One night of total sleep deprivation promotes a state of generalized hyperalgesia: a surrogate pain model to study the relationship of insomnia and pain

Brain functional imaging contributions in osteoarthritis-related pain: A viewpoint

Objective

Neuroimaging investigations are critical to provide a more direct assessment of brain disturbances associated with osteoarthritis (OA)-related pain, and to better understand its pathophysiology to develop new treatment strategies. This viewpoint aims to summarize the importance of the brain in OA pain.

Method

A European working group on pain in osteoarthritis GO-PAIN (Going Inside Osteoarthritis-related Pain Phenotyping) has been created to work on a global assessment of the OA-related pain. Relevant scientific literature was evaluated, summarized and discussed to expose advances in functional brain alterations related-to OA pain.

Results

Findings of neuroimaging studies are highly heterogenous and based on small sample size, but some key brain alterations associated with OA pain can be identified across experiments. A systematic literature review conducted by Hall and colleagues (2023) found lower activity, connectivity, and grey matter volume in the right anterior insula in patients with OA than in healthy controls. Other works also pointed out that activity of specific brain regions could serve as a potential surrogate biomarker, but several limitations and confounding factors needs to be addressed.

Conclusions

Brain functional imaging provides opportunities to accurately address an OA-related pain endophenotype. To encompass limitations and fill the gaps from the previous studies, we propose a blueprint for the next 5 years and stimulate ideas for others working in the field.

Chronic sleep deficiency and its impact on pain perception in healthy females

Acute sleep deprivation in experimental studies has been shown to induce pain hypersensitivity in females. However, the impact of natural sleep deficiency and fluctuations across the week on pain perception remains unclear. A sleep-monitoring headband and self-reports were utilized to assess objective and subjective sleep in longer (> 6 hr) and short sleepers (< 6 hr). Pain sensitivity measures including heat, cold, pressure pain thresholds, pain inhibition (conditioned pain modulation) and facilitation (tonic pain summation) were assessed on Mondays and Fridays. Forty-one healthy young (23.9 ± 0.74 years) women participated. Short sleepers slept on average 2 hr less than longer sleepers (297.9 ± 8.2 min versus 418.5 ± 10.9 min) and experienced impaired pain inhibitory response (mean = -21.14 ± 7.9°C versus mean = 15.39 ± 9.5°C; p = 0.005). However, no effect was observed in pain thresholds and pain summation (p > 0.05). Furthermore, pain modulatory responses differed between Mondays and Fridays. Chronic sleep deficiency (< 6 hr) compromises pain responses, notably on Mondays. Maintaining a consistent sleep pattern with sufficient sleep (> 6 hr) throughout the week may protect against pain sensitization and the development of chronic pain in females. Further research is needed, especially in patients with chronic pain.

Modulating the Pronociceptive Effect of Sleep Deprivation: A Possible Role for Cholinergic Neurons in the Medial Habenula

Sleep deprivation has been shown to exacerbate pain sensitivity and may contribute to the onset of chronic pain, yet the precise neural mechanisms underlying this association remain elusive. In our study, we explored the contribution of cholinergic neurons within the medial habenula (MHb) to hyperalgesia induced by sleep deprivation in rats. Our findings indicate that the activity of MHb cholinergic neurons diminishes during sleep deprivation and that chemogenetic stimulation of these neurons can mitigate the results. Interestingly, we did not find a direct response of MHb cholinergic neurons to pain stimulation. Further investigation identified the interpeduncular nucleus (IPN) and the paraventricular nucleus of the thalamus (PVT) as key players in the pro-nociceptive effect of sleep deprivation. Stimulating the pathways connecting the MHb to the IPN and PVT alleviated the hyperalgesia. These results underscore the important role of MHb cholinergic neurons in modulating pain sensitivity linked to sleep deprivation, highlighting potential neural targets for mitigating sleep deprivation-induced hyperalgesia.

What is associated with painful polyneuropathy? A cross-sectional analysis of symptoms and signs in patients with painful and painless polyneuropathy

ABSTRACT

It is still unclear how and why some patients develop painful and others painless polyneuropathy. The aim of this study was to identify multiple factors associated with painful polyneuropathies (NeuP). A total of 1181 patients of the multicenter DOLORISK database with painful (probable or definite NeuP) or painless (unlikely NeuP) probable or confirmed neuropathy were investigated clinically, with questionnaires and quantitative sensory testing. Multivariate logistic regression including all variables (demographics, medical history, psychological symptoms, personality items, pain-related worrying, life-style factors, as well as results from clinical examination and quantitative sensory testing) and machine learning was used for the identification of predictors and final risk prediction of painful neuropathy. Multivariate logistic regression demonstrated that severity and idiopathic etiology of neuropathy, presence of chronic pain in family, Patient-Reported Outcomes Measurement Information System Fatigue and Depression T-Score, as well as Pain Catastrophizing Scale total score are the most important features associated with the presence of pain in neuropathy. Machine learning (random forest) identified the same variables. Multivariate logistic regression archived an accuracy above 78%, random forest of 76%; thus, almost 4 out of 5 subjects can be classified correctly. This multicenter analysis shows that pain-related worrying, emotional well-being, and clinical phenotype are factors associated with painful (vs painless) neuropathy. Results may help in the future to identify patients at risk of developing painful neuropathy and identify consequences of pain in longitudinal studies.

Effects of therapeutic exercise on pain processing in people with chronic non-specific neck pain - A systematic review and meta-analysis

BACKGROUND

Emerging evidence suggests that individuals with chronic non-specific neck pain may experience altered sensory processing, potentially contributing to the modest response to therapeutic exercise treatments.

OBJECTIVE

This systematic review aims to explore the effect of therapeutic exercise on pain processing among patients with chronic non-specific neck pain.

METHODS

A systematic search was conducted in multiple databases (PubMed, EMBASE, CINAHL, PEDro, SportDiscus, and Cochrane CENTRAL) from inception to June 2023. Inclusion criteria included randomized controlled trials (RCT) comparing therapeutic exercise to non-exercise treatments or no treatment. The screening and data extraction was conducted by two reviewers. The methodological quality was evaluated using the PEDro scale and the certainty of evidence using GRADE. The primary outcomes assessed were pressure pain threshold (PPT), temporal summation, and conditioned pain modulation.

RESULTS

Thirteen trials included a total of 948 participants, with 586 in the exercise therapy group and 362 in the non-exercise group. The therapeutic exercise was not superior to non-exercise treatments for both local and PPT in the immediate (MD = 0.13, 95%CI = -0.18 to 0.43), and short-term follow-up (MD = 0.17, 95%CI = -0.27 to 0.61). In the medium term, therapeutic exercise demonstrated a small effect size in increasing local PPT (Kg/cm2) (MD = 0.64, 95%CI = 0.08 to 1.19) compared to non-exercise interventions. The certainty of evidence for these outcomes was very low.

CONCLUSIONS

There is very low certainty of evidence that therapeutic exercise is not superior than non-exercise treatment on pain processing in patients with chronic non-specific neck pain.

Opioids and Cannabinoids in Neurology Practice

OBJECTIVE

Opioid and cannabinoid therapies for chronic pain conditions including neuropathic pain are controversial. Understanding patient and prescribing factors contributing to risks and implementing risk mitigation strategies optimizes outcomes.

LATEST DEVELOPMENTS

The ongoing transformation from a biomedical model of pain care toward a biopsychosocial model has been accompanied by a shift away from opioid therapy for pain, in particular for chronic pain. Opioid overdose deaths and opioid use disorder have greatly increased in the last several decades, initially because of increases in opioid prescribing and more recently associated with illicit drug use, in particular fentanyl derivatives. Opioid risk mitigation strategies may reduce risks related to opioid prescribing and tapering or discontinuation. Opioid therapy guidelines from the Centers for Disease Control and Prevention have become the consensus best practice for opioid therapy. Regulatory agencies and licensing medical boards have implemented restrictions and other mandates regarding opioid therapy. Meanwhile, interest in and use of cannabinoids for chronic pain has grown in the United States.

ESSENTIAL POINTS

Opioid therapy is generally not recommended for the chronic treatment of neuropathic pain conditions. Opioids may be considered for temporary use in patients with severe pain related to selected neuropathic pain conditions (such as postherpetic neuralgia), and only as part of a multimodal treatment regimen. Opioid risk mitigation strategies include careful patient selection and evaluation, patient education and informed consent, querying the state prescription drug monitoring programs, urine drug testing, and issuance of naloxone as potential rescue medication. Close follow-up when initiating or adjusting opioid therapy and frequent reevaluation during long-term opioid therapy is required. There is evidence for the efficacy of cannabinoids for neuropathic pain, with meaningful response rates in select patient populations.

