Status Epilepticus in Children With Hemophagocytic Lymphohistiocytosis: Literature Review.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder involving systemic inflammation and multi-organ damage, which often affects the central nervous system (CNS). Familial HLH, which is caused by mutations in genes such as PRF1 and UNC13D, impairs the function of cytotoxic cells, leading to uncontrolled immune activation. CNS involvement occurs in 30% to 73% of cases and manifests as seizures, encephalopathy or status epilepticus, which often mimics other neurologic conditions. This article presents the case of a 28-month-old boy with PRF1-related HLH who developed super-refractory status epilepticus during CNS relapse, despite having undergone a prior hematopoietic stem cell transplantation (HSCT). An initial MRI scan revealed diffuse cortical and cerebellar abnormalities, whereas systemic HLH findings emerged later. Treatment included antiseizure medications, immunotherapy and etoposide, but severe neurologic deficits persisted. A review of the literature on 20 pediatric HLH cases presenting with status epilepticus revealed a variety of presentations, including focal, generalized and febrile infection-related epilepsy syndrome (FIRES). Neuroimaging showed white matter lesions, atrophy or diffusion abnormalities, whereas CSF findings ranged from normal to elevated protein and neopterin levels. Mortality was high (45%), with survivors often experiencing cognitive or motor impairments. HLH relapse can initially present with isolated CNS involvement, emphasizing the need for early neuroimaging and cerebrospinal fluid (CSF) analysis in suspected cases. Despite aggressive treatment, outcomes remain poor, highlighting the need for further research into optimal management strategies.