The pathology of drop attacks: a case report.

A 65-year-old man had four drop attacks in several days and then a fixed stroke with quadriplegia. At autopsy infarction in the lower pons and upper medulla affected principally the corticospinal tracts. Tegmental destruction included reticular formation nuclei with rostral projections, but spared the lateral reticular formation nuclei, from which arise the descending reticulospinal tracts. This case is the first detailed autopsy report of a patient with drop attacks, and supports the view that at least some drop attacks are caused by transient ischemia of the corticospinal tracts.