To compare the prevalence of antithyroid antibodies (aTR-ab) in adult onset temporal lobe epilepsy (TLE) patients with known and unknown TLE aetiology (N = 42). Moreover, the sera of these patients was also assayed for antinuclear antibodies (ANA), anticardiolipin antibodies (ACL), anti glutamic acid decarboxylase antibodies (GAD) and antiglidadin antibodies.
Positive aTR-ab in the sera of patients with unknown aetiology was 11/23 (47.8%) vs. 1/19 (4.3%) in the group with known aetiology (p = 0.005). In 9/11 (81%) a pre-existing autoimmune disease was confirmed. Nine (81%) were women and five (45%) had memory impairment. There were 5/11 (45%) pharmacoresistant patients, and corticosteroid treatment was initiated in 3/5 with cognitive and seizure improvement. The results of other immunological tests were only remarkable for antiGAD antibodies with 3/11 (27%) positive patients, but this subgroup does not have any significant clinical differential feature.
Late-onset TLE with positive aTR-ab tends to be middle-aged women with nonpharmacoresistant cryptogenic epilepsy plus cognitive decline and other associated autoimmune diseases. It could be advisable to test aTR-ab in TLE patients with an unknown aetiology, in order to improve diagnosis and resulting treatment.