Cyclodeviation in skew deviation.

Abstract

We examined four patients with dorsolateral pontomedullary lesions and skew deviation, with ocular torsion of varying symmetry. In three patients, the hypotropic eye was excyclodeviated relative to the fellow eye. Observations of these patients, combined with recent evidence, suggest that cyclodeviation is a frequent component of skew deviation and may result from variable involvement of utricular, semicircular canal, and cerebelloocular pathways. Although cyclodeviation is a feature of trochlear-nerve palsies, its presence does not exclude skew deviation and underlying brainstem lesions.