What are the recommended guidelines for managing posterior reversible encephalopathy syndrome (PRES)?

Management of Posterior Reversible Encephalopathy Syndrome (PRES)

Immediate Management Priorities

The cornerstone of PRES management is immediate identification and discontinuation of the offending agent combined with stringent blood pressure control, which leads to complete spontaneous remission in most cases without sequelae. 1

Step 1: Identify and Remove Triggering Factors

• Immediately discontinue any precipitating medications including immunosuppressants (particularly cyclosporine), chemotherapy agents, biotherapy, or other vasoactive drugs to prevent further endothelial injury and progression. 1, 2
• Common triggers requiring immediate cessation include anticancer therapy, allogenic stem-cell transplantation medications, solid organ transplantation immunosuppression, and anti-TNF therapies like infliximab. 1
• For patients on anti-amyloid monoclonal antibodies (Alzheimer's therapy), recognize that amyloid-related imaging abnormalities (ARIA) can mimic PRES and require treatment discontinuation. 1

Step 2: Blood Pressure Management

• Implement very stringent blood pressure control with gradual reduction as the primary therapeutic intervention, avoiding rapid drops that could cause cerebral hypoperfusion. 1, 3
• Monitor blood pressure frequently during the acute phase, targeting a controlled reduction rather than normalization in the first 24 hours. 1
• The goal is gradual blood pressure lowering, particularly when blood pressure is markedly elevated and cerebral autoregulation has failed. 1

Step 3: Seizure Management and Prophylaxis

• Administer antiepileptic treatment immediately for any patient who develops seizures, using benzodiazepines as first-line therapy (lorazepam 0.05 mg/kg, maximum 1 mg per dose IV every 8 hours). 1
• Consider prophylactic anticonvulsants in high-risk patients with significant neurological deficits to prevent further brain injury, though routine prophylaxis is not recommended for all patients. 1
• Obtain EEG if non-convulsive status epilepticus is suspected, particularly in patients with persistent altered consciousness. 1

Step 4: Supportive Care Measures

• Elevate the head of bed to 30 degrees to reduce intracranial pressure. 1
• Implement aspiration precautions and IV hydration for patients with altered consciousness. 1
• Withhold oral intake and assess swallowing function, substituting all oral medications and nutrition with IV forms if swallowing is impaired. 1
• Avoid medications that cause CNS depression; if sedation is required, use low doses of lorazepam or haloperidol with careful monitoring. 1
• Correct electrolyte imbalances (particularly hyponatremia, hypomagnesemia) and monitor renal function closely. 1

Critical Care Level Decisions

• Transfer patients with grade 2 or higher neurological deficits to an ICU or neuro-ICU for optimal monitoring and management. 1
• Consider endotracheal intubation and mechanical ventilation for patients with severe altered consciousness (grade III-IV encephalopathy) to protect the airway. 1
• Perform comprehensive neurological assessment and grading at least twice daily, including cognitive evaluation and motor-strength testing. 1

Special Population Management

Immunotherapy-Related PRES

• Administer high-dose corticosteroids (dexamethasone 10 mg IV every 6 hours or methylprednisolone 1 mg/kg IV every 12 hours) for grade 3-4 neurotoxicity associated with immune-checkpoint inhibitor therapy. 1
• Provide antifungal prophylaxis when prolonged high-dose steroid therapy is required. 1
• Follow Society for Immunotherapy of Cancer guidelines for immune-related adverse events. 1

PRES During ECMO

• Obtain immediate neurological consultation for any acute neurological changes in ECMO patients. 1

Diagnostic Confirmation

Neuroimaging

• MRI is the gold standard for diagnosis, showing T2-weighted or FLAIR hyperintensities in bilateral parietal-occipital lobes, predominantly affecting white matter. 1, 2
• MRI protocol should include T2-weighted and FLAIR sequences, DWI with calculated ADC maps to confirm vasogenic edema, and T2* GRE or SWI sequences to detect microhemorrhages. 4
• CT scan is useful to exclude intracranial hemorrhage when MRI is not immediately available, but has limited sensitivity (may appear normal in up to 37% of confirmed cases). 1, 4

Additional Diagnostic Workup

• Obtain neurology consultation for comprehensive neurological assessment and management guidance. 1
• Consider fundoscopic exam to assess for papilledema. 1
• Perform lumbar puncture with opening pressure measurement if indicated to exclude infectious or inflammatory causes. 1
• Blood tests should include electrolytes, glucose, calcium, complete blood count, inflammatory markers, blood urea, and creatinine. 4

Monitoring During Recovery

• Obtain neurological assessments every 4-6 hours until complete resolution of symptoms. 5
• Prevent and treat fever aggressively during the recovery phase. 6
• Most patients recover completely within 3-5 days without neurological sequelae if treatment is instituted promptly. 5, 7

Common Pitfalls to Avoid

• Failure to identify and discontinue the triggering agent is the most critical error, leading to prolonged illness and increased risk of permanent neurological damage. 1, 7
• Delaying diagnosis and treatment can result in death or irreversible neurological sequelae, including chronic epilepsy. 3, 7
• Missing concomitant conditions such as sepsis, metabolic disturbances, or infectious encephalitis that may complicate management. 1
• Rapid blood pressure reduction causing cerebral hypoperfusion rather than gradual controlled lowering. 1
• Relying solely on CT imaging when MRI is available, as CT has poor sensitivity for early PRES. 4

Differential Diagnoses to Exclude

• Cerebral amyloid angiopathy-related inflammation (CAA-ri/ABRA), particularly in patients on anti-amyloid monoclonal antibody therapy. 4
• Acute ischemic stroke in posterior circulation, which shows restricted diffusion on DWI unlike PRES. 4
• Infectious or autoimmune meningoencephalitis, requiring CSF analysis for exclusion. 4
• Metabolic encephalopathies (uremic, hypoglycemic, thyroid disorders). 4
• Subarachnoid hemorrhage, particularly when sulcal FLAIR hyperintensity is present. 4