PRES: Review of Histological Features.

Posterior reversible encephalopathy syndrome was described in 1996 as a clinical-neuroimaging entity characterized by parieto-occipital watershed-region edema without overt infarction. It has been linked to hypertension, eclampsia, immunosuppressive therapies, infections, and autoimmune disorders. The condition usually has an acute onset, presents with seizures, and ameliorates within days. There have been few neuropathological studies, but in some cases, tissue damage may be more permanent.