A neurological disease (and an autoimmune disease) where the body forms antibodies against the brain's NMDA receptors. The antibodies produced disrupt normal brain activity, causing swelling in the brain (encephalitis). Some patients also have a tumor that is correlated with this disease; most commonly an ovarian teratoma. Symptoms of anti-NMDA receptor encephalitis are as follows: behavior (hallucinations, paranoia), cognition, speech disorder, memory deficit, movement disorder (abnormal movements), seizures, autonomic dysfunction, and loss of consciousness. It is not known exactly what causes this disease, but it is likely environmental and genetic factors that can cause individuals to be more susceptible to this disease.