In the April 4, 2014, issue of the journal Neurology ahead of print, Doctors Toledano and colleagues from the Mayo Clinic in Rochester present an analysis detailing the use of immunotherapy as an aid for diagnosing suspected autoimmune epilepsy. The investigators reviewed the charts of 110 patients seen at an autoimmune neurology clinic with seizures as a chief complaint. The charts revealed 29 patients who met the criteria, which included autoimmune epilepsy, suspected based on the following:
- The presence of more than one neuro autoantibody;
- A personal family history of physical stigmata of autoimmunity and/or frequent or medically intractable seizures;
- Treatment with 6 to 12 week trial of IV methylprednisolone, IVIG, or both.
Patients were defined as responders if there was a 50% or greater reduction in seizure frequency. Eighteen patients (62%) responded and 10 (34%) of those responders became seizure free. Improvement occurred in 52% with the first agent. Of those receiving a second agent, after not responding to the first, 43% improved. A favorable response correlated with a shorter interval between seizure onset and treatment initiation with a median 9.5 vs. 22 months. Responders included 14 out of 16 patients (87%) with antibodies to plasma membrane antigens; 2 out of 6 (33%) of the patients who were seropositive for glutamic acid to decarboxylase 65 antibodies; and 33% of patients without detectable antibodies. Of 13 responders followed for more than six months after initiating long-term oral immunosuppression, response was sustained in 85%.
These retrospective findings justify consideration of a trial of immunotherapy in patients with suspected autoimmune epilepsy.