Value of autoantibodies for prediction of treatment response in patients with autoimmune epilepsy: Review of the literature and suggestions for clinical management

Abstract

SUMMARYThe detection of antineural autoantibodies in patients with epilepsy has led to the new concept of "autoimmune epilepsy." A particularly important implication is that knowledge of the antigenic target of the underlying antibody permits prognostic estimates. Patients with antibodies to the potassium channel complex (mostly to its leucinerich glioma inactivated 1 [LGI1] component) have a high chance of becoming seizure free within days to months upon immunotherapy but less so with antiepileptic drug (AED) treatment alone. Seizures in the setting of antibodies to the N-methyl-D-aspartate receptor also have a high likelihood to remit, again especially with rapid institution of immunotherapy. In contrast to these antibodies to neuronal surface molecules, antibodies directed to intracellular antigens (onconeural antibodies, antibodies to glutamic acid decarboxylase) portend a low likelihood of seizure remission, regardless of the treatments chosen. These outcome differences are probably related to the underlying pathophysiology-with largely reversible functional effects of antibodies to surface antigens and irreversible destructive sequelae (probably caused by T cells) in patients with antibodies to intracellular antigens. With ongoing experience with these conditions, clinical and paraclinical clues to the diagnosis of autoimmune epilepsies are emerging.

Seizure semiology: an important clinical clue to the diagnosis of autoimmune epilepsy

“…An autoimmune cause has been increasingly recognized in the spectrum of limbic encephalitis characterized by cognitive impairment, especially memory impairment, behavioral changes, temporal lobe seizures, and sleep disturbances 2. However, accumulating evidence supports an autoimmune basis for seizures in the absence of syndromic manifestations of limbic encephalitis for a subset of AED‐resistant epilepsy cases 3, 4, 5, 6, 7, 8. Autoimmune epilepsy often does not respond to conventional antiepileptic treatment but might respond to immunotherapy.…”

Neuronal antibodies in pediatric epilepsy: Clinical features and long‐term outcomes of a historical cohort not treated with immunotherapy

“…However, in these studies, follow‐up was short, and immunologic treatments have been tried on an empirical basis at a time when the presence of an antibody was unknown. With increasing interest in the possible etiologic role of autoantibodies in epilepsy, and the recognition that early diagnosis and immunotherapy treatment improves outcome in autoimmune encephalitis, it is important for the clinician to be able to make informed decisions regarding which patients to test and whether the results will affect patient management and epilepsy outcome 13, 14…”

Anti-Neuronal Autoantibodies Associated with Epilepsy and Related Neurological Syndromes

“…[2, 47,48] VGKC-kompleksi antikorları ile ilişkili otoimmün ensefalit ile başvurup izlemi sırasında aylar içerisinde mezial temporal skleroz geliştiren çok sayıda olgu tanımlanmıştır. Ayrıca mezial temporal skleroz olgularında yüksek oranda anti-nöro-nal antikor (genellikle CASPR2, GlyR ve NMDAR antikorları) saptanmış ve bu olguların bir kısmının immünoterapi ile nö-bet sıklıklarının azaldığı gösterilmiştir.…”