The association of sleep and pain: an update and a path forward

The interplay between sleeplessness and high-sensitivity C-reactive protein on risk of chronic musculoskeletal pain: longitudinal data from the Tromsø Study

Study Objectives

To examine independent associations of sleeplessness and high-sensitivity C-reactive protein (hsCRP) with risk of chronic musculoskeletal pain, and to explore the joint effect of sleeplessness and hsCRP on risk of chronic musculoskeletal pain.

Methods

A population-based prospective study of 3214 women and 3142 men (mean age: 55.4, range: 32–87) without severe chronic musculoskeletal pain and with hsCRP ≤ 10 mg/L at baseline in 2007–2008. Modified Poisson regression was used to calculate adjusted risk ratios (RRs) with 95% confidence intervals (CIs) for any chronic musculoskeletal pain and chronic widespread pain (CWP) at follow-up in 2015–2016 associated with self-reported sleeplessness and hsCRP at baseline.

Results

Compared with persons without sleeplessness, women and men reporting often/or always sleeplessness had RRs of CWP of 2.53 (95% CI: 1.94–3.29) and 2.48 (95% CI: 1.63–3.77), respectively. There was no clear association between hsCRP and risk of any chronic musculoskeletal pain or CWP. Joint effect analyses using persons without sleeplessness and with a hsCRP < 1.00 mg/L as the reference gave RRs for chronic musculoskeletal pain of 1.73 (95% CI: 1.26–2.37) for those with often/always sleeplessness and hsCRP < 1.00 mg/L; 1.01 (95% CI: 0.78–1.32) for those without sleeplessness and hsCRP ≥3.00 mg/L; and 2.47 (95% CI: 1.79–3.40) if they had both often/always sleeplessness and hsCRP ≥ 3.00 mg/L. The corresponding RRs for CWP were 1.89 (95% CI: 1.27–2.83), 0.96 (95% CI: 0.68–1.37), and 2.83 (95% CI: 1.91–4.20), respectively.

Conclusions

These results suggest that there is an interplay between sleeplessness and hsCRP on risk of any chronic musculoskeletal pain and CWP.

Sleep Disorders are a Prevalent and Serious Comorbidity in Dry Eye

Purpose

Sleep is an essential life habit and closely associated with lifespan, diabetes, hypertension, and mental health. Sleep disorders are a prominent, but overlooked problem in patients with dry eye disease (DED), characterized by a poor sleep index, short sleep duration, long sleep latency, and poor subjective sleep. DED and sleep disorders are more prevalent in women than men. Moreover, sleep quality in DED is worse than in other eye diseases, including glaucoma, retinal diseases, cataract, and allergic and chronic conjunctivitis.

Methods

We reviewed the literature for studies investigating sleep and health, eyes and sleep, and DED and sleep, in terms of systemic and eye health, especially in women.

Results

Two studies reported that approximately half of patients with DED suffer from poor sleep. The severity of mood disorders, including anxiety and depression, is correlated strongly with sleep disorders in DED, and the symptoms and signs of DED, especially pain, also are correlated with sleep quality. Sleep disorders are documented in primary Sjögren's syndrome and an association with sleep apnea and depression is suggested. Primary Sjögren's syndrome includes arthritis and other rheumatic disease causing pain and fatigue; however, how sicca contributes to sleep disorders is not known.

Conclusions

Possible explanations for sleep disorders in DED may be depression, pain, and eye exposure at night. Reciprocal effects may be expected and consultation-liaison psychiatry is recommended for the management of sleep disorders in DED. Topical medication and lid heating also may be advantageous for sleep quality in DED.

Open-Loop Audiovisual Stimulation Induces Delta EEG Activity in Older Adults With Osteoarthritis Pain and Insomnia

OBJECTIVE

People with chronic insomnia tend to have cortical hyperarousal marked by excessive beta-/gamma-frequency brain activity during both wake and sleep. Currently, treatment options for managing hyperarousal are limited. Open-loop audiovisual stimulation (AVS) may be such a treatment. The purpose of this study was to provide a mechanistic foundation for future AVS research in sleep promotion by examining quantitative electroencephalogram (QEEG) responses to an AVS sleep-induction program.

METHOD

Sixteen older adults with both chronic insomnia and osteoarthritis pain were randomly assigned to either active- or placebo-control AVS. Electroencephalogram (EEG) was collected during baseline (5 min, eyes closed/resting) and throughout 30 min of AVS.

RESULTS

Findings showed significantly elevated mean baseline gamma (35-45 Hz) power in both groups compared to an age- and gender-matched, noninsomnia normative database, supporting cortical hyperarousal. After 30 min of exposure to AVS, the active group showed significantly increased delta power compared to the placebo-control group, providing the first controlled evidence that active AVS induction increases delta QEEG activity in insomnia patients and that these changes are immediate. In the active group, brain locations that showed the most delta induction (Cz, Fp, O1, and O2) were associated with the sensory-thalamic pathway, consistent with the sensory stimulation provided by the active AVS program.

CONCLUSIONS

Findings demonstrate that delta induction, which can promote sleep, is achievable using a 30-min open-loop AVS program. The potential for AVS treatment of insomnia in the general population remains to be demonstrated in well-designed clinical trials.

Factors involved in sleep efficiency: a population-based study of community-dwelling elderly persons

STUDY OBJECTIVES

Research indicates that sleep efficiency below 80% substantially increases mortality risk in elderly persons. The aim of this study was to identify factors that would best predict poor sleep efficiency in the elderly, and to determine whether associations between these factors and sleep efficiency were similar for men and women and for younger and older elderly persons.

METHODS

A total of 2468 individuals aged 65-96 years (40.7% men) participated. They were recruited via random generation of telephone numbers according to a geographic sampling strategy. The participants agreed to have health professionals visit their home and to answer structured interview questions. Sleep efficiency was calculated based on interview responses. Descriptive statistics and logistic regressions were conducted.

RESULTS

The factors most strongly associated with sleep efficiency below 80% were pain, nocturia, sleep medication use, and awakening from bad dreams. Some factors varied by sex: women aged 75 years and older or who had an anxiety disorder were more likely to have sleep efficiency below 80%, whereas being single or having painful illness raised the likelihood for men only. Except for sex, all the factors that showed associations with sleep efficiency affected younger and older elderly persons similarly.

CONCLUSIONS

Poor sleep efficiency is prevalent among elderly persons. The results shed new light on factors associated with poor sleep efficiency, highlighting the presence of sex differences and that certain factors make no significant contribution, such as typically proscribed sleep hygiene behaviors, mood disorders, and illness in general.

