Vertical gaze ophthalmoplegia: selective paralysis of downgaze.

A 58-year-old man developed a selective supranuclear paralysis of downgaze, which was repeatedly documented until it completely resolved after 6 weeks. At autopsy, there was a bilaterally symmetric old infarct in the mesodiencephalic region. In common with four previous similar reports, the lesion involved structures bordering the dorsomedial aspect of the red nucleus. This same region has been implicated in the control of vertical eye movements in recent neuroanatomic and physiologic experiments in nonhuman primates.