Naturalistic changes in insomnia symptoms and pain in temporomandibular joint disorder: a cross-lagged panel analysis

Relationship between insomnia and pain in patients with chronic orofacial pain

OBJECTIVE

Few studies have investigated specific associations between insomnia and orofacial pain (OFP). The aim of this cross-sectional study was to examine relationships of insomnia with pain, mental health, and physical health variables among treatment-seeking patients with chronic OFP.

METHODS

OFP diagnosis, demographics, insomnia symptoms, pain intensity, interference, and duration, mental health measures, and number of medical comorbidities were extracted from the medical records of 450 patients receiving an initial appointment at a university-affiliated tertiary OFP clinic. T-tests compared differences between patients with and without insomnia symptomatology, and between patients with different insomnia subtypes (delayed onset/early wakening).

RESULTS

Compared to patients without insomnia, those with elevated insomnia symptomatology (45.1%) reported higher pain intensity (60.70 ± 20.61 vs 44.15 ± 21.69; P < .001) and interference (43.81 ± 29.84 vs 18.40 ± 23.43; P < 0.001), depression/anxiety symptomatology (5.53 ± 3.32 vs 2.72 ± 2.66; P < 0.001), dissatisfaction with life (21.63 ± 6.95 vs 26.50 ± 6.21; P < .001), and number of medical comorbidities (6.72 ± 5.37 vs 4.37 ± 4.60; P < .001). Patients with Sleep Onset Latency insomnia (SOL-insomnia) (N = 76) reported higher pain intensity (t = 3.57; P < 0.001), and pain interference (t = 4.46; P < .001) compared to those without SOL-insomnia. Those with Early Morning Awakening insomnia (EMA-insomnia) (N = 71) did not significantly differ from those without EMA-insomnia on any of the variables. Differences remained significant after adjusting for age, sex, primary OFP diagnosis, and pain intensity.

CONCLUSIONS

Insomnia is associated with pain outcomes and should be appropriately managed when treating patients with chronic OFP.

Dental sleep medicine education among undergraduate dental students in France

INTRODUCTION

Dental sleep medicine (DSM) is an emerging discipline that studies the oral and maxillofacial causes and consequences of sleep-related problems. DSM is of upmost importance given the major medical challenge it represents. Therefore, to verify whether the future generation of dentists would be ready to face this challenge, the main objective of this study was to assess the degree of involvement of the French dental schools in teaching DSM at the undergraduate level.

MATERIALS AND METHODS

All 16 dental schools in France were asked to participate in the study by answering to an online survey concerning the DSM curriculum during the 2018-2019 academic year. The survey was addressed to the head of the dental school and/or to relevant course coordinators and contained 10 questions related to the type, content and amount of DSM teaching to undergraduate dental students.

RESULTS

Nine of the 16 (56.2%) French dental schools responded to the questionnaire. All these nine reported the inclusion of DSM in their undergraduate curriculum. The total average hours dedicated to teaching DSM was 5.6 h (SD 4.2; range 1-15 h). Seven of the 9 dental schools spent most of their DSM curriculum teaching time in the fifth year. All of them reviewed obstructive sleep apnoea and sleep-related bruxism and covered some topics related to therapies for sleep-related breathing disorders, such as the use of oral appliance.

CONCLUSION

The results of this survey showed that, although the average hourly volume is relatively high, the DSM teaching in French dental schools appeared to be non-standardised, heterogeneous and often lacunar. It is therefore essential to develop a common curriculum and implement it in all dental schools to provide undergraduate students a comprehensive and updated teaching in DSM.

Patients with cluster headache show signs of insomnia and sleep related stress: results from an actigraphy and self-assessed sleep study

BACKGROUND

Cluster headache (CH) is a primary headache disorder which is characterized by circadian timing of headache attacks, usually at nighttime, in around two thirds of patients. Patients with CH often report sleep difficulties, though it is unknown whether this is a cause or a consequence of nightly headache attacks.

OBJECTIVE

In this case-control study we have assessed sleep quality in study participants with CH in cluster bout respectively in remission, compared to a control group of neurologically healthy individuals to investigate the potential connection between sleep and CH.

METHODS

Fifty study participants with CH and 42 controls were recruited for sleep assessment. Sleep was recorded using MotionWatch 8 actigraphs (CamNTech) for a period of two weeks. Study participants were instructed to wear the unit during rest and sleep and to fill out a sleep diary daily through the two-weeks period.

RESULTS

Results from actigraphy recordings and sleep diaries suggested that patients with CH spend longer time in bed than controls (CH 8.1 hours vs. Controls 7.7 hours, p=0.03), but do not sleep more than controls (CH 6.7 hours vs. controls 6.5 hours, p=0.3). In addition, CH patients reported increased sleep latency (p=0.003), particularly during, but not restricted to, cluster bouts. Study participants with CH further reported higher levels of stress at bedtime (p=0.01), and they felt less well rested than controls (p=0.001).

CONCLUSION

Our analysis suggests that sleep is negatively affected in CH both in cluster bout and in remission, manifesting in symptoms consistent with insomnia such as prolonged sleep latency and increased time in bed.

Sleep quality as a mediator of the relation between depression and chronic pain: a systematic review and meta-analysis

BACKGROUND

Chronic pain and depression represent two global health problems with considerable economic consequences. Although existing literature reports on the relation between depression and pain conditions, meta-analytic evidence backing the mediating role of sleep disturbance as one of the main symptoms of depression is scarce. To examine the extent to which sleep disturbance mediates the depression-chronic pain association, we conducted a systematic review and meta-analysis of the associations of chronic pain, depression, and sleep quality.

METHODS

We systematically searched for literature in MEDLINE and other relevant databases and identified cohort and case-control studies on depression, sleep disturbance, and chronic pain. Forty-nine studies were eligible, with a total population of 120 489 individuals. We obtained direct and indirect path coefficients via two-stage meta-analytic structural equation modelling, examined heterogeneity via subgroup analyses, and evaluated primary studies quality.

RESULTS

We found a significant, partial mediation effect of sleep disturbance on the relation between depression and chronic pain. The pooled path coefficient (coef.) of the indirect effect was 0.03 (95% confidence interval [CI]: 0.01-0.05) and accounted for 12.5% of the total effect of depression on chronic pain. This indirect effect also existed for cohort studies (coef. 0.02; 95% CI: 0.002-0.04), European studies (coef. 0.03; 95% CI: 0.004-0.05), and studies that adjusted for confounders (coef. 0.04; 95% CI: 0.01-0.09).

CONCLUSIONS

Sleep disturbance partially mediates the association between depression and pain. Although plausible mechanisms could explain this mediation effect, other explanations, including reverse causation, must be further explored.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42022338201.