Obstructive sleep apnea co-morbidity in patients with fibromyalgia: a single-center retrospective analysis and literature review

Background: Fibromyalgia (FM) is a chronic medical condition characterized by widespread pain, sleep disturbance, and cognitive dysfunction. Sleep disorders are thought to play a prominent role in the etiology and symptomatic management of FM, specifically obstructive sleep apnea (OSA). In order to provide collaborative care, we need a better understanding of any overlapping presentation of FM and OSA. We conducted a site-wide review of patients from 2012-2016 to identify FM patients diagnosed with OSA. Methods: Charts were reviewed in patients aged 18 and above from 2012-2016 using ICD codes from a clinical data repository. Intersection of patients with a diagnosis of FM and OSA in clinics of psychiatry, sleep, rheumatology, and other outpatient clinics was compared. Polysomnography order patterns for FM patients were investigated. Results: Co-morbidity was highest in the sleep clinic (85.8%) compared to psychiatry (42.0%), rheumatology (18.7%), and other outpatient clinics (3.6%) (p<0.001). In the rheumatology and other outpatient clinics, 93.5% and 96% of patients respectively, had no polysomnography ordered. Pairwise comparison of co-morbidity in clinics: sleep vs psychiatry, sleep vs rheumatology, sleep vs other clinics, psychiatry vs rheumatology, psychiatry vs other clinics, and rheumatology vs other clinics were statistically significant after applying a Sidak adjustment to the p-values (all p<0.001). Conclusion: Our analysis suggests that there could be a correlation between FM and OSA, and referral to sleep studies is recommended in the management of patients with FM. The varying prevalence of FM patients with co-morbid OSA in sleep clinics when compared to other outpatient clinics suggests a discrepancy in the identification of FM patients with OSA. When properly screened, OSA co-morbidity has the potential to be higher in other outpatient clinics.

The Interrelationship between Sleep and Chronic Pain in Adolescents

Over half of youth with chronic pain report sleep deficiency including difficulties falling asleep, maintaining sleep, feeling unrested, and experiencing short sleep duration. Sleep deficiency has been shown to play a causal role in the development or worsening of chronic pain, and is associated with a variety of negative consequences for youth with chronic pain. The purpose of this review is to provide a summary of the literature on the interrelationship of sleep and chronic pain in adolescents. We review the impact and prevalence of sleep disturbances, conceptual models of the interrelationship of sleep and pain, biobehavioral mechanisms and risk factors, sleep assessment, and treatment of sleep deficiency and chronic pain in adolescents. Our recommendations for future research include understanding biobehavioral mechanisms that underlie the link between chronic pain and sleep deficiency to help guide development and testing of treatments for co-occurring pain and sleep disturbance in adolescents.

Sensitization of nociceptors and dorsal horn neurons contributes to pain in sickle cell disease

Sickle cell disease (SCD) describes a group of disorders associated with a point mutation in the beta chain of hemoglobin. The mutation leads to the creation of sickle hemoglobin (HbS) and causes distortion of erythrocytes through polymerization under low oxygen, resulting in characteristic sickle red blood cells. Vaso-occlusion episodes caused by accumulation of sRBCs results in ischemia-reperfusion injury, reduced oxygen supply to organs, oxidative stress, organ damage and severe pain that often requires hospitalization and opioid treatment. Further, many patients suffer from chronic pain, including hypersensitivity to heat and cold stimuli. Progress towards the development of novel strategies for both acute and chronic pain in patients with SCD has been impeded by a lack of understanding the mechanisms underlying pain in SCD. The purpose of this review is to highlight evidence for the contribution of peripheral and central sensitization that leads to widespread, chronic pain and hyperalgesia. Targeting the mechanisms that initiate and maintain sensitization in SCD might offer effective approaches to manage the severe and debilitating pain associated with this condition.

Sleep quality in well-defined Lyme disease: a clinical cohort study in Maryland

Study Objectives

Lyme disease (LD) is the most common vector-borne disease in the United States. Approximately 5-15 per cent of patients develop postantibiotic treatment symptoms termed post-treatment Lyme disease syndrome (PTLDS). The primary objective of this study is to examine and quantify sleep quality among patients with early LD during the acute and convalescent periods, including among the subset who met criteria for PTLDS.

Methods

This paper draws from a clinical cohort study of participants with early LD (n = 122) and a subcohort of individuals who later met criteria for PTLDS (n = 6). Participants were followed for 1 year after antibiotic treatment. The Pittsburgh Sleep Quality Index and standardized measures of pain, fatigue, depressive symptoms, and functional impact were administered at all visits for participants and controls (n = 26). Participants meeting criteria for PTLDS at 1 year post-treatment were compared with a subset of PSQI-defined poor sleeping controls (n = 10).

Results

At the pretreatment visit, participants with early LD reported poorer sleep than controls. By 6 months post-treatment, participant sleep scores as a group returned to control levels. Participants with PTLDS reported significantly worse global sleep and sleep disturbance scores and worse fatigue, functional impact, and more cognitive-affective depressive symptoms compared with poor sleeping controls.

Conclusions

Participants with early LD experienced poor sleep quality, which is associated with typical LD symptoms of pain and fatigue. In the subset of patients who developed PTLDS, sleep quality remains affected for up to 1 year post-treatment and is commonly associated with pain. Sleep quality should be considered in the clinical picture for LD and PTLDS.

Delivering Cognitive Behavioral Therapy for Insomnia in Military Personnel and Veterans

Insomnia is commonly reported by military populations, especially those with comorbid mental and physical health conditions. Co-occurring conditions result in an altered presentation of insomnia symptoms, and complicate provision of cognitive-behavioral therapy for insomnia (CBT-I), requiring supplementary assessment or modifications to traditional techniques. CBT-I has consistently demonstrated positive outcomes for active-duty service members and veterans, even in the context of significant comorbidities such as post-traumatic stress disorder, depression, sleep apnea, and chronic pain. Despite its promise, studies of CBT-I in some populations, including women and individuals with substance use disorders, remain relatively understudied in active-duty and veteran populations.

Wireless High-Frequency Spinal Cord Stimulation (10 kHz) Compared with Multiwaveform Low-Frequency Spinal Cord Stimulation in the Management of Chronic Pain in Failed Back Surgery Syndrome Subjects: Preliminary Results of a Multicenter, Prospective Randomized Controlled Study

Background

This study aimed to evaluate the wireless Freedom Spinal Cord Stimulator (WSCS) System for the treatment of chronic back and/or leg pain associated with failed back surgery syndrome (FBSS) refractory to standard medical treatment utilizing 10-kHz stimulation (high-frequency [HF]) in comparison with 10–1,500-Hz stimulation (low-frequency [LF]) waveforms.

Methods

Ninety-nine subjects were randomized in a 1:1 ratio to receive either HF or LF stimulation waveforms utilizing the same Freedom WSCS System. All subjects were implanted with two 8-electrode arrays in the exact same anatomical positions within the dorsal epidural spinal column, with the top electrode positioned at the T8 and T9 vertebrae levels, respectively, and the wireless receiver placed under the skin in a subcutaneous pocket.