Psychophysical changes after total sleep deprivation and experimental muscle pain

Sleep disturbances exacerbate chronic pain, increase psychological load, and increase inflammation. Delayed onset muscle soreness (DOMS) mimics aspects of chronic pain, predominantly affecting peripheral pain mechanisms, while experimental sleep provocations have been shown to impact central pain mechanisms. This study aimed to combine a DOMS model with total sleep deprivation (TSD) to create a novel model affecting both peripheral and central pain mechanisms. A total of 30 healthy participants attended two sessions (baseline and follow-up) separated by 24 h of TSD and a home rating after 48 h. Assessments of interleukin 6 (IL-6) levels, sleep quality, pain catastrophising, affect, and symptoms of depression and anxiety were included in the baseline and follow-up sessions. Additionally, pressure pain and tolerance thresholds, temporal summation, and conditioned pain modulation (CPM) were assessed using cuff-pressure algometry in the baseline and follow-up sessions. DOMS was induced with eccentric calf raises during the baseline session followed by 24 h of TSD. At follow-up pain tolerance (p = 0.012) was significantly reduced, and CPM (p = 0.036) was significantly impaired compared to baseline. Psychological changes included decreases in pain catastrophising (p = 0.027), positive affect (p < 0.001), negative affect (p = 0.003), and anxiety (p = 0.012). Explorative regression models predicted 58% and 68% of DOMS pain intensity after 24 and 48 h, respectively, based on baseline body mass index, pain thresholds, psychological measures, and IL-6 (p < 0.01). Combining DOMS with 1 night of TSD induced pain hypersensitivity, impaired CPM, and altered psychological states. A combination of baseline inflammation, psychological measures, and pain sensitivity significantly predicted DOMS pain intensity after 24 and 48 h.

Spinal bestrophin-1 and anoctamin-1 channels have a pronociceptive role in the tactile allodynia induced by REM sleep deprivation in rats

Bestrophin-1 and anoctamin-1 are members of the calcium-activated chloride channels (CaCCs) family and are involved in inflammatory and neuropathic pain. However, their role in pain hypersensitivity induced by REM sleep deprivation (REMSD) has not been studied. This study aimed to determine if anoctamin-1 and bestrophin-1 are involved in the pain hypersensitivity induced by REMSD. We used the multiple-platform method to induce REMSD. REM sleep deprivation for 48 h induced tactile allodynia and a transient increase in corticosterone concentration at the beginning of the protocol (12 h) in female and male rats. REMSD enhanced c-Fos and α2δ-1 protein expression but did not change activating transcription factor 3 (ATF3) and KCC2 expression in dorsal root ganglia and dorsal spinal cord. Intrathecal injection of CaCCinh-A01, a non-selective bestrophin-1 blocker, and T16Ainh-A01, a specific anoctamin-1 blocker, reverted REMSD-induced tactile allodynia. However, T16Ainh-A01 had a higher antiallodynic effect in male than female rats. In addition, REMSD increased bestrophin-1 protein expression in DRG but not in DSC in male and female rats. In marked contrast, REMSD decreased anoctamin-1 protein expression in DSC but not in DRG, only in female rats. Bestrophin-1 and anoctamin-1 promote pain and maintain tactile allodynia induced by REM sleep deprivation in both male and female rats, but their expression patterns differ between the sexes.

Elevated pain sensitivity is associated with reduced rapid eye movement (REM) sleep in females with comorbid temporomandibular disorder and insomnia

OBJECTIVE

Patients with chronic pain disorders, including Temporomandibular Disorders (TMDs) endorse high levels of sleep disturbances, frequently reporting reduced sleep quality. Despite this, little is known about the effect that daytime pain has on the microstructure and macro-architecture of sleep. Therefore, we aimed to examine the extent to which daytime pain sensitivity, measured using quantitative sensory testing (QST), is associated with objective sleep parameters the following night, including sleep architecture and power spectral density, in women with TMD.

METHODS

144 females with myalgia and arthralgia by examination using the Diagnostic criteria for TMD completed a comprehensive QST battery consisting of General Pain Sensitivity, Central Sensitization Index, and Masseter Pressure Pain Threshold assessments. Polysomnography was collected the same night to measure sleep architecture and calculate relative power in delta, theta, alpha, sigma, and beta power bands.

RESULTS

Central Sensitization (B = -3.069, P = .009), General Pain Sensitivity Indices (B = -3.069, P = .007), and Masseter Pain Pressure Threshold (B = 0.030, P = .008) were significantly associated with lower REM% both before and after controlling for covariates. Pain sensitivity measures were not significantly associated with relative power in any of the spectral bands nor with any other sleep architectural stages.

CONCLUSIONS

Our findings demonstrate that higher generalized pain sensitivity, masseter pain pressure threshold, as well as central sensitization were associated with a lower percentage of REM in participants with myofascial pain and arthralgia of the masticatory system. These findings provide an important step toward understanding the mechanistic underpinnings of how chronic pain interacts with sleep physiology.

A noradrenergic pathway for the induction of pain by sleep loss

An epidemic of sleep loss currently affects modern societies worldwide and is implicated in numerous physiological disorders, including pain sensitization, although few studies have explored the brain pathways affected by active sleep deprivation (ASD; e.g., due to recreation). Here, we describe a neural circuit responsible for pain sensitization in mice treated with 9-h non-stress ASD. Using a combination of advanced neuroscience methods, we found that ASD stimulates noradrenergic inputs from locus coeruleus (LCNA) to glutamatergic neurons of the hindlimb primary somatosensory cortex (S1HLGlu). Moreover, artificial inhibition of this LCNA→S1HLGlu pathway alleviates ASD-induced pain sensitization in mice, while chemogenetic activation of this pathway recapitulates the pain sensitization observed following ASD. Our study thus implicates activation of the LCNA→S1HLGlu pathway in ASD-induced pain sensitization, expanding our fundamental understanding of the multisystem interplay involved in pain processing.

Total Joint Arthroplasty and Sleep: The State of the Evidence

Background

As the number of total hip and knee arthroplasties (TJA) performed increases, there is heightened interest in perioperative optimization to improve outcomes. Sleep is perhaps one of the least understood perioperative factors that affects TJA outcomes. The purpose of this article is to review the current body of knowledge regarding sleep and TJA and the tools available to optimize sleep perioperatively.

Methods

A manual search was performed using PubMed for articles with information about sleep in the perioperative period. Articles were selected that examined: sleep and pain in the perioperative period; the effect of surgery on sleep postoperatively; the relationship between sleep and TJA outcomes; risk factors for perioperative sleep disturbance; the effect of anesthesia on sleep; and the efficacy of interventions to optimize sleep perioperatively.

Results

Sleep and pain are intimately associated; poor sleep is associated with increased pain sensitivity. Enhanced sleep is associated with improved surgical outcomes, although transient sleep disturbances are normal postoperatively. Risk factors for perioperative sleep disturbance include increasing age, pre-existing sleep disorders, medical comorbidities, and type of anesthesia used. Interventions to improve sleep include optimizing medical comorbidities preoperatively, increasing sleep time perioperatively, appropriating sleep hygiene, using cognitive behavioral therapy, utilizing meditation and mindfulness interventions, and using pharmacologic sleep aids.

Conclusions

Sleep is one of many factors that affect TJA. As we better understand the interplay between sleep, risk factors for suboptimal sleep, and interventions that can be used to optimize sleep, we will be able to provide better care and improved outcomes for patients.

Effects of postoperative environmental noise on surgery induced pain: Evidence based on a prospective observational study

CONTEXT

Many patients recovering from surgery in wards are disturbed by environmental noise. However, the effects of environmental noise on postoperative pain are unclear.

OBJECTIVES

This study aimed to assess the association between postoperative noise and pain.

METHODS

This prospective study included 182 women who underwent cesarean sections. Postoperative noise was continuously recorded, and pain intensity at rest was assessed using a numerical rating scale (NRS) for 0-6, 6-12, 12-18, and 18-24 h after the patients were returned to the ward. Cumulative pain scores were calculated by summing the NRS scores at each time point and comprised the primary outcome. The maximum pain NRS score and analgesic consumption during the 24 h after surgery were also recorded.

RESULTS

Mean environmental noise intensity during the daytime was an independent factor for cumulative pain scores, maximum pain scores, and analgesic use during the first postoperative 24 h (β, 0.37; 95% CI, 0.21-0.53 and β, 0.12; 95% CI, 0.07-0.17; P < 0.001 for both; β, 0.86; 95% CI, 0.25-1.46; P = 0.006). Cumulative and maximum NRS pain scores as well as the incidence of NRS ≥ 4 were significantly higher in patients under mean daytime environmental noise of ≥58, than <58 decibels (dB) (8.0 [6.0-11.3] vs. 6.0 (5.0-7.0); 3.0 [2.0-4.0] vs. 2.0 [2.0-2.0, and 25.6% vs. 11.0%; RR, 2.32; 95% CI, 1.19-4.54, respectively; P < 0.001 for all).

