Prevalence and risk factors of musculoskeletal pain symptoms as long-term post-COVID sequelae in hospitalized COVID-19 survivors: a multicenter study

COVID-19 and chronic pain: Implications and lessons learned

The COVID-19 pandemic has profoundly impacted people with chronic pain, affecting their access to pain management services and the social fabric of society. Here we review evidence indicating that during and since the pandemic (1) the overall prevalence and burden of chronic pain has increased, (2) social threats such as social isolation, abuse and neglect, and disparities in access to pain management, have increased, and these changes are associated with worsening pain and pain-related health outcomes, and (3) there has been a surge in research into telehealth interventions for chronic pain, with promising results. We conclude with a discussion of lessons that may guide future research and care for people with chronic pain in a post-COVID world.

Evaluation of the ability of large language models to self-diagnose oral diseases

Large language models (LLMs) offer potential in primary dental care. We conducted an evaluation of LLMs' diagnostic capabilities across various oral diseases and contexts. All LLMs showed diagnostic capabilities for temporomandibular joint disorders, periodontal disease, dental caries, and malocclusion. The prompts did not affect the performance of ChatGPT 3.5. When Chinese was used, the diagnostic ability of ChatGPT 3.5 for pulpitis improved (0% vs. 61.7%, p < 0.001), while the ability to diagnose pericoronitis decreased (8% vs. 0%, p < 0.001). For ChatGPT 4.0 in Chinese, they were both improved (0% vs. 92%, 8% vs. 72%, p < 0.001, respectively). Claude 2 exhibited the highest accuracy in diagnosing pulpitis (36%, p = 0.048), ChatGPT 4.0 showed complete diagnostic capability for pericoronitis. Llama 2 and Claude 3.5 Sonnet exhibited complete diagnostic capability for oral cancer. In conclusion, LLMs may be a potential tool for daily dental care but need further updates.

A clinical approach to the investigation and management of long COVID associated neuropathic pain

COVID-19 has been associated with a wide range of ongoing symptoms following recovery from the acute SARS-CoV-2 infection. Around one in three people with COVID-19 develop neurological symptoms with many reporting neuropathic pain and associated symptoms, including paraesthesia, numbness, and dysesthesia. Whilst the pathophysiology of long COVID-19-associated neuropathic pain remains unclear, it is likely to be multifactorial. Early identification, exclusion of common alternative causes, and a biopsychosocial approach to the management of the symptoms can help in relieving the burden of disease and improving the quality of life for patients.

Epigenetic changes in patients with post-acute COVID-19 symptoms (PACS) and long-COVID: A systematic review

BACKGROUND

Up to 30% of people infected with SARS-CoV-2 report disabling symptoms 2 years after the infection. Over 100 persistent symptoms have been associated with Post-Acute COVID-19 Symptoms (PACS) and/or long-COVID, showing a significant clinical heterogeneity. To develop effective, patient-targeted treatment, a better understanding of underlying mechanisms is needed. Epigenetics has helped elucidating the pathophysiology of several health conditions and it might help unravelling inter-individual differences in patients with PACS and long-COVID. As accumulating research is exploring epigenetic mechanisms in PACS and long-COVID, we systematically summarized the available literature on the topic.

METHODS

We interrogated five databases (Medline, Embase, Web of Science, Scopus and medXriv/bioXriv) and followed PRISMA and SWiM guidelines to report our results.

RESULTS

Eight studies were included in our review. Six studies explored DNA methylation in PACS and/or long-COVID, while two studies explored miRNA expression in long-COVID associated with lung complications. Sample sizes were mostly small and study quality was low or fair. The main limitation of the included studies was a poor characterization of the patient population that made a homogeneous synthesis of the literature challenging. However, studies on DNA methylation showed that mechanisms related to the immune and the autonomic nervous system, and cell metabolism might be implicated in the pathophysiology of PACS and long-COVID.

CONCLUSION

Epigenetic changes might help elucidating PACS and long-COVID underlying mechanisms, aid subgrouping, and point towards tailored treatments. Preliminary evidence is promising but scarce. Biological and epigenetic research on long-COVID will benefit millions of people suffering from long-COVID and has the potential to be transferable and benefit other conditions as well, such as Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). We urge future research to employ longitudinal designs and provide a better characterization of included patients.

TLR2/NF-κB signaling in macrophage/microglia mediated COVID-pain induced by SARS-CoV-2 envelope protein

Pain has become a major symptom of long COVID-19 without effective therapy. Apart from viral infection pathological process, SARS-CoV-2 membranal proteins (envelope [S2E], spike [S2S] and membrane [S2M]) also present pro-inflammatory feature independently. Here, we aim to uncover the neuroinflammatory mechanism of COVID-pain induced by SARS-CoV-2 membranal proteins. We detected the three proteins in both peripheral sensory ganglions and spinal dorsal horn of COVID-19 donors. After intradermal and intrathecal injection, only S2E triggered pain behaviors, accompanied with upregulated-phosphorylation nuclear factor kappa B (NF-κB), which was significantly attenuated by minocycline in mice. We further identified Toll-like receptor 2 (TLR2) among TLRs as the target of S2E to evoke inflammatory responses leading to COVID-pain. This study identified the nociceptive effect of S2E through directly interacting with macrophage/microglia TLR2 and inducing the following NF-κB inflammatory storm. Clearing away S2E and inhibiting macrophage/microglia TLR2 served as perspective therapeutic strategies for COVID-19 pain.

Impact of the COVID-19 pandemic on the productivity and career prospects of musculoskeletal researchers

Academic researchers faced a multitude of challenges posed by the COVID-19 pandemic, including widespread shelter-in-place orders, workplace closures, and cessation of in-person meetings and laboratory activities. The extent to which these challenges impacted musculoskeletal researchers, specifically, is unknown. We developed an anonymous web-based survey to determine the pandemic's impact on research productivity and career prospects among musculoskeletal research trainees and faculty. There were 116 musculoskeletal (MSK) researchers with varying demographic backgrounds who completed the survey. Of respondents, 48.3% (n = 56) believed that musculoskeletal funding opportunities decreased because of COVID-19, with faculty members more likely to hold this belief compared to nonfaculty researchers (p = 0.008). Amongst MSK researchers, 88.8% (n = 103) reported research activity was limited by COVID-19, and 92.2% (n = 107) of researchers reported their research was not able to be refocused on COVID-19-related topics, with basic science researchers less likely to be able to refocus their research compared to clinical researchers (p = 0.030). Additionally, 47.4% (n = 55) reported a decrease in manuscript submissions since the onset of the pandemic. Amongst 51 trainee researchers, 62.8% (n = 32) reported a decrease in job satisfaction directly attributable to the COVID-19 pandemic. In summary, study findings indicated that MSK researchers struggled to overcome challenges imposed by the pandemic, reporting declines in funding opportunities, research productivity, and manuscript submission. Trainee researchers experienced significant disruptions to critical research activities and worsening job satisfaction. Our findings motivate future efforts to support trainees in developing their careers and target the recovery of MSK research from the pandemic stall.