Results

Seventy-two (HF: N = 38; LF: N = 34) subjects had completed the six-month follow-up after an initial 30-day trial period at the time of this report. For both the HF and LF arms, mean visual analog scale (VAS) scores for back and leg pain decreased significantly: 77% and 76%, respectively, for the HF arm and 64% and 64%, respectively, for the LF arm. In addition, most subjects experienced significant improvements in VAS, Oswestry Disability Index, European Quality of Life 5 Dimension questionnaire, Patient Global Impression of Change, and sleep duration.

Conclusions

These preliminary results demonstrate that WSCS devices can reduce FBSS chronic pain substantially with both LF and HF stimulation waveforms over a seven-month period (30-day trial period and six-month post-trial evaluation).

Chronic exposure to insufficient sleep alters processes of pain habituation and sensitization

Chronic pain conditions are highly comorbid with insufficient sleep. While the mechanistic relationships between the 2 are not understood, chronic insufficient sleep may be 1 pathway through which central pain-modulatory circuits deteriorate, thereby contributing to chronic pain vulnerability over time. To test this hypothesis, an in-laboratory model of 3 weeks of restricted sleep with limited recovery (5 nights of 4-hour sleep per night followed by 2 nights of 8-hour sleep per night) was compared with 3 weeks of 8-hour sleep per night (control protocol). Seventeen healthy adults participated, with 14 completing both 3-week protocols. Measures of spontaneous pain, heat-pain thresholds, cold-pain tolerance (measuring habituation to cold over several weeks), and temporal summation of pain (examining the slope of pain ratings during cold water immersion) were assessed at multiple points during each protocol. Compared with the control protocol, participants in the sleep-restriction protocol experienced mild increases in spontaneous pain (P < 0.05). Heat-pain thresholds decreased after the first week of sleep restriction (P < 0.05) but normalized with longer exposure to sleep restriction. By contrast, chronic exposure to restricted sleep was associated with decreased habituation to, and increased temporal summation in response to cold pain (both P < 0.05), although only in the past 2 weeks of the sleep-restriction protocol. These changes may reflect abnormalities in central pain-modulatory processes. Limited recovery sleep did not completely resolve these alterations in pain-modulatory processes, indicating that more extensive recovery sleep is required. Results suggest that exposure to chronic insufficient sleep may increase vulnerability to chronic pain by altering processes of pain habituation and sensitization.

Sleep quality among industrial workers: related factors and impact

Purpose

The purpose of this paper is to explore the prevalence and determinants of poor sleep quality among industrial workers in Thailand. Additionally, the authors assess the risk of work-related injuries associated with poor sleep quality.

Design/methodology/approach

A descriptive correlational research was implemented. A total of 472 workers from the northern region of Thailand contributed to this study. Sleep quality was assessed by the Thai version of the Pittsburgh Sleep Quality Index (Thai-PSQI). The score of more than five indicated poor sleep quality. Participants completed self-administered demographic, work characteristics and work-related injury questionnaires. Data were analyzed by applying descriptive and logistic regression statistical techniques.

Findings

More than one-third of the workers had reported poor sleep quality. Results from multivariable logistic regression analysis yielded male gender (OR = 2.74, 95% CI 1.46–5.17), alcohol drinking (OR=2.1, 95% CI 1.24–3.35), pain (OR=2.05, 95% CI 1.32–3.17) and rotating shift work (OR=1.94, 95% CI 1.23–3.05) increased the risk of poor sleep quality. Furthermore, poor sleep quality was statistically significantly associated with the risk of work-related injuries (OR = 3.98, 95% CI = 2.39–6.66).

Originality/value

Findings of this study indicate that the prevalence of poor sleep quality is high among industrial workers. Work characteristics and health behaviors were associated with poor sleep quality which increases the risk of work-related injuries. Modification of work environment and personal life style choices can improve quality of sleep among workers and consequently lower incidence of work-related injuries.

The management of post-traumatic stress disorder and associated pain and sleep disturbance in refugees

More than 68 million people worldwide have been forcibly displaced and one-third of these are refugees. This article offers an overview of the current literature and reviews the epidemiology and evidence-based psychological and pharmacological management of post-traumatic stress disorder (PTSD), sleep disturbance and pain in refugees and asylum seekers. It also considers the relationship between sleep disturbance and PTSD and explores concepts of pain in relation to physical and psychological trauma and distress. During diagnosis, clinicians must be aware of ethnic variation in the somatic expression of distress. Treatments for PTSD, pain and sleep disturbance among refugees and asylum seekers are essentially the same as those used in the general population, but treatment strategies must allow for cultural and contextual factors, including language barriers, loss of freedom and threat of repatriation.

LEARNING OBJECTIVES

After reading this article you will be able to: •

DECLARATION OF INTEREST

None.

Development of a suite of metrics and indicators for children's nursing using consensus methodology

AIM AND OBJECTIVES

To develop a suite of metrics and indicators to measure the quality of children's nursing care processes. The objectives were to identify available metrics and indicators and to develop consensus on the metrics and indicators to be measured.

BACKGROUND

The Office of Nursing and Midwifery Services Director, Health Service Executive, in Ireland established seven workstreams aligned to the following care areas: acute, older persons, children's, mental health, intellectual disability, public health nursing and midwifery.

DESIGN

A comprehensive design included stakeholder consultation and a survey with embedded open-ended questions.

METHODS

A two-round online Delphi survey was conducted to identify metrics to be measured in practice, followed by a two-round online Delphi survey to identify the associated indicators for these metrics. A face-to-face consensus meeting was held with key stakeholders to review the findings and build consensus on the final metrics and indicators for use. A STROBE checklist was completed.

RESULTS

A suite of eight nursing quality care process metrics and 67 associated process indicators was developed for children's nursing.

CONCLUSIONS

By creating a national suite of metrics and indicators, more robust measurement and monitoring of nursing care processes can be achieved. This will enable the provision of evidence for any local and/or national level changes to policy and practice to enhance care delivery.

RELEVANCE TO CLINICAL PRACTICE

The roll-out of the metrics and indicators in clinical practice has commenced. This national suite of metrics and indicators will ensure that a robust system of measurement for improvement is in place to provide assurance to Directors of Nursing of the quality of nursing care being provided to children and their families. It supports the value of nursing sensitive data to inform change and improvement in healthcare delivery and to demonstrate the contribution of the nursing workforce to safe patient care.

Cognitive behavioral treatments for insomnia and pain in adults with comorbid chronic insomnia and fibromyalgia: clinical outcomes from the SPIN randomized controlled trial

STUDY OBJECTIVES

To examine the effects of cognitive behavioral treatments for insomnia (CBT-I) and pain (CBT-P) in patients with comorbid fibromyalgia and insomnia.

