Posterior Reversible Encephalopathy Syndrome Associated with Bevacizumab

Posterior Reversible Encephalopathy Syndrome (PRES) is characterized by neurologic symptoms with hyperintense lesions on magnetic resonance imaging and it presents signs including a sudden onset headache, hypertension, and fever. The pathophysiology underlying PRES have been postulated to be severe hypertension leading to failed cerebral vascular auto-regulation and endothelial injury/vasogenic edema, vasoconstriction leading to brain ischemic and subsequent vasogenic edema. PRES may be associated with recent chemotherapy agents, in particular, bevacizumab which is a recombinant, humanized, monoclonal IgG1 antibody that binds and inhibits vascular endothelial growth factor. We experienced the case of PRES associated with Reversible Cerebral Vasoconstriction Syndrome (RCVS) 15 months later after a variety of combined chemotherapies containing bevacizumab for metastatic colon cancer. PRES and RCVS are frequently associated like this case and have overlapping or similar pathophysiological mechanism. We speculated that bevacizumab may have induced vasospasm coupled with hypertension and/or endothelial dysfunction due to bevacizumab has been shown able to affect the regulation of the cerebral arterial tone and trigger vasoconstriction with subsequent hypoperfusion, breakdown of the blood-brain barrier, and vasogenic edema, and which led to PRES. It is important to come to mind PRES early in the clinical course when the patient treated with bevacizumab shows the sign and symptoms resembling the cerebrovasucular disease.