Prevalence and Risk Factors of Multitype Post-COVID Pain in a Cohort of Previously Hospitalized COVID-19 Survivors: A Danish Cross-Sectional Survey

This population-based study investigated the prevalence of de novo, multitype, post-coronavirus disease (COVID) pain and its associated risk factors in previously hospitalized coronavirus disease 2019 (COVID-19) survivors. The nationwide, cross-sectional study included a cohort of Danish residents previously hospitalized due to severe acute respiratory syndrome coronavirus-2 infection between March 2020 and December 2021. Demographic data, preexisting medical comorbidities, previous pain-related symptoms, medication use for pain management, pain intensity (4-point scale), and development of de novo, multitype, post-COVID pain were collected by a self-reported survey distributed via e-Boks (a secured national digital mail system used in Denmark to provide public information to residents). The sample comprised 4,712 previously hospitalized COVID-19 survivors (48.6% women, mean age: 60.1 ± 15.6 years). At the time of the study (21 ± 6 months after hospitalization), 18.0% (847) reported the presence of de novo, multitype, post-COVID pain, and 38.6% of any pain. A multivariate analysis revealed that female sex (Odds Ratio (OR) 1.711, 95% Confidence Interval (CI) 1.444-2.023), higher body mass index (OR 1.032, 95% CI 1.019-1.045), intensive care unit admission (OR 1.597, 95% CI 1.324-1.926), previous history of whiplash (OR 2.471, 95% CI 1.004-6.081), anxiety (OR 3.626, 95% CI 1.335-9.708), and younger age (OR .982, 95% CI .976-.987) were factors associated with development of de novo, multitype, post-COVID pain. High income (OR .635, 95% CI .494-.817) and high educational level (OR .774, 95% CI .609-.984) were protective factors. In conclusion, multitype pain as a de novo post-COVID symptom was present in 18.0% of previously hospitalized COVID-19 survivors more than 1 year after hospital discharge and as such can be considered as adding to the global burden of chronic pain. PERSPECTIVE: The study investigates the prevalence of de novo, multitype, post-COVID pain in previously hospitalized COVID-19 survivors. This article presents potential risk factors associated with developing new pain symptoms. The results will contribute to understanding the possibility of predicting postinfectious pain from COVID-19 for future analysis.

The impact of COVID-19 infection on musculoskeletal pain and its associating factors: a cross-sectional study

Objectives

Musculoskeletal pain after COVID-19 infection remains a concerning long-term complication of COVID-19. Here, our study aimed to investigate the prevalence of musculoskeletal pain associated with COVID-19 (MSPC) and healthcare-seeking behaviors, as well as the associating factors.

Methods

A cross-sectional survey was conducted using convenience sampling and distributed to participants anonymously through the online platform Credamo. Demographic and characteristic data of the participants were collected and analyzed. Logistic regression analysis was employed to investigate potential factors associated with MSPC and healthcare-seeking tendencies.

Results

A total of 1,510 participants responded to the survey, with 42.6% (643 individuals) exhibiting MSPC. Higher education level and a greater number of concomitant symptoms were significant risk factors for MSPC, while longer exercise duration and higher PSS-10 scores were protective factors. Additionally, higher income level, frequency and severity of pain, and greater PSS-10 scores increased healthcare-seeking intention.

Conclusion

A significant proportion of individuals experience MSPC. Education level and concomitant symptoms were risk factors for MSPC, while exercise duration and PSS-10 score were potential protective factors. Income level, frequency and severity of pain, and PSS-10 score are significantly related to the willingness to seek medical treatment for MSPC.

Advance in the mechanism and clinical research of myalgia in long COVID

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve, mortality rates of coronavirus disease 2019 (COVID-19) have significantly decreased. However, a variable proportion of patients exhibit persistent prolonged symptoms of COVID-19 infection (long COVID). This virus primarily attacks respiratory system, but numerous individuals complain persistent skeletal muscle pain or worsening pre-existing muscle pain post COVID-19, which severely affects the quality of life and recovery. Currently, there is limited research on the skeletal muscle pain in long COVID. In this brief review, we review potential pathological mechanisms of skeletal muscle pain in long COVID, and summarize the various auxiliary examinations and treatments for skeletal muscle pain in long COVID. We consider abnormal activation of inflammatory response, myopathy, and neurological damages as pivotal pathological mechanisms of skeletal muscle pain in long COVID. A comprehensive examination is significantly important in order to work out effective treatment plans and relieve skeletal muscle pain. So far, rehabilitation interventions for myalgia in long COVID contain but are not limited to drug, nutraceutical therapy, gut microbiome-targeted therapy, interventional therapy and strength training. Our study provides a potential mechanism reference for clinical researches, highlighting the importance of comprehensive approach and management of skeletal muscle pain in long COVID. The relief of skeletal muscle pain will accelerate rehabilitation process, improve activities of daily living and enhance the quality of life, promoting individuals return to society with profound significance.

Clinical Characterization of New-Onset Chronic Musculoskeletal Pain in Long COVID: A Cross-Sectional Study

Purpose

New-onset chronic musculoskeletal (MSK) pain is one of the common persistent symptoms in Long COVID (LC). This study investigated its clinical characteristics, underlying mechanisms, and impact on function, psychological health, and quality of life.

Patients and Methods

Thirty adults (19 female, 11 male) with LC and new-onset chronic MSK pain underwent clinical examination, Quantitative Sensory Testing (QST), and blood tests for inflammatory markers and completed the following outcome measures: Timed Up and Go test (TUG), handgrip strength test, COVID-19 Yorkshire Rehabilitation Scale (C19-YRS), Brief Pain Inventory (BPI), Pain Self-Efficacy Questionnaire (PSEQ), Pain Catastrophizing Scale (PCS), International Physical Activity Questionnaire-short form (IPAQ-sf), Generalized Anxiety Disorder (GAD-7), Patient Health Questionnaire (PHQ-9), and EuroQol Five Dimensions health-related quality of life (EQ-5D-5L).

Results

New-onset chronic MSK pain was widespread and continuous in nature, and worse in the joints. When compared to normative values reported in the literature: a) QST revealed mechanical hyperalgesia, heightened temporal summation of pain, and hypoesthesia to vibration stimuli, which is strongly suggestive of central sensitization; b) Plasma cytokine assays indicated distinct pro-inflammatory profiles; c) TUG time indicated reduced balance and mobility; d) handgrip strength revealed general weakness; e) physical activity was lower; and f) there were moderate levels of depression and anxiety with lower self-efficacy scores and lower levels of pain catastrophizing. LC symptoms were of moderate severity (44.8/100), moderate functional disability (22.8/50) and severely compromised overall health (2.6/10) when compared to pre-COVID scores.

Conclusion

New-onset chronic MSK pain in LC tends to be widespread, constant, and associated with weakness, reduced function, depression, anxiety, and reduced quality of life. There is associated central sensitization and proinflammatory state in the condition. Further research is essential to explore the longitudinal progression and natural evolution of the new-onset chronic MSK pain in LC.

Post-COVID-19 Pain Is Not Associated with DNA Methylation Levels of the ACE2 Promoter in COVID-19 Survivors Hospitalized Due to SARS-CoV-2 Infection

One of theories explaining the development of long-lasting symptoms after an acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection include changes in the methylation pattern of the host. The current study aimed to investigate whether DNA methylation levels associated with the angiotensin-converting enzyme 2 (ACE2) promoter are different when comparing individuals previously hospitalized due to COVID-19 who then developed long-lasting post-COVID pain with those previously hospitalized due to COVID-19 who did not develop post-COVID-19 pain symptoms. Non-stimulated saliva samples were obtained from a cohort of 279 (mean age: 56.5, SD: 13.0 years old, 51.5% male) COVID-19 survivors who needed hospitalization. Clinical data were collected from hospital medical records. Participants were asked to disclose pain symptoms developed during the first three months after hospital admission due to COVID-19 and persisting at the time of the interview. Methylations of five CpG dinucleotides in the ACE2 promoter were quantified (as percentages). Participants were evaluated up to 17.8 (SD: 5.3) months after hospitalization. Thus, 39.1% of patients exhibited post-COVID-19 pain. Most patients (77.05%) in the cohort developed localized post-COVID-19 pain. Headache and pain in the lower extremity were experienced by 29.4% of the patients. Seven patients received a post-infection diagnosis of fibromyalgia based on the presence of widespread pain characteristics (11.6%) and other associated symptoms. No significant differences in methylation percentages at any CpG location of the ACE2 promoter were identified when comparing individuals with and without post-COVID-19 pain. The current study did not observe differences in methylation levels of the ACE2 promoter depending on the presence or absence of long-lasting post-COVID-19 pain symptoms in individuals who needed hospitalization due to COVID-19 during the first wave of the pandemic.

Effectiveness of telerehabilitation in patients with post-COVID-19: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To assess the effects of telerehabilitation on clinical symptoms, physical function, psychological function and quality of life (QoL) in patients with post-COVID-19.

