Musicogenic reflex seizures in epilepsy with glutamic acid decarbocylase antibodies

Background Musicogenic reflex seizures (MRS) are a rare form of seizures described in patients with temporal lobe epilepsy (TLE), mainly of unknown etiology. Epilepsy with antibodies against glutamic acid decarboxylase (GAD‐ab) is a form of autoimmune epilepsy for which no specific semiology has been described. Aim of the study To retrospectively review the incidence of MRS in the general epileptic population and in the series of patients with epilepsy and GAD‐ab and to describe its clinical and paraclinical characteristics. Methods Patients recorded between January 2010 and January 2016 in the Database of Bellvitge Hospital Epilepsy Unit were reviewed. Results From a group of 1510 epileptic patients, three reported MRS (0.0019%) (two patients with epilepsy and GAD‐ab and one patient with cryptogenic TLE). The incidence of MRS in patients with epilepsy and GAD‐ab was 2 of 22 (9%). Both patients had a normal magnetic resonance Imaging (MRI), but FDG‐PET showed medial temporal lobe hypometabolism (unilateral or bilateral) in both and also in the insula in one of them. MRS (recorded via video‐EEG[electroencephalography] in one patient) arose from the right temporal lobe. Conclusions MRS may be a distinctive seizure type in patients with epilepsy and antiGADab. Determination of GAD‐ab should be carried out in all cases of MRS, even those with normal structural MRI.