Marcus Gunn Syndrome associated with an unusual oculo-cardiac reflex.

The Marcus Gunn Syndrome is discussed. It is postulated that an atypical oculocardiac reflex is easily initiated in these patients so that precautions must be taken for its prevention and early detection. Marcus Gunn first described the syndrome in 1883. His patient had a congenital ptosis of the left upper eyelid. Paradoxical lid retraction was evoked by movement of the jaw. Consequently the syndrome also became known as the 'jaw-winking' syndrome. Other varieties of the Marcus Gunn syndrome have also been described. The pathogenesis of this syndrome seems to be the presence of abnormal central connexions between the trigeminal and oculomotor cranial nerves which supply the external pterygoid and the levator palpebrae superioris muscles. The importance of recognition of the oculocardiac reflex in patients undergoing eye surgery under anesthesia is well known to anaesthetists and to eye surgeons. The occurrence of this reflex in patients undergoing surgery on the eyelids has been reported previously. This paper describes a patient with the Marcus Gunn Syndrome who underwent three operations on the left upper eyelid and who exhibited unusual manifestations of the oculocardiac reflex.