DESIGN

Systematic review and meta-analysis of randomised controlled trials (RCTs).

DATA SOURCES

PubMed, Web of Science, Embase and Cochrane Library were searched for publications from 1 January 2020 to 17 April 2024.

ELIGIBILITY CRITERIA

RCTs investigating the effects of telerehabilitation in patients with post-COVID-19 were included. The outcomes of interest encompassed clinical symptoms, physical function, psychological function and QoL. Only studies reported in English were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data and evaluated the risk of bias. Statistical analysis was conducted using Review Manager V.5.3, employing mean difference (MD) with a 95% CI, and the corresponding P value was used to ascertain the treatment effect between groups. Heterogeneity was quantified using the I2 statistic. The quality of evidence was assessed by GRADE.

RESULTS

16 RCTs (n=1129) were included in this systematic review, 15 of which (n=1095, 16 comparisons) were included in the meta-analysis. The primary pooled analysis demonstrated that, compared with no rehabilitation or usual care, telerehabilitation can improve physical function (measured by 30 s sit-to-stand test [6 RCTs, n=310, MD=1.58 stands, 95% CI 0.50 to 2.66; p=0.004]; 6 min walking distance [6 RCTs, n=324, MD=76.90 m, 95% CI 49.47 to 104.33; p<0.00001]; and physical function from the 36-item short-form health survey [5 RCTs, n=380, MD=6.12 units, 95% CI 2.85 to 9.38; p=0.0002]). However, the pooled results did not indicate significant improvements in clinical symptoms, pulmonary function, psychological function or QoL. The quality of the evidence was graded as low for physical function and Hospital Anxiety and Depression Scale-anxiety and very low for other assessed outcomes. The overall treatment completion rate was 78.26%, with no reports of severe adverse events in any included trials.

CONCLUSIONS

Despite the lack of significant improvements in certain variables, telerehabilitation could be an effective and safe option for enhancing physical function in patients with post-COVID-19. It is advisable to conduct further well-designed trials to continue in-depth exploration of this topic.

STUDY REGISTRATION

PROSPERO, CRD42023404647.

Investigating the fluctuating nature of post-COVID pain symptoms in previously hospitalized COVID-19 survivors: the LONG-COVID-EXP multicenter study

Objective

This cohort study used Sankey plots and exponential bar plots for visualizing the fluctuating nature and trajectory of post-COVID pain in previously hospitalized COVID-19 survivors.

Methods

A cohort of 1266 subjects hospitalised because of COVID-19 during the first wave of the pandemic were scheduled for a telephone interview at 8.4 (T1), 13.2 (T2), and 18.3 (T3) months in average after hospitalization for collecting data about post-COVID pain. Patients were asked for about pain symptomatology that was attributed to the infection. Hospitalization and clinical data were collected from medical records.

Results

The prevalence of myalgia as COVID-19-associated symptom was 29.82% (n = 389) at hospitalization (T0). The prevalence of post-COVID pain was 41.07% (n = 520) at T1, 34.29% (n = 434) at T2, and 28.47% (n = 360) at T3. The recovery exponential curve revealed a decrease trend visualizing that post-COVID pain improved over the time span investigated. Pain in the lower extremity and widespread pain were the most prevalent locations. Female sex (OR 1.507, 95% CI 1.047-2.169), pre-existing pain symptoms (OR 1.724, 95% CI 1.237-2.403), headache as onset-symptom (OR 2.374, 95% CI 1.550-3.639), days at hospital (OR 1.012, 95% CI 1.000-1.025), and presence of post-COVID pain at T1 (OR 13.243, 95% CI 9.428-18.601) were associated with post-COVID pain at T2. Only the presence of post-COVID pain at T1 (OR 5.383, 95% CI 3.896-7.439) was associated with post-COVID pain at T3.

Conclusion

Current results show a fluctuating evolution with a decreasing tendency of post-COVID pain during the first years after hospitalization. The development of post-COVID pain soon after SARS-CoV-2 infection predispose for long-lasting chronic pain.

[Updated S1 guideline on long/post-COVID: relevant aspects for pain medicine]

BACKGROUND

The S1 guideline on long/post-COVID of the AWMF [German Association of the Medical Scientific Societies] registration number 020-027) was updated in August 2022.

METHODS

Under the coordination of the German Society of Pneumology, the guideline was updated by 21 scientific associations, two professional associations and clinical centers each and one institute and statutory accident insurance each. Each scientific association was responsible for its own chapter. The German Pain Society prepared the chapter "Pain". The coordinators of each chapter performed a selective literature search and also received approval for the chapter within their scientific association. During an internal period of comments, all representatives of the participating institutions could comment on all chapters. The AWMF task force commented on the draft of the guideline, which was then finally approved by the boards of all participating institutions.

RESULTS

Coronavirus disease 2019 (COVID-19) increases the risk of persistent headache and musculoskeletal pain. Long/Post-COVID pain is frequently associated with fatigue and cognitive problems. A specialist assessment might be considered if symptoms with limitations of daily activities persist 3 months after the infection. The diagnostic workup of long/post-COVID-associated pain should be performed according to the standards of pain medicine. Management should follow the pain guidelines of the AWMF.

CONCLUSIONS

The updated S1 guideline on long/post-COVID is a clinical manual which offers orientation for diagnostics and treatment despite limited data.

Impact of the COVID-19 pandemic on clinical and psychological aspects of temporomandibular disorders

BACKGROUND

The Coronavirus 2019 disease (COVID-19) caused drastic changes in people's lifestyle that affected TMD characteristics through its physical and psychological influences. The aim of this study was to define the clinical and psychological characteristics of a large group of well-defined TMD patients and seek their differences between before and during the COVID-19 pandemic to establish points of care to be emphasized in the post-pandemic era.

METHODS

TMD patients diagnosed by the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) aged ≥ 18 were analyzed. Samples between September, 2017 to July, 2019 (n = 455) and March, 2021 to June, 2022 (n = 338) were collected to represent before and during COVID-19, respectively. The Graded Chronic Pain Scale (GCPS) and Symptom Checklist-90-Revision (SCL-90-R) were used to evaluate disability levels and psychological status. Clinical indices were compared between COVID periods and factors related to higher pain levels were investigated according to pandemic period.

RESULTS

More patients reported pain on palpation of the masticatory muscles during the pandemic (p = 0.021) while the number decreased for neck muscles (p = 0.001) and TMJ (p < 0.001) areas. Patients reporting nocturnal bruxism (23.3-29.6%) and clenching (45.1-54.7%) significantly increased during the pandemic. TMD patients with pain without disability were more common during the pandemic regardless of pain intensity (p < 0.001). The number of patients expressing interference in daily activities decreased drastically during COVID-19 regardless of disability level (p < 0.001). Factors associated with higher than moderate pain intensity (CPI ≥ 50) were insomnia (odds ratio [OR] = 1.603, p = 0.047) and somatization (OR = 1.082, p < 0.001) before the pandemic. During the pandemic, age (OR = 1.024, p = 0.007), somatization (OR = 1.070, p = 0.006), and paranoid ideation (OR = 1.117, p = 0.003) were significantly associated with higher pain intensity.

CONCLUSIONS

The results of our study underline the importance of evaluating psychological profiles of TMD patients, especially somatization, paranoid ideation and psychoticism, in exceptional situations that may cause a change in individual mental status. This will lead to a better understanding of the individual TMD patient and help in planning personalized treatment strategies that will assist the patient in adjusting to changes occurring in special environments such as the COVID-19 pandemic.

Predictors for Long COVID and Differences in Long COVID Symptoms, Findings on Chest Imaging and Pulmonary Function between Hospitalized COVID-19 Patients with versus without Intensive Care Unit Admission

INTRODUCTION

Many COVID-19 survivors suffer from persisting sequelae after acute disease. This is referred to as long COVID. The objectives of this study were to assess factors associated with long COVID and to analyze differences in persistent symptoms, findings on chest imaging, and pulmonary function between intensive care unit (ICU) and non-ICU hospitalized patients.

