What is the management for Posterior Reversible Encephalopathy Syndrome (PRES)?

Management of Posterior Reversible Encephalopathy Syndrome (PRES)

The management of PRES requires immediate discontinuation of the offending agent (if identified), aggressive blood pressure control, and treatment of seizures to prevent permanent neurological damage.

Pathophysiology and Clinical Presentation

PRES is characterized by vasogenic edema primarily affecting the posterior brain regions due to:

• Endothelial injury leading to increased vascular permeability
• Compromise of blood-brain barrier integrity
• Autoregulatory failure with subsequent vasogenic edema 1

Typical clinical manifestations include:

• Acute neurological deficits
• Altered mental status/consciousness
• Visual disturbances or blindness
• Headaches
• Seizures 1, 2

Diagnostic Approach

MRI is the gold standard for diagnosis, showing:

• Hyperintensities on T2-weighted sequences
• Predominant involvement of parieto-occipital lobes
• Greater involvement of white matter than gray matter 1

Brain CT may be used initially to rule out other causes of decreased mental status, though it is less sensitive than MRI 1.

Management Algorithm

1. Address the Underlying Cause

• Discontinue the offending agent (e.g., cyclophosphamide or other immunosuppressants) 1
• Identify and treat other potential causes (preeclampsia/eclampsia, autoimmune disorders) 2

2. Blood Pressure Management

• Control hypertension if present (a common precipitating factor)
• Target gradual reduction to avoid cerebral hypoperfusion 1, 3
• The goal is to lower blood pressure without causing rapid drops that could worsen cerebral perfusion

3. Seizure Management

• Administer antiepileptic treatment for seizures 1
• Benzodiazepines may be used for acute seizure control 1

4. Management of Cerebral Edema

• Elevate head of bed to 30 degrees to decrease hydrostatic pressure 1
• For patients with evidence of cerebral edema or increased intracranial pressure:
  • Hyperosmolar therapy with either:
    • Mannitol: 0.5-1 g/kg IV initially, followed by 0.25-1 g/kg every 6 hours, or
    • Hypertonic 3% saline: 5 ml/kg IV over 15 minutes, followed by 1 ml/kg/hour IV to target serum sodium 150-155 meq/L 1

5. Supportive Care

• Correct electrolyte imbalances 1
• Monitor neurological status closely
• Intensive care unit monitoring for unstable patients 2, 4

Follow-up and Prognosis

• PRES is typically reversible with appropriate management within 2 weeks 1
• Follow-up MRI to assess resolution of lesions is recommended 1
• Early recognition and intervention lead to better outcomes 1, 5

Important Considerations and Pitfalls

• Delayed diagnosis and treatment can lead to permanent neurological sequelae 1, 4

• Poor prognostic factors include:

  • Altered sensorium
  • Extensive cerebral edema
  • Presence of hemorrhage on imaging
  • Delayed control of causative factors 1

• While PRES is generally reversible, some patients may develop chronic epilepsy as a long-term complication 4

• The diagnosis has critical therapeutic and prognostic implications because reversibility depends on prompt control of blood pressure and/or discontinuation of the offending agent 3