Clinical studies of ocular motility disturbances. Part 1. Ocular motility disturbances: causes and incidence.

Between January 1985 and December 1994, 500 cases of ocular motility disturbances were encountered in our department; we analyzed these statistically. There were 48 cases of supranuclear palsy (10%), 281 of ocular motor nerve palsies (56%), 19 with myasthenia gravis (4%), 29 with myogenic palsy (6%), 57 with abnormal innervation (11%), and 63 instances of mechanical disturbances (13%). There were more men than women in all groups except myasthenia gravis. Eighty-four ocular motor nerve palsy and 15 blowout fracture patients recovered spontaneously. Spontaneous recovery occurred within 6 months in 80 (93%) patients with ocular motor nerve palsy. The abnormality detection rate, using diagnostic imaging, was high for supranuclear and myogenic palsy and the mechanical disturbance groups, but very low for the ocular motor nerve palsy groups. In 3 supranuclear palsy patients, small infarctions of the brainstem were discovered by magnetic resonance imaging (MRI) but were not found with computed tomography (CT). MRI thus proved useful in detecting abnormalities of brainstem lesions.