Associated neurologic abnormalities in congenital third nerve palsies.

A study of ten patients (six girls and four boys ranging in age from 17 months to 9 1/2 years) with congenital third nerve palsies showed that not all cases are benign without other signs of focal neurologic damage. Six of the ten children showed some degree of pupillary involvement, five had signs of oculomotor synkinesis, four had associated focal neurologic abnormalities, and two had generalized developmental delay. Only three children showed no signs of neurologic change except the third nerve palsy. Although congenital third nerve palsies are incompletely understood, these lesions probably occur as a result of the damage both to the peripheral nerve and to the brain stem itself. Signs of oculomotor synkinesis do not occur in all cases and the pupil is frequently spared.