“Autoimmune Epilepsy”: Encephalitis with Autoantibodies for Epileptologists

Abstract

Autoimmune encephalitides may account for epilepsies of so far unknown cause. These “autoimmune epilepsies” may respond well to immunotherapy. More than a dozen autoantibodies have been found with this constellation; therefore, broad autoantibody testing of serum-CSF pairs offers the best diagnostic yield. Several particular features raise the suspicion of an autoimmune cause in otherwise unexplained seizure disorders.

Neuronal antibodies in adult patients with new‐onset seizures: A prospective study

“…Nonparaneoplastic cases are more common than paraneoplastic ones, and autoimmune epilepsy has been suggested to account for up to 20% of epilepsy of unknown etiology (Bien & Holtkamp, 2017;Dubey, Alqallaf, et al, 2017;Irani, Bien, & Lang, 2011).…”

Commentary: 2017 clinical Epilepsia prize

“…The authors explicitly describe them in their Epilepsia paper . Some cases with GAD antibodies or VGKC complex antibodies who are negative for LGI1 or CASPR2 antibodies behave oddly; they all belong to the usual subjects of antibody reactivities questionable for their specificity or treatability …”

“…2 Some cases with GAD antibodies or VGKC complex antibodies who are negative for LGI1 or CASPR2 antibodies behave oddly; they all belong to the usual subjects of antibody reactivities questionable for their specificity or treatability. 7 These examples show that even with these useful scores, individual judgment by informed and experienced clinicians is still indispensable for an appropriate selection of diagnostic tools and treatments in individual patients. There is some reason to believe that the general discussion of "autoimmune epilepsy" will be refined by antibody-and syndrome-specific considerations in the future.…”

Searching for Autoimmune Epilepsy: Why, Where, and When?

“…In a thoroughly detailed position statement, Graus et.al lay out the clinical scenarios that should raise suspicion for autoimmune encephalitis/epilepsy, thereby identifying patients with the highest expected yield for antibody testing, but more importantly, those with a clinical picture that would justify treatment for autoimmune encephalitis even while waiting to receive the results of antibody testing. Such efforts to define autoimmune epilepsy on clinical grounds are even more critical as we recognize that patients may be "seronegative" but still have autoimmune epilepsy, given the lag of our knowledge as we are only starting to scratch the surface of this entity and still have many more pathogenic antibodies to discover [2][3][4]8 .…”

“…The existing challenge though is that once we reach the clinical judgment that "immunomodulation is needed because we suspect autoimmune epilepsy", we don't know exactly how best to proceed. In a recent review 4 , Bien and Holtkamp outline a treatment protocol based on their clinical experience, starting with a first line therapy of intravenous immunoglobulins or high dose oral methylprednisolone with a subsequent taper to a maintenance dose. Escalating to rituximab or cyclophosphamide is recommended in case of no response to methylprednisolone or intravenous immunoglobulin.…”