METHODS

One hundred thirteen patients (Mage = 53, SD = 10.9) were randomized to eight sessions of CBT-I (n = 39), CBT-P (n = 37), or a waitlist control (WLC, n = 37). Primary (self-reported sleep onset latency [SOL], wake after sleep onset [WASO], sleep efficiency [SE], sleep quality [SQ], and pain ratings) and secondary outcomes (dysfunctional beliefs and attitudes about sleep [DBAS]; actigraphy and polysomnography SOL, WASO, and SE; McGill Pain Questionnaire; Pain Disability Index; depression; and anxiety) were examined at posttreatment and 6 months.

RESULTS

Mixed effects analyses revealed that both treatments improved self-reported WASO, SE, and SQ relative to control at posttreatment and follow-up, with generally larger effect sizes for CBT-I. DBAS improved in CBT-I only. Pain and mood improvements did not differ by group. Clinical significance analyses revealed the proportion of participants no longer reporting difficulties initiating and maintaining sleep was higher for CBT-I posttreatment and for both treatments at 6 months relative to control. Few participants achieved >50% pain reductions. Proportion achieving pain reductions of >30% (~1/3) was higher for both treatments posttreatment and for CBT-I at 6 months relative to control.

CONCLUSIONS

CBT-I and CBT-P improved self-reported insomnia symptoms. CBT-I prompted improvements of larger magnitude that were maintained. Neither treatment improved pain or mood. However, both prompted clinically meaningful, immediate pain reductions in one third of patients. Improvements persisted for CBT-I, suggesting that CBT-I may provide better long-term pain reduction than CBT-P. Research identifying which patients benefit and mechanisms driving intervention effects is needed.

CLINICAL TRIAL

Sleep and Pain Interventions in Fibromyalgia (SPIN), clinicaltrials.gov, NCT02001077.

The association between psychological and social factors and spinal pain in adolescents

Spinal pain, back pain, and/or neck pain begins early in life and is strongly associated with spinal pain in adulthood. Understanding the relationship between psychological and social factors and adolescent spinal pain may be important in both the prevention and treatment of spinal pain in this age group. We aimed to determine if psychological and social factors were associated with spinal pain in a cross-sectional study of a school-based cohort of 1279 Danish adolescents aged 11-13, who were categorized into "any" and "substantial" spinal pain. "Substantial spinal pain" was defined as a lifetime frequency of "sometimes" or "often" and a pain intensity of at least two on the revised Faces Pain Scale. Logistic regression analyses, stratified by sex, were conducted for single and all variables together. Eighty-six percent of participants reported "any spinal pain" and 28% reported "substantial spinal pain". Frequency of psychological and social factors was significantly higher in those with spinal pain compared to those without. As the frequency of psychological and social factors increased, the odds of both "any spinal pain" and "substantial spinal pain" also increased.Conclusion: Psychological and social factors may be important determinants in adolescent spinal pain. What is Known: • Spinal pain begins early in life to reach adult levels by age 18. Spinal pain in adolescence is strongly associated with spinal pain in adulthood. • In adults, psychological and social factors and spinal pain are strongly related; however, this relationship in adolescence is poorly understood. What is New: • Adolescents with spinal pain reported a significantly higher frequency of psychological factors and loneliness and lower levels of pupil acceptance. • Adolescents reporting higher levels of loneliness, lower levels of pupil acceptance, and increased frequency of psychological factors had increased odds of reporting "substantial spinal pain".

The influence of rapid eye movement sleep deprivation on nociceptive transmission and the duration of facial allodynia in rats: a behavioral and Fos immunohistochemical study

Background

Disrupted sleep is associated with a reciprocal influence on headaches and is one of the contributing factors in the process of chronicity. The goal of the present study was to investigate the influence of sleep on headaches using animal rapid eye movement (REM) sleep deprivation and supradural capsaicin infusion models.

Method

Sprague-Dawley rats underwent REM sleep deprivation (REMSD) for 96 h. The sensory threshold to mechanical stimuli, assessed by the von Frey monofilament test, was measured during the REMSD period. Additionally, the Fos protein expression level was measured in the trigeminocervical complex, periaqueductal gray, and hypothalamus. Following supradural infusion of capsaicin, we evaluated the duration of facial allodynia for 28 days after REMSD.

Results

After REMSD, the sensory threshold to mechanical stimuli was significantly decreased (p < 0.01) and Fos-positivity in the posterior (p = 0.010) and dorsomedial hypothalamus (p = 0.024), ventrolateral periaqueductal gray (p = 0.016), and superficial layer of the trigeminocervical complex (p = 0.019) were significantly increased. The duration of facial allodynia induced by supradural capsaicin infusion was significantly longer in the REM sleep deprivation and capsaicin infusion group (Day 10 PSD vs. Day 25 PSD).

Conclusion

The present study demonstrates that REM sleep deprivation increased nociceptive transmission from trigeminal nerve endings. Furthermore, it suggests that sleep deprivation may contribute to the chronicity of facial allodynia.

Conditioned Pain Modulation in Sexual Assault Survivors

Sexual assault (SA) is associated with an increased risk of chronic pain, but the mechanisms for this relationship are poorly understood. To explore whether disrupted descending inhibition is involved, this study used a conditioned pain modulation task to study the inhibition of pain and the nociceptive flexion reflex (NFR; a correlate of spinal nociception) in 32 pain-free SA survivors. This group was compared with 32 pain-free, trauma-exposed persons without SA and a group of 40 pain-free persons who reported no trauma exposure. Conditioned pain modulation was assessed from painful electric stimulations (test stimulus) delivered to the ankle before, during, and after participants submerged their hand in painful 10°C water (conditioning stimulus). Pain ratings and NFR were assessed in response to test stimuli. All groups demonstrated significant inhibition of pain during conditioned pain modulation. However, only the no trauma exposure group demonstrated significant inhibition of NFR. The persons without SA group showed no inhibition of NFR, whereas the SA group showed significant facilitation of the NFR. These findings suggest that trauma exposure may impair inhibitory cerebrospinal circuits, but that SA may specifically promote facilitation of spinal nociception. Perspective: This study suggests that trauma exposure disrupts the cerebrospinal inhibition of spinal nociception, but that exposure to SA further promotes chronic pain risk by facilitating spinal nociception. This finding help may help to elucidate the pain risk mechanisms in trauma survivors.

Impact of transcutaneous electrical nerve stimulation on sleep in chronic low back pain: a real-world retrospective cohort study

Objective

The purpose of this study was to determine if transcutaneous electrical nerve stimulation (TENS) improves sleep in chronic low back pain (CLBP).

