Comorbid Pain and Cognitive Impairment in a Nationally Representative Adult Population: Prevalence and Associations With Health Status, Health Care Utilization, and Satisfaction With Care

Chronic Pain-Related Cognitive Deficits: Preclinical Insights into Molecular, Cellular, and Circuit Mechanisms

Cognitive impairment is a common comorbidity of chronic pain, significantly disrupting patients' quality of life. Despite this comorbidity being clinically recognized, the underlying neuropathological mechanisms remain unclear. Recent preclinical studies have focused on the fundamental mechanisms underlying the coexistence of chronic pain and cognitive decline. Pain chronification is accompanied by structural and functional changes in the neural substrate of cognition. Based on the developments in electrophysiology and optogenetics/chemogenetics, we summarized the relevant neural circuits involved in pain-induced cognitive impairment, as well as changes in connectivity and function in brain regions. We then present the cellular and molecular alternations related to pain-induced cognitive impairment in preclinical studies, mainly including modifications in neuronal excitability and structure, synaptic plasticity, glial cells and cytokines, neurotransmitters and other neurochemicals, and the gut-brain axis. Finally, we also discussed the potential treatment strategies and future research directions.

Exploring mechanisms of improvement in the Active Brains intervention for older adults with chronic pain and early cognitive decline

OBJECTIVES

We iteratively developed, optimized, and established the feasibility of a virtual, group-based, mind-body activity program (Active Brains, AB), supported by Fitbit for older adults with chronic pain (CP) and early cognitive decline (ECD). Guided by the principles of the NIH stage model we 1) explore signals of improvement in AB outcomes and hypothesized mechanisms of action and 2) explore relationships between changes in outcomes with changes in mechanisms.

METHODS

Participants were N = 15 older adults (age ≥ 60) with CP-ECD from two NIH stage 1 pilot studies of AB. We conducted paired t-tests to explore pre-post improvements, and correlations to investigate associations between changes in outcomes and mechanisms.

RESULTS

We observed small to large improvements across co-primary and secondary outcomes (d = 0.24-1.09). We observed small to medium improvements in 4 out of 5 hypothesized mechanisms (d = 0.23-0.47). Overall, improvements in outcomes had moderate to large associations with improvements in hypothesized mechanisms.

CONCLUSION

AB was associated with improvements across several co-primary and secondary outcomes, and hypothesized mechanisms. Pain-specific coping and general coping skills are promising treatment targets to address the CP-ECD comorbidity among older adults.

Validation of the Danish version of the knowledge and attitudes survey regarding pain

OBJECTIVES

Pain management is critical for nurses; therefore, knowledge assessment is also critical. The Knowledge and Attitudes Survey Regarding Pain (KASRP), designed for testing pain management knowledge among nurses, finds widespread use internationally; yet, key validity evidence according to American Psychological Association standards is missing. Therefore, this study aimed to translate and test the psychometric traits of KASRP based on an item response theory model.

METHODS

Cronbach's α was included to assess internal consistency, and the Kolmogorov-Smirnov test was included to assess the total score normal distribution goodness of fit. KASRP was tested using the Kaiser-Meyer-Olkin (KMO) test for sphericity to examine its suitability for factor analysis and exploratory factor analysis to examine construct evidence. The Kruskal-Wallis H test was used to assess discriminant evidence. The correlation between KASRP and the Brockopp-Warden Pain Knowledge Questionnaire (BWPKQ) was included as a measure of convergent validity evidence, and correlation with self-assessed knowledge was tested as a divergent validity measure.

RESULTS

The questionnaire was translated using back-forth and parallel translation. The KMO test for sphericity was 0.49 for all items and 0.53 for the adjusted scale without items 30, 33, and 36, with factor analysis explaining 70.42% of the variation suggesting unacceptable construct validity evidence. Cronbach's α was 0.75, suggesting acceptable reliability evidence; the Kolmogorov-Smirnov test revealed an insignificant skewness of -0.195 and a kurtosis of 0.001, while the Kruskal-Wallis H test revealed a significance of p < 0.001. The correlation between KASRP and the BWPKQ was 0.69 (p = 0.0001), suggesting acceptable convergent validity evidence. A correlation between KASRP and self-assessed knowledge of -0.59 was also found, which suggests acceptable divergent validity evidence.

CONCLUSIONS

The translated KASRP passed six out of seven tests based on the given sample.

Distinct Worst Pain Profiles in Oncology Outpatients Undergoing Chemotherapy

BACKGROUND

While pain is a significant problem for oncology patients, little is known about interindividual variability in pain characteristics.

