Antiepileptic drug therapy in autoimmune epilepsy associated with antibodies targeting the leucine-rich glioma-inactivated protein 1

Anteneh M Feyissa; Christopher Lamb; Sean J Pittock; Avi Gadoth; Andrew McKeon; Christopher J Klein; Jeffrey W Britton

doi:10.1002/epi4.12226

Antiepileptic drug therapy in autoimmune epilepsy associated with antibodies targeting the leucine-rich glioma-inactivated protein 1

Epilepsia Open. 2018 Jun 25;3(3):348-356. doi: 10.1002/epi4.12226. eCollection 2018 Sep.

Authors

Anteneh M Feyissa¹, Christopher Lamb¹, Sean J Pittock^{2

3}, Avi Gadoth^{2

3}, Andrew McKeon^{2

3}, Christopher J Klein^{2

3}, Jeffrey W Britton²

Affiliations

¹ Department of Neurology Mayo Clinic Jacksonville Florida U.S.A.
² Department of Neurology Mayo Clinic Rochester Minnesota U.S.A.
³ Department of Laboratory Medicine and Pathology Mayo Clinic Rochester Minnesota U.S.A.

Abstract

Objective: To characterize seizure semiology and the utility of antiepileptic drug (AED) therapy in leucine-rich glioma inactivated-1 ( LGI1-Ab) autoimmune epilepsy (AE).

Methods: Patients with voltage-gated potassium channel complex (VGKCc) titers higher than 0.02 nmol/L who were evaluated between May 2008 and June 2016 at the 3 Mayo Clinic sites (Arizona, Florida, or Minnesota) were identified. We then performed a retrospective review of those who were LGI1-Ab positive and were treated for seizures.

Results: A total of 1,095 patients with VGKCc titers higher than 0.02 nmol/L were identified, in which 77 were LGI1 positive. Of these, 56 patients with seizures were included in the analysis. Mean age at symptom onset was 62.9 years; 66% (n = 37) were male. The most common seizure semiology was focal faciobrachial dystonic seizures with preserved awareness (FBDS) (n = 35, 63%), followed by focal with impaired awareness (FIA) (n = 29, 52%), generalized tonic-clonic (GTCs) (n = 28, 50%), and focal non-motor seizures with preserved awareness (n = 28, 50%). The majority had more than one seizure type (n = 49, 88%; median = 2.5). Thirty-eight patients (68%) became seizure free: 29 (76%) with immunotherapy, 3 (5%) with AEDs alone, 2 (3%) with AEDs before any immunotherapy, and 4 (7%) with AEDs after immunotherapy. Levetiracetam (n = 47, 84%) and valproic acid (n = 21, 38%) were the most commonly used AEDs, but neither were associated with seizure freedom. Sodium channel blocking (NCB) AEDs were associated with seizure freedom in 4 patients compared to none treated with non-NCB AEDs. Regardless of class, AEDs prior to or apart from immunotherapy were associated with seizure freedom in only five patients (9%). In patients with FBDS, seizure freedom was more often associated with immunotherapy than AEDs (20/30 vs. 3/34, p = 0.001).

Significance: Although FBDS are the most characteristic seizure type seen in LGI1-Ab AE, other seizure types including FIA and GTCs also occur. Immunotherapy was the treatment most frequently associated with seizure freedom in LGI1-Ab AE. In general, AEDs seemed to confer a very low chance for seizure freedom, although AEDs with NCB-blocking properties were associated with seizure freedom in a limited number. Levetiracetam in particular appears to be ineffective in this patient population.

Keywords: Autoimmune encephalitis; Drug‐resistant epilepsy; Faciobrachial dystonic seizures; Sodium channel blockers; Voltage‐gated potassium channel complex.