What is Posterior Reversible Encephalopathy Syndrome (PRES)?

From the Guidelines

Posterior Reversible Encephalopathy Syndrome (PRES)

PRES is a neurological disorder characterized by acute neurological deficits, including altered consciousness, visual disturbances, blindness, headaches, and seizures, often due to disruption of the blood-brain barrier caused by endothelial injury from abrupt blood pressure changes, leading to vasogenic edema 1.

• The syndrome typically presents with symptoms such as:
  • Altered consciousness
  • Visual disturbances
  • Blindness
  • Headaches
  • Seizures
• Treatment is primarily symptomatic and involves:
  • Discontinuation of the offending agent, such as ifosfamide
  • Correction of electrolyte imbalances
  • Symptomatic treatment with medications like benzodiazepines 1
• In most cases, spontaneous full remission can be expected without sequelae, emphasizing the importance of prompt recognition and management of PRES 1.

From the Research

Definition and Characteristics of Posterior Reversible Encephalopathy Syndrome (PRES)

• Posterior Reversible Encephalopathy Syndrome (PRES) is a clinical entity characterized by acute neurological symptoms such as severe headache, seizures, and visual disturbance, and by typical reversible lesions on brain magnetic resonance (MR) images 2.
• PRES is a clinicoradiologic disorder characterized by seizures, headache, altered mental status, and visual disturbances, and is often associated with acute hypertension 3.
• The syndrome is typically reversible if recognized on presentation and promptly and appropriately managed 3.

Pathophysiology and Causes

• The pathophysiology of PRES is theorized to involve dysfunction of cerebral autoregulation leading to vascular leak or endothelial dysfunction resulting in vasogenic edema 3.
• Hypertension and endothelial injury seem to be almost always present in PRES 4.
• PRES is associated with a variety of factors, including acute rise in blood pressure, renal disease, preeclampsia/eclampsia, and immunosuppressive therapy 3.

Clinical Presentation and Diagnosis

• Clinical symptoms of PRES include headache, altered mental status, seizures, and visual disturbances 2, 3, 5.
• Magnetic resonance imaging (MRI) is the recommended neuroimaging modality for diagnosis, and may demonstrate cerebral vasogenic edema, most often in the distribution of the posterior circulation 3.
• Computed tomography (CT) scans may also show symmetrical white matter abnormalities suggestive of edema, commonly but not exclusively in the posterior parieto-occipital regions of the cerebral hemispheres 4.

Management and Treatment

• Treatment involves management of seizures, control of blood pressure if elevated, and treatment of any underlying trigger 3.
• Early diagnosis and prompt control of blood pressure or removal of precipitating factors and treatment of epileptic seizures or status epilepticus are crucial to prevent irreversible neurological sequelae 5.
• The management is chiefly concerned with stabilization of the patient, adequate and prompt control of blood pressure, prevention of seizures, and timely caesarean section in obstetric cases with pre-eclampsia/eclampsia 4.