Temporomandibular Joint Disorder Comorbidities

Comorbidity is a distinct additional condition that either existed or exists during the clinical course of a patient afflicted by the condition/entity in question. The clinician attempting to manage temporomandibular joint disorder (TMD) and TMD pain must realize that recognition and management of the comorbidities are essential to the successful management of the same with optimal pain control. When TMD presents with multiple comorbidities, the task for the clinician becomes more complex. It is the hope of the authors that this condensed version of TMD-associated comorbidities acts as a primer for understanding the significance of the same in pain management.

Focus Groups to Inform the Development of a Patient-Reported Outcome Measure (PROM) for Temporomandibular Joint Disorders (TMDs)

BACKGROUND

Understanding symptoms of temporomandibular joint disorders (TMDs) can help doctors and patients document, monitor, and manage the disease and help researchers evaluate interventions. Patients with TMDs experience symptoms ranging from mild to severe, primarily in the head and neck region. This study describes findings from formative patient focus groups to capture, categorize, and prioritize symptoms of TMDs towards the development of a patient-reported outcome measure (PROM).

METHODS

We conducted ten focus groups with 40 men and women with mild, moderate, and severe TMD. Focus groups elicited descriptions of symptoms and asked participants to review a list of existing patient-reported outcomes (PROs) from the literature and patient advisor input and speak to how those PROs reflect their own experience, including rating their importance.

RESULTS

We identified 52 distinct concepts across six domains: somatic, physical, social, sexual, affective, and sleep. Focus groups identified the ability to chew and eat; clicking, popping, and other jaw noises; jaw pain and headaches; jaw misalignment or dislocation; grinding, clenching, or chewing, including at night; and ear sensations as most important. Participants with severe TMDs more often reported affective concepts like depression and shame than did participants with mild or moderate TMDs.

CONCLUSION

Findings support PROM item development for TMDs, including selecting existing PROMs or developing new ones that reflect patients' lived experiences, priorities, and preferred terminology. Such measures are needed to increase understanding of TMDs, promote accurate diagnosis and effective treatment, and help advance research on TMDs.

Is there any association between sleep disorder and temporomandibular joint dysfunction in adults? - A systematic review

OBJECTIVE

To answer the question, "Is there any association between sleep disorder and temporomandibular joint dysfunction (TMD) in adults?"

METHODS

This study followed PRISMA guidelines and was registered in PROSPERO. As eligibility criteria, observational studies that evaluated the association between sleep disorder and TMD were included. Exclusion criteria included a) studies that evaluated sleep quality and not the association of sleep disorders with TMD, b) experimental studies, book chapters, conference proceedings, and systematic reviews. The Joanna Briggs Institute tool was used to assess the risk of bias.

RESULTS

In the literature search, 3425 articles were found. After the exclusion of duplicates, 2752 were selected for reading the title and abstract, of which 26 were read in full, and 18 met eligibility criteria.

CONCLUSION

The association of sleep bruxism with TMD is controversial. While, for obstructive sleep apnea, insomnia, snoring, and gastroesophageal reflux, the analyzed studies showed a positive association.

Insomnia with objective short sleep duration in women with temporomandibular joint disorder: quantitative sensory testing, inflammation and clinical pain profiles

OBJECTIVES/BACKGROUND

Temporomandibular joint disorder (TMD) is a disabling facial pain syndrome with a high prevalence of insomnia that primarily affects women. Insomnia with objective short sleep duration (ISSD) is an emerging phenotype linked to cardiometabolic morbidity and increased mortality. The present report examines the association of ISSD on clinical and laboratory pain and systemic inflammation in TMD.

METHODS

We collected baseline data from 128 women with TMD and insomnia as part of a clinical trial evaluating psychological interventions for sleep and pain. Participants completed self-report questionnaires, one-night polysomnography, a two-week actigraphy assessment, quantitative sensory testing (QST) to assess cold pain tolerance, pain sensitivity and central sensitization and circulating Interleukin-6 levels were measured to assess systemic inflammation.

RESULTS

24.2% (n = 31) of the sample met criteria for ISSD [polysomnography (sleep duration <6 h)]. Compared to those with insomnia and normal sleep duration, ISSD were older (40.4 vs. 34.9,p < 0.05) and a greater proportion self-identified as Black (48.4% vs 11.3%,p < 0.001). Multivariate regressions revealed that ISSD endorsed higher self-report pain severity and functional limitation of the jaw. ISSD also demonstrated increased generalized pain sensitivity, enhanced central sensitization, cold pressor tolerance and higher resting interleukin-6 levels.

CONCLUSIONS

This is the first study to characterize the ISSD phenotype in a chronic pain sample and expand the scope of its negative health outcomes to chronic pain. ISSD may be an important chronic pain phenotype associated with a more severe clinical and laboratory pain profile, and future studies should focus on implications for treatment response and disease trajectory.

CLINICAL TRIAL

ClinicalTrials.gov Identifier: NCT01794624.

The Use of Spiritual and Religious Interventions for the Treatment for Insomnia: A Scoping Review

Insomnia is a common problem, affecting individuals' health and quality of life. Among several therapies used to treat this condition, spiritual interventions are suggested to have beneficial outcomes on sleep disturbances. Nevertheless, a systematic compilation of the evidence available is still needed in the literature in order to scientifically investigate the topic. To examine the most common spiritual interventions proposed to treat sleep disorders and to assess the scientific evidence of these interventions. This is a scoping literature review conducted by independent researchers on the following databases: PubMed, SCOPUS, Web of Science, Cochrane Library and OpenGrey. A boolean expression was used, and all studies published in the last 5 years investigating the role of spiritual or religious interventions on insomnia were included. From a total of 3257 articles retrieved in our search, ten studies were included in the final analysis. There is a wide array of techniques used to treat insomnia or the mental disorders associated with insomnia, such as mantra, yoga, mindfulness, praying/meditation, daily spiritual experiences, psycho-religious training and intervention. The included studies showed a positive influence of spiritual/religious interventions on insomnia directly and indirectly. However, there is a scarcity of clinical trials and most studies have small sample sizes and used only subjective measures, resulting in a low evidence. The results of the present review point to a promising role of spirituality and religion on better sleep outcomes, particularly in the improvement in insomnia. However, the heterogeneity and the quality of these studies suggest caution while interpreting these findings. More clinical trials are needed in this area to provide a recommendation of these methods in clinical practice.

The Relationship Between Primary Sleep Disorders and Temporomandibular Disorders: An 8-Year Nationwide Cohort Study in South Korea

Background

While evidence is accumulating to propose a specific contribution of sleep disorders and low quality sleep in the pathogenesis of temporomandibular disorders (TMD), management of primary sleep disorders in the process of preventing and treating TMD still remains scientifically unsupported.

Objective

To investigate the association of primary sleep disorders with TMD risk in South Korea.

