Is the Deficit in Pain Inhibition in Fibromyalgia Influenced by Sleep Impairments?

Abstract

It has been proposed that a deficit in inhibitory conditioned pain modulation (ICPM) underlies the pathophysiology of fibromyalgia (FM), but there is high variability in ICPM efficacy in this syndrome that remains poorly understood. Based on emerging data showing that age, anxiety, depression and sleep can modulate ICPM efficacy, the main objective of this study was to determine the clinical correlates of experimentally-induced pain perception in FM. Fifty FM patients and 39 healthy controls (HC) were tested. Anxiety, depression, sleep and FM symptoms were measured with questionnaires or interview-type scales. Experimental pain testing consisted of two tonic heat pain stimulations separated by a 2-minute cold pressor test (CPT). Thermal pain thresholds and tolerance were higher in HC compared to FM patients. Pain ratings during the CPT were lower in HC relative to FM patients. ICPM efficacy was stronger in HC compared to FM patients. Finally, sleep quality was the only factor significantly related to ICPM efficacy. To our knowledge, this is the first study to report this association in FM. Future studies will need to replicate this finding, to determine whether impaired sleep is primary or secondary to deficient pain inhibition, and to characterize the neurobiological mechanisms underlying this association.

Chronic Pain and Depression

“…These data coincidence with the recent results of Paul-Savoie [18] who believes that the role of deiciency of endogenous inhibitors of pain mechanisms and sleep disorder in the FM is quite polemical, and requires further analysis. Indeed, as evidenced by these data, indicators of the level of pain and sleep disorders in patients with common ferromagnetic sample are statistically signiicant negative correlation (Figure 5).…”

The Association of Sleep and Pain: An Update and a Path Forward

“…In a polysomnography study of TMD patients, poor sleep efficiency was significantly associated with diminished CPM efficacy, or impaired pain inhibition 28 . Self-reported sleep efficiency was also inversely correlated with CPM efficacy in fibromyalgia patients 82 . Further, CPM efficacy is reduced in rheumatoid arthritis patients relative to healthy controls, and appears to be mediated by self-reported sleep disturbance in that patient group 56 .…”

Hypoalgesia After Exercise and the Cold Pressor Test is Reduced in Chronic Musculoskeletal Pain Patients With High Pain Sensitivity

“…Dysfunctional pain-inhibitory systems have been suggested to be important for the transition from acute to chronic pain and impaired CPM has previously been shown in chronic pain conditions such as chronic pancreatitis, 51,52 irritable bowel syndrome, 53 tension-type headache, 49,54,55 FM, [13][14][15][16][17] temporomandibular disorder, 56 chronic whiplash-associated disorder, 18,19 and osteoarthritis. 20,21 The present study extends these findings by showing a reduced CPM response in patients with high pain sensitivity compared with patients with less pain sensitivity.…”

“…The efficiency of the modulatory pain pathways is often assessed by recordings of pain thresholds, pain tolerance, or pain ratings to stimulation before and during or after a cold pressor test, also known as conditioned pain modulation (CPM), 8,9 or before and after an exercise condition, also known as exerciseinduced hypoalgesia (EIH). [10][11][12] Chronic musculoskeletal pain conditions in which the degree of hypoalgesia after the cold pressor test (CPT) is reduced include fibromyalgia, [13][14][15][16][17] chronic whiplash-associated disorder, 18,19 and osteoarthritis. 20,21 Similarly, chronic musculoskeletal pain conditions with attenuated hypoalgesia after exercise include fibromyalgia (FM) [22][23][24][25] and chronic whiplash-associated disorder.…”