A 16-year-old girl in California went to an emergency department after experiencing hallucinations: she saw a flying green dinosaur and heard voices that were not real. She was also shaking and sweating, and her heart was beating rapidly. These physical signs led doctors to suspect a physical illness behind her mental symptoms.
Early tests did not explain her condition. However, a later test of the fluid around her brain and spinal cord found antibodies, proteins from the immune system, attacking her nerve tissue. Doctors diagnosed autoimmune encephalitis, a rare condition in which the body's defenses attack nervous tissue and cause inflammation. Scans found no tumors, which can trigger this illness.
Treatment included medicines to reduce inflammation and control the harmful immune response. She also had five procedures to replace the liquid portion of her blood, helping remove the harmful antibodies. She left the hospital after almost two months. Her symptoms improved over the following year, allowing her to stop medicines for her mental symptoms while continuing treatment for the immune condition.
