[Limbic encephalitis. A misdiagnosed syndrome].

Patients with limbic encephalitis (LE) display various disorders including anterograde amnesia, mood disturbances (irritability, agitation or pseudo-depressive symptoms) and epilepsy, often partial but sometimes generalized, and rapidely progressive course. On account of the variability of the initial symptoms, limbic encephalitis is clearly under-diagnosed and often misdiagnosed as viral encephalitis. From a pathophysiological point of view, two types of LE can be identified. First, LE associated with antibodies directed against an intracellular neuronal antigen. They correspond to the traditional paraneoplastic LE, and are characterized by a weak response to treatment even when the causal tumor is treated. Second, LE associated with antibodies directed against antigens present on cellular membranes. These LE can be paraneoplastic or idiopathic, and present a better response to immunological treatments.