CONCLUSIONS

Higher-level postoperative noise exposure was associated with more severe postoperative pain and increased analgesic needs, as well as a higher incidence of moderate-to-severe pain in patients recovering from cesarean delivery. Our findings indicate that reducing environmental ward noise might benefit for postoperative pain management.

The Impact of Sleep Disturbances on Endogenous Pain Modulation: A Systematic Review and Meta-Analysis

The bidirectional relationship between sleep and pain problems has been extensively demonstrated but despite all the accumulating evidence, their shared mechanisms are currently not fully understood. This review examined the association between sleep disturbances, defined as a broad array of sleep-related outcomes (eg, poor quality, short duration, insomnia), and endogenous pain modulation (EPM) in healthy and clinical populations. Our search yielded 6,151 references, and 37 studies met the eligibility criteria. Qualitative results showed mixed findings regarding the association between sleep disturbances and temporal summation of pain (TSP) and conditioned pain modulation (CPM), with poor sleep more commonly associated with decreased pain inhibition in both populations. Quantitative results indicated that such associations were not statistically significant, neither in healthy populations when EPM outcomes were assessed for changes pre-/post-sleep intervention (TSP: .31 [95%CI: -.30 to .92]; P = .321; CPM: .40 [95%CI: -.06 to .85] P = .088) nor in clinical populations when such association was assessed via correlation (TSP: -.00 [95%CI: -.22 to .21] P = .970; CPM: .12 [95%CI: -.05 to .29]; P = .181). For studies that reported results by sex, meta-analysis showed that experimental sleep disturbances impaired pain inhibition in females (1.43 [95%CI: .98-1.88]; P < .001) but not in males (-.30 [95%CI: -2.69 to 1.60]; P = .760). Only one study investigating the association between sleep disturbances and offset analgesia was identified, while no studies assessing spatial summation of pain were found. Overall, this review provides a comprehensive overview of the association between sleep disturbances and EPM function, emphasizing the need for further investigation to clarify specific mechanisms and phenotypic subtypes. PERSPECTIVE: This review shines a light on the association between sleep disturbances and endogenous pain modulation function. Qualitatively, we found a frequent association between reduced sleep quality and impaired pain inhibition. However, quantitatively such an association was not corroborated. Sex-specific effects were observed, with females presenting sleep-related impaired pain inhibition but not males.

Pain in Austrian hospitals: evaluation of 1089 in-patients

BACKGROUND

Despite the existence of internationally consistent guidelines for the management of pain, efficient regional anesthesia techniques, safe pain medications, and organizational structures, e.g., acute pain services, various studies have shown that pain is still common among both surgical and non-surgical in-patients.

OBJECTIVE

The primary objective of this study was to evaluate, on a multi-center basis, the point pain prevalence of surgical and non-surgical in-patients. We further analyzed pain intensities, in-hospital pain triggers, pain-related impairments, pain assessments, patient information about pain, and patient satisfaction with pain therapy. This benchmark information should lead to better implementation of pain management strategies and thus improve health care quality.

METHODS

We surveyed all adult in-patients in three general hospitals in Austria (general hospital Klagenfurt am Wörthersee, general hospital Villach, general hospital Wolfsberg) on the index day with two standardized questionnaires for both surgical and non-surgical patients.

RESULTS

Overall, a pain prevalence of 40.0%, with no statistically significant difference between surgical and non-surgical patients, was shown. Higher pain prevalence in female patients, high pain prevalence in the age group 18-30 years, and highest pain prevalence in the age group over 90 years old was found. Overall pain intensity was relatively low, but unacceptable maximum pain within the preceding 24 h was shown. Different in-hospital pain triggers like patient's care and mobilization were found. Our survey has shown that pain has an impact on personal hygiene, mobilization, mood, sleep, and appetite. However, patients were very satisfied with their pain therapy.

CONCLUSION

Medical staff and nurses have to be sensitized to the urgent need to improve pain management strategies.

[The clinical significance of insomnia in chronic headache]

OBJECTIVE

To study the features of the manifestation of insomnia and its impact on the condition and quality of life in patients with chronic tension-type headache.

MATERIAL AND METHODS

The study included 65 patients with chronic tension-type headache and insomnia. Patients filled out questionnaires on headache severity, sleep quality, emotional status and quality of life. Seventeen patients underwent polysomnography.

RESULTS

Patients with more severe insomnia had significantly more severe anxiety (p<0.001) and depression (p=0.025). Such patients assessed their quality of life worse according to the SF-12 questionnaire (p<0.002) and the Subjective Well-Being Scale (p<0.001), a higher level of central sensitization was observed in patients with more severe insomnia (p<0.001).

CONCLUSION

The negative impact of insomnia on the condition of patients is not so much an increase in pain as such, but rather its influence on the quality of the emotional state and life in general, as well as an increase in the interdependence and mutual influence of other clinical and psychophysiological manifestations of the disease. Therefore, the clinical significance of insomnia is the deterioration of a person's ability to tolerate pain, which is the main prerequisite for a decrease in quality of life.

Insomnia is common in inflammatory bowel disease (IBD) and is associated with mental health conditions as well as IBD activity

BACKGROUND/AIMS

Insomnia is common in people with chronic medical conditions, such as inflammatory bowel disease (IBD), and is readily treatable through cognitive behavioral therapy for insomnia. This study aimed to describe the associations with insomnia in people with IBD and its relationship to IBD-related disability.

METHODS

An online questionnaire was administered through 3 tertiary IBD centers, social media, and Crohn's Colitis Australia. The questionnaire included the Insomnia Severity Index (ISI), a validated assessment of insomnia. Measures of anxiety, depression, physical activity, and disability were also included. IBD activity was assessed using validated patient reported scores. A multivariate model was constructed for clinically significant insomnia and ISI scores. Subpopulations of Crohn's disease and ulcerative colitis were considered.

RESULTS

In a cohort of 670 respondents the median age was 41 years (range, 32-70 years), with the majority female (78.4%), the majority had Crohn's disease (57.3%). Increasingly severe disability was associated with worse insomnia score. Clinically significant insomnia was associated with clinically active IBD, abdominal pain, anxiety, and depression, in a multivariate model. In an ulcerative colitis population, Simple Clinical Colitis Activity Index components of general well-being and urgency were associated with worse ISI score in a model including depression and anxiety. In those with Crohn's disease, the multivariate model included Harvey Bradshaw Index score in addition to depression and anxiety.

CONCLUSIONS

Insomnia is common in people with IBD and is associated with increased disability. Abdominal pain and mental health conditions should prompt consideration for screening for insomnia and referral for cognitive behavioral therapy for insomnia.

Washed microbiota transplantation targeting both gastrointestinal and extraintestinal symptoms in patients with irritable bowel syndrome

OBJECTIVE

Fecal microbiota transplantation (FMT) has been reported with the treatment potential for irritable bowel syndrome (IBS). However, the knowledge of its effect on extraintestinal symptoms of IBS is limited. This study aimed to evaluate the efficacy of the improved methodology of FMT, washed microbiota transplantation (WMT), on sleep disturbances, and psychological and gastrointestinal symptoms among patients with IBS.

METHODS

This was a prospective observational study involving patients with IBS who underwent WMT. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. The Gastrointestinal Symptom Rating Scale (GSRS) and IBS Severity Scoring System (IBS-SSS) were used to evaluate gastrointestinal symptoms and IBS severity, respectively. The Self-rating Depression Scale (SDS) and Self-rating Anxiety Scale (SAS) were used to evaluate depression and anxiety, respectively. All the symptoms were evaluated at baseline and one month after WMT. A multiple logistic regression model was used to determine the predictive factors of sleep improvement one month after WMT.

RESULTS

Seventy-three patients with IBS were included in the study. Sleep quality (Z = -4.211, P < 0.001), anxiety (Z = -4.775, P < 0.001), depression (Z = -4.610, P < 0.001), gastrointestinal symptoms (Z = -5.364, P < 0.001), and IBS severity (Z = -6.468, P < 0.001) significantly improved one month after WMT in all patients. The scores of the five components of PSQI including subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, and sleep disturbances decreased in 52 patients with poor sleep quality (all P < 0.05). Baseline sleep duration scores were identified as an independent predictive factor of sleep improvement one month after WMT in patients with poor sleep quality (OR 2.180 [95% CI = 1.017-4.673]; P = 0.045). Patients that experienced sleep improvement demonstrated greater alleviation in depression (Z = -1.990, P = 0.047) and IBS severity (Z = -2.486, P = 0.013) compared with patients without sleep improvement.

CONCLUSION

This study suggested that WMT might be a promising therapy for patients with IBS, especially those with comorbid sleep and psychological disorders.

The relation of psychological status and type D personality with central sensitization in knee osteoarthritis: everything is in your mind!

