Musicogenic epilepsy is a rare type of reflex epilepsy, and its link to antiglutamic decarboxylase (GAD) antibodies needs better understanding; however, patients with musicogenic epilepsy who do not respond to preventive measures or become drug resistant may benefit from immunotherapy, while select cases may also require surgical intervention, according to findings from a case report published in Epilepsia Open.
The International League Against Epilepsy task force updated the definition of epilepsy to reflect circumstances that do not meet the required definition of 2 unprovoked seizures more than 24 hours apart. Musicogenic epilepsy, a reflex seizure triggered by sound, is uncommonly rare, affecting 1 in 10 million people. Neurologic conditions such as musicogenic epilepsy have been linked to antibodies against GAD.
In this case report, study investigators highlighted findings in a 50-year-old woman who was diagnosed with a seizure disorder for 14 years.
The patient, a housewife and mother of 5 children, had a history of hypothyroidism and insulin-dependent diabetes mellitus. She reported an aura with infrequent smells on occasion and reported experiencing a recurrent loss of awareness associated with oral and left-hand automatism, which proceeded to generalized tonic-clonic seizures.
Seizures occurred 4 to 5 times a month and each episode for a few seconds and did not have diurnal variation. The primary stimulus for these seizures was loud sounds such as particular music or songs and never occurred spontaneously, which lead to the patient’s avoidance of such sounds.
The patient did not have a history of central nervous system infection, febrile seizures, or significant head trauma, and did not report a family history of epilepsy. She reported using control-released carbamazepine (400 mg every 12 hours) for the last 14 years, lamotrigine (100 mg every 12 hours) for the last 14 years, and levetiracetam (1500 mg every 12 hours) for the last 2 years. She stopped using valproate medication, as she did not experience benefit from the treatment.
The patient had normal results for complete blood count, renal profile, hepatic profile, and thyroid function tests. Results for positron emission tomography and magnetic resonance imaging were unremarkable. In contrast, the patient had increased glycated hemoglobin and was positive for anti-GAD antibodies.
The study investigators reported seizures from the left temporal lobe but 2 of the seizures were found in the right temporal lobe; they used video-electroencephalography and semiology to confirm that the patient suffered from focal epilepsy. This was triggered by listening to music, arising from the left temporal lobe.
In neuropsychologic assessment, the patient showed a decline in her verbal memory, processing, and psychomotor speed; however, her other cognitive abilities were in the normal range.
The patient was recommended initiating intravenous immunoglobulin immunotherapy but declined and was discharged on levetiracetam (1500 mg), control-released carbamazepine (400 mg), and lamotrigine (100 mg).
“An autoimmune workup with an anti-GAD antibody determination should be performed in patients with ME. In addition, a trial of immunotherapy may be considered in patients with drug-resistant epilepsy and anti-GAD antibodies,” the investigators reported.
They concluded, “Our patient chose to avoid the specific triggering music and remain on antiepileptic drugs. Hence, in the absence of the effects of immunotherapy on seizures, an immune pathogenesis in this case report cannot be confirmed.”
Al-Attas AA, Al Anazi RF, Swailem SK. Musicogenic reflex seizure with positive anti-glutamic decarboxylase antibody: A case report. Epilepsia Open. Published online July 4, 2021. doi:10.1002/epi4.12518