Posterior reversible encephalopathy syndrome (PRES)

Reviewed and revised [last-modified]

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

The pathophysiology of PRES is 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

Specfic therapy

• Control hypertension
• Treat seizures
• Treat underlying cause
  • e.g. IV magnesium and emergent delivery if pregnant
• 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

Journal articles

• Moratalla MB. Posterior Reversible Encephalopathy Syndrome. Emerg Med J. 2010 Jul;27(7):547 [pubmed]

FOAM and web resources

• Radiopaedia — Posterior Reversible Encephalopathy Syndrome (PRES)