Status epilepticus as a main manifestation of posterior reversible encephalopathy syndrome after pediatric hematopoietic stem cell transplantation

Abstract

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a severe neurological complication after pediatric allogeneic hematopoietic stem cell transplantation (allo-HSCT). Seizures are a common manifestation of PRES. Status epilepticus (SE) is a potentially life-threatening event rarely described in this condition. The aim of this study was to describe the clinical and electroencephalographic features of SE as a manifestation of PRES in children after allo-HSCT. PROCEDURE: We retrospectively identified episodes of SE as a consequence of PRES out of 211 children who received allo-HSCT in the period January 2000 to June 2008. RESULTS: PRES was diagnosed in 11 patients. We identified 12 episodes of SE associated to PRES in 10 patients. Nonconvulsive SE (NCSE) involving posterior regions of the brain (confirmed by EEG monitoring) was observed in four cases; convulsive SE (CSE) was observed in eight cases. Gaze deviation, oculoclonic movements, nystagmus, and altered mental status were the main clinical signs during NCSE and preceded CSE in 5/8 cases. Most patients needed intensive care management. A complete normalization of neurological examination and EEG pattern was observed in all patients after SE and withdrawal of causative agent. Follow-up MRI showed complete resolution of brain edema in all patients. CONCLUSIONS: Our experience shows that SE is more frequent than previously reported and is often the main manifestation of PRES after pediatric allo-HSCT. Looking for suggestive clinical signs as well as routine use of EEG monitoring may allow prompt recognition of SE and therapy of both SE and PRES.