Background: The hypothalamic neuropeptide hypocretin (orexin) modulates sleep-wake, feeding and endocrine functions. Cerebrospinal fluid (CSF) hypocretin-1 (Hcrt-1) concentrations are low in patients with narcolepsy-cataplexy, a sleep disorder characterized by hypersomnolence and rapid eye movement (REM) sleep abnormalities. Methods: We determined CSF Hcrt-1 concentrations of patients with the fibromyalgia syndrome (FMS), a condition characterized by fatigue, insomnia and in some cases daytime hypersomnolence. Results: Basal CSF levels of Hcrt-1 in FMS did not differ from those in healthy normal controls. Conclusions: These findings suggest that abnormally low Hcrt-1 is not a likely cause of fatigue in FMS.
Bibliographical noteFunding Information:
This work was supported by NS23724 (EM) and the National Institutes of Health Grants DA 07234 (OBT) from the National Institute on Drug Abuse and NS39740 (AAL) funded by the National Institute of Neurological Disorders and Stroke and the National Institutes on Arthritis and Musculoskeletal and Skin Diseases. This work was also supported, in part, by a grant from Elan Pharmaceuticals and by a grant from the RGK Foundation of Austin, Texas.
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