METHODS

We conducted a retrospective study including patients hospitalized with COVID-19. Patients were stratified into ICU patients and non-ICU patients. We analyzed the outcomes of patients who were in clinical follow-up 6 months after discharge with persistent symptoms, radiological and/or functional abnormalities. Logistic regression was used to examine the association between long COVID and patient characteristics.

RESULTS

A total of 549 patients were included. Eighty-one ICU patients (66%) and 146 (34%) non-ICU patients had persistent symptoms or abnormalities on chest imaging or lung function test minimally 6 months after discharge. Significantly more ICU patients had residual fibrotic abnormalities on chest CT and functional impairment. Female gender, myocardial infarction, OSAS, low PCO2 at admission, and longer hospital stay were associated with a higher risk of developing long COVID. Diabetes and treatment with tocilizumab were associated with a lower risk of developing long COVID.

CONCLUSION

Of the patients hospitalized for COVID-19, 34-66% suffered from persistent symptoms, residual abnormalities on chest imaging, or reduced lung function at around 6 months after discharge. While persistent sequelae were more frequent in ICU patients, admission to the ICU was not found to be an independent risk factor for developing long COVID.

Exacerbation of Pre-Existing Chronic Pain in Older Adults After SARS-CoV-2 Infection: A Single-Center, Cross-Sectional, Observational Study

Purpose

To identify the prevalence of exacerbation of pre-existing chronic pain after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and investigate the impact of exacerbated previous chronic pain on quality of life, sleep quality, anxiety and depression levels and risk factors associated with exacerbated chronic pain among elderly coronavirus disease of 2019 (COVID-19) survivors.

Patients and Methods

In this cross-sectional study, elderly COVID-19 survivors with chronic pain residing in Continuing Care Retirement Community (CCRC) were recruited from April 2023 to June 2023. Eligible individuals were divided into exacerbation and non-exacerbation groups based on the patient-reported worsening symptoms of previous chronic pain after SARS-CoV-2 infection. Baseline information, COVID-19 symptoms, laboratory parameters, characteristics of exacerbated chronic pain, quality of life, anxiety and depression levels were systematically collected.

Results

Ninety-five (95/441, 21.5%) older adults suffered from exacerbated chronic pain with a median numerical rating scale (NRS) score of 6 (4-7) on a median duration of 4.9 (4.3-5.6) months after SARS-CoV-2 infection. More participants were not vaccinated against COVID-19 (46.5%, 40/86 vs 26.1%, 86/330, P < 0.001) in exacerbation group. Exacerbation group exhibited poor quality of life (EQ5D index: 0.734 [0.536-0.862] vs 0.837 [0.716-0.942], P < 0.001), more severe anxiety (GAD-7: 2 [0-5] vs 0 [0-3], P < 0.001) and depression (PHQ-9: 4 [2-7] vs 2.5 [0-5], P < 0.001) than non-exacerbation group. Risk factors significantly associated with exacerbation of pre-existing chronic pain were neuropathic pain (aOR 4.81, 95% CI 1.73-13.32, P = 0.003), lymphocyte count (aOR 0.31, 95% CI 0.12-0.78, P = 0.013) and D-dimer levels (aOR 6.46, 95% CI 1.92-21.74, P = 0.003).

Conclusion

Our study observed a prevalence of 21.5% exacerbation of pre-existing chronic pain after SARS-CoV-2 infection, with a consequence of poor quality of life, more severe anxiety and depression. Previous chronic neuropathic pain, lower lymphocyte count and higher D-dimer levels were risk factors associated with the development of exacerbated previous chronic pain.

Early Effects of a Pain-Informed Movement Program in Patients with Post-COVID-19 Condition Experiencing Persistent Pain: Protocol for a Randomized Controlled Trial

(1) Background: The COVID-19 pandemic has generated 771 million confirmed cases. Of these patients, 60% have developed persistent symptoms including pain. This pain is a complex symptom that needs comprehensive therapeutic strategies to address it holistically. The main objective of this study will be to evaluate the early impact of the Pain Informed Movement (PIM) program in patients with post-COVID-19 conditions experiencing new-onset persistent pain. (2) Methods: A randomized, single-blind clinical trial will be performed. Patients will be randomly assigned (1:1) to the experimental or control group. The experimental group will undergo a PIM program consisting of low-intensity functional exercises, pain neuroscience education, and relaxation techniques. The control group will receive no intervention. (3) Results: The results will be published as a peer-reviewed article. (4) Conclusions: This study will provide a basis for future research to support the implementation of comprehensive therapeutic approaches in the care of patients with post-COVID-19 persistent pain.

The incidence, characteristics, impact and risk factors of post-COVID chronic pain in Thailand: A single-center cross-sectional study

The COVID-19 pandemic has affected millions of individuals worldwide. Pain has emerged as a significant post-COVID-19 symptom. This study investigated the incidence, characteristics, and risk factors of post-COVID chronic pain (PCCP) in Thailand. A cross-sectional study was conducted in participants who had been infected, including those hospitalized and monitored at home by SARS-CoV-2 from August to September 2021. Data were collected for screening from medical records, and phone interviews were done between 3 to 6 months post-infection. Participants were classified into 1) no-pain, 2) PCCP, 3) chronic pain that has been aggravated by COVID-19, or 4) chronic pain that has not been aggravated by COVID-19. Pain interference and quality of life were evaluated with the Brief Pain Inventory and EuroQol Five Dimensions Five Levels Questionnaire. From 1,019 participants, 90% of the participants had mild infection, assessed by WHO progression scale. The overall incidence of PCCP was 3.2% (95% CI 2.3-4.5), with 2.8% (95% CI 2.0-4.1) in mild infection, 5.2% (95% CI 1.2-14.1) in moderate infection and 8.5% (95% CI 3.4-19.9) in severe infection. Most participants (83.3%) reported pain in the back and lower extremities and were classified as musculoskeletal pain and headache (8.3%). Risk factors associated with PCCP, included female sex (relative risk [RR] 2.2, 95% CI 1.0-4.9) and greater COVID-19 severity (RR 3.5, 95% CI 1.1-11.7). Participants with COVID-19-related exacerbated chronic pain displayed higher pain interferences and lower utility scores than other groups. In conclusion, this study highlights the incidence, features, and risk factors of post-COVID chronic pain (PCCP) in Thailand. It emphasizes the need to monitor and address PCCP, especially in severe cases, among females, and individuals with a history of chronic pain to improve their quality of life in the context of the ongoing COVID-19 pandemic.

Rheumatology and Long COVID: lessons from the study of fibromyalgia

Rheumatology, such as other subspecialties, has both a unique perspective to offer as well as an evolving role to play in the global COVID-19 pandemic. Our field has already contributed meaningfully to the development and repurposing of many of the immune-based therapeutics which are now standard treatments for severe forms of the disease as well as to the understanding of the epidemiology, risk factors and natural history of COVID-19 in immune-mediated inflammatory diseases. Still in evolution is our potential to contribute to burgeoning research efforts in the next phase of the pandemic: the syndrome of postacute sequelae of COVID-19 or Long COVID. While our field brings many assets to the study of Long COVID including our expertise in the investigation of chronic inflammation and autoimmunity, our Viewpoint focuses on the strong similarities between fibromyalgia (FM) and Long COVID. While one can speculate on how embracing and confident practising rheumatologists already are regarding these interrelationships, we assert that in the emerging field of Long COVID the potential lessons from the field of fibromyalgia care and research have been underappreciated and marginalised and most importantly now deserve a critical appraisal.

Prevalence of poor sleep quality in COVID-19 patients: a systematic review and meta-analysis

Objective

The coronavirus disease (COVID-19) and the public health responses were associated with a huge health burden, which could influence sleep quality. This meta-analysis and systematic review examined the prevalence of poor sleep quality in COVID-19 patients.

Methods

PubMed, Web of Science, Embase, and PsycINFO were systematically searched from their respective inception to October 27, 2022. Prevalence rates of poor sleep were analyzed using a random effects model.