Background

There is uncertainty over the effectiveness of TENS in CLBP. In most studies, pain intensity has been the primary outcome measure. Although sleep abnormalities are common in CLBP, sleep outcomes have not been evaluated in most studies of TENS effectiveness. Subjective and objective sleep measures are often inconsistent in CLBP, suggesting that perception of sleep and actual sleep may differ.

Methods

This retrospective cohort study evaluated TENS for CLBP over 10 weeks. The source database included demographics, pain characteristics, pain intensity and interference on an 11-point numerical rating scale, adherence and actigraphic sleep data from real-world TENS users. Key inclusion criteria were CLBP with self-reported history of back injury and baseline pain interference with sleep ≥4. Study participants were stratified into improved and unimproved groups based on changes in pain interference with sleep (improved ≥1-point decrease). Actigraphic sleep metrics were compared between the two groups for weeks 1–2 and weeks 9–10.

Results

The inclusion criteria were met by 554 TENS users. There were 282 (50.9%) participants in the improved group and 272 (49.1%) in the unimproved group. The two groups had similar baseline characteristics and high TENS adherence. At the weeks 1–2 assessment, there were no differences among actigraphic sleep. At the weeks 9–10 assessment, there was a difference in total sleep time, with the improved group sleeping 29 minutes longer. In addition, the periodic leg movement (PLM) index was lower in the improved group.

Conclusion

Regular TENS improved self-reported and objective sleep measures in individuals with CLBP. When compared to the unimproved group, the improved group had longer total sleep time and fewer PLMs. Sleep may be an important outcome for TENS effectiveness in CLBP.

Chronic Pain and Chronic Opioid Use After Intensive Care Discharge - Is It Time to Change Practice?

Almost half of patients treated on intensive care unit (ICU) experience moderate to severe pain. Managing pain in the critically ill patient is challenging, as their pain is complex with multiple causes. Pharmacological treatment often focuses on opioids, and over a prolonged admission this can represent high cumulative doses which risk opioid dependence at discharge. Despite analgesia the incidence of chronic pain after treatment on ICU is high ranging from 33-73%. Measures need to be taken to prevent the transition from acute to chronic pain, whilst avoiding opioid overuse. This narrative review discusses preventive measures for the development of chronic pain in ICU patients. It considers a number of strategies that can be employed including non-opioid analgesics, regional analgesia, and non-pharmacological methods. We reason that individualized pain management plans should become the cornerstone for critically ill patients to facilitate physical and psychological well being after discharge from critical care and hospital.

Temporal Analysis of Chronic Musculoskeletal Pain and Sleep in Postmenopausal Women

STUDY OBJECTIVES

To investigate the temporal association between chronic musculoskeletal pain (CMP) and sleep in women who are postmenopausal in a 10-day actigraphic study. This is a microlongitudinal study in which 52 participants were allocated to 4 groups women who are postmenopausal: control (CTRL, n = 10), chronic musculoskeletal pain (CMP, n = 12), insomnia (INS, n = 15) and chronic musculoskeletal pain+insomnia (CMP+INS, n = 15).

METHODS

All volunteers underwent a clinical interview and completed questionnaires, used an actigraph, and kept sleep diaries for 10 consecutive days.

RESULTS

Women in the CMP+INS group presented more sleep episodes (mean of 1.02 episodes) and longer sleep latency (8.97 minutes), as well as higher pain intensity during the day compared to the other groups. Sleep duration recorded by actigraphy directly predicted pain intensity the following morning on waking, with a 1-unit increase in pain intensity, for every 6.9 minutes more of sleep. Higher pain intensity at bedtime was a significant predictor of both increased time in bed and sleep duration, meaning that for each 1-unit increase in pain intensity at bedtime, sleep duration increased by an average of 6.7 minutes.

CONCLUSIONS

Data showed that the coexistence of insomnia and CMP results in greater pain intensity and alterations in sleep homeostasis. Collectively, the data indicate that there is a bidirectional and directly proportional relationship between sleep duration and pain intensity in women who are postmenopausal with insomnia. This result strongly suggests that both sleep and pain conditions should be targeted in the treatment of women who are postmenopausal.

Sleep quality and noise: comparisons between hospital and home settings

BACKGROUND

Children and their parents report poor sleep in hospital and complain about noise.

OBJECTIVE

To measure sleep quality and noise levels in hospital and compare these with the home environment.

DESIGN

Observational within case-controlled study.

SETTING

Paediatric medical wards at Southampton Children's Hospital and bedrooms at home.

PARTICIPANTS AND METHODS

Participants were children aged 3-16 years and their co-sleeping parents. Sleep quality was measured using actigraphy for a maximum of 5 nights in each setting. Median sound levels at the bedside were monitored overnight in a subgroup in both settings.

MAIN OUTCOME MEASURES

Total sleep time, sleep efficiency, median sound levels overnight.

RESULTS

40 children and 16 mothers completed actigraphy in both settings. Children had on average 62.9 min, and parents 72.8 min, per night less sleep in hospital than at home. Both children and parents had poorer sleep quality in hospital than at home: mean sleep efficiency 77.0% vs 83.2% for children and 77.1% vs 88.9% for parents, respectively. Median sound levels in hospital measured in 8 children averaged 48.6 dBA compared with 34.7 dBA at home and exceeded World Health Organization recommendations of 30 dB.

CONCLUSIONS

Children and their mothers have poor quality sleep in paediatric wards. This may affect the child's behaviour, recovery and pain tolerance. Sleep deprivation adds to parental burden and stress. Sound levels are significantly raised in hospital and may contribute to poor sleep. Reduction in the level of noise might lead to an improvement in sleep, affecting the quality of stay of both parent and child.

Personal resource profiles of individuals with chronic pain: Sociodemographic and pain interference differences

PURPOSE/OBJECTIVE

Previous studies have demonstrated important associations between personal resources and pain interference. Using latent profile analysis, the present study (a) identified subgroups of individuals with chronic pain who have different personal resource profiles; (b) explored sociodemographic differences among subgroups; and (c) examined how these subgroups differ in pain interference. Research Method/Design: Study 1 is based on daily diary and survey data from 220 individuals with fibromyalgia (FM). Study 2 is based on 4 annual surveys of 483 individuals with long-term neurological/neuromuscular disease or injury, and chronic pain. Modifiable personal resource variables including sense of resilience, social support, pain acceptance, and sleep quality were included in latent profile analyses.

RESULTS

Three subgroups were identified in both studies: High, Moderate, and Low Personal Resource groups. In both studies, annual income level was significantly different among subgroups. Study 1 results showed a significant between-groups difference in pain interference across 21-days only between High and Moderate Personal Resource groups controlling for the level of pain intensity and depressive symptoms. In Study 2, however, all subgroups were significantly different with respect to their levels of pain interference at baseline over and above various covariates, with the Low Personal Resource group reporting the highest level of pain interference at baseline. These baseline differences remained stable over 4 years.

