Progressive supranuclear palsy: functional analysis of the response to methysergide and antiparkinsonian agents.

Twelve patients with progressive supranuclear palsy were treated with methysergide; the response was monitored with videotaped examination, electrooculography, and psychometric assessment. Used alone and with antiparkinsonian agents, methysergide improved the quality of life in eight patients for 6 months to 2 years. Benefits were especially dramatic in four patients with severe dysphagia. The disorder of visually guided behavior included abnormal orienting responses, visuosocial expression and regard, and visual search. Mesencephalic visuomotor centers appear to be important not only in control of ocular motility but also in the elaboration of visually guided behavior and the orienting of spatial attention.