Results

Totally, 24 epidemiological and 12 comparative studies with 8,146 COVID-19 patients and 5,787 healthy controls were included. The pooled prevalence of poor sleep quality based on the included studies was 65.0% (95%CI: 59.56-70.44%, I2 = 97.6%). COVID-19 patients had a higher risk of poor sleep quality compared to healthy controls (OR = 1.73, 95% CI: 1.30-2.30, p < 0.01, I2 = 78.1%) based on the 12 comparative studies. Subgroup analysis revealed that COVID-19 patients in low-income countries (p = 0.011) and in studies using a lower Pittsburgh Sleep Quality Index score cut-off (p < 0.001) were more likely to have poor sleep quality. Meta-regression analyses revealed that being female (p = 0.044), older (p < 0.001) and married (p = 0.009) were significantly correlated with a higher risk of poor sleep quality while quality score (p = 0.014) were negatively correlated with the prevalence of poor sleep quality in COVID-19 patients.

Conclusion

Poor sleep quality was found to be very common in COVID-19 patients. Considering the negative effects of poor sleep quality on daily life, sleep quality should be routinely assessed and appropriately addressed in COVID-19 patients.

Prevalence and Risk Factors of De Novo Widespread Post-COVID Pain in Nonhospitalized COVID-19 Survivors: A Nationwide Exploratory Population-Based Survey

This survey investigated the prevalence of de novo widespread musculoskeletal post-COVID pain and risk factors for its development in nonhospitalized COVID-19 survivors. A nationwide exploratory cross-sectional study was conducted, including a cohort of 593,741 Danish residents who had suffered from a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection from March 2020 to December 2021. A questionnaire was distributed to the Danish population via the digital mail system (e-Boks). Self-reported demographic data, previous medical comorbidities (diagnosed), socioeconomic data, time of infection, prior chronic pain conditions (diagnosed), development of de novo widespread pain after infection, pain medication, and pain intensity information were collected. Responders consisted of 130,443 nonhospitalized participants (58.2% women; mean age: 50.2 years). At a mean of 14.4 (standard deviation 6.0) months after infection, 6,875 (5.3%) patients reported the presence of de novo widespread musculoskeletal post-COVID pain. Almost 75% of the patients reported a moderate to severe intensity of the pain. In conclusion, de novo widespread post-COVID pain was present in 5.3% of nonhospitalized COVID-19 survivors 1 year after infection (14.4 ± 6.0 months). Older age, female sex, higher BMI, and history of migraine, whiplash, stress, type-2 diabetes, neurological disorders, and lower socioeconomic status were risk factors associated with the development of de novo widespread post-COVID pain in nonhospitalized patients. As de novo widespread pain is considered a sign of sensitization, this group will require specialized pain management attention. PERSPECTIVE: This article presents de novo widespread post-COVID pain prevalence in a cohort of 130,443 citizens infected with COVID-19. The study identifies potential risk factors associated with the development of these new pain symptoms. The results may increase focus on this patient group and potentially help identify predictors for postinfection pain development.

Assessing the causal relationship between COVID-19 and post-COVID-19 syndrome: A Mendelian randomisation study

Background

In the aftermath of the coronavirus disease 2019 (COVID-19) pandemic, we sought to explore the causal association between COVID-19 and 17 prevalent post-COVID-19 syndrome (PCS) symptoms using Mendelian randomisation (MR) methodology.

Methods

We used 22 extensive genome-wide association study (GWAS) data sets, incorporating genetic variants as instrumental variables. Univariate Mendelian randomisation (UVMR) analyses involved 15 single nucleotide polymorphisms (SNPs) for COVID-19 patients, 33 for hospitalised COVID-19 patients, and 29 for patients with severe respiratory symptoms due to COVID-19. Furthermore, we further used multivariable Mendelian randomisation (MVMR) analyses based on 93 SNPs for COVID-19 patients, 105 for hospitalised COVID-19 patients, and 99 for patients with severe respiratory symptoms due to COVID-19. With these analyses, we aimed to assess the causal associations between varying levels of COVID-19 infection and 17 prevalent PCS symptoms while accounting for the influence of educational and income levels.

Results

UVMR analysis identified potential causal effects of COVID-19 genetic susceptibility on myalgia and pain in various regions. Hospitalised COVID-19 was potentially linked to erectile dysfunction and alopecia areata. Very severe respiratory confirmed patients exhibited increased pain and tobacco use. Meanwhile, the MVMR analysis demonstrated a potential causal link between hospitalised COVID-19 and heart arrhythmia, and a protective effect of COVID-19 on tobacco use after adjusting for educational and income levels.

Conclusions

Our MR analysis provides compelling evidence of causal associations between genetic susceptibility to COVID-19 and specific PCS symptoms, in which educational and income levels play a mediating role. These findings shed light on PCS pathogenesis and underscore the importance of considering social factors in its management. Tailored interventions and policies are crucial for PCS-affected individuals' well-being. Further research is needed to explore the impact of social determinants on COVID-19 patients and the wider population.

Is recovery just the beginning? Persistent symptoms and health and performance deterioration in post-COVID-19, non-hospitalized university students-a cross-sectional study

Many individuals experience persistent symptoms such as deteriorated physical and mental health, increased fatigue, and reduced cognitive performance months after recovering from coronavirus disease 2019 (COVID-19). There is limited data on the long-term trajectory and prevalence of these symptoms, especially in milder cases. Our study aimed to assess the persistent effects of COVID-19 on physical and mental health, fatigue, and cognitive performance in a cohort of 214 students, averaging 21.8 years of age. Of these, 148 had contracted COVID-19 but were not hospitalized, with the time since infection ranging from 1 to 39 months. We utilized a comprehensive panel of cognitive tests to measure intelligence, memory, and psychomotor skills, and a detailed anamnestic questionnaire to evaluate physical and mental health. While contracting COVID-19 did not significantly impact overall health and performance, it was associated with increased reports of fatigue. However, the reported severity of the disease had a pronounced negative influence on physical health, mental well-being, fatigue, and reaction time. Trends of improvement in physical and mental health, as well as error rate, were observed within the first 2 years post-infection. However, fatigue and reaction time showed a trend of deterioration. Beyond the 2-year mark, physical health and error rate continued to improve, while mental health began to deteriorate. Fatigue and reaction time continued to decline. Overall, our findings suggest that some effects of contracting COVID-19 can persist or even deteriorate over time, even in younger individuals who had mild cases that did not require hospitalization.

COVID-19 and musculoskeletal pain: an overview of the current knowledge

The Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) has provoked billions of infections worldwide. Several meta-analyses have observed that up to 50% of individuals who had survived to a SARS-CoV-2 acute infection suffer from post-COVID symptoms lasting for weeks or months and up to one year after infection. The prevalence of post-COVID pain ranges between 10% to 20% when assessed with other overall post-COVID symptoms and can reach up to 50% to 60% when investigated specifically. The most common musculoskeletal manifestations of post-COVID-19 condition include fatigue, myalgia, arthralgia or back pain. Despite pain of musculoskeletal origin is one of the most prevalent post-COVID pain symptoms, the exact pathophysiological mechanisms of musculoskeletal post-COVID pain are not completely understood. Studies have reported the complexity of post-COVID pain including immune, biological, and psychological factors, and more recently, they have suggested that genetic and epigenetic factors may also play a potential role, highlighting the need for further investigation into these mechanisms. Its management is still controversial, as no specific guideline for treating musculoskeletal post-COVID pain has been proposed with only general consideration about the relevance of multidisciplinary and multimodal treatment approaches. In this paper we will highlight the clinical features, the mechanism, and the management possibilities of musculoskeletal post-COVID pain.

Hospital admission is associated with disability and late musculoskeletal pain in individuals with long COVID

Background

The acute clinical repercussions of SARS-CoV-2 infection have been widely studied. However, the possible late repercussions of long COVID have not yet been well defined in the literature.

Objectives

To identify the presence of pain and musculoskeletal disability in patients with Long COVID and also to identify predictive factors for pain intensity in this population.

