Isolated sixth-nerve palsies in younger adults.

Acquired sixth-nerve palsies are relatively rare in younger adults. We reexamined 49 patients, aged from 15 to 50 years, with isolated sixth-nerve palsies who were seen between 1972 and 1982 at the Wills Eye Hospital in Philadelphia. In this group, the following etiologies were encountered: vasculopathy (14 patients [29%]), tumors (eight patients [16%]), multiple sclerosis (six patients [12%]), presumed inflammation (four patients [8%]), trauma (three patients [6%]), postlumbar puncture (two patients [4%]), and orbital amyloidosis (one patient [2%]). Eleven patients (22%) had no determined cause of their sixth-nerve palsy. The implications for the clinical management of isolated sixth-nerve palsies in younger adults are discussed.