When the rhythm moves you

Abstract

A 47-year-old lady presented with a 6-year history of increasing refractory seizures and scoliosis despite trials of multiple anti-epileptic drugs(AEDs). She described seizures of temporal lobe(TLE) semiology provoked mainly by music which evoked elation. These musicogenic reflex seizures (MRS) were occurring up to twice weekly.CT and MRI brain, paraspinal EMG, and routine EEG were unremarkable. Provoked EEG captured a gen- eralised seizure with focal left mid-anterior temporal focus with rapid bilateral spreading within 2 minutes of playing a piece of music and lasted for 90 seconds, followed by a prolonged post-ictal phase. Auto- antibody screen revealed persistently elevated and rising serum GAD-Ab(glutamic acid decarboxylase antibodies) at 11618 U/mL with GAD positive on CSF testing. CT body, PET and transvaginal ultrasound revealed no significant abnormalities. Plasmapheresis was trialled with some effect.We present a rare case of GAD-Ab mediated MRS. MRS are well described, with 9% mediated by GAD-Ab. This mechanistically accounts for the limbic MRS semiology. We highlight the importance of GAD-Ab screening for refractory new onset TLE in an adult, with high serum GAD-Ab titre (≥2000 U/mL) and evidence of intrathecal synthesis. Unlike other immune-mediated epilepsies, GAD-Ab-mediated epilepsy responds poorly to AEDs and may require immunosuppression with rituximab or cyclophosphamide.