To evaluate the relation of psychosocial parameters and type D personality with central sensitization in knee osteoarthritis (OA). The study included 126 patients with knee OA according to the American College of Rheumatology criteria. Sociodemographic variables (age, gender, education, marital status, annual income), alcohol consumption/smoking, body mass index, comorbidities, and duration of symptoms were noted. Radiographic evaluation was performed according to the Kellgren-Lawrence grading system. The Western Ontario and McMaster Universities Osteoarthritis Index was used for clinical evaluation. Type D personality, negative affectivity, and social inhibition were evaluated using the type D Scale-14 (DS14). Central sensitization was assessed by the central sensitization inventory (CSI), while psychological status, quality of life, and sleep were assessed by the Hospital Anxiety and Depression Scale (HADS), an abbreviated version of the World Health Organization Quality of Life Instrument (WHOQOL-BREF), and the Jenkins Sleep Evaluation Scale (JSS), respectively. The effect of type D personality on study parameters including central sensitization, as well as the risk factors for the development of central sensitization were assessed by regression analyses. Patients with type D personality had higher CSI, HADS scores and lower WHOQOL-BREF scores for psychological health, social relationship, environment and general quality of life. Linear regression analysis showed that the DS14 total score has a significant positive relation with CSI (β = 0.4, p < 0.05), HADS-depression (β = 0.4, p < 0.05), HADS-anxiety (β = 0.5, p < 0.05), and HADS-total scores (β = 0.5, p < 0.05). It also had a significant negative effect on all domains of WHOQOL-BREF (p < 0.05 for all). Logistic regression analysis revealed that JSS [Odds ratio (OR) 0.83, 95% CI 0.73-0.94; p = 0.003] and negative affectivity (OR 0.78, 95% CI 0.65-0.94; p = 0.008) were independent risk factors for the development of central sensitization in knee OA. Type D personality has an impact on quality of life, central sensitization, and psychological health, with negative affectivity and sleep impairment serving as independent risk factors for central sensitization. While managing patients with knee OA, these intimate relationships should be taken into consideration.

Beyond biopsychosocial: The keystone mechanism theory of pain

Pain is a deeply personal experience, with interindividual differences in its chronification and treatment presenting a formidable healthcare challenge. The biopsychosocial model (BPSm) has been hugely influential within nascent attempts at precision pain medicine, steering the field away from a reductionist biomechanical viewpoint and emphasising complex interactions of biological, psychological, and social factors which shape the individuality of pain. However, despite offering a strong theoretical foundation and holistic perspective, we contend that the BPSm remains limited in its capacity to deliver truly mechanistically informed treatment of pain. We therefore propose the keystone model of pain which offers a pragmatic balance between the dimensionality expansive BPSm and overly reductive approaches, providing both theoretical and practical advantages for the transition from treating populations to individual people.

The endocannabinoid N-arachidonoyl dopamine is critical for hyperalgesia induced by chronic sleep disruption

Chronic pain is highly prevalent and is linked to a broad range of comorbidities, including sleep disorders. Epidemiological and clinical evidence suggests that chronic sleep disruption (CSD) leads to heightened pain sensitivity, referred to as CSD-induced hyperalgesia. However, the underlying mechanisms are unclear. The thalamic reticular nucleus (TRN) has unique integrative functions in sensory processing, attention/arousal and sleep spindle generation. We report that the TRN played an important role in CSD-induced hyperalgesia in mice, through its projections to the ventroposterior region of the thalamus. Metabolomics revealed that the level of N-arachidonoyl dopamine (NADA), an endocannabinoid, was decreased in the TRN after CSD. Using a recently developed CB1 receptor (cannabinoid receptor 1) activity sensor with spatiotemporal resolution, CB1 receptor activity in the TRN was found to be decreased after CSD. Moreover, CSD-induced hyperalgesia was attenuated by local NADA administration to the TRN. Taken together, these results suggest that TRN NADA signaling is critical for CSD-induced hyperalgesia.

Association of Sleep Disturbance With Catastrophizing and Knee Pain: Data From the Osteoarthritis Initiative

OBJECTIVE

To investigate the relationship between sleep disturbance, catastrophizing, and knee pain in middle-aged and older individuals.

METHODS

Data from the Osteoarthritis Initiative cohort from months 48 to 96 were used, where month 48 was treated as baseline. Knee pain (Western Ontario and McMaster Universities Osteoarthritis Index pain scale score ≥5 [range 0-20]), catastrophizing (extracted from Coping Strategies Questionnaire score ≥3 [range 0-6]), and sleep quality (extracted from Center for Epidemiologic Studies Depression Scale [range 1-4]) were assessed annually. We described the association of sleep disturbance with the presence and risk of knee pain and catastrophizing. The mediation effect of knee pain and catastrophizing on the sleep-catastrophizing and sleep-pain association was evaluated, respectively.

RESULTS

Catastrophizing and knee pain were reported in 346 (10%) and 917 (24%) of the 3,813 participants (mean 64.9 years, 58% female) at baseline. Participants with worse sleep disturbance were more likely to have knee pain (prevalence ratio [PR] 1.4-2.0, P for trend <0.001) and catastrophizing (PR 1.4-3.1, P for trend <0.001). Sleep disturbance at baseline predicted the risk of knee pain (risk ratio [RR] 1.1, P for trend <0.001) and catastrophizing (RR 1.2-1.7, P for trend <0.001) during follow-up. No statistically significant interactions between sleep disturbance and knee pain or catastrophizing were observed. Knee pain and catastrophizing mediated the sleep-catastrophizing and sleep-pain association, respectively, at baseline, and knee pain negatively mediated the sleep-catastrophizing association longitudinally.

CONCLUSION

Sleep disturbance was associated with the presence and risk of catastrophizing and knee pain. Sleep interventions may have a universal and independent effect in preventing incident knee pain.

The impact of sleep disturbance on pain perception: A systematic review examining the moderating effect of sex and age

Females have increased pain sensitivity and are more vulnerable to chronic pain conditions. Sleep disturbances are comorbid with chronic pain and exacerbate pain symptoms. Different types of sleep disturbance affect pain perception distinctly, but it is not clear if these effects are equal in men and women. This systematic review investigated potential differences in how sleep disturbance affects pain in males and females. We searched EBSCO, MEDLINE, Psych INFO, Science Direct, and Web of Science from January 2001 to November 2022 and found 38 studies with 978 participants. Separate random-effects models were used to estimate the pooled effect sizes based on standardized mean differences (SMDs) of experimental sleep disturbance paradigms on various pain outcomes. Sex moderated the effect of sleep disturbance on pain facilitation (SMD = 0.13; 95%CI: 0.004 to 0.022; p=.009) and pain inhibition (SMD = 0.033; 95%CI: 0.011 to 0.054; p=.005), with increased facilitation and decreased inhibition in females, but the opposite effect in males. Further, age moderated the effects of total sleep deprivation (SMD = -0.194; 95%CI -0.328 to -0.060; p=.008) on pain sensitivity and fragmented sleep (SMD = -0.110; 95%CI: 0.148 to -0.072; p<.001) on pain threshold. While the moderating effect of sex and age on the sleep-pain relationship was small, these factors need to be considered in future sleep-pain research.

Efficacy of combined strategies of physical activity, diet and sleep disorders as treatment in patients with chronic shoulder pain. A systematic review

Introduction: The objective of this systematic review was to analyze the existing scientific evidence on the influence of dietary strategies, exercise, and sleep disorders on the symptomatology of patients with chronic shoulder pain, as well as to assess the methodological quality of the literature collected. Methods: The selection criteria were as follows: we included randomized controlled clinical trials written in English that investigated the effects of such interventions in patients with chronic shoulder pain and excluded studies where pre-operative rehabilitation or rehabilitation combined with corticosteroid injections was performed. We searched six databases Pubmed, Cochrane Library, Web of Science, CINAHL, Sportdiscus and Scopus, using the keywords "shoulder pain," "fasting," "physical therapy modalities," "rehabilitation," "exercise," "circadian clocks," and "chronic pain" to select randomized controlled clinical trials conducted in humans and written in English. The last search was conducted on 24/01/2023. (PROSPERO:CRD42023379925). Results: We used the tool proposed by the Cochrane Handbook to assess the risk of bias in the included studies of the 17 studies included, nine had a high risk of bias, two studies had an unclear risk of bias, and the remaining six studies had a low risk of bias. A total of 17 articles were selected, including 10 studies that showed a positive influences of exercise on chronic shoulder pain and five studies that showed a negative influence of sleep disorders on this patient profile. The remaining two articles analyzed the influence of nutritional strategies and metabolic problems in patients with chronic shoulder pain. The total sample size of the 17 included articles amounted to 9,991 individuals. Discussion: Studies confirm that exercise generates a hypoalgesic effect that improves chronic shoulder pain, functionality, and quality of life. Although dietary strategies and sleep disorders are known to influence chronic shoulder pain, there is a lack of studies that conduct interventions on these problems to assess how chronic shoulder pain varies.

