Perfusion Deficits in Patients with Posterior Reversible Encephalopathy Syndrome: a Retrospective, Two-Center Study

Background: Posterior reversible encephalopathy syndrome (PRES) is manifested by acute neurological symptoms in patients with varied predisposing factors and characteristic findings on brain imaging. Cerebrovascular autoregulation is thought to be altered in PRES. However, it remains unclear whether cerebral hypoperfusion or hyperperfusion is the initiating event. We aimed to describe the brain perfusion status in untreated patients with PRES. Methods: Patients with PRES who underwent cerebral perfusion studies on presentation were retrospectively identified from (1) a prospective database of patients with PRES admitted to Saint Mary’s Hospital, Mayo Clinic, Rochester from January 2005 to December 2021 and (2) University of Nebraska Medical Center electronic database from January 2010 to December 2021. Demographics, past medical history, presenting symptoms, cause of PRES, and clinical outcomes were recorded. Brain imaging studies were reviewed. We recorded the location of brain lesions, the time from symptoms onset to perfusion study, blood pressure at the time of the perfusion study, and blood pressure lowering treatments. Results: Five patients (four women, median age 66 years) were included. Causes of PRES were acute hypertension (n = 3), perioperative blood pressure fluctuations, and treatment with pazopanib. Four patients had chronic hypertension. Presenting symptoms were encephalopathy (n = 5), focal neurological symptoms (n = 4), and seizures (n = 2). All patients underwent computed tomography (CT) perfusion performed within 12 h of symptoms onset. All but one patient was hypertensive at the time of CT perfusion. Scans showed diffuse cerebral hypoperfusion, more pronounced in the corona radiata and areas with brain edema. No patient had critical cerebral ischemia or arterial vasoconstriction on CT angiogram. Conclusions: Patients with PRES can have cerebral hypoperfusion despite severe hypertension. A perfusion study in the acute setting may be helpful to better understand the perfusion status and guide blood pressure treatment.