CONCLUSIONS/IMPLICATIONS

The findings suggest a robust association between economic disparity and personal resource profiles among individuals with chronic pain. The role of different personal resource profiles in pain interference appears to differ by chronic pain condition. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The Pain of Sleep Loss: A Brain Characterization in Humans

Sleep loss increases the experience of pain. However, the brain mechanisms underlying altered pain processing following sleep deprivation are unknown. Moreover, it remains unclear whether ecologically modest night-to-night changes in sleep, within an individual, confer consequential day-to-day changes in experienced pain. Here, we demonstrate that acute sleep deprivation amplifies pain reactivity within human (male and female) primary somatosensory cortex yet blunts pain reactivity in higher-order valuation and decision-making regions of the striatum and insula cortex. Consistent with this altered neural signature, we further show that sleep deprivation expands the temperature range for classifying a stimulus as painful, specifically through a lowering of pain thresholds. Moreover, the degree of amplified reactivity within somatosensory cortex following sleep deprivation significantly predicts this expansion of experienced pain across individuals. Finally, outside of the laboratory setting, we similarly show that even modest nightly changes in sleep quality (increases and decreases) within an individual determine consequential day-to-day changes in experienced pain (decreases and increases, respectively). Together, these data provide a novel framework underlying the impact of sleep loss on pain and, furthermore, establish that the association between sleep and pain is expressed in a night-to-day, bidirectional relationship within a sample of the general population. More broadly, our findings highlight sleep as a novel therapeutic target for pain management within and outside the clinic, including circumstances where sleep is frequently short yet pain is abundant (e.g., the hospital setting).SIGNIFICANCE STATEMENT Are you experiencing pain? Did you have a bad night of sleep? This study provides underlying brain and behavioral mechanisms explaining this common co-occurrence. We show that sleep deprivation enhances pain responsivity within the primary sensing regions of the brain's cortex yet blunts activity in other regions that modulate pain processing, the striatum and insula. We further establish that even subtle night-to-night changes in sleep in a sample of the general population predict consequential day-to-day changes in pain (bidirectionally). Considering the societal rise in chronic pain conditions in lock-step with the decline in sleep time through the industrial world, our data support the hypothesis that these two trends may not simply be co-occurring but are significantly interrelated.

Sleep Shortage Is Associated With Postherpetic Neuralgia Development Through Hyperesthesia and Acute Pain Intensity: A Community-Based Prospective Cohort Study

OBJECTIVES

There have been no community-based studies investigating the association between sleep duration and postherpetic neuralgia (PHN) development. The aim of the current study was to examine the association of sleep with herpes zoster (HZ) incidence and PHN.

METHODS

In total, 12,329 residents (ages 50 to 103 years) of Shozu County, Japan, participated in our study from December 2009 to November 2010 and were followed up for 3 years. At baseline, the participants completed self-administered health questionnaires, including those on usual sleep duration. Three dermatologists diagnosed HZ on the basis of clinical symptoms and virus identification testing by polymerase chain reaction and serological tests, and evaluated pain using a modified Zoster Brief Pain Inventory survey form via telephone. We used a Cox proportional hazard regression model to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident HZ and PHN. We also performed mediation analysis to examine whether hyperesthesia and acute pain intensity mediated the association between sleep shortage and chronic pain intensity.

RESULTS

During follow-up, 400 cases of HZ were identified. Of these, 55 participants developed PHN. Sleep duration was not associated with HZ incidence. Sleep shortage increased the risk for PHN (HR 2.02 [95% CI: 1.06 to 3.85]). Hyperesthesia and acute pain intensity mediated the association between sleep shortage and chronic pain intensity (indirect/total effect ratio = 50% mediation).

CONCLUSIONS

Sleep shortage was associated with increased risk for PHN, and hyperesthesia and acute pain intensity appeared to mediate this association. Sleep shortage may be a novel risk factor for PHN.

Relationships Between Chronic Musculoskeletal Pain and Working Hours and Sleeping Hours: A Cross-sectional Study

Ten to twenty percent of the population of Japan has chronic pain. Although studies have confirmed a relationship between sleeping hours and chronic pain, it remains unclear whether there is an association between working hours and chronic pain, especially chronic musculoskeletal pain (CMP), in workers. A self-administered questionnaire that sought information regarding background characteristics and work-related factors was sent to 118 enterprises; finally, 1,747 participants were included in the analysis and were classified into CMP (n = 448) and non-CMP (n = 1299) groups. Logistic regression analysis revealed that age (odds ratio [OR] = 1.02, 95% confidence interval [CI]: 1.01-1.03), sex (reference: female, OR = 0.68, 95% CI: 0.52-0.88), working hours (OR = 1.11, 95% CI: 1.03-1.20), and sleeping hours (OR = 0.84, 95% CI: 0.75-0.95) were significantly associated with CMP. Participants were categorized into four groups according to working hours (long: ≥ 9 hours/day [long-work], short: < 9 hours/day [short-work]) and sleeping hours (long: ≥ 7 hours/day [long-sleep], short: < 7 hours/day [short-sleep]). Furthermore, logistic regression analysis showed that the CMP OR was 2.02 (95% CI: 1.46-2.78) times higher in 'long-work plus short-sleep workers' and 1.47 (95% CI: 0.94-2.30) times higher in 'long-work plus long-sleep workers' than in 'short-work plus long-sleep workers'. Thus, working hours are associated with CMP frequency, but sleeping sufficiently may prevent CMP in workers even if they work for long hours. In conclusion, adequate instructions on sleeping hours should be provided by occupational health staff, as this may be effective in preventing CMP.

Non-pharmacological solutions to sleep and circadian rhythm disruption: voiced bedside experiences of hospice and end-of-life staff caregivers

Background

Sleep disturbance is a significant issue, particularly for patients with advanced terminal illness. Currently, there are no practice-based recommended approaches for managing sleep and circadian disruptions in this population. To address this gap, a cross-sectional focus group study was performed engaging 32 staff members at four hospices/end-of-life programs in three demographically diverse counties in New York State.

Methods

Participants responded to structured open-ended questions. Responses were transcribed and subjected to qualitative content analysis. The themes and recommendations for improved practice that emerged were tabulated using Atlas TI qualitative software.

Results

This report details the experiences of hospice and end-of-life care staff in managing sleep and circadian disruptions affecting patients and analyzes their recommendations for improving care. Caregivers involved in the study described potential interventions that would improve sleep and reduce circadian disruptions. They particularly highlighted a need for improved evaluation and monitoring systems, as well as sleep education programs for both formal and informal caregivers.

