Posterior Reversible Encephalopathy Syndrome (PRES)

Posterior reversible encephalopathy syndrome (PRES) starts with rapid onset of symptoms including headache, seizures, altered consciousness, and visual disturbance, including blurry vision. It is often associated with acute hypertension . If promptly recognized and treated, the clinical syndrome usually resolves within a week , and the changes seen in magnetic resonance imaging (MRI) resolve over a few days to few weeks.

Chronic kidney disease and acute kidney injury are both commonly present in patients with PRES , and PRES is strongly associated with conditions that exist in patients with renal disease, such as hypertension, vascular and autoimmune diseases, exposure to immunosuppressive drugs, chemotoxic drugs and organ transplantation.

The cause of PRES remains controversial, but the most popular theory is that severe hypertension causes interruption to brain autoregulation . Cerebral blood flow is usually regulated by dilatation and constriction of vessels to maintain adequate tissue perfusion and to simultaneously avoid excessive intracranial hypertension. Breakdown in autoregulation occurs above arterial blood pressure of 160 - 190 mmHg; in chronic hypertension, it occurs at even higher pressures . Uncontrolled hypertension leads to hyperperfusion and cerebral vessel damage, resulting in interstitial extravasation of proteins and fluids, causing vasogenic edema, typically in the Occipital and Parietal lobes.

Treatment: rapid withdrawal of the trigger appears to hasten recovery and to avoid complications: for e.g., aggressive blood pressure management , withdrawal of the offending drug, or delivery in eclampsia . Antiepileptic drugs may be used to treat seizures, and anesthesia and ventilation should be instituted as necessary. Corticosteroids may theoretically improve vasogenic edema, but there is no evidence for their use in PRES.

Prognosis:  Whereas PRES was initially described as a benign entity that was reversible with a good outcome, about 20% do not make it and functional impairments of varying degrees have been reported in the others.

If your BP is HIGH, take your meds as prescribed. If any or all of the PRES symptoms are present, call 911. DO NOT DELAY. GET HELP ASAP.

https://www.youtube.com/watch?v=SWevH90oNp0&t=14s

Author

Paddy Kalish OD, JD and B.Arch