Methods

In this cross-sectional and retrospective observational study individuals with Long COVID symptoms were included. It was collected musculoskeletal disability measures, data from patient-related outcome measures and variables from a COVID-19 outpatient service database. Associations and sub-group analyses were performed considering the variables pain, disability and hospitalization. Linear regression was performed to identify predictive factors for pain intensity in Long COVID patients.

Results

We evaluated 195 patients and most of them (57%) presented musculoskeletal pain in one area of the body. Pain sub-group presented worse disability indices and worse clinical course during hospitalization. Hospitalized patients presented worse disability indices comparing to non-hospitalized. Significant correlations were found between pain and days of non-invasive oxygen support (r = 0.21; p = 0.003); days in intensive care unit (r = 0.22; p = 0.002) and days in invasive mechanical ventilation (r = 0.35; p = 0.001). Hospitalized individuals showed a higher chance of presenting late musculoskeletal pain (OR = 1.42: 95%CI 1.09-2.04). Days in intensive care unit (β = 0,234: P = 0,001) and days in invasive mechanical ventilation (β = 0.764: P = 0.001) were predictors of pain intensity [F(2,192) = 18.559; R2 = 0.231; p = 0.001].

Conclusion

Individuals with Long COVID presented musculoskeletal pain and disability. Hospitalized patients showed a greater chance of having musculoskeletal pain. Days in intensive care unit and days in invasive mechanical ventilation were predictors of late musculoskeletal pain intensity.

Patterns of Opioid and Non-Opioid Analgesic Consumption in Patients with Post-COVID-19 Conditions

Pain is a major health issue for healthcare systems, and access to pain treatment is a fundamental human right. Pain is a common symptom experienced in the post-COVID phase by a significant percentage of patients. This study describes the prevalence and associated factors associated with the use of opioid and non-opioid analgesics in subjects with post-COVID-19 condition. Sociodemographic data, post-COVID symptoms, health profile, and opioid and non-opioid analgesic consumption were collected in 390 subjects with post-COVID-19 condition. We analyzed the independent effect of all variables on opioid/non-opioid analgesic consumption by using logistic multivariate regressions. The prevalence of opioid and non-opioid analgesic consumption was 24.1% and 82.3%, respectively. Tramadol (17.18%) and codeine (7.95%) were the most commonly used opioid analgesics, and Paracetamol (70%) and ibuprofen (45.4%) were the most commonly used non-opioid analgesics. Females were more likely to consume non-opioid analgesics (aOR2.20, 95%CI 1.15, 4.22) than males. Marital status of married/partner vs. single (aOR2.96; 95% CI 1.43, 6.12), monthly income < EUR 1000 VS. > EUR 2000 (aOR3.81; 95% CI 1.37, 10.61), number of post-COVID symptoms < 5 (aOR2.64, 95%CI 1.18, 5.87), and anxiolytics consumption (aOR 1.85, 95%CI 1.05, 3.25) were associated with a greater likelihood of opioid analgesic consumption. Age > 55 years (aOR3.30, 95%CI 1.34, 8.09) and anxiolytics consumption (aOR2.61, 95%CI 1.36, 4.98) were associated with a greater likelihood of non-opioid analgesic consumption. Opioid analgesic consumption was highly associated (aOR 3.41, 95%CI 1.27, 6.11) with non-opioid analgesic consumption. The prevalence of opioid analgesic and non-opioid analgesic consumption in individuals with post-COVID-19 condition was 24.1% and 82.3%. Females with post-COVID-19 condition showed higher non-opioid analgesic consumption than men. Predictors of opioid consumption were marital status, lower monthly income, number of post-COVID symptoms, and anxiolytic consumption. Older age and anxiolytic consumption were predictors of non-opioid consumption.

Serological Biomarkers at Hospital Admission and Hospitalization Treatments Are Not Related to Sensitization-Associated Symptoms in Patients with Post-COVID Pain

Current evidence suggests that a group of patients who had survived coronavirus disease, 2019 (COVID-19) and developed post-COVID pain can exhibit altered nociceptive processing. The role of serological biomarkers and hospitalization treatments in post-COVID pain is unclear. This study aimed to investigate the association of serological biomarkers and treatments received during hospitalization with sensitization-associated symptoms in COVID-19 survivors with post-COVID pain. One hundred and eighty-three (n = 183) patients who had been hospitalized due to COVID-19 in one urban hospital of Madrid (Spain) during the first wave of the pandemic were assessed in a face-to-face interview 9.4 (SD 3.4) months after hospitalization. Levels of 19 serological biomarkers, hospitalization data, and treatments during hospitalization were obtained from hospital records. Sensitization-associated symptoms (Central Sensitization Inventory, CSI), sleep quality (Pittsburgh Sleep Quality Index, PSQI), pain catastrophism (Pain Catastrophizing Scale), and anxiety/depressive level (Hospital Anxiety and Depression Scale, HADS) were assessed. The prevalence of post-COVID pain was 40.9% (n = 75). Twenty-nine (38.6%) patients had sensitization-associated symptoms. Overall, no differences in hospitalization data and serological biomarkers were identified according to the presence of sensitization-associated symptoms. The analysis revealed that patients with sensitization-associated symptoms exhibited higher lymphocyte count and lower urea levels than those without sensitization-associated symptoms, but differences were small. Pain catastrophism and depressive levels, but not fatigue, dyspnea, brain fog, anxiety levels, or poor sleep, were higher in individuals with sensitization-associated symptoms. In conclusion, this study revealed that sensitization-associated post-COVID pain symptoms are not associated with serological biomarkers at hospital admission and hospitalization treatments received.

Precision management of post-COVID pain: An evidence and clinical-based approach

Background Pain after a SARS-CoV-2 acute infection (post-COVID pain) is becoming a new healthcare emergency but remains underestimated and most likely undertreated due to a lack of recognition of the phenomenon and knowledge of the underlying pain mechanisms. Evidence supporting any particular treatment approach for the management of post-COVID pain is lacking. Large variability in the patient response to any standard pain treatments is clinically observed, which has led to calls for a personalized, tailored approach to treating patients with chronic post-COVID pain (i.e. 'precision pain medicine'). Applying the global concerted action towards precision medicine to post-COVID pain could help guide clinical decision-making and aid in more effective treatments. Methods The current position paper discusses factors to be considered by clinicians for managing post-COVID pain ranging from identification of the pain phenotype to genetic consideration. Results The ability of clinicians to phenotype post-COVID pain into nociceptive, neuropathic, nociplastic or mixed type is suggested as the first step to better planification of a treatment programme. Further, the consideration of other factors, such as gender, comorbidities, treatments received at the acute phase of infection for onset-associated COVID-19 symptoms, factors during hospitalization or the presence of emotional disturbances should be implemented into a treatment programme. Conclusions Accordingly, considering these factors, management of post-COVID pain should include multimodal pharmacological and non-pharmacological modalities targeting emotional/cognitive aspects (i.e. psychological and/or coping strategies), central sensitization-associated mechanisms (i.e. pain neuroscience education), exercise programmes as well as lifestyle interventions (e.g. nutritional support and sleep management). SIGNIFICANCE: This position paper presents an evidence-based clinical reasoning approach for precision management of post-COVID pain.

Post-COVID Patients With New-Onset Chronic Pain 2 Years After Infection: Cross-Sectional Study

BACKGROUND

Although pain is common in non-hospitalized post-COVID-19 syndrome, only a few studies have provided information on the pain experience of these patients.

AIM

To identify the clinical and psychosocial profile associated with pain in non-hospitalized patients with post-COVID-19 syndrome.

METHOD

In this study there were three groups: healthy control group, successfully recovered group, and post-COVID syndrome group. Pain-related clinical profile and pain-related psychosocial variables were collected. Pain-related clinical profile included: pain intensity and interference (Brief Pain Inventory), central sensitization (Central Sensitization Scale), insomnia severity (Insomnia Severity Index), and pain treatment. Pain-related psychosocial variables were: fear of movement and (re)injury (Tampa Scale for Kinesiophobia), catastrophizing (Pain Catastrophizing Scale), depression, anxiety and stress (Depression, Anxiety and Stress Scale), and fear-avoidance beliefs (Fear Avoidance Beliefs Questionnaire).

