Posterior reversible encephalopathy syndrome (PRES)

FACTS

  • epidemiology: can occur in all ages but more likely in adults, F > M, Black > White/Hispanic
  • pathophysiology: acute HTN, systemic inflammation, endothelial dysfunction disrupt cerebral autoregulation

HPI

universal ROS, with emphasis on
  • seizures
  • encephalopathy
  • HA
  • visual disturbances
Risk factors
  • acute HTN,
  • eclampsia, pregnancy, HELLP, post-partum status,
  • autoimmune disease (SLE, Crohn’s, autoimmune hemolytic anemia, hypothyroidism, RA, Sjogren’s, primary sclerosing cholangitis),
  • renal failure,
  • sepsis, hematological disorders (TTP)
  • electrolyte disturbances
  • medicinal toxins (tacrolimus, anti-angiogenic drugs e.g. bevacizumab, tyrosine kinase inhibitors, anti-CD19 CAR-T therapies)
  • drugs: cocaine, amphetamine, synthetic cannabinoids (via acute HTN, direct neurotoxic effects, endothelial dysfunction)
From Rabinestein et al 2025
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PHYSICAL EXAM

universal neuro exam
  • include vision assessment
  • include speech assessment (aphasia can occurr)

IMAGING

MRI Brain without contrast
  • FLAIR: symmetric subcortical vasogenic edema affecting parieto-occipital regions although can be anywhere (frontal lobes, temporal lobes, thalamus, brainstem, BG, cerebellar)
  • DWI: can restrict diffusion
  • T1 + c: can enhance
CT angiography
  • vasoconstriction, especially posteriorly, can be seen (co-occurring RCVS)
CT perfusion
  • can show hyperperfusion or reduced perfusion
 
A/P
Diagnosing PRES (Rabinestein et al 2025)
  • LP: should show elevated protein concentration without pleocytosis
notion image
 
Treatment
  • supportive care
    • AED
    • cEEG if mental status poor or fluctuating
    • mannitol / HTS only if herniation imminent
  • address underlying etiology
    • most patients will get better with blood pressure control
    • remove the triggering medicine
    • delivery of baby/placenta
  • Counsel:
    • in absence of strokes / severe hemorrhage requiring CSF diversion, most will make a full recovery following prompt diagnosis and treatment