What is the recommended immediate treatment for posterior reversible encephalopathy syndrome (PRES)?

Treatment of Posterior Reversible Encephalopathy Syndrome (PRES)

Immediately discontinue the offending agent and implement stringent blood pressure control with gradual reduction, while treating seizures if present—these three interventions form the cornerstone of PRES management and should be initiated simultaneously. 1

Immediate Management Algorithm

Step 1: Identify and Remove Triggering Factors

• Discontinue the causative agent immediately (anticancer therapy, immunosuppressants, cyclosporine, or other vasoactive drugs) to prevent further endothelial injury and progression of PRES 1, 2
• Common triggers include hypertensive crisis, pre-eclampsia/eclampsia, renal impairment, immunosuppressive therapy (particularly calcineurin inhibitors), high-dose chemotherapy, solid organ or bone marrow transplantation, and autoimmune diseases 1, 3

Step 2: Blood Pressure Management (Primary Therapeutic Intervention)

• Implement very stringent blood pressure control with gradual reduction as the cornerstone of management—this is critical to avoid cerebral hypoperfusion while preventing further blood-brain barrier disruption 1, 2
• The rate of blood pressure reduction matters more than achieving specific target values; avoid precipitous drops that could cause cerebral ischemia 1
• Monitor blood pressure frequently during the acute phase, ideally in a neurointensive care unit setting 3

Critical pitfall to avoid: Overly aggressive blood pressure reduction can cause cerebral hypoperfusion in patients whose autoregulation is already compromised. The goal is gradual normalization, not rapid correction. 1

Step 3: Seizure Management

• Administer antiepileptic treatment immediately for patients who develop seizures, using benzodiazepines (lorazepam 0.05 mg/kg IV, maximum 1 mg per dose every 8 hours) for acute symptomatic control 1
• Consider prophylactic anticonvulsants in high-risk patients with significant neurological deficits to prevent further brain injury 1
• Treat status epilepticus aggressively per institutional protocols if it develops 4, 3
• Obtain EEG if there is suspicion of non-convulsive seizure activity, particularly in patients with altered consciousness 1

Step 4: Supportive Care Measures

• Elevate the head of bed to 30 degrees to help reduce intracranial pressure 1
• Implement aspiration precautions and provide intravenous hydration for patients with altered consciousness 1
• Withhold oral intake and assess swallowing function; substitute all oral medications and nutrition with IV forms if swallowing is impaired 1
• Avoid medications that cause CNS depression (except those needed for seizure treatment), using only low doses of lorazepam or haloperidol with careful monitoring if sedation is required 1

Step 5: Electrolyte and Metabolic Management

• Correct electrolyte imbalances if present, particularly hyponatremia, hypomagnesemia, and hypercalcemia 1
• Monitor renal function closely, especially in patients with pre-existing renal impairment 1

Neurological Monitoring and Assessment

• Conduct neurological assessment and grading at least twice daily, including cognitive assessment and evaluation for motor weakness 5
• Obtain neurology consultation for comprehensive neurological assessment and management guidance 1
• Consider fundoscopic exam to assess for papilledema or signs of elevated intracranial pressure 1
• Perform lumbar puncture with opening pressure measurement if intracranial pressure elevation is excluded and diagnosis remains uncertain 1

Diagnostic Confirmation

• MRI with FLAIR sequences is the gold standard for diagnosis, showing increased signal intensity in posterior brain regions (typically bilateral parieto-occipital lobes) representing vasogenic edema 1, 2, 6
• CT scan can be useful to exclude intracranial hemorrhage when MRI is not immediately feasible, but has limited sensitivity (may appear normal in up to 37% of confirmed cases) 1
• If CT is normal but clinical symptoms suggest PRES, perform MRI promptly as it is far more sensitive for detecting characteristic lesions 1

Level of Care

• Transfer to ICU or neurointensive care unit is recommended for optimal monitoring and management, particularly for patients with grade 2 or higher neurological deficits 5, 3
• Consider mechanical ventilation for airway protection in patients with severe altered consciousness 5

Special Clinical Scenarios

PRES Associated with Immunotherapy

• Follow Society for Immunotherapy of Cancer guidelines for immune-related adverse events 1
• High-dose corticosteroids (dexamethasone 10 mg IV every 6 hours or methylprednisolone 1 mg/kg IV every 12 hours) may be indicated for grade 3-4 neurotoxicity 5
• Consider antifungal prophylaxis in patients receiving prolonged steroid therapy 5

PRES in Pregnancy (Eclampsia/Pre-eclampsia)

• Magnesium sulfate should be administered for seizure prophylaxis in eclampsia cases 4
• Delivery may be necessary to resolve the underlying trigger 4

VZV-Associated PRES

• Consider VZV reactivation as a trigger, especially in immunocompromised patients, even without significant hypertension 1
• Antiviral therapy may be warranted if VZV infection is confirmed 1

Common Pitfalls to Avoid

• Failure to identify and discontinue the triggering agent is the most critical error—this can lead to prolonged illness, irreversible neurological sequelae, or death 1, 2, 4
• Missing concomitant conditions (sepsis, metabolic disturbances, infection) that may complicate management 1
• Overlooking the multifactorial nature of PRES—most cases involve multiple simultaneous insults creating additive endothelial stress 1
• Delaying diagnosis and treatment, which significantly increases risk of permanent neurological damage 2, 4, 3

Prognosis and Follow-up

• Complete spontaneous remission occurs in most cases without sequelae when early detection and appropriate management are implemented 1, 7
• Most patients recover completely within 3-5 days, with neurological and radiological abnormalities resolving after appropriate treatment 4, 3
• However, delayed diagnosis and treatment may result in death or irreversible neurological deficits, including chronic epilepsy 2, 4
• Consider repeat neuroimaging (MRI preferred) to document resolution of vasogenic edema and exclude complications 1