Autoimmune-induced seizures and epilepsy: a concept based on pathophysiology

The majority of autoimmune-mediated disorders of the brain are associated with epileptic seizures. Whereas T-cell mediated encephalitides only rarely respond to treatment, autoimmune encephalitides with autoantibodies to membrane surface proteins can be treated by immunotherapy. As only few of these patients develop epilepsy, they should not be classified under the collective term autoimmune epilepsy. These patients suffer more from symptomatic seizures during the acute and active phase of the autoimmune disorder. Recent experimental findings suggest that seizures in these cases could be induced by an intrinsic pathophysiological effect of the autoantibodies. This article highlights how autoantibodies can affect synaptic and neuronal function probably leading to increased seizure susceptibility, using the example of LGI1 and NMDA receptor encephalitis.