To identify distinct clinical and radiologic features in posterior reversible encephalopathy syndrome (PRES) specifically associated with pediatric brain tumors (PBT).

PRES is a potentially severe condition with abrupt onset of neurologic symptoms, often precipitated by uncontrolled hypertension or immunomodulatory agents. PRES in PBT is rare, with fewer than 20 reported cases, and its unique clinical and radiologic characteristics are underreported.

We conducted a single center retrospective cohort study of all participants under age 18 from 1/1/2000 to 1/1/2025 diagnosed with PRES, and a comprehensive literature review for published cases of PRES in PBT. We compared clinical and radiologic features for PBT-PRES and non-PBT PRES cases using descriptive analyses, Fisher’s Exact Test for categorical variables and Wilcoxon rank-sum test for continuous variables. A p-value of <0.05 was considered significant.

Twenty PBT-PRES cases (5 from current cohort, 15 from literature review, median age 9 years, IQR=6.5-12.5, 75% male) and 50 non-PBT PRES cases from the current cohort (median age 10.4 years, IQR=8.25-13, 36% male) were included. In PBT-PRES, 80% had posterior fossa tumors, and 66% developed PRES within 30 days of primary or subsequent resection. PBT-PRES had a higher proportion of males (83.3% vs 36%, p=<0.001), ongoing neurologic sequelae (50% vs 6%, p=<0.001), brainstem involvement (22.2% vs 4.1%, p=0.041), hemorrhagic conversion (60% vs 14.3%, p=0.0049), disease necessitating intubation (75% vs 29%, p=0.017) and 90 day mortality (16.7% vs 0%, p=0.016) compared with non-PBT, but lower presentation with isolated altered mental status (63.2% vs 88%, p=0.035). There were no significant differences in highest systolic blood pressure, length of admission, ICU admission, or supratentorial pattern on imaging.

PBT-PRES patients commonly present perioperatively and with a more severe neurologic phenotype with hemorrhagic conversion, brainstem involvement, and increased mortality compared with non-PBT PRES cases. Further studies with larger samples are needed to confirm these findings.