RESULTS

In all, 170 participants were included in the study (healthy control group n = 58, successfully recovered group n = 57, and post-COVID syndrome group n = 55). Post-COVID syndrome group obtained significantly worse punctuation in pain-related clinical profile and psychosocial variables than the other two groups (p < .05).

CONCLUSIONS

In conclusion, patients with post-COVID-19 syndrome have experienced high pain intensity and interference, central sensitization, increased insomnia severity, fear of movement, catastrophizing, fear-avoidance beliefs, depression, anxiety, and stress.

COVID-19 symptom load as a risk factor for chronic pain: A national cross-sectional study

INTRODUCTION

Emerging evidence suggests that a COVID-19 infection with a high initial severity may be associated with development of long-COVID conditions such as chronic pain. At the population level, it is unknown if severity of a COVID-19 infection might be a new risk factor for chronic pain above and beyond the traditional slate of pre-established risk factors. The purpose of this study is to examine whether COVID-19 severity of infection may be a new risk factor for chronic pain.

METHODS

Using data from the 2021 National Health Interview Survey (n = 15,335), this study examined the adjusted odds of experiencing high frequency levels of pain in the past 3 months for those who reported no/mild symptoms from a COVID-19 infection, and those reporting moderate/severe symptoms from COVID-19, compared to those never infected. A 1:1:1 propensity score matched analysis was also performed to examine the odds of pain.

RESULTS

Prevalence of pain was higher in the moderate/severe symptom group compared to the no infection group (25.48% vs 19.44%, p <0.001). Both the adjusted model (odds ratio [OR] = 1.28, 95% confidence interval [CI] = 1.09, 1.51) and matched model (OR = 1.45, CI = 1.14, 1.83) revealed higher odds of pain for those with moderate/high COVID-19 symptoms compared to no infection.

CONCLUSIONS

A moderate/highly symptomatic COVID-19 infection may be a new risk factor for chronic pain. As the absolute number of severe COVID-19 infections continues to rise, overall prevalence of chronic pain may also increase. While knowledge continues to unfold on long-haul symptoms, prevention of severe infections remains essential.

Characteristics of Frailty in Perimenopausal Women with Long COVID-19

The aim of this study was to compare the prevalence of risk factors for frailty between perimenopausal women with long COVID-19 syndrome, women having successfully recovered from COVID-19, and controls from the community. Women with a diagnosis of long COVID-19 and at least one symptom related to the perimenopausal period, women who had successfully recovered from COVID-19, and healthy women of comparable age were included in this study. Symptom severity and functional disability were assessed with the COVID-19 Yorkshire Rehabilitation Scale, and the presence of frailty was evaluated considering the Fried criteria. A total of 195 women were included in the study, distributed over the three groups. The long COVID-19 group showed a higher prevalence of perimenopausal symptoms and impact of COVID-19. Statistically significant differences were found between the long COVID-19 group and the other two groups for the frailty variables. When studying the associations between frailty variables and COVID-19 symptom impact, significant positive correlations were found. Perimenopausal women with long COVID-19 syndrome present more frailty-related factors and experience a higher range of debilitating ongoing symptoms. A significant relationship is shown to exist between long COVID-19 syndrome-related disability and symptoms and frailty variables, resulting in an increased chance of presenting disability.

SARS-CoV-2 airway infection results in the development of somatosensory abnormalities in a hamster model

Although largely confined to the airways, SARS-CoV-2 infection has been associated with sensory abnormalities that manifest in both acute and chronic phenotypes. To gain insight on the molecular basis of these sensory abnormalities, we used the golden hamster model to characterize and compare the effects of infection with SARS-CoV-2 and influenza A virus (IAV) on the sensory nervous system. We detected SARS-CoV-2 transcripts but no infectious material in the cervical and thoracic spinal cord and dorsal root ganglia (DRGs) within the first 24 hours of intranasal virus infection. SARS-CoV-2-infected hamsters exhibited mechanical hypersensitivity that was milder but prolonged compared with that observed in IAV-infected hamsters. RNA sequencing analysis of thoracic DRGs 1 to 4 days after infection suggested perturbations in predominantly neuronal signaling in SARS-CoV-2-infected animals as opposed to type I interferon signaling in IAV-infected animals. Later, 31 days after infection, a neuropathic transcriptome emerged in thoracic DRGs from SARS-CoV-2-infected animals, which coincided with SARS-CoV-2-specific mechanical hypersensitivity. These data revealed potential targets for pain management, including the RNA binding protein ILF3, which was validated in murine pain models. This work elucidates transcriptomic signatures in the DRGs triggered by SARS-CoV-2 that may underlie both short- and long-term sensory abnormalities.

Pain Management in the Post-COVID Era-An Update: A Narrative Review

An extensive computer search (from January 2020 to January 2023) was conducted including literature from the PubMed, Scopus, MEDLINE, Web of Science, and EMBASE databases. According to preset criteria, a total of 58 articles were included in this review article. Generally, any patient who becomes infected with COVID-19 can develop post-COVID-19 conditions. The course of COVID-19 is divided into three main stages: acute COVID-19 (up to 4 weeks), post-acute COVID-19 (from 4 to 12 weeks), and post-COVID (from 12 weeks to 6 months). If a more protracted course of COVID (over 6 months) is demonstrated, the term "long-COVID" is used. Although the acute stage of COVID-19 infection most commonly manifests with acute respiratory symptoms, one very common symptom of the disease is pain, while the most common symptoms of post-COVID syndrome are shortness of breath, dry cough, fatigue, loss of olfactory and gustatory function, tightness and chest pain, sleep and mood disturbances, body aches, muscle and joint pain, sore throat, fever, and persistent headaches. All observations demonstrated a high incidence of chronic pain syndromes of various localization in the post- and long-COVID period. Post-COVID chronic pain might include a newly developed chronic pain as a part of post-viral syndrome; worsening of preexisting chronic pain due to the associated changes in the medical services, or a de novo chronic pain in healthy individuals who are not infected with COVID. Chronic pain during and post-COVID-19 pandemic is an important health issue due to the significant impacts of pain on the patients, health care systems, and society as well. Therefore, it is important that patients with chronic pain receive effective treatment according to their specific needs. Accordingly, the main goal of this review article is to provide a broad description about the post-COVID pain and to explore the impact of long COVID-19 on chronic pain patients, and also to give brief reports about the prevalence, risk factors, possible mechanisms, different presentations, and the management tools through a systematic approach.

Could the fibromyalgia syndrome be triggered or enhanced by COVID-19?

Fibromyalgia (FM) is a complex disease with an uncertain aetiology and intricate pathophysiology. Although its genesis is not fully explained, potential environmental factors, such as viral infections might trigger FM or worsen patients' clinical outcomes. The SARS-CoV-2 virus may affect central and peripheral nervous systems, leading to musculoskeletal, neurological, and psychological disturbances. These symptoms might persist at least 12 months beyond the recovery, often referred to as post-COVID syndrome, which resembles FM syndrome. In this sense, we argued the potential consequences of COVID-19 exclusively on FM syndrome. First, we have described post-COVID syndrome and its painful symptoms. Afterwards, we argued whether FM syndrome could be triggered or enhanced by COVID-19 infection or by numerous and persistent stressors imposed daily by the pandemic setting (isolation, uncertainty, depression, mental stress, generalized anxiety, and fear of the virus). In addition, we have demonstrated similarities between pathophysiological mechanisms and cardinal symptoms of FM and COVID-19, speculating that SARS-CoV-2 might represent a critical mediator of FM or an exacerbator of its symptoms once both syndromes share similar mechanisms and complaints. Therefore, pharmacologic and non-pharmacological approaches commonly used to treat FM could serve as strategic therapies to attenuate painful and neurological manifestations of post-COVID syndrome. Although it is still theoretical, clinicians and researchers should be alert of patients who develop symptoms similar to FM or those who had their FM symptoms increased post-COVID to manage them better.

