Objective: To evaluate a trial of immunotherapy as an aid to diagnosis in suspected autoimmune epilepsy.
Method:We reviewed the charts of 110 patients seen at our autoimmune neurology clinic with seizures as a chief complaint. Twenty-nine patients met the following inclusion criteria: (1) autoimmune epilepsy suspected based on the presence of $1 neural autoantibody (n 5 23), personal or family history or physical stigmata of autoimmunity, and frequent or medically intractable seizures; and (2) initiated a 6-to 12-week trial of IV methylprednisolone (IVMP), IV immune globulin (IVIg), or both. Patients were defined as responders if there was a 50% or greater reduction in seizure frequency.Results: Eighteen patients (62%) responded, of whom 10 (34%) became seizure-free; 52% improved with the first agent. Of those receiving a second agent after not responding to the first, 43% improved. A favorable response correlated with shorter interval between symptom onset and treatment initiation (median 9.5 vs 22 months; p 5 0.048). Responders included 14/16 (87.5%) patients with antibodies to plasma membrane antigens, 2/6 (33%) patients seropositive for glutamic acid decarboxylase 65 antibodies, and 2/6 (33%) patients without detectable antibodies. Of 13 responders followed for more than 6 months after initiating long-term oral immunosuppression, response was sustained in 11 (85%).Conclusions: These retrospective findings justify consideration of a trial of immunotherapy in patients with suspected autoimmune epilepsy.
Classification of evidence:This study provides Class IV evidence that in patients with suspected autoimmune epilepsy, IVMP, IVIg, or both improve seizure control. Neurology ® 2014;82:1578-1586 GLOSSARY AED 5 antiepileptic drug; CASPR2 5 contactin-associated protein-like 2; CC 5 calcium channel; gAChR 5 neuronal acetylcholine receptor, ganglionic-type; GAD65 5 glutamic acid decarboxylase 65; IgG 5 immunoglobulin G; IVIg 5 IV immune globulin; IVMP 5 IV methylprednisolone; LGI1 5 leucine-rich, glioma-inactivated 1; PMA Abs 5 antibodies to neural plasma membrane antigen; VGKC 5 voltage-gated potassium channel.Approximately one-third of epilepsy cases are intractable to antiepileptic drug (AED) therapy.