Answers: 2004 series - February 3, 2004
Lecture 48 of 50 NEXT»
This 4-year-old boy has been noted by his parents to have a droopy right lid since birth. In addition, they noted as an infant his right upper lid "bounced" up and down when he fed from a bottle and the lid continues to act in this manner when he chews. The boy is healthy and has no known blood relatives with any sort of ptosis.
||The most likely diagnosis is:|
b -- This boy has Marcus-Gunn jaw winking. This type of ptosis is said to amount for from 4 to 6% of all congenital ptosis.
||The cause of this condition is:|
d -- Marcus-Gunn jaw winking is caused by a misdirection of the branch of the fifth cranial nerve. A branch of this nerve that normally innervates the external pterygoid muscle goes to innervate the partially dennervated levator palpebri muscle on the same side.
||Treatment of this condition depends on all but one of the following: |
c -- The treatment of Marcus-Gunn jaw winking depends on several factors. The first has to do with the symptoms of the patient. If the ptosis is mild and the wink minimal, no treatment is indicated. Actually, it is thought that this condition becomes less severe with age, but this may really mean that the patient is able to manage the situation better by avoiding jaw movement that would cause the wink. If the wink is minimal and the levator function fairly good, 4 mm or more, for example, some form of levator resection would be considered. However, if the wink is severe, it may be necessary to abolish levator function by disabling the levator palpebri and then performing a suspension procedure on the upper. As with any form of congenital ptosis, Marcus-Gunn jaw winking presents a challenge to treatment. This challenge being even greater because of the misdirection of innervation. The other prominent misdirection involving the eye is misdirection of the third cranial nerve, which occurs in about one half of patients with third nerve palsy where there is disruption and then repair of the nerve.