Mesial Temporal Sclerosis as Late Consequence of Posterior Reversible Encephalopathy Syndrome in Pediatric Hemato-oncologic Patients

Objectives: Drug resistant epilepsy has rarely been reported following posterior reversible encephalopathy syndrome (PRES), with few cases of mesial temporal sclerosis (MTS). The aim of this study was to report clinical and neuroimaging features of MTS subsequent to PRES in hemato-oncologic/stem cell transplanted children. Materials and Methods: Among 70 children treated in 2 pediatric hemato-oncologic Italian centers between 1994 and 2018 and presenting an episode of PRES, we retrospectively identified and analyzed a subgroup of patients who developed epilepsy and MTS. Results: Nine of 70 patients (12.8%) developed post-PRES persistent seizures with magnetic resonance imaging evidence of MTS. One patient died few months after MTS diagnosis, because of hematologic complications; the remaining 8 patients showed unprovoked seizures over time leading to the diagnosis of epilepsy, focal in all and drug resistant in 4. At PRES diagnosis, all patients with further evidence of epilepsy and MTS suffered of convulsive seizures, evolving into status epilepticus in 3. In 3 patients a borderline cognitive level or intellectual disability were diagnosed after the onset of epilepsy, and 2 had behavioral problems impacting their quality of life. Conclusions: MTS and long-term focal epilepsy, along with potential cognitive and behavioral disorders, are not uncommon in older pediatric patients following PRES.