Posterior Reversible Encephalopathy Syndrome

Abstract

Purpose of review: This review provides an updated discussion on the clinical presentation, diagnosis and radiographic features, mechanisms, associations and epidemiology, treatment, and prognosis of posterior reversible encephalopathy syndrome (PRES). Headache is common in PRES, though headache associated with PRES was not identified as a separate entity in the 2018 International Classification of Headache Disorders. Here, we review the relevant literature and suggest criteria for consideration of its inclusion.

Recent findings: COVID-19 has been identified as a potential risk factor for PRES, with a prevalence of 1-4% in patients with SARS-CoV-2 infection undergoing neuroimaging, thus making a discussion of its identification and treatment particularly timely given the ongoing global pandemic at the time of this writing. PRES is a neuro-clinical syndrome with specific imaging findings. The clinical manifestations of PRES include headache, seizures, encephalopathy, visual disturbances, and focal neurologic deficits. Associations with PRES include renal failure, preeclampsia and eclampsia, autoimmune conditions, and immunosuppression. PRES is theorized to be a syndrome of disordered autoregulation and endothelial dysfunction resulting in preferential hyperperfusion of the posterior circulation. Treatment typically focuses on treating the underlying cause and removal of the offending agents.

Keywords: Headache; Hypertensive encephalopathy; Immunosuppressive drugs; Reversible posterior encephalopathy syndrome; Vasogenic edema.

Fig. 1

Mechanisms contributing to the development of PRES. Disordered cerebrovascular autoregulation in hypertension can lead to hyperperfusion. Blood-brain barrier breakdown results from increased cerebral perfusion pressure leading to extravasation of plasma and macromolecules into the interstitial space through tight junction proteins. Release of cytokines activates the secretion of vasoactive factors from endothelial cells that increase vascular permeability leading to interstitial edema. Release of these cytokines can also influence downstream gene expression cascades