P2.K211: A Beacon of Hope: Innovative Management of Febrile Infection-Related Epilepsy Syndrome (FIRES) with Intrathecal Steroids

Introduction: Febrile Infection-Related Epilepsy Syndrome (FIRES) is an exceedingly rare, catastrophic neurological condition marked by the abrupt emergence of severe seizures in a child without prior neurological issues, following a febrile episode. Occurring in an estimated one in a million children, the etiology of FIRES remains elusive. Diagnosis requires comprehensive evaluation to rule out other causes, and it falls within the spectrum of new-onset refractory status epilepticus (NORSE). The prognosis for FIRES is generally dire, with most survivors facing significant cognitive and motor impairments or intractable epilepsy, while others face a high risk of mortality. This case report sheds light on the complexities of managing FIRES, detailing an extensive ICU stay and a successful intervention with Intrathecal steroids after conventional immunotherapies failed, culminating in a notable recovery.

Case Description: A 5-year-old boy, previously healthy and with a recent history of streptococcal pharyngitis, presented with recurrent seizures leading to hospital admission. Continuous EEG monitoring identified an initial status epilepticus, alongside 20-30 daily generalized subclinical seizures, each lasting 30-40 seconds, often exacerbated by sensory stimuli. Despite extensive treatment attempts, including 11 antiseizure medications at maximum dosages and three anesthetic agents (midazolam, ketamine, and pentobarbital) to achieve EEG burst suppression, seizure control was inadequate. A thorough diagnostic workup, including autoimmune, serological, cultural, CSF, and MRI studies, was largely non-revealing, except for elevated CSF interleukins (IL-2, IL-6, IL-8). Treatments with high-dose corticosteroids, two IVIG courses, anakinra and tocilizumab showed no lasting effects, and dietary ketosis induction had minimal impact on seizure frequency. After comprehensive discussions with a multidisciplinary team, Intrathecal steroid therapy was initiated, resulting in significant improvement and ongoing recovery. Remarkably, the patient has remained seizure-free for over six months and is progressively regaining cognitive, linguistic, and motor skills through dedicated therapeutic interventions.

Discussion: High index of suspicion is needed for FIRES in school-aged children with new onset epilepsy and no previous history of seizures in order to give first-line immunotherapy within 72 hours. During this time, alternative causes including metabolic, infectious, rheumatologic or genetic, must be ruled out. Given the rarity of this disease process, many institutions do not have a protocol to guide management which can lead in delays of effective treatment.

Conclusion: FIRES presents as a formidable challenge in pediatric neurology, affecting otherwise healthy children and leading to severe neurological impairments. The underlying pathogenesis remains a mystery, with ongoing debates about its inflammatory or autoimmune basis and its relationship with NORSE. The refractory nature of FIRES-induced seizures underscores the limitations of current therapeutic options, highlighting the urgent need for innovative approaches to understand and treat this disorder. This case underscores the potential of Intrathecal steroids as a safe and effective treatment modality for FIRES, marking a significant step towards improving outcomes in this difficult-to-treat population.