Posterior leukoencephalopathy syndrome

In medicine, posterior leukoencephalopathy syndrome (also called posterior reversible encephalopathy syndrome, PRES) is "a condition that is characterized by headache; seizures; and visual loss with edema in the posterior aspects of the cerebral hemispheres, such as the brain stem. Generally, lesions involve the white matter (nerve fibers) but occasionally the grey matter (nerve cell bodies)."

PRES may manifest as a transient neurological attack.