Abstract
An 18-year-old man with congenital weakness in the facial and mastication muscles was referred to us. His facial senses were intact; however, the bilateral massetter and facial muscles were extremely weak and atrophic. He presented lagophthalmos and had difficulty in closing his mouth. The voluntary movements of his left eye, such as abduction, adduction, and elevation, were partially impaired, without the impairment of the Bell phenomenon. Nerve conduction studies of the facial nerves revealed normal distal latencies for bilateral orbicularis oculi. Blink reflexes were not evoked on both sides. Needle electromyography showed a chronic neurogenic change in the tongue. A biopsy of the biceps brachii and skin did not show abnormality. We diagnosed his condition as Möbius syndrome with congenital facial palsy and supranuclear oculomotor palsy. Möbius syndrome, which manifests itself as congenital and non-progressing facial and abducens palsy, is associated with many clinical symptoms and is probably heterogenous nosological entity. Although several cases of Möbius syndrome with supranuclear binocular elevation palsy were previously known, this is the first case of Möbius syndrome presenting supranuclear monocular elevation palsy.
