Mobius's syndrome.

Various terms have been applied to this condition: Mobius's syndrome, congenital facial diplegia, congenital oculo-facial paralysis, nuclear agenesis, and congenital nuclear aplasia. It was originally described by von Graefe (1880), Harlan (1881), and Chisolm (1882). M6bius (1892) collected 43 cases of congenital and acquired cranial nerve palsies and classified them into six groups. One group consisted of six cases of bilateral abducens and facial nerve palsies. Since then Mobius's name has been associated with this condition. It is relatively uncommon and its bizarre association of lesions may cause affected children to be taken to a paediatrician, an orthopaedic surgeon, an ophthalmologist, or a child psychiatrist. The purposes of the present paper are to record three more cases of this rare condition, to report the absence of any association with Rh incompatibility, and to suggest that the clue to its aetiology may lie in a more detailed investigation of pregnancy histories. A typical case of Mobius's syndrome shows the following features: (1) Bilateral Facial Palsy.-This is the most obvious feature and it may or may not be complete. If it is not complete the lower part of the face is usually less affected than the upper. This is unlike a supranuclear facial palsy in which the upper part of the face escapes, nor does it resemble a nerve trunk lesion in which the whole side of the face is equally affected. Another feature characteristic of this condition is the absence of the sagging of the facial tissues, which is so disfiguring a feature of acquired seventh-nerve palsies. If the flesh of the cheek is palpated between finger and thumb it feels peculiarly thin. Contraction of the facial muscles, like that which occurs in cases of Bell's palsy with recovery, is never seen. Invariably there is a history of sucking and feeding problems in infancy. Dribbling tends to persist into childhood, and when the child is eating, food tends -to lodge in the cheeks and has to be pushed out with the fingers. The orbicularis oculi muscle is defective so that there is incomplete closure of -the lids in sleep, infrequent blinking, tearing, and a tendency to a recurrent lowgrade kerato-conjunctivitis from exposure. (2) Absence of Abduction of either eye beyond the mid-line, and palsy of the horizontal gaze, so that when looking to either side the child must turn the head. (3) Convergence.-This is usually present but defective. The pupils constrict -normally during convergence. (4) Vertical Gaze.-Movements are normal and Bell's phenomenon is intact. (5) Convergent Strabismus is occasionally present.