The Assessment and Significance of the Sleep/Waking Brain in Patients with Chronic Widespread Musculoskeletal Pain and Fatigue Syndromes

Abstract

Objectives: To review 1. the animal and human experimental evidence that implicates disordered sleep/wake physiology in the etiology of widespread pain and fatigue and 2. the significance of circadian sleep/wake-related biological and behavioral functions in the assessment and management of patients with fibromyalgia syndrome [FMS] and related illnesses.

Methods: Critical review of clinical and experimental evidence on the interrelationship of pain and sleep disturbances in FMS and allied disorders.

Results: Psychophysiological studies demonstrate that total, partial, and rapid eye movement sleep deprivations decrease pain threshold. Pain stimuli disturb sleep and nonpainful stimuli [e.g., noise] that disrupt sleep [e.g., slow wave sleep] cause unrefreshing sleep, myalgia, and fatigue. Forced awakenings from sleep reduce pain inhibition and yields pain and nonpainful symptoms. Neurotransmitter dysfunctions, for example, central nervous system serotonin and substance P affect both sleep and pain. In clinical studies of FMS and CFS, unrefreshing sleep is associated with frequent periodic electroencephalogram arousals from sleep, i.e., the cyclical alternating pattern, sleep apneas, and periodic limb movements.

Conclusions: These experimental and clinical findings have clinical and therapeutic implications in the assessment and management of FMS. Diurnal sleep/wake-related physiological studies provide objective evidence that further the understanding of FMS and chronic fatigue syndrome. Preliminary studies of novel treatments that aim to facilitate restorative sleep suggest a rationale for better management of FMS and related illnesses.

KEYWORDS:

• Fibromyalgia syndrome
• chronic fatigue
• sleep