Characteristics and Outcomes of Critically Ill Pediatric Patients with Posterior Reversible Encephalopathy Syndrome.

Background/objective: Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiologic entity, typically manifesting as reversible neurological symptoms and signs of white matter edema on magnetic resonance imaging. PRES has been widely described in adults. Studies of PRES in children are mostly limited to case series and case controls.

Methods: Retrospective chart review of patients under 21 years with PRES admitted at a tertiary children's hospital from 2011 to 2016. They were compared to controls matched for age and mortality risk using the Pediatric Index of Mortality-2 score.
 RESULTS: Sixteen cases of PRES were identified in 13 patients (ages 5-17 years, 46% male). PRES presented with altered mental status (75%), seizures (77%), headache (31%), and vision changes (23%). In patients who recovered (n = 11), median days to symptom resolution was three (range 1-8). PRES patients had a higher mortality rate (15% vs. 5%, p < 0.05) and higher mean length of stay (13.1 vs. 4.6 days) and were more likely to have autoimmune disease (p < 0.05), immunosuppression (p < 0.05), and anemia (p < 0.05). No PRES patients were diagnosed with epilepsy by last known follow-up, and all of whom had been started on an antiepileptic drug were discontinued within 13 months. Sepsis was suspected in 53% of PRES patients and 59% of controls (p = 1.00). All PRES patients had stage II hypertension, versus 41% of controls (p < 0.05). Average creatinine in PRES was 2.35 mg/dL compared to 0.90 mg/dL in controls (p < 0.05). PRES patients had lower serum calcium (p < 0.05). After correcting for albumin, no association between PRES and hypocalcemia remained. PRES patients had a higher length of stay (13.1 vs. 4.6 days, p < 0.05) and mortality rate (15% vs. 3%, p < 0.05).

Conclusions: Immunosuppression, autoimmune disease, renal insufficiency, anemia, and hypertension are associated with PRES after controlling for mortality risk in critically ill children. There was no association between corrected serum calcium and sepsis with PRES.