We thank Zhang and colleagues for their comments on our article and wholeheartedly agree that there is a need to increase our understanding of PRES as a disorder or group of disorders that share clinical and radiological manifestations. To achieve this, reaching a consensus on how best to define the entity is the first challenge. In our article, we used the most widely used definition (ie, presence of vasogenic edema on brain imaging with proof of clinical or radiological reversibility); the other options for explaining vasogenic edema listed by Zhang and colleagues were clearly not the cause of the radiological findings in the cases we classified as PRES. Specifically, regarding stroke, the presence of cytotoxic edema was required for this diagnosis when magnetic resonance imaging was available.
Rabinstein A. A Clue to the Pathophysiology of Posterior Reversible Encephalopathy Syndrome—Reply. Arch Neurol. 2010;67(12):1536-1537. doi:10.1001/archneurol.2010.316