Associated neurologic and ophthalmologic findings in congenital oculomotor nerve palsy

Unlike acquired oculomotor nerve palsy in childhood, the congenital form is usually considered to be an isolated disorder, not associated with other neurologic or systemic disease. In a series of 14 patients with this diagnosis, 10 had associated neurologic disorders. Clinical-neuroradiologic correlation identified the brainstem as the site of the lesion in some patients. The ipsilateral pupil was involved in 12 patients and was miotic with a trace or no reaction to light on the side of the palsy in 8 of the 12 patients. In two of these eight patients, the pupil was documented to be dilated and fixed in early infancy and subsequently became miotic at several months of age, concurrent with emergence of other signs of aberrant reinnervation. Pupillary miosis as a result of aberrant reinnervation appears to be much more frequent after congenital than acquired pupillary-involving oculomotor palsy. Four patients showed better visual acuity in the paretic eye, an unexpected finding. The paretic eye appeared to have a fixational advantage if the patient had nystagmus, presumably due to asymmetric dampening of the nystagmus. Significant anisometropia and astigmatic errors in the paretic eye were present in essentially all patients.