Patients and Methods

This study was based on the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) of South Korea with 468,882 participants. After excluding participants diagnosed in 2002, those with a diagnosis of a primary sleep disorder in 2003–2005 were recruited. All participants diagnosed with TMD between January 1, 2006 and December 31, 2013 received follow-up. Cox proportional hazards regression was performed to determine the adjusted hazard ratios (aHR) and 95% confidence interval (CI) for TMD according to the presence or absence of a primary sleep disorder diagnosis.

Results

After adjusting for all covariates, primary sleep disorder patients had a 44% higher risk for TMD compared with non-sleep disorder participants (aHR 1.44, 95% CI 1.02–2.04). The incidence rate of TMD was nearly twice as high in participants with sleep disorders compared with those without (6.08 vs 3.27, per 10⁴ person-years). In subgroup analysis, an association was observed with those over 60 years old or who frequently exercised physically.

Conclusion

Primary sleep disorders could be an important independent risk factor for the initiation and maintenance of TMD. Patients with sleep disorders should be monitored for possible co-occurrence of TMD-related symptoms that could aggravate sleep disorders in turn.

Sleep disturbance and pain in U.S. adults over 50: evidence for reciprocal, longitudinal effects

OBJECTIVE

To examine the relationship between sleep disturbance and pain over a 14-year period.

METHODS

This study used data from the 2002-2016 waves of the Health and Retirement Study (HRS), an observational study of U.S. adults over age 50 (n = 17,756). Sleep disturbance was measured via four items (assessing difficulty falling asleep, staying asleep, and waking up too early as well as restedness) and pain via two items assessing the presence and degree of pain. Analyses consisted of path analysis; more specifically, random intercept cross-lagged panel modeling (RI-CLPM) was used to examine how pain and sleep disturbance predict one another over two-year intervals after accounting for the trait-like nature of both factors.

RESULTS

There was evidence of reciprocal effects between sleep disturbance and pain across some, but not all, intervals. Moreover, the latent variables representing the trait-like nature of sleep disturbance and pain both showed significant variance (p < 0.001), indicating stable differences between persons in sleep and pain. These trait-like characteristics were strongly associated (β = 0.51, p < 0.001). The findings remained after adjusting the model for baseline age, self-reported health, partner status, depression, years of education, and sex.

CONCLUSION

Sleep disturbance and pain are stable experiences. Moreover, there was some evidence that sleep disturbance and pain are bidirectionally linked across time among adults over 50, whereby across some intervals deviations in one's typical level of sleep disturbance predicted corresponding deviations in one's typical level of pain and vice versa. Clinically, this comorbidity and potential longitudinal bidirectionality underscore the importance of evidence-based interventions that target both sleep and pain among older individuals. Further studies should replicate these findings by collecting validated and/or objective sleep and pain measures on a more frequent basis.

Temporomandibular disorder subtypes, emotional distress, impaired sleep, and oral health-related quality of life in Asian patients

OBJECTIVES

This study determined the differences in emotional states, sleep and oral health-related quality of life (OHRQoL) between patients with pain-related and intra-articular Temporomandibular disorders (TMDs), and associated emotional symptoms with sleep and OHRQoL.

METHODS

Participants were recruited from a tertiary TMDs referral centre. The Depression, Anxiety, Stress Scales-21 (DASS-21), Pittsburgh Sleep Quality Index (PSQI) and Oral Health Impact Profile-TMDs (OHIP-TMDs) were used to assess emotional states, sleep and Oral health-related quality of life (OHRQoL), respectively. TMD-related and sociodemographic data were also gathered. Patients were divided into pain-related (PT), intra-articular (IT) and combined TMDs (CT) groups based on the Diagnostic Criteria for TMDs. Data were analysed using one-way ANOVA, Chi-square test, Pearson's correlation and logistic regression analysis with the significance level set at P < .05.

RESULTS

Data from 1079 participants with a mean age of 29.6 ± 14.2 years were appraised (93.3% response rate). The severity/prevalence of emotional distress, impaired sleep and OHRQoL of the PT/CT groups were higher than the IT group. Moderate-to-strong inter-relationships between emotional, sleep and OHRQoL variables were more explicit for participants with painful TMDs. Logistic regression analysis demonstrated that painful TMDs were associated with higher stress and poorer OHRQoL with odds ratios (ORs) of 1.482 (95% CI 1.039-2.114) and 6.502 (95% CI 3.201-13.210), respectively.

CONCLUSIONS

Painful TMDs are associated with higher levels of emotional distress, sleep and OHRQoL impairments. Routine evaluation of the biopsychosocial distress, especially stress and life quality, is necessary for patients with painful TMDs.

Ultrasound-Guided Thoracic Paravertebral Nerve Block on Postoperative Pain, Quality of Life, and Recovery in Patients with Non-Small-Cell Lung Cancer

Objectives

Our study will investigate the effect of ultrasound-guided thoracic paravertebral block (UG-TPVB) on postoperative pain, quality of life, and enhanced recovery in patients with non-small-cell lung cancer (NSCLC) undergoing lobectomy surgery.

Methods

Our study included 100 patients aged 52 to 75 years who underwent lobectomy surgery with pathological diagnosis of NSCLC. Patients received ultrasound-guided thoracic paravertebral block or general anesthesia with tracheal intubation. Patients' pain score was recorded on a numeric rating scale (NRS) 24 hours post operation. The total postoperative dosage of tramadol hydrochloride, length of hospitalization, quality of life (QoL), and inflammation levels were recorded.

Results

Compared with patients who received general anesthesia with tracheal intubation, patients in the UG-TPVB group had lower postoperative NRS scores at 24 h (1.8 vs. 3.5, P = 0.035); the average 24 h postoperative NRS score of the UG-TPVB group is lower than that of the general anesthesia with tracheal intubation (4.6 vs. 5.3, P = 0.012), thus receiving less dosage of tramadol hydrochloride (221 ± 45 vs. 250 ± 38 mg, P < 0.01). Patients in the UG-TPVB group had better EORTC QLQ-C30 scores compared with patients in the general anesthesia with tracheal intubation group. The difference of length of hospitalization, hs-CRP, and IL-6 between two groups did not reach statistical difference (length of hospitalization 6.2 vs. 6.9 days, P = 0.055; hs-CRP: 7.1 ± 1.9 vs. 10.4 ± 6.6, P = 0.095; and IL-6: 71.3 ± 7.2 vs. 68.9 ± 8.7, P = 0.529). Discussion. NSCLC patients undergoing lobectomy surgery who received UG-TPVB had less postoperative pain, used less dosage of tramadol hydrochloride, and had better QoL.

Comparison of the Effectiveness of Three Different Acupuncture Methods for TMD-Related Pain: A Randomized Clinical Study

PURPOSE

This study aimed to compare the effectiveness of three acupuncture methods for temporomandibular disorders- (TMDs-) related pain.

