Interest Balance Auto-immune Population in Patients With Focal Epilepsy of Unknown Cause, Not Structural, Not Genetics, Newly Diagnosed

The knowledge of encephalitis associated with antibodies targeting intracellular antigens, and neuronal surface antibody syndromes has expanded considerably in recent times. The primary purpose of the investigators protocole is to determine the incidence of anti-neuronal antibodies (blood and CSF) in a population of patients suffering from focal epilepsy of unknown cause to guide the management of these patients. The investigators hypothesis is that dysimmune encephalitis is more common than is suggested by the current literature, and that sometimes forms of encephalitis dysimmune "at minimum" can be observed only in the form of focal epilepsy without further manifestation associated.