The association of self-reported symptoms of central sensitization and sleep disturbances in neuropathic pain

Introduction

Patients with neuropathic pain (NP) report a higher impairment of quality of life and sleep than patients with chronic pain without neuropathic characteristics. These include somatosensory peculiarities like allodynia, a surrogate marker for central sensitization.

Objectives

This study aimed to investigate the relation between symptoms of central sensitization and sleep disturbances in patients with NP.

Methods

Within this cross-sectional study, data sets of 3339 patients with chronic NP syndromes (painful diabetic polyneuropathy, n = 543; postherpetic neuralgia, n = 1480) or complex regional pain syndromes (CRPS, n = 1316) were analyzed. Neuropathic pain symptoms were assessed with the painDETECT questionnaire (PD-Q), depression with the Patient Health Questionnaire-9, and sleep impairment with items of the Medical Outcomes Study Sleep Scale in 4 subscales. The association of demographic/clinical data, somatosensory phenotype, depression, and pain intensity with sleep impairment was assessed by unadjusted Spearman correlation analyses and multivariable regression analyses.

Results

Sleep impairment was observed in all pain aetiologies although with some significant differences in the single sleep items. The intensity of the individual PD-Q items differed to some extent between the 3 pain entities, whereas the PD-Q sum score was similar. Thermal hyperalgesia and burning assessed by the PD-Q were significantly associated with sleep disturbance, adequacy, and quantity but not with sleep somnolence. Only depression and self-reported allodynia had a significant relation to all 4 sleep elements.

Conclusion

Beside depression, allodynia as a surrogate marker hints to a possible impact of central sensitization on the sleep disruption of patients with NP.

Sleep deprivation increases pain sensitivity following acute muscle soreness

OBJECTIVE

The aim of this cross-sectional group comparison study was to investigate whether sleep disturbance facilitates pain sensitivity caused by an acute muscle injury.

METHODS

Thirty-six healthy individuals were included and randomly assigned to one of three groups in a non-balanced manner: a control group (n = 11) and two groups who performed eccentric exercise for quadriceps to cause delayed onset of muscle soreness (DOMS). The difference between the DOMS groups was that one followed their habitual sleep pattern (Sleep group, n = 12) and the other had their sleep withdrawn for one night (No-Sleep group, n = 13). The level of DOMS was indicated using a 6-point Likert Scale and pain sensitivity was assessed using Pressure Pain Thresholds (PPT) at the lower legs and shoulder at baseline (Day-1) and after 48 h (Day-3). Additionally, pain distribution following suprathreshold pressure stimulation (STPS) on the quadriceps muscle was assessed on the same days.

RESULTS

PPTs were significantly reduced at Day-3 compared with Day-1 in both DOMS groups. The relative change between days was larger in the No-Sleep group compared with controls (P<0.05) whilst no significant change was seen in the Sleep group compared with controls. Furthermore, no significant differences were found between groups nor days for the subjective perception of DOMS (Likert Scale) and the size of the area of STPS.

CONCLUSIONS

The loss of sleep further increases pain sensitivity following an acute soft tissue injury, demonstrating a potential causative role of the lack of sleep on complex pain states following musculoskeletal injuries.

Patients with neuropathic pain from lumbosacral radiculopathy demonstrate similar pressure pain thresholds and conditioned pain modulation to those with fibromyalgia

OBJECTIVE

The purpose of the study was to evaluate pain thresholds, impairment of the endogenous pain modulatory system, and self-reported cognitive-emotional and central sensitization-related symptoms among three subject groups: a rarely studied patient cohort with neuropathic pain from lumbosacral radiculopathy (NPLSR), patients with fibromyalgia (FM) and healthy controls (HC).

METHODS

Patient-reported pain-related symptomology was evaluated with psychometricallyvalidated questionnaires. Pressure pain threshold (PPT), heat pain threshold (HPT), and cold pain threshold (CPT) were assessed in the low back and contralateral forearm. Conditioned pain modulation (CPM) was evaluated with a recently introduced methodology that accounts for a standard error of measurement.

RESULTS

Compared to the HC subjects, the FM and NPLSR subjects had significantly lower pain thresholds and more CPM impairment. No significant differences in PPT and CPM were observed between the FM and NPLSR groups. Significant group differences were found in self-reported symptoms of depression, anxiety, stress, and central sensitization. Self-reported symptom severity increased in a stair-step fashion, with the HC group scoring lowest and FM group scoring highest.

CONCLUSION

The NPLSR group manifested CPM dysfunction and pressure hyperalgesia at similar levels to the FM group, indicating that these two chronic pain syndromes, likely based on different pathophysiological mechanisms, in fact share some common pain processing features. However, though both patient groups demonstrated similarities in pain processing, self-reported cognitive-emotional and central sensitization-related symptom severity was significantly higher in the FM cohort, which distinguished them from the chronic NPLSR cohort.

[Nociplastic pain in research and practice : Overview of biopsychosocial principles, possibilities and difficulties]

Traditionally, two mechanistic pain categories were distinguished: nociceptive and neuropathic pain. After the definitions of these two mechanistic descriptors were refined more precisely in the International Association for the Study of Pain (IASP) taxonomy in 2011, a large group of patients remained whose pain could not be assigned to either of the two categories. Nociplastic pain was therefore proposed as a third mechanistic descriptor in 2016. This review article presents the current state of the integration of nociplastic pain into research and clinical practice. In particular, the possibilities and difficulties of applying this concept are addressed from a human and animal experimental research perspective.

A randomized, placebo-controlled, double-blinded mechanistic clinical trial using endotoxin to evaluate the relationship between insomnia, inflammation, and affective disturbance on pain in older adults: A protocol for the sleep and Healthy Aging Research for pain (SHARE-P) study

Chronic pain is prevalent in older adults. Treatment, especially with opioids, is often ineffective and poses considerable negative consequences in this population. To improve treatment, it is important to understand why older adults are at a heightened risk for developing chronic pain. Insomnia is a major modifiable risk factor for chronic pain that is ubiquitous among older adults. Insomnia can also lead to heightened systemic inflammation and affective disturbance, both of which may further exacerbate pain conditions in older adults. Endotoxin exposure can be used as an experimental model of systemic inflammation and affective disturbance. The current study aims to understand how insomnia status and endotoxin-induced changes in inflammation and affect (increased negative affect and decreased positive affect) may interact to impact pain facilitatory and inhibitory processes in older adults. Longitudinal data will also assess how pain processing, affective, and inflammatory responses to endotoxin may predict the development of pain and/or depressive symptoms. The current study is a randomized, double-blinded, placebo-controlled, mechanistic clinical trial in men and women, with and without insomnia, aged 50 years and older. Participants were randomized to either 0.8ng/kg endotoxin injection or saline placebo injection. Daily diaries were used to collect variables related to sleep, mood, and pain at two-week intervals during baseline and 3-, 6-, 9-, and 12-months post-injection. Primary outcomes during the experimental phase include conditioned pain modulation, temporal summation, and affective pain modulation ∼5.5 hours after injection. Primary outcomes for longitudinal assessments are self-reported pain intensity and depressive symptoms. The current study uses endotoxin as an experimental model for pain. In doing so, it aims to extend the current literature by: (1) including older adults, (2) investigating insomnia as a potential risk factor for chronic pain, (3) evaluating the role of endotoxin-induced affective disturbances on pain sensitivity, and (4) assessing sex differences in endotoxin-induced hyperalgesia.

Clinicaltrialsgov

NCT03256760.

Trial sponsor

NIH R01AG057750-01.

Sleep as a Therapeutic Target for Pain Management

PURPOSE OF REVIEW

The purpose of this review is to provide a summary of the utilization of sleep as a therapeutic target for chronic pain and to evaluate the recent literature on current and proposed pharmacologic and non-pharmacologic sleep interventions used in the management of pain disorders.

RECENT FINDINGS

Sleep is a promising therapeutic target in the treatment of pain disorders with both non-pharmacologic and pharmacologic therapies. Non-pharmacologic therapies include cognitive behavioral therapy and sensory-based therapies such as pink noise, audio-visual stimulation, and morning bright light therapy. Pharmacologic therapies include melatonin, z-drugs, gabapentinoids, and the novel orexin antagonists. However, more research is needed to clarify if these therapies can improve pain specifically by improving sleep. There is a vast array of investigational opportunities in sleep-targeted therapies for pathologic pain, and larger controlled, prospective trials are needed to fully elucidate their efficacy.

Development and validation of a nomogram for postoperative sleep disturbance in adults: a prospective survey of 640 patients undergoing spinal surgery

BACKGROUND

Postoperative sleep disturbance (PSD) is a prevalent clinical complication that may arise due to various factors. The purpose of this investigation is to identify the risk factors for PSD in spinal surgery and establish a risk prediction nomogram.

METHODS

The clinical records of individuals who underwent spinal surgery from January 2020 to January 2021 were gathered prospectively. The least absolute shrinkage and selection operator (LASSO) regression, along with multivariate logistic regression analysis, was employed to establish independent risk factors. A nomogram prediction model was devised based on these factors. The nomogram's effectiveness was evaluated and verified via the receiver operating characteristic (ROC) curve, calibration plot, and decision curve analysis (DCA).