MATERIALS AND METHODS

Different locations of pain, according to DC/TMD clinical assessment, were considered: temporomandibular joint (TMJ), masticatory muscles, head, and neck. Sixty patients were assigned randomly to one of three treatment groups (20 patients in each): group BA received body acupuncture, group EA received electroacupuncture, and group CA received acupuncture + cupping. The groups were compared in terms of pain (verbal numeric scale), pain-related disability (Brief Inventory Pain, BPI), and impression of the treatment's effectiveness (Patients' Global Impression of Improvement Scale, PGI-I). These were recorded before sessions of acupuncture treatment (T0), after 8 sessions of acupuncture treatment (T1), and after 4 weeks of follow-up after treatment (T2). The between-group and within-group differences in the data were analyzed statistically. The baseline characteristics were similar in all groups (p > 0.05).

RESULTS

Significant improvements were noted in all types of pain compared to baseline values in all groups (all p < 0.05). No significant differences were noted in the improvement of TMDs-related pain according to the different acupuncture techniques (all p > 0.05). All acupuncture methods used resulted to be significantly effective in improving the pain-related interference in the patient's common activities and quality of life. EA resulted to be significantly more effective than BA and CA in improving the interference of pain with patients' mood (p=0.015) and quality of sleep (p=0.014).

CONCLUSION

BA, EA, and CA are all effective acupuncture methods in reducing pain and pain interference with common activities and quality of life in patients affected by TMD.

The role of sleep dysfunction in temporomandibular onset and progression: A systematic review and meta-analyses

BACKGROUND

Painful temporomandibular (TM) disorders result in 4.3 billion dollars spent annually in the United States. The complex interplay of physiological processes in persistent pain and dysfunctional sleep has been established. Recently, dysfunctional sleep has been identified as a potential pathway to the onset of painful TM disorder.

OBJECTIVES

The aims were to (1) identify self-report outcome measures (SROMs) of sleep quality that are clinimetrically sound in patients with painful TM disorders and (2) determine whether sleep dysfunction has any diagnostic or prognostic value for this population.

METHODS

A systematic search following PRISMA guidelines was run in six databases: CINAHL, Dental, PsychALL, PubMed, Scopus and Web of Science. Any study involving minors was excluded. Risks of biases were examined in all studies. Diagnostic pooled findings were reported.

RESULTS

Of the identified articles (n = 681), 18 were included in this systematic review (n = 1 clinimetric studies, n = 11 diagnostic studies, n = 6 prognostic studies). Nine different assessment tools were used; only the Pittsburg Sleep Quality Index (PSQI) has been validated in patients with painful TM disorders. Overall, sleep dysfunction was diagnostic for painful TM disorders. The pooled relative risk of sleep dysfunction was 1.71 (95% CI 1.30. 2.26). When PSQI scores were greater than 5/21, the unadjusted hazard ratio for development of painful TM disorders was reported to be 2.1.

CONCLUSION

At present, the only SROM that has diagnostic and prognostic value in evaluating and managing patients with painful TM disorders is the PSQI.

Sleep and Pain: A Systematic Review of Studies of Mediation

Supplemental Digital Content is available in the text.

Objectives:

A relationship between sleep and pain is well established. A better understanding of the mechanisms that link sleep and pain intensity is urgently needed to optimize pain management interventions. The objective of this systematic review was to identify, synthesize, and critically appraise studies that have investigated putative mediators on the path between sleep and pain intensity.

Methods:

A systematic search of 5 electronic bibliographic databases (EMBASE, MEDLINE, CINAHL, PsycINFO, and the Cochrane Central Register of Controlled Trials) was conducted. Eligible studies had to apply a formal test of mediation to variables on the path between a sleep variable and pain intensity or vice versa. All searches, data extraction and quality assessment were conducted by at least 2 independent reviewers.

Results:

The search yielded 2839 unique articles, 9 of which were eligible. Of 13 mediation analyses, 11 investigated pathways from a sleep variable to pain intensity. Putative mediators included affect/mood, depression and/or anxiety, attention to pain, pain helplessness, stress, fatigue, and physical activity. Two analyses investigated pathways from pain intensity to a sleep variable, examining the potentially mediating role of depressive symptoms and mood. Although evidence supported a mediating role for psychological and physiological aspects of emotional experiences and attentional processes, methodological limitations were common, including use of cross-sectional data and minimal adjustment for potential confounders.

Discussion:

A growing body of research is applying mediation analysis to elucidate mechanistic pathways between sleep and pain intensity. Currently sparse evidence would be illuminated by more intensively collected longitudinal data and improvements in analysis.

Chronic Pain and Sleep Disturbances: A Pragmatic Review of Their Relationships, Comorbidities, and Treatments

Objective

The objective of this review is to answer three questions: 1) How are chronic pain severity and pain duration affected in patients with chronic pain and sleep disturbances that occur simultaneously? 2) What are common comorbidities and pain-related symptoms seen in patients with chronic pain and sleep disturbances? and 3) What are potentially effective pharmacological and nonpharmacological treatment options for both conditions?

Methods

Ovid Medline and PubMed were searched. Search terms included sleep wake disorder, chronic pain, fibromyalgia, treatment outcome, psychotherapy, complementary therapies, and therapeutics. Studies that assessed outcomes between individuals with chronic pain and those with concurrent chronic pain and sleep disturbances were included. Randomized controlled clinical trials of treatments for both conditions were included.

Results

Sixteen studies indicated that patients with both chronic pain and sleep disturbances have greater pain severity, longer duration of pain, greater disability, and are less physically active than those without sleep disturbances. Patients with both conditions are more likely to have concurrent depression, catastrophizing, anxiety, and suicidal ideation. Thirty-three randomized controlled trials assessed treatment for both chronic pain and sleep disturbances. Pregabalin was the most frequently studied medication, showing improvement in pain and sleep symptoms. Cognitive behavioral therapy for insomnia showed long-term improvement in sleep for patients with chronic pain.

Conclusions

Individuals with chronic pain and sleep disturbances have greater symptom severity, longer duration of symptoms, more disability, and additional comorbidities. Pharmacological and nonpharmacological treatments may be useful in the treatment of concurrent chronic pain and sleep disturbances, but further study is needed.

Factors associated with signs of temporomandibular pain: an 11-year-follow-up study on Finnish adults

Background: Pain in the temporomandibular region is a main complaint causing disability and distress among temporomandibular disorders sufferers.Objectives: The aim of the study was, over an 11-year follow-up on Finnish adult population, to investigate the prevalence of clinically assessed pain-related temporomandibular disorder (TMD) signs, i.e. temporomandibular joint (TMJ) and masticatory muscles (MM) pain on palpation, and their association with sociodemographic background and denture status.Methods: The data were based on the nationally representative Finnish Health 2000 and Health 2011 Surveys (BRIF8901). The sample comprised 1210 adults who underwent clinical oral examinations including TMD signs assessment. Statistical evaluations included chi-square tests and logistic regressions.Results: The prevalence of palpatory MM pain decreased from 9.5% at baseline to 4.6% in the follow-up. Cross-sectionally, presence of palpatory MM pain significantly associated with gender (p < .001, p = .002) and educational level (p < .001, p = .001) in both years, and with age (p = .006) and denture status (p = .022) at baseline. The prevalence of palpatory TMJ pain increased from 2.1% at baseline to 3.5% in the follow-up. Presence of palpatory TMJ pain significantly associated with gender in both years (p = .012, p = .032). Female gender, lower education and palpatory MM pain at baseline predicted palpatory MM pain in the follow-up.Conclusion: Palpatory MM pain is relatively prevalent in adults, yet with a favourable prognosis. Women and people with low education are more susceptible groups. Previous experience of palpatory MM pain increases the risk of exhibiting it later in life.

