological findings.

Mobius syndrome is characterized by congenital bilateral facial palsy and abducens nerve paralysis, but reports of radiological and electrophysiological findings are scarce. A 4-year-old boy presented with mask-like facies noted at birth after a 34-week pregnancy. Examination revealed bilateral facial and abducens nerve paralysis with no other neurological abnormalities. Computed tomography revealed bilateral absence of facial nerve canal in the middle ear. Brain magnetic resonance imaging indicated a narrow than expected nerve in the internal auditory canal (IAC). Evoked electromyography and blink reflex testing to evaluate facial nerve function yielded no responses bilaterally. Facial palsy thus appears to be caused by facial nerve dysplasia or aplasia.