RESULTS

A total of 640 patients who underwent spinal surgery were analyzed in this investigation, among which 393 patients experienced PSD with an incidence rate of 61.4%. After conducting LASSO regression and logistic regression analyses using R software on the variables in training set, 8 independent risk factors associated to PSD were identified, including female, preoperative sleep disorder, high preoperative anxiety score, high intraoperative bleeding volume, high postoperative pain score, dissatisfaction with ward sleep environment, non-use of dexmedetomidine and non-use of erector spinae plane block (ESPB). The nomogram and online dynamic nomogram were constructed after incorporating these variables. In the training and validation sets, the area under the curve (AUC) in the receiver operating characteristic (ROC) curves were 0.806 (0.768-0.844) and 0.755 (0.667-0.844), respectively. The calibration plots indicated that the mean absolute error (MAE) values in both sets were respectively 1.2% and 1.7%. The decision curve analysis demonstrated the model had a substantial net benefit within the range of threshold probabilities between 20% and 90%.

CONCLUSIONS

The nomogram model proposed in this study included eight frequently observed clinical factors and exhibited favorable accuracy and calibration.

TRIAL REGISTRATION

The study was retrospectively registered with the Chinese Clinical Trial Registry (ChiCTR2200061257, 18/06/2022).

Musculoskeletal physiotherapy and perceptions on lifestyle interventions: A review

Musculoskeletal pain treatments are widespread in the clinical practice of physiotherapists. A multifaceted biopsychosocial approach should guide modern pain therapy. The study aimed to investigate the association of musculoskeletal problems with lifestyle behaviors. The study adopted a qualitative literature review methodology. About 200 papers have been reviewed for this study. The categories of the study had been classified according to the factors that are interconnected to the life intervention. The inclusion criteria of the selected literature depend upon the data received. This is a review-based study. The results of cross-sectional and correlational analysis dominated the literature on lifestyle implications on musculoskeletal health, which included pain and its correlated inflammation. Long-term prospective studies, however, are difficult to enroll in due to ethical concerns about denying patients' therapies shown to benefit them, notably lifestyle behavior modification. By conducting intervention studies, it determines lifestyle modifications that determine the beneficial aspects. These aspects are avoiding and reducing pain by increasing exercise capacity. The study concluded that the quantity of beneficial health practices boosted the health-related quality of life. To achieve long-term health, the complexity of the behaviour change needs to be supported by the individual's lifestyle pattern and the support of the data. Therefore, in this century characterized by chronic lifestyle-related illnesses, various health behavior modifications may be claimed to be a primary therapeutic skill of health professionals (individually and collectively).

Biopsychosocial factors should be considered when evaluating central sensitization in axial spondyloarthritis

To identify the determinants of central sensitization (CS) in patients with axial spondyloarthritis (axSpA). Central Sensitization Inventory (CSI) was used to determine CS frequency. Disease-related variables including Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Disease Activity Score (ASDAS-CRP/-ESR), Maastricht Ankylosing Spondylitis Enthesitis Score (MASES), Bath Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Quality of Life Questionnaire (ASQoL) and Numeric Rating Scale (NRS)GLOBAL were assessed. Biopsychosocial variables were evaluated by the Multidimensional Scale of Perceived Social Support (MSPSS), Brief Illness Perception Questionnaire (B-IPQ), Hospital Anxiety and Depression Scale (HADS) and subscales for Anxiety (HADS-A) and Depression (HADS-D), and Jenkins Sleep Evaluation Scale (JSS). To determine the predictors of the development and severity of CS, multiple linear and logistic regression analyses were performed. The frequency of CS was 57.4% in the study population (n = 108). CSI score was correlated with the duration of morning stiffness, BASDAI, ASDAS-CRP, ASDAS-ESR, NRSGLOBAL, BASFI, MASES, ASOoL, JSS, HADS, and B-IPQ total scores (ρ ranged from 0.510 to 0.853). Multiple regression analysis indicated that BASDAI (OR: 10.44, 95% CI: 2.65-41.09), MASES (OR: 2.47, 95% CI: 1.09-5.56) and HADS-A (OR: 1.62, 95% CI: 1.11-2.37) were independent predictors of the development of CS. Additionally, higher NRSGLOBAL, JSS, HADS-D, and HADS-A scores appeared to determine the severity of CS. This study confirms that worse disease activity, more enthesal involvement, and anxiety independently predict the development of CS. Additionally, higher patient-perceived disease activity, sleep impairment and poor mental health significantly contribute to the severity of CS.

Society of Anesthesia and Sleep Medicine Position Paper on Patient Sleep During Hospitalization

This article addresses the issue of patient sleep during hospitalization, which the Society of Anesthesia and Sleep Medicine believes merits wider consideration by health authorities than it has received to date. Adequate sleep is fundamental to health and well-being, and insufficiencies in its duration, quality, or timing have adverse effects that are acutely evident. These include cardiovascular dysfunction, impaired ventilatory function, cognitive impairment, increased pain perception, psychomotor disturbance (including increased fall risk), psychological disturbance (including anxiety and depression), metabolic dysfunction (including increased insulin resistance and catabolic propensity), and immune dysfunction and proinflammatory effects (increasing infection risk and pain generation). All these changes negatively impact health status and are counterproductive to recovery from illness and operation. Hospitalization challenges sleep in a variety of ways. These challenges include environmental factors such as noise, bright light, and overnight awakenings for observations, interventions, and transfers; physiological factors such as pain, dyspnea, bowel or urinary dysfunction, or discomfort from therapeutic devices; psychological factors such as stress and anxiety; care-related factors including medications or medication withdrawal; and preexisting sleep disorders that may not be recognized or adequately managed. Many of these challenges appear readily addressable. The key to doing so is to give sleep greater priority, with attention directed at ensuring that patients' sleep needs are recognized and met, both within the hospital and beyond. Requirements include staff education, creation of protocols to enhance the prospect of sleep needs being addressed, and improvement in hospital design to mitigate environmental disturbances. Hospitals and health care providers have a duty to provide, to the greatest extent possible, appropriate preconditions for healing. Accumulating evidence suggests that these preconditions include adequate patient sleep duration and quality. The Society of Anesthesia and Sleep Medicine calls for systematic changes in the approach of hospital leadership and staff to this issue. Measures required include incorporation of optimization of patient sleep into the objectives of perioperative and general patient care guidelines. These steps should be complemented by further research into the impact of hospitalization on sleep, the effects of poor sleep on health outcomes after hospitalization, and assessment of interventions to improve it.

Investigation of pain sensitivity following 3 nights of disrupted sleep in healthy individuals

BACKGROUND

Poor quality sleep is a common complaint among people with chronic pain. The co-occurrence of poor sleep quality and chronic pain often comes with increased pain intensity, more disability and a higher cost of healthcare. Poor sleep has been suggested to affect measures of peripheral and central pain mechanisms. To date, sleep provocations are the only models proven to affect measures of central pain mechanisms in healthy subjects. However, there are limited studies investigating the effect of several nights of sleep disruption on measures of central pain mechanisms.

METHODS

The current study implemented three nights of sleep disruption with three planned awakenings per night in 30 healthy subjects sleeping at home. Pain testing was conducted at the same time of day at baseline and follow-up for each subject. Pressure pain thresholds were assessed bilaterally on the infraspinatus and gastrocnemius muscles. Using handheld pressure algometry, suprathreshold pressure pain sensitivity and area were also investigated on the dominant infraspinatus muscle. Cuff-pressure pain detection and tolerance thresholds, temporal summation of pain and conditioned pain modulation were investigated using cuff-pressure algometry.

RESULTS

Temporal summation of pain was significantly facilitated (p = 0.022), suprathreshold pain areas (p = 0.005) and intensities (p < 0.05) were significantly increased, and all pressure pain thresholds were decreased (p < 0.005) after sleep disruption compared to baseline.

CONCLUSIONS

The current study found that three consecutive nights of sleep disruption at home induced pressure hyperalgesia and increased measures of pain facilitation in healthy subjects, which is consistent with previous findings.

SIGNIFICANCE

Poor quality of sleep is often experienced by patients with chronic pain, with the most common complaint being nightly awakenings. This exploratory study is the first to investigate changes in measures of central and peripheral pain sensitivity in healthy subjects after sleep disruptions for three consecutive nights without any restrictions on total sleep time. The findings suggest that disruptions to sleep continuity in healthy individuals can induce increased sensitivity to measures of central and peripheral pain sensitization.

Effects of Preoperative Anxiety on Postoperative Outcomes and Sleep Quality in Patients Undergoing Laparoscopic Gynecological Surgery

OBJECTIVE

Preoperative anxiety is a psychological state that commonly occurs before surgery and may have a negative impact on postoperative outcomes. This study aimed to investigate the effects of preoperative anxiety on postoperative sleep quality and recovery outcomes among patients undergoing laparoscopic gynecological surgery.

