Möbius syndrome as a syndrome of rhombencephalic maldevelopment: a case report.

Möbius syndrome is a rare congenital disorder characterized by congenital facial weakness with impairment of ocular abduction. It is considered as a rhombencephalic disorder, and is often accompanied with hypoplasia of the pons and cerebellum. Here we report a male infant who had congenital facial asymmetry with absence of right-sided expression. Evident developmental delay was also found. The bilateral auditory brain stem response showed no response at 85dB. A reconstructive brain magnetic resonance imaging (MRI) revealed the absence of the right facial nerve as well as hypoplasia of the pons and cerebellum of the same side. Some voluntary contraction over the patient's right lower face was noted after facial muscle electrical stimulation.