Conclusions

The voiced experiences of frontline hospice and end-of-life caregivers confirmed that disruption in sleep and circadian rhythms is a common issue for their patients and is not effectively addressed in current research and practice. The caregivers’ recommendations focused on management strategies and underscored the need for well-tested interventions to promote sleep in patients receiving end-of-life care. Additional research is needed to examine the effectiveness of systematic programs that can be easily integrated into the end-of-life care process to attenuate sleep disturbances.

Cognitive behavioural therapy in pain and psychological disorders: Towards a hybrid future

Cognitive Behavioural Therapy (CBT) is a form of evidence-based talking therapy that emphasises the importance of behaviour and conscious thoughts in shaping our emotional experiences. As pain becomes increasingly accepted as not only a sensory but also an emotional experience, success in using CBT to treat emotional disorders has resulted in the incorporation of cognitive-behavioural principles into the management of chronic pain. Outcomes of CBT-informed interdisciplinary pain management programmes are modest at best, despite rapid methodological improvements in trial design and implementation. Whilst the field searches for new treatment directions, a hybrid CBT approach that seeks to simultaneously tackle pain and its comorbidities shows promise in optimising treatment effectiveness and flexibility. This article provides a brief description of the core characteristics of CBT and the transformation this therapeutic model has brought to our understanding and management of chronic pain. Current evidence on efficacy of CBT for chronic pain is then reviewed, followed by a critical consideration of the advantages and disadvantages of the new hybrid treatment approach that conceptualises and treats chronic pain in connection with its comorbidities. Recent progress made in the area of pain and insomnia is highlighted as an example to project therapeutic innovations in the near future.

Sleep and pain interference in individuals with chronic pain in mid- to late-life: The influence of negative and positive affect

Poor sleep and chronic pain are known to be interrelated, but the influence of negative and positive affect on this relationship is not fully understood. The present study sought to examine whether negative and positive affect mediate the relationship between sleep and pain interference. Secondary data analysis from Midlife in the United States (MIDUS-III) was used to examine 948 individuals with chronic pain (mean age = 64.73 years). Sleep disturbance was conceptualized as the sum of self-reported difficulty with sleep-onset latency, wake after sleep onset, early morning awakening and daytime sleepiness, and total sleep time was assessed via self-reported sleep duration. Pain interference was operationalized as the sum of pain-related interference with general activity, relationships and enjoyment of life. Finally, items from the Positive and Negative Affect Schedule were used to measure affect. Mediation analyses revealed that sleep disturbance indirectly predicted pain interference via both negative affect (β = 0.15, confidence interval: 0.10, 0.21) and positive affect (β = 0.18, confidence interval: 0.12, 0.25). Similarly, negative (β = -0.003, confidence interval: -0.01, -0.001) and positive affect (β = -0.003, confidence interval: -0.01, -0.001) also mediated the effect between total sleep time and pain interference. This study highlights the unique role of negative and positive affect on pain interference for individuals with chronic pain in mid- to late-life. Additionally, findings suggest that holistic treatment approaches, which assess both sleep and affect in the context of chronic pain, may be beneficial.

Benefits and adverse effects of cannabis use among adults with persistent pain

BACKGROUND

Increasingly, states are legalizing cannabis for recreational use. Improved accessibility may allow adults with pain to use cannabis more liberally. Greater understanding is needed about how adults with pain perceive the effects of cannabis, particularly those who also use opioid analgesics.

PURPOSE

To examine the perceived effects of cannabis among adults who have been prescribed opioids for persistent pain.

METHODS

A survey-based study was conducted on 150 adults with persistent pain. Data from two open-ended questions were analyzed using a qualitative descriptive approach and content analysis.

FINDINGS

Data analysis led to identification of two main categories and five subcategories: (a) cannabis benefits with two subcategories of "physiological" and "mental health"; (b) adverse effects with three subcategories of "physiological," "mental health," and "social and economic concerns."

DISCUSSION

Both positive and negative effects of cannabis were described. Nursing practice, including open communication with patients, can be guided by patient perspectives surrounding benefits and adverse effects of cannabis use.

AAPT Diagnostic Criteria for Peripheral Neuropathic Pain: Focal and Segmental Disorders

Peripheral neuropathic pain is among the most prevalent types of neuropathic pain. No comprehensive peripheral neuropathic pain classification system that incorporates contemporary clinical, diagnostic, biological, and psychological information exists. To address this need, this article covers the taxonomy for 4 focal or segmental peripheral neuropathic pain disorders, as part of the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership and the American Pain Society (APS) collaborative to develop a standardized, evidence-based taxonomy initiative: the ACTTION-APS Pain Taxonomy (AAPT). The disorders-postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia-were selected because of their clinical and clinical research relevance. The multidimensional features of the taxonomy are suitable for clinical trials and can also facilitate hypothesis-driven case-control and cohort epidemiologic studies. PERSPECTIVE: The AAPT peripheral neuropathic pain taxonomy subdivides the peripheral neuropathic pain disorders into those that are generalized and symmetric and those that are focal or segmental and asymmetric. In this article, we cover the focal and segmental disorders: postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia. The taxonomy is evidence-based and multidimensional, with the following dimensions: 1) core diagnostic criteria; 2) common features; 3) common medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors.

Prediction of therapeutic response to pregabalin in subjects with neuropathic pain

OBJECTIVE

To evaluate four models based on potential predictors for achieving a response to pregabalin treatment for neuropathic pain (NeP).

METHODS

In total, 46 pain studies were screened, of which 27 NeP studies met the criteria for inclusion in this analysis. Data were pooled from these 27 placebo-controlled randomized trials to assess if baseline characteristics (including mean pain and pain-related sleep interference [PRSI] scores), early clinical response during weeks 1-3 of treatment (change from baseline in pain and PRSI scores), and presence of treatment-emergent adverse events (AEs) were predictive of therapeutic response. Therapeutic response was defined as a ≥30% reduction from baseline in either pain and/or PRSI scores at week 5 with supplemental analyses to predict pain outcomes at weeks 8 and 12. Predictors of Patient Global Impression of Change (PGIC) were also evaluated. Four models were assessed: Random Forest, Logistic Regression, Naïve Bayes, and Partial Least Squares.

RESULTS

The number of pregabalin-treated subjects in the training/test datasets, respectively, were 2818/1407 (30% pain analysis), 2812/1405 (30% sleep analysis), and 2693/1345 (PGIC analysis). All four models demonstrated consistent results, and the most important predictors of treatment outcomes at week 5 and pain outcomes at weeks 8 and 12 were the reduction in pain score and sleep score in the first 1-3 weeks. The presence or absence of the most common AEs in the first 1-3 weeks was not correlated with any treatment outcome.

CONCLUSIONS

Subjects with an early response to pregabalin are more likely to experience an end-of-treatment response.