METHODS

The study was conducted as a prospective cohort study. A total of 330 patients were enrolled and underwent laparoscopic gynecological surgery. After assessing the patient's preoperative anxiety score on the APAIS scale, 100 patients were classified into the preoperative anxiety (PA) group (preoperative anxiety score > 10) and 230 patients into the non-preoperative-anxiety (NPA) group (preoperative anxiety score ≤ 10). The Athens Insomnia Scale (AIS) was assessed on the night before surgery (Sleep Pre 1), the first night after surgery (Sleep POD 1), the second night after surgery (Sleep POD2), and the third night after surgery (Sleep POD 3). Postoperative pain was evaluated by the Visual Analog Scale (VAS), and the postoperative recovery outcomes and adverse effects were also recorded.

RESULT

The AIS score in the PA group was higher than that of the NPA group at Sleep-pre 1, Sleep POD 1, Sleep POD 2, and Sleep POD 3 (p < 0.05). The VAS score was higher in the PA group than in the NPA group within 48 h postoperatively (p < 0.05). In the PA group, the total dosage of sufentanil was significantly higher, and more rescue analgesics were required. Patients with preoperative anxiety showed a higher incidence of nausea, vomiting, and dizziness than those without preoperative anxiety. However, there was no significant difference in the satisfaction rate between the two groups.

CONCLUSION

The perioperative sleep quality of patients with preoperative anxiety is worse than that of patients without preoperative anxiety. Moreover, high preoperative anxiety is related to more severe postoperative pain and an increased requirement for analgesia.

A crossover study evaluating the sex-dependent and sensitizing effects of sleep deprivation using a nociceptive test battery in healthy subjects

AIM

We assessed whether total sleep deprivation (TSD) in combination with pain tests yields a reliable method to assess altered pain thresholds, which subsequently may be used to investigate (novel) analgesics in healthy subjects.

METHODS

This was a two-part randomized crossover study in 24 healthy men and 24 women. Subjects were randomized 1:1 to first complete a day of nonsleep-deprived nociceptive threshold testing, followed directly by a TSD night and morning of sleep-deprived testing, or first complete the TSD night and morning sleep-deprived testing, returning 7 days later for a day of nonsleep-deprived testing. A validated pain test battery (heat, pressure, electrical burst and stair, cold pressor pain test and conditioned pain modulation [CPM] paradigm) and sleep questionnaires were performed.

RESULTS

Subjects were significantly sleepier after TSD as measured using sleepiness questionnaires. Cold pressor pain tolerance (PTT, estimate of difference [ED] -10.8%, 95% CI -17.5 to -3.6%), CPM PTT (ED -0.69 mA, 95% CI -1.36 to -0.03 mA), pressure PTT (ED -11.2%, 95% CI -17.5% to -4.3%) and heat pain detection thresholds (ED -0.74 °C, 95% CI -1.34 to -0.14 °C) were significantly decreased after TSD compared to the baseline morning assessment in the combined analysis (men + women). Heat hyperalgesia was primarily driven by an effect of TSD in men, whereas cold and pressure hyperalgesia was primarily driven by the effects of TSD observed in women.

CONCLUSIONS

TSD induced sex-dependent hyperalgesia on cold, heat and pressure pain, and CPM response. These results suggest that the TSD model may be suitable to evaluate (novel) analgesics in early-phase drug studies.

Contemporary management of pain in cirrhosis: Toward precision therapy for pain

Chronic pain is highly prevalent in patients with cirrhosis and is associated with poor health-related quality of life and poor functional status. However, there is limited guidance on appropriate pain management in this population, and pharmacologic treatment can be harmful, leading to adverse outcomes, such as gastrointestinal bleeding, renal injury, falls, and hepatic encephalopathy. Chronic pain can be categorized mechanistically into three pain types: nociceptive, neuropathic, and nociplastic, each responsive to different therapies. By discussing the identification, etiology, and treatment of these three mechanistic pain descriptors with a focus on specific challenges in patients with cirrhosis, we provide a framework for better tailoring treatments, including nonpharmacologic therapies, to patients' needs.

Clinical and functional impact of central sensitization on patients with familial Mediterranean fever: a cross-sectional study

This study aimed to investigate the frequency of CS and its clinical and functional effects on familial Mediterranean fever (FMF). A hundred FMF patients were included in this study. The presence of CS was investigated by the central sensitization inventory (CSI). In addition to the detailed clinical features of patients and genetic mutations, quality of life, disability, sleep disorders, depression, anxiety, and fibromyalgia frequency were examined to evaluate the negative effects of CS on the individual. Patients were divided into groups according to the presence and severity of CS, and their results were compared. Correlation and multivariate regression analysis were performed to investigate the association of CS  with selected demographic and clinical parameters. The mean CSI was 37.72 (SD: 19.35), and thirty-eight (38%) patients had CS. Sacroiliitis occurred in 11 patients (11%), amyloidosis in 3 (3%), and erysipelas-like erythema in 11 (11%). The most prevalent genetic mutation was M694/any compound heterogeneous (35.7%), followed by M69V homogeneous (30%). Regarding comparing the patients with and without CS, the number of attacks, disease activity, daily colchicine dose, and all investigated comorbidities were significantly higher in the patients with CS (p < 0.05). In regression analysis, gender, colchicine dose and sleep disturbance were detected as related parameters with CS (OR (95% CI): 6.05 (1.39; 26.32), p: 0.017, OR (95% CI): 6.69 (1.65; 27.18), p: 0.008, OR (95% CI): 1.35 (1.35; 1.59), p: 0.001, respectively). Concomitant pain sensitization appears to be related to FMF patients' clinical and functional characteristics. These results suggest taking into consideration CS in the management of FMF patients.

Effects of kinesiology taping and core stability exercise on clinical variables in patients with non-specific chronic low back pain: A randomized controlled trial

OBJECTIVE

Properly-designed exercises and use of different physiotherapeutic modalities have been shown to be useful in the management of patients with non-specific chronic low back pain (NSCLBP). This research examined the effects of Kinesiology taping (KT) and Core-stabilization exercises (CSE) on pain intensity, lumbar range of motion, functional disability, depression, anxiety, sleep disturbance and Kinesiophobia in patients with NSCLBP.

DESIGN

Randomized controlled trial.

SETTINGS

Two tertiary health facilities.

PARTICIPANTS

Thirty-five patients (28 males and 7 females) with NSCLBP were allocated into three groups (KT + CSE, CSE and KT only).

MAIN OUTCOME MEASURE

Pain intensity, functional disability, psychological status, sleep disturbance, kinesiophobia and lumbar range of motion (LROM) were assessed.

RESULTS

The results revealed reduction in pain intensity, improved functional ability, psychological status (Depression and Anxiety), kinesiophobia, decreased sleep disturbance and increased LROM (P < 0.001) within each of the groups post-intervention.

CONCLUSION

All participants had improved clinical outcomes. However, KT + CSE group had better result in all the clinical outcomes.

CLINICAL TRIAL REGISTRY NUMBER

PACTR201807604459572.

Effect of sleep loss on pain-New conceptual and mechanistic avenues

Introduction

Sleep disturbances increase pain sensitivity in clinical and preclinical settings, but the precise mechanisms are unknown. This represents a major public health issue because of the growing sleep deficiency epidemic fueled by modern lifestyle. To understand the neural pathways at the intersection between sleep and pain processes, it is critical to determine the precise nature of the sleep disruptions that increase pain and the specific component of the pain response that is targeted.

Methods

We performed a review of the literature about sleep disturbances and pain sensitivity in humans and rodents by taking into consideration the targeted sleep stage (REMS, non-NREMS, or both), the amount of sleep lost, and the different types of sleep disruptions (partial or total sleep loss, duration, sleep fragmentation or interruptions), and how these differences might affect distinct components of the pain response.

Results

We find that the effects of sleep disturbances on pain are highly conserved among species. The major driver for pain hypersensitivity appears to be the total amount of sleep lost, while REMS loss by itself does not seem to have a direct effect on pain sensitivity. Sleep loss caused by extended wakefulness preferentially increases pain perception, whereas interrupted and limited sleep strongly dysregulates descending controls such as DNIC, especially in women.

Discussion

We discuss the possible mechanisms involved, including an increase in inflammatory processes, a loss of nociceptive inhibitory pathways, and a defect in the cognitive processing of noxious input.

Differences in pain, disability, and psychological function in low back pain patients with and without anxiety

Objectives: Non-specific low back pain affects people of all ages and is a leading contributor to disease burden worldwide. Chronic low back pain (LBP) reduces working hours, increases comorbidities, and increases rehabilitation needs. The aim of this study was to evaluate whether there were differences in pain, dysfunction, and psychological factors between two groups. The supplementary demonstrated the relationship between these influencing factors and anxiety.

