CYCLODEVIATION IN SKEW DEVIATION

We examined four patients with dorsolateral pontomedullary lesions and skew deviation, with ocular torsion of varying symmetry. In three pat ients, the hypotropic eye was excyclodeviated relative to the fellow e ye. Observations of these patients, combined with recent evidence, sug gest that cyclodeviation is a frequent component of a skew deviation a nd may result from variable involvement of utricular, semicircular can al, and cerebello-ocular pathways. Although cyclodeviation is a featur e of trochlear-nerve palsies, its presence does not exclude skew devia tion and underlying brainstem lesions.