The role of sleep quality on the relationship between posttraumatic stress symptoms and pain in women

Pain frequently co-occurs with elevated posttraumatic stress symptoms (PTSS); women are at elevated risk for their co-occurrence. PTSS and pain are associated with poor sleep quality; yet, little research has examined how sleep impacts their co-occurrence. The current study examines the indirect role of sleep on the relationship between PTSS and pain. A community sample of 182 women completed psychometrically-sound questionnaires assessing PTSS, sleep quality, pain characteristics, depression and anxiety symptoms, and anxiety sensitivity. We examined how sleep quality impacted associations among PTSS and pain intensity and pain interference, while controlling for key psychological factors. Greater PTSS was associated with worse pain interference, and poor sleep quality had a significant indirect effect on this relationship. Sleep may represent a modifiable behavioral mechanism that contributes to the mutual maintenance of PTSS and pain in women. Future research is needed to further clarify the role of sleep quality in their co-occurrence.

Influence of craniocervical and craniomandibular dysfunction to nonrestorative sleep and sleep disorders

Objective: Nonrestorative sleep and sleep disorders are commonly reported in patients suffering from craniomandibular (CMD) and craniocervical dysfunctions (CCD). This study aimed to investigate polysomnographic characteristics and the reduction of pain before and after treatment in these patients.Methods: Seventy-four patients with sleep disorders and evident CMD and CCD were included. Manual therapy and an Aqualizer® were used in the therapeutic group. Polysomnographic measurements were conducted pre- and post-therapy.Results: The number of sleep stage alterations and the sleep stage index differed significantly between pre- and post-therapeutic measurements. Between both groups, these parameters were significantly different, as well (p = .001 and p = .012). The subjective perception of sleep quality improved in 81.6% post-therapy (p < .001).Discussion: Manual therapy and the application of an Aqualizer® may improve sleep quality in patients suffering from CMD and CCD. Pain may not be the main cause for the sleep disorders in CMD and CCD.

Exploring the Role of Negative Cognitions in the Relationship Between Ethnicity, Sleep, and Pain in Women With Temporomandibular Joint Disorder

Negative cognitions are central to the perpetuation of chronic pain and sleep disturbances. Patients with temporomandibular joint disorder (TMJD), a chronic pain condition characterized by pain and limitation in the jaw area, have a high comorbidity of sleep disturbances that possibly exacerbate their condition. Ethnic group differences are documented in pain, sleep, and coping, yet the mechanisms driving these differences are still unclear, especially in clinical pain populations. We recruited 156 women (79% white, 21% African American) diagnosed with TMJD as part of a randomized, controlled trial evaluating the effectiveness of interventions targeting sleep and pain catastrophizing on pain in TMJD. Analysis of baseline data demonstrated that, relative to white participants, African Americans exhibited higher levels of clinical pain, insomnia severity, and pain catastrophizing, yet there was no ethnic group difference in negative sleep-related cognitions. Mediation models revealed pain catastrophizing, but not sleep-related cognitions or insomnia severity, to be a significant single mediator of the relationship between ethnicity and clinical pain. Only the helplessness component of catastrophizing together with insomnia severity sequentially mediated the ethnicity-pain relationship. These findings identify pain catastrophizing as a potentially important link between ethnicity and clinical pain and suggest that interventions targeting pain-related helplessness could improve both sleep and pain, especially for African American patients. Perspective:Pain-related helplessness and insomnia severity contribute to ethnic differences found in clinical pain among woman with TMJD. Findings can potentially inform interventions that target insomnia and catastrophizing to assist in reducing ethnic disparities in clinical pain.

Depressive symptoms account for differences between self-reported versus polysomnographic assessment of sleep quality in women with myofascial TMD

Patients with temporomandibular disorder (TMD) report poor sleep quality on the Pittsburgh Sleep Quality Index (PSQI). However, polysomnographic (PSG) studies show meagre evidence of sleep disturbance on standard physiological measures. The present aim was to analyse self-reported sleep quality in TMD as a function of myofascial pain, PSG parameters and depressive symptomatology. PSQI scores from 124 women with myofascial TMD and 46 matched controls were hierarchically regressed onto TMD presence, ratings of pain intensity and pain-related disability, in-laboratory PSG variables and depressive symptoms (Symptoms Checklist-90). Relative to controls, TMD cases had higher PSQI scores, representing poorer subjective sleep and more depressive symptoms (both P < 0·001). Higher PSQI scores were strongly predicted by more depressive symptoms (P < 0·001, R² = 26%). Of 19 PSG variables, two had modest contributions to higher PSQI scores: longer rapid eye movement latency in TMD cases (P = 0·01, R² = 3%) and more awakenings in all participants (P = 0·03, R² = 2%). After accounting for these factors, TMD presence and pain ratings were not significantly related to PSQI scores. These results show that reported poor sleep quality in TMD is better explained by depressive symptoms than by PSG-assessed sleep disturbances or myofascial pain. As TMD cases lacked typical PSG features of clinical depression, the results suggest a negative cognitive bias in TMD and caution against interpreting self-report sleep measures as accurate indicators of PSG sleep disturbance. Future investigations should take account of depressive symptomatology when interpreting reports of poor sleep.

Racial/ethnic differences in sleep quality among older adults with osteoarthritis

OBJECTIVE

To examine racial/ethnic differences in sleep quality and the pain-sleep association among older adults with osteoarthritis of the knee.

DESIGN

Baseline interview followed by a 7-day microlongitudinal study using accelerometry and self-reports.

SETTING

Participants were community residents in western Alabama and Long Island, NY.

PARTICIPANTS

Ninety-six African Americans (AAs) and 128 non-Hispanic whites (NHWs) with physician-diagnosed knee osteoarthritis, recruited from a variety of clinical and community settings.

MEASUREMENTS

Self-reports yielded demographics, body mass index, physical health problems, and depressive symptoms. Sleep quality was measured for 3 to 7 nights using wrist-worn accelerometers; pain was self-reported daily over the same period.

