Autoimmune Status Epilepticus

Autoimmune status epilepticus is a rare condition but one that has been increasingly recognized by neurologists and clinicians in the intensive care unit. As more cases are described in the literature and more antibody tests become commercially available, diagnosis is now feasible; however, early diagnosis remains a challenge. For practical purposes, status epilepticus may be considered as possibly autoimmune if it is refractory to anticonvulsant treatment and there is no other known cause; this may then lead to empiric immunomodulatory therapy. Major factors that raise the index of suspicion are recent cognitive or behavioral alterations, a history of malignancy or tumor, or presence of other neurological features. There is a lack of high level evidence in the literature for treatment of status epilepticus, and almost none for autoimmune encephalitis. Patients with autoimmune status epilepticus may be treated with immunomodulatory therapy, including steroids, intravenous immunoglobulin (IVIG), plasmapheresis (PLEX), and other immunosuppressive agents while maximizing their anticonvulsant therapy. For some patients, resective surgery may be necessary, such as hemispherectomy for Rasmussen’s encephalopathy. In the case of status epilepticus due to paraneoplastic autoantibodies, urgent and aggressive testing and treatment of a primary malignancy is needed. Importantly, any suspicion of autoimmune mediated status epilepticus should prompt the transfer of the patient to a specialized center with experience in refractory status epilepticus whenever possible.