Department of Neurology, General Hospital of Chinese Peoples Armed Police Forces, Beijing, 100039, China.|Department of Neurology, General Hospital of Chinese Peoples Armed Police Forces, Beijing, 100039, China.|Department of Neurology, General Hospital of Chinese Peoples Armed Police Forces, Beijing, 100039, China.|Department of Neurology, General Hospital of Chinese Peoples Armed Police Forces, Beijing, 100039, China. wu_shiwen@yahoo.com.