OBJECTIVE

The aims of this study were to identify subgroups of patients with distinct worst pain severity profiles and evaluate for differences among these subgroups in demographic, clinical, and pain characteristics and stress and symptom scores.

METHODS

Patients (n = 934) completed questionnaires 6 times over 2 chemotherapy cycles. Worst pain intensity was assessed using a 0- to 10-point numeric rating scale. Brief Pain Inventory was used to assess various pain characteristics. Latent profile analysis was used to identify subgroups of patients with distinct pain profiles.

RESULTS

Three worst pain profiles were identified (low [17.5%], moderate [39.9%], severe [42.6%]). Compared with the other 2 classes, severe class was more likely to be single and unemployed and had a lower annual household income, a higher body mass index, a higher level of comorbidity, and a poorer functional status. Severe class was more likely to have both cancer and noncancer pain, a higher number of pain locations, higher frequency and duration of pain, worse pain quality scores, and higher pain interference scores. Compared with the other 2 classes, severe class reported lower satisfaction with pain management and higher global, disease-specific, and cumulative life stress, as well as higher anxiety, depression, fatigue, sleep disturbance, and cognitive dysfunction scores.

CONCLUSIONS

Unrelieved pain is a significant problem for more than 80% of outpatients.

IMPLICATIONS FOR PRACTICE

Clinicians need to perform comprehensive pain assessments; prescribe pharmacologic and nonpharmacologic interventions; and initiate referrals for pain management and psychological services.

Cross-Sectional Analyses of High-Impact Pain Across Pregnancy Status by Race and Ethnicity

Background: Preclinical and clinical research has suggested the existence of pregnancy-associated analgesia, wherein responses to painful stimulation or pain from disease decrease during pregnancy. Materials and Methods: We combined data from multiple years (2012-2015) of the National Health Interview Survey to examine high-impact pain by Hispanic ethnicity and race in women with no prior pregnancy, during pregnancy, and previously pregnant. Results: High-impact pain was less common for women during pregnancy (10.3%; 95% confidence interval [CI]: 7.0%-13.7%) than it was for women who had never been pregnant (13.7%; 95% CI: 12.8%-14.5%) and for women who had previously been pregnant (19.8%; 95% CI: 16.0%-23.7%). However, when we examined the data by Hispanic ethnicity and race, we found that non-Hispanic White (NHW) women were less likely to report high-impact pain during pregnancy, but non-Hispanic Black (NHB) women and Hispanic White women were not. In women who reported no prior pregnancy, NHW women were most likely to report high-impact pain, followed by NHB women and Hispanic women. In post hoc analyses, we found that while menstrual problems were associated with increased odds of having high-impact pain, an interaction was not observed between menstrual problems and race/ethnicity (p = 0.48). Conclusions: This cross-sectional study presents a nationally representative examination of the prevalence of high-impact pain across pregnancy status. Using a nationally representative sample of women, we have demonstrated that the prevalence of high-impact pain varies across pregnancy status and that race/ethnicity and the presence of menstrual problems independently affect this prevalence.

Normalization of Neuroinflammation: A New Strategy for Treatment of Persistent Pain and Memory/Emotional Deficits in Chronic Pain

Chronic pain, which affects around 1/3 of the world population and is often comorbid with memory deficit and mood depression, is a leading source of suffering and disability. Studies in past decades have shown that hyperexcitability of primary sensory neurons resulting from abnormal expression of ion channels and central sensitization mediated pathological synaptic plasticity, such as long-term potentiation in spinal dorsal horn, underlie the persistent pain. The memory/emotional deficits are associated with impaired synaptic connectivity in hippocampus. Dysregulation of numerous endogenous proteins including receptors and intracellular signaling molecules is involved in the pathological processes. However, increasing knowledge contributes little to clinical treatment. Emerging evidence has demonstrated that the neuroinflammation, characterized by overproduction of pro-inflammatory cytokines and glial activation, is reliably detected in humans and animals with chronic pain, and is sufficient to induce persistent pain and memory/emotional deficits. The abnormal expression of ion channels and pathological synaptic plasticity in spinal dorsal horn and in hippocampus are resulting from neuroinflammation. The neuroinflammation is initiated and maintained by the interactions of circulating monocytes, glial cells and neurons. Obviously, unlike infectious diseases and cancer, which are caused by pathogens or malignant cells, chronic pain is resulting from alterations of cells and molecules which have numerous physiological functions. Therefore, normalization (counterbalance) but not simple inhibition of the neuroinflammation is the right strategy for treating neuronal disorders. Currently, no such agent is available in clinic. While experimental studies have demonstrated that intracellular Mg²⁺ deficiency is a common feature of chronic pain in animal models and supplement Mg²⁺ are capable of normalizing the neuroinflammation, activation of upregulated proteins that promote recovery, such as translocator protein (18k Da) or liver X receptors, has a similar effect. In this article, relevant experimental and clinical evidence is reviewed and discussed.

