What are the current treatment recommendations for a patient diagnosed with Posterior Reversible Encephalopathy Syndrome (PRES)?

Management of Posterior Reversible Encephalopathy Syndrome (PRES)

Diagnosis

PRES is diagnosed by MRI showing T2-weighted or FLAIR hyperintensities in bilateral parietal-occipital lobes, predominantly affecting white matter, in patients presenting with acute neurological symptoms. 1

Clinical Presentation

• Patients present with altered consciousness, visual disturbances, headaches, and seizures 1
• Confusion occurs in 71% of cases, seizures in 58%, and headache in 48% 2
• Additional symptoms include blurred vision, vomiting, and focal neurological deficits 3, 4

Diagnostic Imaging

• MRI is the gold standard and mandatory for diagnosis - it shows increased signal intensity on T2-weighted or FLAIR sequences in posterior brain regions 1, 5
• CT scan has significant limitations with low tissue contrast resolution and may appear completely normal in early PRES 5
• In one study, 37% of patients with both MRI and CT had normal CT concurrent with PRES visible on MRI 2
• The optimal MRI protocol includes T2-weighted/FLAIR sequences, DWI with ADC maps to confirm vasogenic edema, and T2* GRE or SWI sequences to detect microhemorrhages 5

Immediate Management Algorithm

Step 1: Discontinue Offending Agent (CRITICAL)

Immediately discontinue the triggering medication - this is the cornerstone of treatment and typically leads to complete resolution within 3-5 days. 1, 6

• Common triggers include chemotherapy (particularly bevacizumab), immunosuppressants (especially cyclosporine and tacrolimus), and targeted therapies 1, 2
• In cancer patients, 55% received chemotherapy or targeted therapy within the month preceding PRES 2
• Complete clinical resolution occurs with discontinuation of calcineurin inhibitors like tacrolimus 6

Step 2: Blood Pressure Control (ESSENTIAL)

Implement very stringent blood pressure control with gradual reduction to avoid cerebral hypoperfusion - target systolic BP below 140 mmHg. 1, 4

• This is the primary therapeutic intervention alongside agent discontinuation 1
• Monitor blood pressure frequently during the acute phase 1
• Avoid rapid reduction that could cause cerebral hypoperfusion 1

Step 3: Seizure Management

Administer antiepileptic treatment for patients who develop seizures; consider prophylactic anticonvulsants in high-risk patients with significant neurological deficits. 1

• Use lorazepam 0.05 mg/kg (maximum 1 mg per dose IV every 8 hours) for acute symptomatic treatment 1
• Control seizures with a single anti-epileptic agent in most cases 3
• Successful anticonvulsant taper is achieved in 51% of patients after recovery 2

Step 4: Supportive Care Measures

• Elevate 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 with IV forms if swallowing is impaired 1
• Avoid medications that cause CNS depression 1
• Correct electrolyte imbalances, particularly hyponatremia, and monitor renal function 1, 3

Step 5: Neurological Consultation

Obtain neurology consultation for comprehensive neurological assessment and management guidance. 1

• Consider additional diagnostic workup including fundoscopic exam for papilledema, EEG if seizures are suspected, and lumbar puncture with opening pressure if indicated 1

Prognosis and Recovery

Complete spontaneous remission occurs in most cases without sequelae - 84% of patients return to neurologic baseline at a median of 7.5 days from onset. 2

• Most patients recover completely within 3-5 days without neurological sequelae 1, 7
• Neurological symptoms typically normalize within 48 hours, and neuroradiological findings return to normal within 2 weeks 4
• Early detection and management are key factors for rapid recovery and good outcomes 1

Chemotherapy Rechallenge

Chemotherapy rechallenge is often possible and was successfully attempted in 41% of patients without recurrent PRES. 2

• This decision should be made carefully after complete resolution of symptoms 2
• Consider alternative agents if the offending medication was clearly identified 6, 4

Common Pitfalls to Avoid

• Failure to obtain MRI: CT may be completely normal while MRI shows characteristic PRES findings - do not rely on CT alone 5, 2
• Failure to discontinue the triggering agent: This is the most critical error and can lead to prolonged illness and permanent neurological deficits 1, 6
• Overly aggressive blood pressure reduction: Gradual reduction is essential to avoid cerebral hypoperfusion 1
• Missing concomitant conditions: Evaluate for sepsis, metabolic disturbances, and in immunosuppressed patients, perform stool examination for parasitosis 1, 4
• Delayed diagnosis: Vague symptomatology may delay recognition - maintain high clinical suspicion in patients on immunosuppressants or chemotherapy presenting with headache, visual changes, altered mentation, or seizures 6

Special Populations

Cancer Patients

• Recent chemotherapy, particularly bevacizumab, is common in cancer patients with PRES 2
• Solid tumors (71%) are more common than hematologic malignancies 2
• PRES may follow allogeneic stem cell transplantation 2

Transplant Recipients

• PRES occurs with calcineurin inhibitors (tacrolimus, cyclosporine) and other immunosuppressants 1, 6, 4
• Consider changing immunosuppression regimen (e.g., mycophenolate mofetil to everolimus) after resolution 4

Patients with Renal Disease

• Underlying kidney disease even without immunosuppressive agents can cause PRES 8
• Monitor for nephrotic syndrome and maintain strict blood pressure control 8