Chronic isolated sixth nerve palsies.

Twenty-seven cases of chronic isolated abduction deficit, seen in 25 years of neuro-ophthalmology consultation, were reviewed. "Isolated" was defined as the lack of any other neurologic or ophthalmologic findings for at least six months. Cases were further subdivided into the categories of true and pseudo-abducens paresis. The origin, diagnosis, and management of long-standing abducens palsies were determined. Cases of pontine glioma, chordoma, chondrosarcoma, and meningioma that presented as an isolated abducens palsy and remained undiagnosed for at least six months were reviewed.