What is the management approach for a patient with posterior reversible encephalopathy syndrome (PRES), presenting with symptoms such as headache, confusion, seizures, and visual disturbances, and a history of hypertension, eclampsia, immunosuppressive therapy, renal disease, or recent chemotherapy?

Management of Posterior Reversible Encephalopathy Syndrome (PRES)

The immediate management of PRES requires stringent blood pressure control with gradual reduction (target MAP reduction of 20-25%), discontinuation of the offending agent, and antiepileptic treatment for seizures, with most patients achieving complete recovery within 2 weeks. 1

Immediate Actions (First Hour)

1. Discontinue Triggering Agents

• Stop all potentially causative medications immediately, including immunosuppressants (especially cyclosporin), chemotherapy agents, or other cytotoxic drugs 1, 2
• Common triggers include calcineurin inhibitors, high-dose antineoplastic therapy, allogenic stem-cell transplantation medications, and immunosuppressive agents 1

2. Blood Pressure Management

• Implement very stringent blood pressure control as the cornerstone of treatment 1, 2
• Target gradual reduction: decrease mean arterial pressure (MAP) by 20-25% over several hours to avoid cerebral hypoperfusion 1, 2
• For hypertensive encephalopathy specifically, achieve MAP reduction of 20-25% immediately 1
• Monitor blood pressure frequently during the acute phase to prevent overly rapid reduction that could worsen cerebral perfusion 2

3. Seizure Control

• Administer antiepileptic drugs for active seizures: benzodiazepines (lorazepam 0.05 mg/kg, maximum 1 mg per dose IV every 8 hours) are first-line 1, 2
• Consider prophylactic anticonvulsants in high-risk patients with significant neurological deficits 2
• Avoid medications that cause excessive CNS depression in patients with altered consciousness 2

Supportive Care Measures

Metabolic Management

• Correct electrolyte imbalances immediately, particularly sodium disturbances which can exacerbate encephalopathy 1
• Monitor renal function closely, especially in patients with pre-existing renal impairment 1

Neurological Precautions

• Elevate head of bed to 30 degrees to reduce intracranial pressure 2
• Implement aspiration precautions for patients with altered consciousness 2
• Withhold oral intake and assess swallowing function; substitute all oral medications with IV forms if swallowing is impaired 2
• Provide intravenous hydration while maintaining careful fluid balance 2

Diagnostic Confirmation

Imaging

• MRI with T2-weighted or FLAIR sequences is the gold standard, showing hyperintensities in bilateral parietal-occipital lobes predominantly affecting white matter 1, 2, 3
• CT scan is useful to exclude intracranial hemorrhage when MRI is not immediately available, but has limited sensitivity (may be normal in up to 37% of early PRES cases) 2, 3
• Include DWI sequences to confirm vasogenic (not cytotoxic) edema 3
• T2* GRE or SWI sequences help detect microhemorrhages 3

Additional Workup

• Obtain neurology consultation for comprehensive assessment 2
• Fundoscopic exam to assess for papilledema 2
• EEG if seizures are suspected or to rule out non-convulsive status epilepticus 2
• Consider lumbar puncture with opening pressure measurement if diagnosis is uncertain 2

Risk Factors to Identify

The following conditions predispose to PRES and should be documented 1:

• Pre-existing arterial hypertension
• Renal impairment or renal failure
• Autoimmune diseases
• High-dose antineoplastic therapy
• Allogenic stem-cell transplantation
• Solid organ transplantation
• Immunosuppression (particularly cyclosporin)
• Eclampsia or pre-eclampsia

Prognosis and Follow-Up

• PRES is usually reversible with appropriate supportive management within 2 weeks, with spontaneous full remission in almost all cases without sequelae 1, 2
• However, severe forms can result in long-standing morbidity and mortality 4
• Factors associated with poor outcomes include altered sensorium, hypertensive etiology, hyperglycemia, longer time to control causative factor, elevated C-reactive protein, coagulopathy, extensive cerebral edema, and hemorrhage on imaging 4

Reintroduction of Causative Therapy

• Reintroduction of prior anticancer therapy or immunosuppression must be decided on an individual basis, weighing the risk of PRES recurrence against the need for continued treatment 1
• This decision requires careful consideration of the underlying condition's severity and alternative treatment options 1

Critical Pitfalls to Avoid

• Failure to discontinue the triggering agent promptly leads to prolonged illness and increased complications 1, 2
• Overly aggressive blood pressure reduction can cause cerebral hypoperfusion and worsen outcomes 1, 2
• Missing concomitant conditions (sepsis, metabolic disturbances, CNS infection) that complicate management 2
• Assuming all cases are benign—severe forms with hemorrhage or extensive edema require aggressive care 4
• Overlooking that multiple simultaneous insults (hypertension + immunosuppression + renal failure) create additive endothelial stress 5