RESULTS

With demographics and health controlled, AAs displayed poorer sleep efficiency, greater time awake after sleep onset and sleep fragmentation, and marginally more awakenings during the night, but no differences in total sleep time. AAs also showed greater night-to-night variability in number of awakenings and sleep fragmentation, and marginally greater variability in total sleep time and sleep efficiency. Sleep quality was not associated with pain either the day before sleep or the day after. Average daily pain interacted with race, whereas AAs displayed no effect of pain on sleep efficiency, NHWs exhibited better sleep efficiency at higher levels of average pain.

CONCLUSIONS

These data corroborate previous studies documenting poorer sleep among AAs vs NHWs. The findings of greater night-to-night variability in sleep among AAs, as well as a negative association of pain with sleep quality among NHWs, are unique. Further study is needed to elucidate these findings.

The reciprocal associations between catastrophizing and pain outcomes in patients being treated for neuropathic pain: a cross-lagged panel analysis study

Catastrophizing is recognized as a key psychosocial factor associated with pain-related negative outcomes in individuals with chronic pain. Longitudinal studies are needed to better understand the temporal relationship between these constructs. The aim of this study was to determine if changes in catastrophizing early in treatment predicted subsequent changes in pain intensity and interference later in treatment, or alternately, if early changes in pain intensity and interference predicted subsequent changes in catastrophizing. A total of 538 patients with neuropathic pain were recruited from 6 multidisciplinary pain clinics across Canada. Study participants were asked to complete measures of catastrophizing, pain intensity, and interference when first seen in the clinic and then again at 3- and 6-month follow-ups. Cross-lagged panel analyses were used to determine the temporal associations among the study variables. The results showed that decreases in catastrophizing early in treatment prospectively predicted improvement in both pain intensity and interference later in treatment. Converse temporal relationships were also found, where a reduction in pain intensity and interference early in treatment predicted a subsequent diminishing of catastrophizing. All 4 unique cross-lagged correlations significantly accounted for an additional 4% to 7% of the total variance. The findings are consistent with theoretical models hypothesizing a causal impact of catastrophizing on pain, suggesting a mutual causation between these factors. The results support that treatments targeting catastrophizing may influence other pain-related outcomes, and conversely that treatments aiming to reduce pain could potentially influence catastrophizing. There may therefore be multiple paths to positive outcomes.

The Neurobiology of Orofacial Pain and Sleep and Their Interactions

This article provides an overview of the neurobiology of orofacial pain as well as the neural processes underlying sleep, with a particular focus on the mechanisms that underlie pain and sleep interactions including sleep disorders. Acute pain is part of a hypervigilance system that alerts the individual to injury or potential injury of tissues. It can also disturb sleep. Disrupted sleep is often associated with chronic pain states, including those that occur in the orofacial region. The article presents many insights that have been gained in the last few decades into the peripheral and central mechanisms involved in orofacial pain and its modulation, as well as the circuits and processes in the central nervous system that underlie sleep. Although it has become clear that sleep is essential to preserve and maintain health, it has also been found that pain, particularly chronic pain, is commonly associated with disturbed sleep. In the presence of chronic pain, a circular relationship may prevail, with mutual deleterious influences causing an increase in pain and a disruption of sleep. This article also reviews findings that indicate that reducing orofacial pain and improving sleep need to be targeted together in the management of acute to chronic orofacial pain states in order to improve an orofacial pain patient’s quality of life, to prevent mood alterations or exacerbation of sleep disorder (e.g., insomnia, sleep-disordered breathing) that can negatively affect their pain, and to promote healing and optimize their health.

A review of chronic pain impact on patients, their social environment and the health care system

Chronic pain (CP) seriously affects the patient’s daily activities and quality of life, but few studies on CP have considered its effects on the patient’s social and family environment. In this work, through a review of the literature, we assessed several aspects of how CP influences the patient’s daily activities and quality of life, as well as its repercussions in the workplace, and on the family and social environment. Finally, the consequences of pain on the health care system are discussed. On the basis of the results, we concluded that in addition to the serious consequences on the patient’s life, CP has a severe detrimental effect on their social and family environment, as well as on health care services. Thus, we want to emphasize on the need to adopt a multidisciplinary approach to treatment so as to obtain more comprehensive improvements for patients in familial and social contexts. Accordingly, it would be beneficial to promote more social- and family-oriented research initiatives.

Subjective Sleep Quality Deteriorates Before Development of Painful Temporomandibular Disorder

There is good evidence that poor sleep quality increases risk of painful temporomandibular disorder (TMD). However, little is known about the course of sleep quality in the months preceding TMD onset, and whether the relationship is mediated by heightened sensitivity to pain. The Pittsburgh Sleep Quality Index was administered at enrollment into the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) prospective cohort study. Thereafter the Sleep Quality Numeric Rating Scale was administered every 3 months to 2,453 participants. Sensitivity to experimental pressure pain and pinprick pain stimuli was measured at baseline and repeated during follow-up of incident TMD cases (n = 220) and matched TMD-free controls (n = 193). Subjective sleep quality deteriorated progressively, but only in those who subsequently developed TMD. A Cox proportional hazards model showed that risk of TMD was greater among participants whose sleep quality worsened during follow-up (adjusted hazard ratio = 1.73, 95% confidence limits = 1.29, 2.32). This association was independent of baseline measures of sleep quality, psychological stress, somatic awareness, comorbid conditions, nonpain facial symptoms, and demographic characteristics. Poor baseline sleep quality was not significantly associated with baseline pain sensitivity or with subsequent change in pain sensitivity. Furthermore the relationship between sleep quality and TMD incidence was not mediated via baseline pain sensitivity or change in pain sensitivity.

PERSPECTIVE

Subjective sleep quality deteriorates progressively before the onset of painful TMD, but sensitivity to experimental pain does not mediate this relationship. Furthermore, the relationship is independent of potential confounders such as psychological stress, somatic awareness, comorbid conditions, nonpain facial symptoms, and various demographic factors.

Evidence for Sustained Mechanical Pain Sensitization in Women With Chronic Temporomandibular Disorder Versus Healthy Female Participants

Generalized dysfunction of the nociceptive system has been hypothesized to be an important pathophysiologic process underlying temporomandibular disorder (TMD) pain. Studies have not identified sensitization to painful stimuli administered prospectively across consecutive days among participants with TMD with chronic pain. We attempted to isolate an empirically derived laboratory-based marker of sustained mechanical pain sensitization. We examined whether this index accounted for variance in prospective assessments of clinical TMD pain. Participants were women with a clinical diagnosis of chronic TMD (n = 30) and healthy female controls (n = 30). Pain thresholds were assessed using digital algometry 4 times at 12-hour intervals over 48 consecutive hours and clinical TMD pain via follow-up telephone assessments. Sustained mechanical pain sensitization, defined by statistically significant linear decrements in pressure pain thresholds across the consecutive testing sessions, discriminated chronic TMD and control participants. An index of sustained sensitization at the masseter accounted for unique variance in clinical TMD pain over the subsequent 3-month assessment period, even controlling for mean pain threshold and baseline pain severity. These preliminary findings highlight discriminant and predictive validity characteristics of a novel marker of protracted pain sensitization among women with chronic TMD pain.

