2020 年 37 巻 4 号 p. 636-639
Autoimmune encephalopathies are clinically and immunologically heterogeneous disorders. Many different types of autoimmune encephalopathy have been discovered, and most common type may be Hashimoto encephalopathy in it. In clinical situations, we often recognize that patients with autoimmune encephalopathy are misdiagnosed as exhibiting functional psychogenic movement, conversion, or somatoform disorders. Most patients with autoimmune encephalopathy showed motor disturbance mostly with unsustained and/or give–way weakness. About 70% of patients showed sensory abnormalities that was not explainable anatomically. One–fourth of patients exhibited involuntary movements such as tremor entrainment, dystonia, or coarse involuntary movement. Although give–way weakness, anatomically unexplainable pain, and strange involuntary movements were thought to be psychogenic, the presence of one of these three symptoms was indicative of autoimmune encephalopathy. As autoimmune encephalitis exhibits diffuse involvement with the whole brain, these symptoms were entirely understandable. Except for the presence of organic disease, most patients were classified into somatoform disorders or functional movement disorders. Without first excluding autoimmune encephalopathy, physicians should not diagnose somatoform disorders.
