The pretectal syndrome: 206 patients.

The pretectal syndrome occurred in 2.3% of patients personally examined over an 18-year period. The symptoms were nonspecific, but the signs (abnormal pupils in 198 patients, vertical gaze limitation in 180, disjunctive horizontal eye position in 90 and vertical in 79, lid retraction in 83, and convergence-retraction nystagmus in 71) were exquisitely localizing. The etiology, skewed by the local prevalence of cysticercosis, was hydrocephalus in 80 patients, stroke in 53, and tumor in 45. The importance of timely diagnosis was underscored by the relatively good prognosis of many patients.