When pain gets stuck: the evolution of pain chronification and treatment resistance

It is well-recognized that, despite similar pain characteristics, some people with chronic pain recover, whereas others do not. In this review, we discuss possible contributions and interactions of biological, social, and psychological perturbations that underlie the evolution of treatment-resistant chronic pain. Behavior and brain are intimately implicated in the production and maintenance of perception. Our understandings of potential mechanisms that produce or exacerbate persistent pain remain relatively unclear. We provide an overview of these interactions and how differences in relative contribution of dimensions such as stress, age, genetics, environment, and immune responsivity may produce different risk profiles for disease development, pain severity, and chronicity. We propose the concept of "stickiness" as a soubriquet for capturing the multiple influences on the persistence of pain and pain behavior, and their stubborn resistance to therapeutic intervention. We then focus on the neurobiology of reward and aversion to address how alterations in synaptic complexity, neural networks, and systems (eg, opioidergic and dopaminergic) may contribute to pain stickiness. Finally, we propose an integration of the neurobiological with what is known about environmental and social demands on pain behavior and explore treatment approaches based on the nature of the individual's vulnerability to or protection from allostatic load.

Pain intensity as a moderator of the association between opioid use and insomnia symptoms among adults with chronic pain

OBJECTIVE

Research documenting the impact of opioid use on sleep among individuals with chronic pain has been mixed. This study aimed to determine if pain intensity moderates the association between opioid use and insomnia symptoms among adults with comorbid symptoms of insomnia and chronic widespread pain.

METHODS

Participants (N = 144; 95% female; mean age = 51.6, SD = 11.4) completed assessments of insomnia symptoms, pain and use of sleep/pain medication. Multiple regression was used to determine if pain intensity moderates the association between opioid use (yes/no) sleep onset latency (SOL), wake after sleep onset (WASO), sleep quality, or time in bed. Analyses controlled for gender, symptoms of sleep apnea, symptoms of depression, use of sleep medication (yes/no), and use of non-opioid pain medication (yes/no).

RESULTS

Stronger pain intensity was associated with longer self-reported WASO and worse sleep quality, independent of opioid use. Conversely, opioid use was associated with longer time in bed, independent of pain intensity. Opioid use and pain intensity interacted in the prediction of SOL, such that opioid use (vs. non-use) was associated with longer SOL in the context of mild but not moderate to severe pain intensity.

CONCLUSIONS

Opioid use was associated with more difficulty falling asleep among adults with chronic pain; however, this cross-sectional effect was only significant among those reporting lower pain intensity. Authors speculate that this effect is masked among those with severe pain because the pain-related sleep debt they acquire throughout the night then facilitates sleep onset the next day.

A questionnaire-based study of sleep-wake patterns and sleep quality in a TMJ and orofacial pain clinic

OBJECTIVE

To determine the relationships among sleep quality, perceived pain, and psychological distress among patients with TMJ and orofacial pain.

METHODS

The authors examined 3276 patients with temporomandibular disorder (TMD) who visited the Orofacial Pain Clinic at Yonsei University College of Dentistry. The authors conducted a survey using the sleep-quality questionnaire and classified TMD patients into two groups based on Diagnostic Criteria for TMD. For statistical analysis, the authors calculated the correlations between pain intensity as measured using a numeric rating scale (NRS) and various factors.

RESULTS

The statistical analysis revealed correlations between pain intensity on the NRS and some of the factors in the sleep questionnaire. The pain intensity increased with age and for lower sleep efficiency (both p < 0.05).

CONCLUSION

These results imply that clinicians treating patients with orofacial pain should examine their sleep-wake patterns and sleep quality.

The Role of Sleep Quality and Fatigue on the Benefits of an Interdisciplinary Treatment for Adults With Chronic Pain

BACKGROUND

Interdisciplinary chronic pain treatment is effective for reducing pain intensity and pain-related disability, and for improving psychological function. However, the mechanisms that underlie these treatment-related benefits are not yet well understood. Sleep problems and fatigue are modifiable factors often comorbid with chronic pain. The goal of this study was to evaluate the role that changes in sleep quality and fatigue might have on the benefits of an interdisciplinary chronic pain treatment.

METHODS

A total of 125 adults with chronic pain participated in a 4-week interdisciplinary pain management program. Measures of depression, sleep disturbance, fatigue, pain intensity, and physical function were administered at pre- and post-treatment. Three regression analyses were conducted to evaluate the contribution of pre- to post-treatment improvements in fatigue and sleep disturbance to the pre- to post-treatment improvements in pain intensity, disability, and depression, while controlling for demographic characteristics (age and sex) and pain intensity.

RESULTS

Changes in fatigue and sleep disturbance made independent and significant contributions to the prediction of treatment-related benefits in pain intensity; improvements in depressive symptoms were predicted by improvements in fatigue, and improvements in disability were only predicted by pre-treatment and pre- to post-treatment decreases in pain intensity (one of the control variables).

CONCLUSIONS

In addition to sleep, fatigue emerged as a key potential mechanism of multidisciplinary chronic pain treatment-related improvements, suggesting that interventions including elements that effectively target sleep and fatigue may enhance the efficacy of interdisciplinary chronic pain programs. This possibility should be evaluated in future research.

The Association of Dry Eye Symptom Severity and Comorbid Insomnia in US Veterans

PURPOSE

To investigate the association between dry eye (DE) and insomnia symptom severity.

METHODS

Cross-sectional study of 187 individuals seen in the Miami Veterans Affairs eye clinic. An evaluation was performed consisting of questionnaires regarding insomnia (insomnia severity index [ISI]) and DE symptoms, including ocular pain, followed by a comprehensive ocular surface examination. Using a two-step cluster analysis based on intensity ratings of ocular pain, the patient population was divided into two groups (high and low ocular pain groups: HOP and LOP). A control group was ascertained at the same time from the same clinic as defined by no symptoms of DE (Dry Eye Questionnaire 5 [DEQ5], <6). The main outcome measure was the frequency of moderate or greater insomnia in the DE groups.

RESULTS

The mean age of the study sample was 63 years, and 93% were male. All insomnia complaints were rated higher in the HOP group compared with the LOP and control groups (P<0.0005). Most (61%) individuals in the HOP group experienced insomnia of at least moderate severity (ISI≥15) compared with the LOP (41%) and control groups (18%) (P<0.0005). Black race (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.2-6.0; P=0.02), depression severity (OR, 1.2; 95% CI, 1.1-1.3; P<0.0005), and DE symptom severity (DEQ5; OR, 1.1; 95% CI, 1.01-1.2; P=0.03) were significantly associated with clinical insomnia (ISI≥15) after controlling for potential confounders.

CONCLUSIONS

After adjusting for demographics and medical comorbidities, we show that DE symptom severity is positively associated with insomnia severity.