What is Posterior Reversible Encephalopathy Syndrome (PRES)?

From the Guidelines

PRES syndrome should be managed with immediate discontinuation of the offending agent, such as ifosfamide, and symptomatic treatment, including correction of electrolytes and administration of benzodiazepines, to prevent further neurological deterioration and promote full recovery. The clinical presentation of PRES syndrome typically includes acute neurological deficits, such as altered consciousness, visual disturbances, blindness, headaches, and seizures, as noted in the study by 1.

Key Considerations

• The pathophysiology of PRES involves disruption of the blood-brain barrier due to endothelial injury by abrupt blood pressure changes, leading to typical vasogenic edema, as described in the study by 1.
• Treatment is primarily symptomatic and focused on addressing the underlying cause, with the goal of achieving a spontaneous full remission without sequelae, as reported in the study by 1.
• The use of benzodiazepines for symptomatic treatment is recommended, as mentioned in the study by 1.

Diagnostic Approach

• Brain MRI with T2-weighted and FLAIR sequences is the diagnostic test of choice, showing characteristic white matter edema in posterior cerebral regions.
• Prompt diagnosis and treatment are crucial for preventing long-term neurological damage and promoting complete recovery.

Management Strategies

• Discontinuation of the offending agent, such as ifosfamide, is essential in managing PRES syndrome, as noted in the study by 1.
• Correction of electrolytes and administration of benzodiazepines are important components of symptomatic treatment, as mentioned in the study by 1.
• Aggressive blood pressure control may be necessary in some cases, particularly if hypertension is present, to reduce the risk of further neurological deterioration.

From the Research

Definition and Symptoms of PRES

• Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder characterized by variable symptoms, including visual disturbances, headache, vomiting, seizures, and altered consciousness 2.
• The symptoms of PRES can develop quickly and are often indistinguishable from eclampsia 3.
• Seizures can occur secondary to cerebral edema and mark later stages of the disease 3.

Pathophysiology and Risk Factors

• The exact pathophysiology of PRES has not been completely explained, but hypertension and endothelial injury seem to be almost always present 2.
• Endothelial dysfunction combined with hypertension is thought to cause disruption in the blood-brain barrier, resulting in cerebral edema 3.
• Risk factors for PRES include hypertension, pre-eclampsia, eclampsia, acute kidney injury, and numerous drugs, such as antineoplastics, immunosuppressants, and drugs that can increase blood pressure or fluid and sodium retention 4.
• Adrenal insufficiency has also been identified as a possible novel precipitant of the central variant of PRES, with labile blood pressure causing rapid alterations in cerebral perfusion pressure (CPP) precipitating PRES 5.

Diagnosis and Treatment

• Diagnosis of PRES is typically made through imaging studies, such as computer tomography (CT) and magnetic resonance imaging (MRI) scans, which show symmetrical white matter abnormalities suggestive of edema, commonly in the posterior parieto-occipital regions of the cerebral hemispheres 2.
• Treatment of PRES is aimed at reducing blood pressure with antihypertensive therapy and seizure control with magnesium sulfate 3.
• Nifedipine, labetalol, and hydralazine are commonly used as first-line therapies in preeclampsia, with nifedipine being the most effective drug to reduce blood pressure when single dose administration is used, and hydralazine being the most effective when the drug administration is maxed up to three doses within 60 minutes with 20 minutes interval 6.
• Early diagnosis and treatment are crucial to prevent further complications and permanent brain damage 2, 3.