A Review of Potential National Chronic Pain Surveillance Systems in the United States

Pain has been established as a major public health problem in the United States (U.S.) with 50 million adults experiencing chronic pain and 20 million afflicted with high-impact chronic pain (ie, chronic pain that interferes with life or work activities). High financial and social costs are associated with chronic pain. Over the past 2 decades, pain management has been complicated by the marked increase in opioids prescribed to treat chronic noncancer pain and by the concurrent opioid crisis. Monitoring the prevalence of chronic pain and pain management is especially important because pain management is changing in uncertain ways. We review potential U.S. chronic pain surveillance systems, present potential difficulties of chronic pain surveillance, and explore how to address chronic pain surveillance in the current opioid era. We consider case definitions, severity, anatomic site, and varieties of chronic pain management strategies in reviewing and evaluating national surveys for chronic pain surveillance. Based on the criteria evaluated, the National Health Interview Survey offers the best single source for pain surveillance as the pain-related questions administered are brief, valid, and cover a broad scope of pain-related phenomena. PERSPECTIVE: This review article describes data sources that can be leveraged to conduct national chronic pain surveillance in the United States, explores case defining or pain-related questions administered, and evaluates them against 8 surveillance attributes.

Pain and the Alzheimer's Disease and Related Dementia Spectrum in Community-Dwelling Older Americans: A Nationally Representative Study

CONTEXT

Pain is a significant concern among older adults with Alzheimer's disease and related dementias (ADRD).

OBJECTIVES

Examine the association between cognitive impairment across the ADRD spectrum and pain assessment and treatment in community-dwelling older Americans.

METHODS

This cross-sectional, population-based study included 16,836 community-dwelling participants ≥ 50 years in the 2018 Health and Retirement Study. ADRD, assessed by validated cognitive measures, was categorized into "dementia," "cognitive impairment, no dementia (CIND)" and "intact cognition." Pain assessment included pain presence (often being troubled with pain), pain severity (degree of pain most of the time [mild/moderate/severe]), and pain interference (pain making it difficult to do usual activities). Pain treatment included recent use of over-the-counter pain medications and opioids (past 3 months), and regular intake of prescriptions for pain.

RESULTS

Dementia were associated with lower likelihood of reporting pain presence (Odds Ratio [OR]= 0.61, P = 0.01), pain interference (OR = 0.46, P < 0.001), reporting lower pain severity (e.g., moderate vs. no: Relative Risk Ratio = 0.38, P < 0.001), and lower likelihood of receiving pain treatment, that is, recent use of over-the-counter pain medications (OR = 0.60, P = 0.02) and opioids (OR = 0.33, P < 0.001), and regular intake of prescriptions for pain (OR = 0.461, P = 0.002). CIND was associated with reporting lower pain severity (e.g., moderate vs. no: Relative Risk Ratio = 0.75, P = 0.021), lower likelihood of reporting pain interference (OR = 0.79, P = 0.045) and recent over-the-counter pain medication use (OR = 0.74, P = 0.026).

CONCLUSION

CIND and dementia increased the risk of under-report and under-treatment of pain. Systematic efforts are needed to improve pain recognition and treatment among older adults with cognitive impairment, regardless of dementia diagnosis.

Pain Prevalence, Chronicity and Impact Within Subpopulations Based on Both Hispanic Ancestry and Race: United States, 2010-2017

We provide national surveillance estimates of pain chronicity, severity and impact in adult subpopulations defined by both Hispanic Ancestry and Race. Data are from 144,434 adults who completed validated questionnaires in the 2010-2017 National Health Interview Survey asking about pain status within the last 3 (N = 84,664) or 6 months (N = 59,770). Multivariable logistic regression was used to assess the relationship between pain and ethnicity/race. Compared to White Puerto Rican participants, White participants with Central/South American and Mexican ancestry had reduced odds of reporting Category 3-4 pain and High-Impact Chronic Pain (HICP), while those of Cuban ancestry had reduced odds of only HICP - eg, White participants with Mexican ancestry had 32% lower odds of having Category 3-4 pain and 50% lower odds of having HICP. While no differences were seen between White Puerto Rican and White Non-Hispanic participants for Category 3-4 pain, White Non-Hispanics had 40% lower odds of reporting HICP. Asian Non-Hispanic and Black Non-Hispanic participants had significantly lower odds of reporting Category 3-4 pain and HICP compared to White Puerto Rican participants, eg, Black Non-Hispanic participants had 26% lower odds off having Category 3-4 pain and 42% lower odds of having HICP. Perspective: By examining pain status in discrete demographic groups based on Hispanic Ancestry and Race, this report further documents substantial difference in health status among underserved populations and provides a baseline for continuing surveillance research on pain, with the eventual goal of eliminating disparities in pain assessment and treatment.