Methods: A cross-sectional study was designed to analyze the differences in pain, disability, and psychological function in non-specific LBP patients with and without anxiety. In total, 60 subjects were divided into two groups based on self-rated anxiety scores: 30 patients with SAS score ≥50 were in the low back pain with anxiety group, and 30 for the LBP without anxiety group with SAS score &lt;50. The pain intensity was assessed using the Visual Analog Scale; psychological function, using the Pain Anxiety Symptoms Scale, the Tampa Scale for Kinesiophobia, and the Fear Avoidance Beliefs Questionnaire; functional disability, using the Oswestry Disability Index and the Roland–Morris Disability Questionnaire; quality of life using 36-Item Short-Form Health Survey questionnaire; and the quality of sleep using Pittsburgh Sleep Quality Index, and the relationships between variables and anxiety scores were estimated using Spearman correlation analysis.

Results: A total of 60 participants were enrolled after self-rated anxiety was assessed and the full investigation was finished. The analyses showed significant differences of pain intensity (p = 0.034, disability (ODI, p = 0.007; RMDQ, p = 0.012) and psychological function (TSK, p = 0.000; PASS, p = 0.009; FABQ, p = 0.000; SF-36, p = 0.000; and PSQI, p = 0.000) between the two groups. Spearman correlation analysis showed that the anxiety score had significant positive correlations with functional disability (ODI, p = 0.004 and 95% CI = 0.112–0.573; RMDQ, p = 0.003, 95% CI = 0.135–0.586) and psychological function (TSK, p = 0.001, 95% CI = 0.174–0.612), excellent positive correlation with quality of sleep (PASS, p = 0.025, 95% CI = 0.031–0.512), and strongly negative correlations with the quality of life (SF-36, p = 0.000, 95% CI = 0.761–0.433).

Conclusion: We recognized that anxiety in low back pain patients was mainly due to interaction with the intensity of pain, disability level, and a mass of psychological function. The future research direction could be to alleviate the anxiety on the comprehensive efficacy of patients with low back pain.

The Influence of Sleep Disturbance on Chronic Pain

PURPOSE OF REVIEW

The purpose of this review is to present an overview of common sleep disturbance pathologies and their impact on chronic pain, while examining various factors that are implicit in the relationship between sleep disturbance and chronic pain, including neurobiochemistry, anatomy, and systemic mediators, and reviewing recent and landmark literature.

RECENT FINDINGS

Earlier literature reviews and studies have introduced the bidirectional relationship between sleep disturbance and chronic pain; that is, impaired sleep may worsen chronic pain, and chronic pain causes sleep disturbance. However, more recent reviews and studies seem to show a more associative, rather than causative relationship. There have been recent studies that attempt to determine mechanisms that link sleep disturbance and chronic pain; the results of these studies were more varied, ultimately concluding that there may be a separate, yet-to-be discovered mechanism that shows the causative relationship between sleep disturbance and pain. There are several neurotransmitters that are involved in the mediation of chronic pain and sleep disturbance as separate entities, and some studies have shown that there may be mechanisms that govern both chronic pain and sleep disturbance as a single unit. Other neuroendocrine substances also serve to mediate chronic pain and sleep disturbance. All these substances are found to be associated with various sleep disorders and are also associated with chronic pain symptoms as well. Inflammation plays a role in chronic pain and sleep disturbance, with an increase in inflammatory substances and mediators associated with an increase or worsening in chronic pain symptoms and sleep disorders. The HPA axis plays a role in chronic pain and sleep disorders, influencing pain and sleep pathways through stress response, inflammation, and maintenance of homeostasis. There are several variables that influence both chronic pain and sleep disturbance, and more research into these variables may further our understanding into the complex pathways governing the influence of sleep disturbance on pain, and ultimately to improve treatment for this issue.

Frozen shoulder

Frozen shoulder is a common debilitating disorder characterized by shoulder pain and progressive loss of shoulder movement. Frozen shoulder is frequently associated with other systemic conditions or occurs following periods of immobilization, and has a protracted clinical course, which can be frustrating for patients as well as health-care professionals. Frozen shoulder is characterized by fibroproliferative tissue fibrosis, whereby fibroblasts, producing predominantly type I and type III collagen, transform into myofibroblasts (a smooth muscle phenotype), which is accompanied by inflammation, neoangiogenesis and neoinnervation, resulting in shoulder capsular fibrotic contractures and the associated clinical stiffness. Diagnosis is heavily based on physical examination and can be difficult depending on the stage of disease or if concomitant shoulder pathology is present. Management consists of physiotherapy, therapeutic modalities such as steroid injections, anti-inflammatory medications, hydrodilation and surgical interventions; however, their effectiveness remains unclear. Facilitating translational science should aid in development of novel therapies to improve outcomes among individuals with this debilitating condition.

Combining Cognitive Behavioral Therapy for Insomnia and Chronic Spinal Pain Within Physical Therapy: A Practical Guide for the Implementation of an Integrated Approach

Most people who have nonspecific chronic spinal pain (nCSP) report comorbid insomnia. However, in current treatment strategies for nCSP, insomnia is usually not addressed. Considering the bidirectional interaction between pain and sleep and its underlying psychophysiological mechanisms, insomnia may increase the risk of developing adverse physical and psychological health outcomes and should thus no longer be left untreated. As suggested by previous pilot studies, adding cognitive behavioral therapy for insomnia to the contemporary evidence-based biopsychosocial physical therapy approach may also improve pain outcomes in nCSP. This manuscript aims to provide practical guidelines on hybrid physical therapy, including the combination of the following components: (1) pain neuroscience education (eg, to reconceptualize pain) and cognition-targeted exercise therapy (eg, graded exposure to functional daily life movements), and (2) cognitive behavioral therapy for insomnia (sleep psychoeducation, behavioral and cognitive therapy, correction of sleep hygiene, and relaxation therapy) can be deployed for the management of patients who have chronic spinal pain. Impact. Due to the major impact sleep disturbances have on pain and disability, insomnia as a comorbidity should no longer be ignored when treating patients with chronic spinal pain.

Gut Bless Your Pain—Roles of the Gut Microbiota, Sleep, and Melatonin in Chronic Orofacial Pain and Depression

Background. Increased attention has been paid to the gut–brain axis recently, but little is known so far regarding how this translates into pain susceptibility. Aim. The aim of this review is to determine whether gastroenterological disorders and sleep disorders (directly or indirectly) contribute to an increased susceptibility to depression and chronic orofacial pain. Method. A search was performed in the U.S. National Library of Medicine (PubMed) database in order to find studies published before 19 December 2021. We used the following terms: gut microbiome, OR sleep quality, OR melatonin, OR GERD, OR IBS, AND: depression OR chronic pain, in different configurations. Only papers in English were selected. Given the large number of papers retrieved in the search, their findings were described and organized narratively. Results. A link exists between sleep disorders and gastroenterological disorders, which, by adversely affecting the psyche and increasing inflammation, disturb the metabolism of tryptophan and cause excessive microglial activation, leading to increased susceptibility to pain sensation and depression. Conclusions. Pain therapists should pay close attention to sleep and gastrointestinal disorders in patients with chronic pain and depression.

Chronic Musculoskeletal Pain Moderates the Association between Sleep Quality and Dorsostriatal-Sensorimotor Resting State Functional Connectivity in Community-Dwelling Older Adults

Aging is associated with poor sleep quality and greater chronic pain prevalence, with age-related changes in brain function as potential underlying mechanisms. Objective. The following cross-sectional study aimed to determine whether self-reported chronic musculoskeletal pain in community-dwelling older adults moderates the association between sleep quality and resting state functional brain connectivity (rsFC). Methods. Community-dwelling older individuals (mean age = 73.29 years) part of the NEPAL study who completed the Pittsburg Sleep Quality Index (PSQI) and a rsFC scan were included (n = 48) in the present investigation. To that end, we tested the effect of chronic pain-by-PSQI interaction on rsFC among atlas-based brain regions-of-interest, controlling for age and sex. Results and Discussion. A significant network connecting the bilateral putamen and left caudate with bilateral precentral gyrus, postcentral gyrus, and juxtapositional lobule cortex, survived global multiple comparisons (FDR; q < 0.05) and threshold-free network-based-statistics. Greater PSQI scores were significantly associated with greater dorsostriatal-sensorimotor rsFC in the no-pain group, suggesting that a state of somatomotor hyperarousal may be associated with poorer sleep quality in this group. However, in the pain group, greater PSQI scores were associated with less dorsostriatal-sensorimotor rsFC, possibly due to a shift of striatal functions toward regulation sensorimotor aspects of the pain experience, and/or aberrant cortico-striatal loops in the presence of chronic pain. This preliminary investigation advances knowledge about the neurobiology underlying the associations between chronic pain and sleep in community-dwelling older adults that may contribute to the development of effective therapies to decrease disability in geriatric populations.