Oculomotor nerve paresis starting as isolated internal ophthalmoplegia

Abstract

Oculomotor nerve palsies involving only the internal eye muscles are extremely rare. The authors report a 33-year-old female who presented with isolated pupillary and ciliary dysfunction that eventually turned into a typical third nerve palsy. In 1979 she developed a tonically dilated pupil with preserved, but reduced accommodation. In 1993 she began to develop diplopia on eccentric gaze direction. The pupil had become dilated and completely immobile and the ciliary muscle was paralytic. Eye motility abnormalities were consistent with a mild third nerve paresis and there was an elevation of the upper eyelid on adduction (primary misdirected regeneration). MRI revealed a parasellar mass lesion, probably a neurinoma, arising from the right oculomotor nerve. The authors decided not to treat this slowly growing tumor.

Key Words:

• Third nerve palsy
• pupil
• tonic pupil
• tumor of the oculomotor nerve
• cranial nerves
• primary aberrant regeneration