Cogstate Brief Battery: Cognition and the feigning of cognitive impairment in chronic pain

Chronic pain (CP) is often associated with cognitive impairment. The Cogstate Brief Battery (CBB), a computerized assessment battery, has been studied in several neuropsychiatric disorders but not in CP. Since feigning of cognitive impairment is common in CP, the current study aimed to assess the CBB's utility in differentiating CP patients (n = 64) from healthy participants (n = 33), as well as to assess the effect of simulating cognitive impairment by CP patients on performance in the battery. CP outpatients were randomly assigned to one of two groups: (a) Patients performing the CBB to the best of their ability. (b) Patients simulating cognitive impairment. Independent-samples t-tests indicated that three of four CBB tasks successfully differentiated CP patients from matched healthy controls. Additionally, an analysis of covariance (ANCOVA) indicated that CP patients who simulated cognitive impairment performed more poorly in all four CBB tasks, with the detection task having the strongest discrimination capacity. This is the first study to point toward the usefulness and sensitivity of the CBB for assessment of cognition and detection of feigned cognitive impairment in CP. Further studies are required to validate these preliminary findings and assess the CBB's utility in daily clinical practice.

Live Video Adaptations to a Mind-Body Activity Program for Chronic Pain and Cognitive Decline: Protocol for the Virtual Active Brains Study

BACKGROUND

Chronic pain (CP) and cognitive decline (CD) are costly, challenging to treat, prevalent among older adults, and worsen each other over time. We are iteratively developing Active Brains-Fitbit (AB-F), a live video program for older adults with CP and CD that teaches mind-body skills and gradual increases in step count. AB-F has demonstrated feasibility; acceptability; and signs of improvement in emotional, physical, and cognitive functions when delivered in person to older adults.

OBJECTIVE

We are conducting a feasibility randomized controlled trial (RCT) of AB-F versus a time- and dose-matched educational control (health enhancement program [HEP]) in older adults with CP and CD. Here, we describe virtual adaptions to our study protocol, manualized treatments, evaluation plan, and study design in response to feedback from former participants and COVID-19. We will evaluate the feasibility benchmarks and the potential of AB-F to improve physical, emotional, and cognitive functions.

METHODS

This is a single-blind pilot RCT. Participants are randomized to AB-F or HEP. Patients are recruited through pain clinic referrals, institutional registries, and flyers. Interested participants are screened for eligibility via telephone and provide electronic informed consent. After randomization, participants are mailed all study documents, including their treatment manual, an ActiGraph accelerometer, and a Fitbit (separate envelope for AB-F only). Both conditions are manualized and delivered over 8 weekly sessions via Zoom. Participants complete self-report and performance-based (6-min walk test and Montreal Cognitive Assessment) outcome measures via Zoom at baseline and post intervention. Primary outcomes are a priori set feasibility (recruitment, quantitative measures, and adherence), acceptability, credibility, expectancy, and satisfaction benchmarks. Secondary outcomes are physical, cognitive, and emotional functions as well as intervention targets (social function, pain intensity, pain-specific coping, and mindfulness).

RESULTS

The trial is ongoing. We have recruited 21 participants (10 AB-F and 11 HEP) across 2 rounds. Only 2 participants have withdrawn (1 before baseline and 1 before the first session). All 19 remaining participants have completed the baseline assessment. In the first round, attendance is high (11 out of 12 participants completed all 4 sessions so far), and AB-F participants are adherent to their Fitbit and step goals (5 out of 6 participants).

CONCLUSIONS

Preliminary findings are promising for the feasibility of our completely virtual AB-F intervention. However, these findings need to be confirmed at the trial conclusion. This study will answer important questions about the feasibility of delivering a completely virtual mind-body activity program to older adults with comorbid CP and CD, which, to our knowledge, is unprecedented. Details on integrating multiple digital platforms for virtual assessments and intervention delivery will inform treatment development for older adults and those with comorbid CP and CD, which is crucial during the COVID-19 pandemic.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04044183; https://clinicaltrials.gov/ct2/show/NCT04044183.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/25351.