Intravenous Immunoglobulin Therapy for Late-Stage Rasmussen’s Encephalitis: Long-Term Seizure Freedom (P6.344)

OBJECTIVE To present a case of Rasmussen’s Encephalitis with 20 year history of seizures who has been seizure free for over 2 years on intravenous immunoglobulin therapy (IVIg). BACKGROUND Rasmussen’s Encephalitis is typically a pediatric-onset intractable focal epilepsy syndrome associated with cerebral hemiatrophy. The etiolology is believed to be due to immune dysregulation, but specific autoantibodies have not been identified. Surgical approaches such as hemispherectomy may be an unsatisfactory option in older patients with dominant hemisphere involvement. Recently, there has been increasing interest in immunomodulatory therapies for treatment of Rasmussen9s, including tacrolimus, rituximab, natalizumab and IVIg. Here, we report successful treatment of late-stage Rasmussen9s Encephalitis with IVIg. DESIGN Case report RESULTS A 27 year old right-handed man had history of epilepsy since 8 years of age characterized by right-sided clonic movements. Over the next few years, he developed intractable epilepsy and, in 2010, presented with epilepsy partialis continua (EPC). Temporary seizure arrest was achieved with pentobarbital coma. On barbiturate withdrawal, however, he remained in status epilepticus despite 7 concurrent anti-epileptic medications. EEG confirmed a unilateral seizure focus. MRI revealed left sided cerebral atrophy and left motor cortex FLAIR signal. These findings confirm the diagnosis of Rasmussen’s Encephalitis. Evaluation for infectious, paraneoplastic and autoimmune etiologies was negative. Given his age and dominant lobe involvement, surgery was not considered to be a feasible option. IVIg was empirically given, and one dose resulted in dramatic improvement in seizure frequency. He has now been seizure-free for over 2 years on monthly IVIg with gradual improvement in motor and cognitive function. Withdrawal of IVIg leads to seizure recurrence. CONCLUSIONS This is the first successful treatment for late-stage Rasmussen Encephalitis using immunomodulatory therapy. Study supported by: not applicable Disclosure: Dr. Dave has nothing to disclose. Dr. Serrano has nothing to disclose.