PERSPECTIVE

A laboratory-based and empirically defined marker of sustained mechanical pain sensitization over the course of days with acceptable discriminant and predictive validity was identified. This marker may represent a clinically useful marker of chronic TMD pain in women.

Effects of insomnia disorder and knee osteoarthritis on resting and pain-evoked inflammatory markers

Osteoarthritis is the most prevalent arthritic condition. Systemic inflammatory cytokines appear to have an important role in the onset and maintenance of the disease. Sleep disturbances are prevalent in osteoarthritis and associated with alterations in systemic inflammatory cytokines, suggesting a common pathophysiology across these conditions. A comparative investigation of the effects of insomnia disorder and osteoarthritis on pain-evoked cytokine responses has yet to be undertaken. We examined the influence of symptomatic knee osteoarthritis and insomnia disorder on resting C-reactive protein (CRP), interleukin (IL)-6, and IL-10 levels, and pain-evoked IL-6 and IL-10 responses. Participants were N=117 older adults (mean age=59.7years; 61.8% women) rigorously evaluated for knee osteoarthritis and insomnia disorder using established diagnostic guidelines. Results revealed no association of osteoarthritis or insomnia disorder with CRP. Resting IL-6 was greater in osteoarthritis participants versus those without osteoarthritis, although this association was largely attributable to BMI. IL-10 was highest among participants with osteoarthritis or insomnia disorder. Growth curve modeling revealed that participants with insomnia disorder had greater pain-evoked IL-6 responses than participants without insomnia disorder or osteoarthritis. These findings highlight the utility of laboratory pain testing methods for understanding individual differences in inflammatory cytokines. Moreover, our findings provide evidence for amplified pain-evoked pro-inflammatory cytokine reactivity among older adults with clinically diagnosed insomnia disorder, even after controlling for individual differences in BMI and age. Additional research will be required determine whether an amplified pain-related cytokine response contributes to OA, and possibly other age-related disease, associated with insomnia disorder.

Indirect associations of combat exposure with post-deployment physical symptoms in U.S. soldiers: roles of post-traumatic stress disorder, depression and insomnia

OBJECTIVE

To characterize the indirect associations of combat exposure with post-deployment physical symptoms through shared associations with post-traumatic stress disorder (PTSD), depression and insomnia symptoms.

METHODS

Surveys were administered to a sample of U.S. soldiers (N = 587) three months after a 15-month deployment to Iraq. A multiple indirect effects model was used to characterize direct and indirect associations between combat exposure and physical symptoms.

RESULTS

Despite a zero-order correlation between combat exposure and physical symptoms, the multiple indirect effects analysis did not provide evidence of a direct association between these variables. Evidence for a significant indirect association of combat exposure and physical symptoms was observed through PTSD, depression, and insomnia symptoms. In fact, 92% of the total effect of combat exposure on physical symptoms scores was indirect. These findings were evident even after adjusting for the physical injury and relevant demographics.

CONCLUSION

This is the first empirical study to suggest that PTSD, depression and insomnia collectively and independently contribute to the association between combat exposure and post-deployment physical symptoms. Limitations, future research directions, and potential policy implications are discussed.

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

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.

Parasympathetic reactivity in fibromyalgia and temporomandibular disorder: associations with sleep problems, symptom severity, and functional impairment

Despite evidence of autonomic disturbances in chronic multisymptom illnesses such as temporomandibular disorder (TMD) and fibromyalgia, additional work is needed to characterize the role of parasympathetic reactivity in these disorders. Given the high levels of comorbidity with psychiatric disorders characterized by stronger parasympathetic decline than controls in safe contexts (leading to higher arousal), it was hypothesized that individuals with TMD and fibromyalgia would respond similarly. In this preliminary investigation, 43 women with TMD (n = 17), TMD + fibromyalgia (n = 11), or neither (controls; n = 15) completed a baseline assessment of respiratory sinus arrhythmia (a measure of parasympathetic activity) followed by ongoing parasympathetic assessment during a questionnaire period. As predicted, patients showed greater parasympathetic decline during psychosocial assessment, suggesting an autonomic stance that supports defensive rather than engagement behaviors. Individual differences in parasympathetic reduction during the questionnaire period were related to a variety of physical and psychosocial variables. Although this study has a number of key limitations, including a convenience sampling approach and small group sizes, if replicated in larger samples, the findings would have important implications for the treatment of patients with these disorders.

PERSPECTIVE

Compared to controls, individuals with TMD or TMD and fibromyalgia demonstrated greater parasympathetic decline during psychosocial assessment, and individual differences in parasympathetic decline predicted negative patient outcomes. Such parasympathetic decline may demonstrate a tendency to readily perceive danger in safe environments.

Affective disturbance associated with premenstrual dysphoric disorder does not disrupt emotional modulation of pain and spinal nociception

In healthy individuals, emotions modulate pain and spinal nociception according to a valence linear trend (ie, pain/nociception is highest during negative emotions and lowest during positive emotions). However, emerging evidence suggests that emotional modulation of pain (but not spinal nociception) is disrupted in fibromyalgia and disorders associated with chronic pain risk (eg, major depression, insomnia). The present study attempted to extend this work and to examine whether women with premenstrual dysphoric disorder (PMDD), a cyclical syndrome associated with debilitating affective symptoms during the late-luteal (premenstrual) phase of the menstrual cycle, is also associated with disrupted emotional modulation of pain. To do so, an affective picture-viewing procedure was used to study emotional modulation of pain and spinal nociception in 14 women with PMDD and 14 control women during mid-follicular, ovulatory, and late-luteal phases of the menstrual cycle (verified by salivary hormone levels and luteinizing hormone tests). At each phase, mutilation, neutral, and erotic pictures were presented to manipulate emotion. During picture viewing, suprathreshold electrocutaneous stimuli were presented to evoke pain and the nociceptive flexion reflex (NFR; a physiological measure of spinal nociception). Statistically powerful linear mixed model analyses confirmed that pictures evoked the intended emotional states in both groups across all menstrual phases. Furthermore, emotion modulated pain and NFR according to a valence linear trend in both groups and across all menstrual phases. Thus, PMDD-related affective disturbance is not associated with a failure to emotionally modulate pain, suggesting that PMDD does not share this pain phenotype with major depression, insomnia, and fibromyalgia.

Emotional modulation of pain and spinal nociception in persons with severe insomnia symptoms

BACKGROUND

Impaired sleep enhances pain, perhaps by disrupting pain modulation.

PURPOSE

Given that emotion modulates pain, the present study examined whether emotional modulation of pain and nociception is impaired in persons with severe insomnia symptoms relative to controls.

