Polysomnographic characteristics in nonmalignant chronic pain populations: A review of controlled studies

Abstract

Summary Sleep and pain are critical homeostatic systems that interact in a bidirectional manner. Complaints of sleep disturbance are ubiquitous among patients with chronic pain disorders, and conversely, patients with persistent insomnia symptoms commonly report suffering from chronic pain. Sleep deprivation paradigms demonstrate that partial or complete sleep loss induce hyperalgesia, possibly due to shared mechanistic pathways including neuroanatomic and molecular substrates. Further, chronic pain conditions and sleep disturbances are intertwined through comorbidities, which together cause detrimental psychological and physical consequences. This critical review examines 29 polysomnography studies to evaluate whether nonmalignant chronic pain patients, as compared to controls, show differences in objective measures of sleep continuity and sleep architecture. Whereas these controlled studies did not reveal a consistent pattern of objective sleep disturbances, alterations of sleep continuity were commonly reported. Alterations of sleep architecture such as increases in light sleep or decreases in slow-wave sleep were less commonly reported and findings were mixed and also inconsistent. Methodological flaws were identified, which complicated interpretation and limited conclusions; hence, recommendations for future research are suggested. Knowledge of abnormalities in the sleep process has implications for understanding the pathophysiology of chronic pain conditions, which might also direct the development of novel intervention strategies.

The effect of sleep deprivation on pain perception in healthy subjects: a meta-analysis

“…Furthermore, increased amounts of superficial sleep and decreased levels of slow-wave sleep were found, whereas sleep architecture was commonly preserved. A consistent pattern of objective sleep disturbances was not found in nonmalignant chronic pain populations [70].…”

“…A recent review on 29 controlled polysomnographic studies found a fragmentation of sleep as the most common alteration of sleep in chronic pain patients [70]. Furthermore, increased amounts of superficial sleep and decreased levels of slow-wave sleep were found, whereas sleep architecture was commonly preserved.…”

“…This could be due to the fact that self-reported pain is more closely associated with anxiety than with pain threshold [74]. Sleep and pain are critical homeostatic systems that interact in a bidirectional manner [70]. For example, less than six hours of sleep per night is associated with greater pain the following day [75] and sleep quality is a consistent predictor of pain the next day [76,77].…”

Reciprocal Relationship Between Sleep Macrostructure and Evening and Morning Cellular Inflammation in Rheumatoid Arthritis

“…Clinically significant sleep disturbance is found in over 60% of RA patients (1,2), which is thought to have adverse impact on systemic inflammation, synovitis, joint function, and quality-of-life, as well as medical co-morbidity and all-cause mortality (3–8). Despite the prevalence of sleep problems in RA, few studies have objectively examined sleep using polysomnography (PSG), and this prior work is limited by small sample size (9–13), lack of control group (12,13) and inadequate consideration of confounding factors (14). PSG provides a laboratory-based assessment of disturbances of sleep continuity and sleep architecture.…”

Causal Mediation in the Development of Painful Temporomandibular Disorder

“…37,54 Apart from problems with sleep initiation and maintenance, sleep-disordered breathing, 2 restless legs syndrome, 27 and narcolepsy, 17 are also more common among people with pain disorders than in pain-free individuals, although there is little evidence that sleep architecture differs in people with pain. 6,57 Longitudinal studies show that although disturbed sleep and pain have bidirectional relationships, the effect of sleep disturbance on pain development is greater than the effect of pain on sleep disturbance. 21 Moreover, the extent of sleep disturbance predicts sensitivity to experimental pain 52 and intensity of clinical pain 1 in a dose-response manner.…”