Affiliations: Department of Physiology, Osaka City University Graduate School of Medicine, Abeno-ku, Osaka, Japan | RIKEN Center for Life Science Technologies, Minatojima-minamimachi, Chuo-ku, Hyogo, Japan
Note: [] Correspondence to: Masaaki Tanaka, MD, PhD, Department of Physiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka City, Osaka 545-8585, Japan. Tel.: +81 6 6645 3711; Fax: +81 6 6645 3712; E-mail: [email protected]
Abstract: Chronic fatigue syndrome (CFS) is characterized by a profound, disabling, and unexplained sensation of fatigue lasting an unexplained severe fatigue which lasts for at least 6 months with a combination of various symptoms, and it impairs patients' ability to live their days normally. Patients with CFS complain of neuropsychological symptoms, including cognitive impairment (thinking difficulties, decreased alertness, and impaired memory and concentration), chronic widespread pain (muscle pain, pain in multiple joints, headaches, and sore throat), and depressive symptoms. In addition, many studies have shown abnormalities in the central nervous system (CNS) in patients with CFS. These findings suggest that the CNS is primarily involved in the pathophysiology of CFS. Here, we review data primarily from behavioral, electrophysiological, and neuroimaging experiments related to neural dysfunction in CFS. Dysfunction of a facilitation system and central sensitization and classical conditioning of an inhibition system in the CNS seem to play pivotal roles in the pathophysiology of CFS. We also propose a treatment strategy for CFS on the basis of these suggested underlying neural mechanisms.