METHODS

Insomnia group (n = 12) met the International Classification of Diseases, tenth revision symptoms for primary insomnia and controls (n = 13) reported no sleep impairment. Participants were shown emotionally evocative pictures (mutilation, neutral, and erotica) during which suprathreshold pain stimuli were delivered to evoke pain and the nociceptive flexion reflex (NFR; physiological correlate of spinal nociception).

RESULTS

Emotional responses to pictures were similar in both groups, except that subjective valence/pleasure ratings were blunted in insomnia. Emotional modulation of pain and NFR was observed in controls, but only emotional modulation of NFR was observed in insomnia.

CONCLUSIONS

Consistent with previous findings, pain modulation is disrupted in insomnia, which might promote pain. This may stem from disrupted supraspinal circuits not disrupted brain-to-spinal cord circuits.

Cognitive-Behavioral Therapy for Comorbid Insomnia and Chronic Pain

This article summarizes the literature on cognitive-behavioral therapy for insomnia (CBT-I) in patients with comorbid insomnia and chronic pain. An empirical rationale for the development of CBT-I in chronic pain is provided. The six randomized controlled trials in this area are described and contrasted. The data suggest that CBT-I for patients with comorbid insomnia and chronic pain produces clinically meaningful improvements in sleep symptoms. Effects on pain are inconsistent, but tend to favor functional measures over pain severity. Hybrid interventions for insomnia and pain have demonstrated feasibility, but larger trials must be conducted to determine efficacy relative to CBT-I alone. Future efforts should employ more comprehensive assessments of pain and psychosocial factors.

Effects of sleep deprivation on pain-related factors in the temporomandibular joint

BACKGROUND

The objective of this study was to investigate the effects of experimental sleep deprivation (SD) on the temporomandibular joint (TMJ) in rats by examining pain-related factors and to determine the possible involvement of estrogen and NF (nuclear factor) κB signaling in the TMJ synovial membrane.

METHODS

The influence of SD, conducted in rats using the modified multiple platform method, was estimated by observing behavioral manifestations and examining changes in serum hormone levels. The morphologic changes of synovial tissue were observed with light microscopy and the serum levels of estrogen were measured by radioimmunoassay. Activation of NF-κB in the synovial membrane was examined using an immunofluorescence technique, and the expression levels of interleukin (IL) 1β, IL-6, tumor necrosis factor α, cyclooxygenase 2, and inducible nitric oxide synthase were measured with real-time polymerase chain reaction.

RESULTS

The SD group showed evidence of elevated anxiety and stress, and increased plasma levels of estradiol compared with the control group. The activity of NF-κB was significantly enhanced and translocation of NF-κB p65 was evident in the synovial membrane after SD. The expression of pain-related factors IL-1β, IL-6, cyclooxygenase-2, tumor necrosis factor α, and inducible nitric oxide synthase in the synovial membrane significantly increased after SD.

CONCLUSIONS

These results indicate that SD increases serum levels of estrogen and induces alterations in pain-related factors in the TMJ. The NF-κB pathway has been associated with the regulation of these inflammatory cytokines and plays an important role in temporomandibular disorders.

Symbolic number abilities predict later approximate number system acuity in preschool children

An ongoing debate in research on numerical cognition concerns the extent to which the approximate number system and symbolic number knowledge influence each other during development. The current study aims at establishing the direction of the developmental association between these two kinds of abilities at an early age. Fifty-seven children of 3-4 years performed two assessments at 7 months interval. In each assessment, children's precision in discriminating numerosities as well as their capacity to manipulate number words and Arabic digits was measured. By comparing relationships between pairs of measures across the two time points, we were able to assess the predictive direction of the link. Our data indicate that both cardinality proficiency and symbolic number knowledge predict later accuracy in numerosity comparison whereas the reverse links are not significant. The present findings are the first to provide longitudinal evidence that the early acquisition of symbolic numbers is an important precursor in the developmental refinement of the approximate number representation system.

Polysomnographic investigation of sleep and respiratory parameters in women with temporomandibular pain disorders

STUDY OBJECTIVES

Temporomandibular pain disorders (TMD) and myofascial pain were linked to increased prevalence of insomnia and obstructive sleep apnea (OSA) on clinical grounds. However, the literature lacks an accurate polysomnographic (PSG) characterization of sleep abnormalities associated with TMD, given that prior studies included small or uncontrolled samples of TMD patients. The present investigation aims to objectively evaluate measures of sleep and respiratory disturbance in a large representative sample of TMD cases in comparison with matched controls.

METHODS

Sleep, respiration, and limb movements were measured using a 2-night attended PSG protocol in 170 women-124 TMD cases with myofascial pain and 46 demographically matched controls. The second night data were compared between the groups using ANCOVAs. In TMD cases, the relationship between pain ratings and sleep parameters was analyzed using multiple regressions.

RESULTS

In comparison to healthy controls, TMD cased evidenced a significant increase in stage N1 sleep (12.2% ± 7.6% vs. 9.2% ± 5.0%, p = 0.03), which was only mild relative to normative values. TMD cases also demonstrated mild but significant elevations in arousals associated with all types of respiratory events (6.0/h ± 6.1 vs. 3.5/h ± 3.3 p = 0.02) and in respiratory effort related arousals (RERAs, 4.3/h ± 4.3 vs. 2.6/h ± 2.7, p = 0.02). Myofascial pain predicted a lower sleep efficiency (p = 0.01), more frequent awakenings (p = 0.04), and higher RERA index (p = 0.04) among TMD cases.

CONCLUSIONS

Myofascial pain in TMD is associated with mild elevation in sleep fragmentation and increased frequency of RERA events. Further research is required to evaluate the clinical significance of these findings.

A 10-year trend of insomnia prevalence in the adult Norwegian population

OBJECTIVE

We aimed to investigate the 10-year trend in the prevalence of insomnia symptoms, insomnia cases, and use of hypnotic agents in the adult Norwegian population.

METHODS

Data from two representative surveys assessing identical insomnia symptoms in the adult population of Norway, one conducted in 1999-2000 (N=2001) and one conducted in 2009-2010 (N=2000), were compared.

RESULTS

Controlling for basic demographic variables, significant increases were found over the 10-year study period in the prevalence of sleep-onset insomnia from 13.1% to 15.2%, dissatisfaction with sleep from 8.2% to 13.6%, daytime impairment from 14.8% to 18.8%, Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) insomnia cases from 11.9% to 15.5%, and hypnotic agent use from 6.9% to 11.1%. No secular trend was found for maintenance insomnia or for early morning awakening insomnia. Across the two surveys, women reported a higher prevalence of insomnia than men. Age was positively associated with the prevalence of nocturnal sleep problems and use of hypnotic agents but was inversely associated with daytime impairment. Individuals with low socioeconomic status (SES) reported a higher prevalence of several insomnia symptoms.

CONCLUSIONS

Insomnia seems to be on the rise in the general adult population, which gives reason for concern. Prevention of insomnia and cost-effective interventions should receive higher priority in the future.