Posterior reversible encephalopathy syndrome (PRES)

OVERVIEW

• Posterior reversible encephalopathy syndrome (PRES) is a syndrome of ‘cephalgia, convulsions, confusion, and vision loss’ (CCCV) typically in the context of severe hypertension

PATHOPHYSIOLOGY

• poorly understood
• classically affects the posterior circulation of the brain
• combination of endothelial damage, impaired auto-regulation and increased cerebral perfusion pressure
• leads to hyperperfusion with resultant disruption of the blood brain barrier causing vasogenic oedema

CLINICAL MANIFESTATIONS

• headache
• seizures
• confusion
• vision loss
• hypertension
• risk factors

RISK FACTORS

• severe hypertension
• eclampsia
• renal failure
• immunosuppressive medications such as tacrolimus and cyclosporine
• hypomagnesemia
• post-transplant

INVESTIGATIONS

• MRI brain —  classically  bilateral hyperintense densities in the parieto-occipital regions on T2 weighted images
• analogous finds may be seen on a CT head

MANAGEMENT

• Control hypertension
• Treat seizures
• Treat underlying cause
  — IV magnesium and emergent delivery if pregnat
• Stop precipitating medications (e.g tacrolimus, cyclosporin)

PROGNOSIS

• partial to complete recovery is usual with appropriate treatment
• residual neurological and visual deficits may persist

References and Links

• Radiopaedia — Posterior Reversible Encephalopathy Syndrome (PRES)
• Moratalla MB. Posterior Reversible Encephalopathy Syndrome. Emerg Med J. 2010 Jul;27(7):547 Pubmed PMID: 20584957