Abstracts

Rationale: Etiology in a sizable portion of pharmacoresistant partial onset epilepsy remains elusive in spite of current advanced structural and functional neuroimaging modalities. Recently, several autoantibodies associated with such individuals have been reported but the exact spectrum of the disorders and their significance remains ill defined.Methods: We retrospectively reviewed the medical records of patients with pharmacoresistant epilepsy who had immunological work-up performed. All demographics, clinical, and laboratory data was evaluated. The following serum antibodies (Ab) were screened in these patients, although all tests were not performed in every patient: ANA (antinuclear antigen), dsDNA Ab (anti-double stranded DNA), ENA panel (screening for anti-SM, anti-RNP, SSA, SSB, SCL70, anti-JO1), anti-TPO (thyroid peroxidase Ab ), thyroglobulin Ab, anti NMDA-receptor Ab, anti-GAD (anti-glutamic acid decarboxylase Ab), paraneoplastic Ab panel (screening for AChR ganglionic neuronal Ab, ANNAT1, ANNAT2, ANNAT3, PCCAB1, PCCAB2, PCCABT, AMPHI, CRMP5, CACBAB, CABAPQ, ACHBAB, STRMB, anti-glial nuclear Ab T1, Neuronal K channel Ab). We also obtained erythrocyte sedimentation rate and C-reactive protein level as non-specific measure of active ongoing inflammation.Results: A total of 32 adults with medically-refractory epilepsy were included in the study. Eighteen were African American, while 14 were Caucasian. Of the 32 patients in the study, 7 were male. See Table for a complete profile of the Abs screened. Of the patients tested, ANA was positive in 36% (10 of 28), anti-TPO was positive in 35% (8 of 23), thyroglobulin Ab in 15% (3 of 21), anti-GAD Ab in 13% (4 of 30), paraneoplastic panel was positive in two patients, one had a striated muscle Ab, and another had minimally positive AChR ganglionic Ab. The dsDNA Abs were positive in two patients with established diagnosis of systemic lupus who also had a positive ENA screen (one had Abs against SSA, and the other had anti-RNP Abs).Conclusions: A variety of antibodies are elevated in patients with pharmacoresistant localization-related epilepsy. These include non-specific ANA, but also present is a high frequency of anti-thyroid Abs and a subset of anti-GAD Abs. Autoimmunity may play a role in the pathogenesis of drug resistant epilepsy and a larger study with expanded immunological, pathological, and clinical characterization is needed to understand the exact role of these antibodies.