Seizure is one of the most common symptoms in autoimmune encephalitis with neuronal surface-mediated antibodies. Interestingly, some patients may exhibit new-onset seizures as the initial manifestation without fulminant sign of encephalitis, particularly in the early stage. It is essential to recognize these patients early and to perform antibody testing, as studies have reported early immunotherapy can improve their clinical outcomes. At the same time, it is important to limit the number of patients who require testing, for the sake of specificity and cost effectiveness. Thus, this prospective, multicenter study aims to identify neural antibodies in patients with focal seizures of unknown etiology, and to create a score to preselect patients requiring autoantibody testing.