Musicogenic reflex seizure with positive antiglutamic decarboxylase antibody: A case report

Seizure semiology and predictors of outcomes in Chinese patients with glutamic acid decarboxylase antibody-associated neurological syndrome

BACKGROUND

In the current study, seizure semiology and potential predictive factors of seizure outcomes in glutamic acid decarboxylase antibody (GAD Ab)-associated neurological syndrome were investigated.

METHODS

In this study, 32 Chinese patients with GAD Ab-associated neurological syndrome who presented with seizures at Peking Union Medical College Hospital from January 2017 to October 2022 were reviewed; 30 had a follow-up duration of more than 1 year.

RESULTS

Among the 32 patients, 10 presented with epilepsy alone. Concomitant neurological syndromes were observed in 22 patients, including limbic encephalitis (n = 20), stiff-person syndrome (SPS, n = 1), and cerebellar ataxia (n = 1). Bilateral tonic-clonic seizures were observed in 21 patients (65.6%). Focal seizures occurred in 27 patients (84.4%); 17 had focal motor seizures and 18 focal non-motor seizures. Among 30 patients with long-term follow-up, 11 (36.7%) were seizure-free. Acute/subacute onset (p = 0.049) and comorbidity of limbic encephalitis with epilepsy (p = 0.023) led to better seizure outcomes. Patients with persistent epilepsy were more likely to have focal seizure (p = 0.003) and higher frequency of seizure (p = 0.001). Furthermore, these patients tended to have longer intervals from onset to immunomodulatory treatments. Early immunotherapy (within 6 months from onset) was administered in 81.8% of seizure-free patients but only in 42.1% of patients with persistent seizures. However, steroid and immunosuppressant duration did not differ in the two groups. Repeated serum GAD Ab tests during the follow-up showed no association with seizure outcomes.

CONCLUSIONS

The seizure manifestations are diverse and variable. Approximately one third of patients achieved seizure remission during long-term follow-up. The type and frequency of seizures may influence the seizure outcomes. Early immunotherapy, especially within 6 months, may lead to better seizure outcomes.

Musicogenic reflex seizure with positive antiglutamic decarboxylase antibody: A case report

The association of musicogenic epilepsy (ME) with antibodies against glutamic decarboxylase (GAD) supports autoimmune workups for these patients. No appropriate treatment has been established for ME; therefore, immunotherapy should be considered for patients who become drug-resistant. The connection between neurological manifestations and antibodies against GAD, a rate-limiting enzyme that helps create the inhibitory neurotransmitter gamma-aminobutyric acid, has been well established. Furthermore, a strong correlation has been found between ME and the temporal lobe. However, its connection with anti-GAD antibodies is still unclear. This paper reports on a 50-year-old right-handed female who has had ME symptoms for 14 years and been found to be anti-GAD antibody-positive. Therefore, we will elaborate on the relation between ME and anti-GAD antibodies.