Association of Kinesiophobia with Catastrophism and Sensitization-Associated Symptoms in COVID-19 Survivors with Post-COVID Pain

Pain symptoms after the acute phase of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are present in almost 50% of COVID-19 survivors. The presence of kinesiophobia is a risk factor which may promote and perpetuate pain. This study aimed to investigate variables associated with the presence of kinesiophobia in a sample of previously hospitalized COVID-19 survivors exhibiting post-COVID pain. An observational study was conducted in three urban hospitals in Spain, including one hundred and forty-six COVID-19 survivors with post-COVID pain. Demographic (age, weight, height), clinical (intensity and duration of pain), psychological (anxiety level, depressive level, sleep quality), cognitive (catastrophizing), sensitization-associated symptoms, and health-related quality of life variables were collected in 146 survivors with post-COVID pain, as well as whether they exhibited kinesiophobia. Stepwise multiple linear regression models were conducted to identify variables significantly associated with kinesiophobia. Patients were assessed a mean of 18.8 (SD 1.8) months after hospital discharge. Kinesiophobia levels were positively associated with anxiety levels (r: 0.356, p < 0.001), depression levels (r: 0.306, p < 0.001), sleep quality (r: 0.288, p < 0.001), catastrophism (r: 0.578, p < 0.001), and sensitization-associated symptoms (r: 0.450, p < 0.001). The stepwise regression analysis revealed that 38.1% of kinesiophobia variance was explained by catastrophism (r2 adj: 0.329, B = 0.416, t = 8.377, p < 0.001) and sensitization-associated symptoms (r2 adj: 0.381, B = 0.130, t = 3.585, p < 0.001). Kinesiophobia levels were associated with catastrophism and sensitization-associated symptoms in previously hospitalized COVID-19 survivors with post-COVID pain. Identification of patients at a higher risk of developing a higher level of kinesiophobia, associated with post-COVID pain symptoms, could lead to better therapeutic strategies.

Exploring the trajectory curve of long-term musculoskeletal post-COVID pain symptoms in hospitalized COVID-19 survivors: a multicenter study

ABSTRACT

This multicenter cohort study investigated the prevalence of musculoskeletal post-COVID pain during the first year after the infection with mosaic plots and an exponential bar plot model and its associated risk factors. Patients hospitalized because of COVID-19 in 5 hospitals of Madrid (Spain) were scheduled for a telephone interview at 2 follow-up periods after hospitalization for collecting data about musculoskeletal post-COVID pain. Hospitalization and clinical data were collected from hospital medical records. From 2000 patients initially recruited, 1593 (44.6% women, age: 61 ± 15 years) were assessed at T0 (hospital admission), T1 (mean: 8.0 ± 1.5 months after discharge), and T2 (mean: 13.2 ± 1.5 months after discharge). The prevalence of musculoskeletal pain (myalgia) was 30.3% (n = 483) at T0, increased to 43.4% (n = 692) at T1, and decreased to 37.8% (n = 603) at T2. The trajectory curve revealed a decreasing prevalence trend of musculoskeletal post-COVID pain the following years after hospitalization. According to the presence of pre-existing pain symptoms, the prevalence of new-onset post-COVID pain was 75.9%. Female sex (odds ratio [OR] 1.593, 95% confidence interval [CI] 1.148-2.211), history of musculoskeletal pain (OR 1.591, 95% CI 1.211-2.07), the presence of myalgia (OR 1.371, 95% CI 1.032-1.821) or headache (OR 2.278, 95% CI 1.622-3.199) at hospitalization, the days of hospitalization (OR 1.013, 95% CI 1.000-1.025), and the presence of post-COVID pain at T1 (OR 11.02, 95% CI 8.493-14.305) were factors associated with musculoskeletal post-COVID pain 1 year after hospitalization. In conclusion, musculoskeletal post-COVID pain remains highly prevalent 1 year after hospitalization. Female sex, previous history of pain symptoms, pain symptoms at onset, and days at hospital were factors associated with musculoskeletal post-COVID pain 1 year after hospitalization.

Post-COVID-19 syndrome: nature of symptoms and associated factors

Aim

Post-COVID-19 syndrome is defined as continuous symptoms related to SARS-CoV-2 infection, which can persist for several weeks or months. Previous studies identified risk factors associated with post-COVID-19 syndrome, including female sex, hypertension, and allergic respiratory diseases. This study aims to investigate the frequency of this syndrome among Arabic patients.

Subject and methods

A cross-sectional study was conducted from March to August 2022. The study included 520 Arabic patients with confirmed COVID-19 diagnosis, who were asked about possible symptoms persisting for ≥28 days.

Results

Twenty-five percent (25%) of the included patients developed post-COVID-19 syndrome. The most common recorded symptoms were cough (32%), anosmia (32%), fatigue (28%), headache (19%), muscle pain (19%), and shortness of breath (17%). It was found that female sex, hospitalization due to initial COVID-19 infection, and the presence of chronic diseases were significant risk factors for developing post-COVID-19 syndrome.

Conclusion

The study recorded post-COVID-19 syndrome among 25% of Arabic participants. Initial COVID-19 hospitalization, initial symptomatic COVID-19, and female sex were significant risk factors for developing post-COVID-19 syndrome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-022-01802-3.

Sensitization symptoms are associated with psychological and cognitive variables in COVID-19 survivors exhibiting post-COVID pain

OBJECTIVE

To investigate the association between demographic, clinical, psychological, cognitive, and health-related variables and the Central Sensitization Inventory (CSI) in previously hospitalized COVID-19 survivors exhibiting "de novo" post-COVID pain.

METHODS

Seventy-seven (n = 77) COVID-19 survivors with "de novo" post-COVID pain completed demographic (age, height, and weight), clinical (duration and intensity of the pain), psychological (depressive/anxiety levels and sleep quality), cognitive (catastrophizing and kinesiophobia levels), and health-related quality of life variables as well as the CSI. A multivariable correlation analysis was conducted to determine the association between variables, and a stepwise multiple linear regression model was performed to identify CSI predictors.

RESULTS

Patients were assessed a mean of 6.0 (SD 0.8) months after hospital discharge. Twenty-six (33.7%) individuals showed indications of sensitization-associated symptoms (CSI score ≥40 points). The CSI score was positively associated with pain intensity (r: 0.371), anxiety (r: 0.784), depressive (r: 0.709), catastrophizing (r: 0.620), and kinesiophobia (r: 0.359) levels (all, p < 0.001). The stepwise regression analysis revealed that 60.2% of CSI was explained by anxiety levels and pain intensity.

CONCLUSION

This study found that psychological and cognitive variables were associated with the CSI score in previously hospitalized COVID-19 survivors with "de novo" post-COVID pain. Anxiety levels and the intensity of pain symptoms were independently associated with CSI score suggesting a significant overlap with psychological construct. The "de novo" post-COVID pain association with CSI may indicate changes in the pain processing important for managing the pain.

Preliminary outcomes of the COVID-19 pandemic: a new chronic pain profile

In summing up the preliminary results of the COVID-19 pandemic that has not yet ended, modern research pays much attention to the so-called post-COVID syndrome, which includes the long-term consequences of the disease. In English, symptoms are reported as long COVID, post-acute COVID, or chronic post-COVID syndrome and are described as symptoms of fatigue, respiratory disorders, memory, and sleep problems. Symptoms such as muscle pain and decreased endurance when performing habitual physical exertion are mentioned much less often. Meanwhile, among the complaints of those who have been ill, this symptom is present quite often, reducing the quality of life and tolerability of normal physical exertion. This review aimed to provide an in-depth study of a new type of the chronic myofascial pain syndrome after COVID-19, i.e., the frequency of occurrence, causes of the development, and pathophysiology of chronic pain syndrome associated with COVID-19 and manifested as fibromyalgia of various localizations. To answer the questions posed, the authors searched for information in four electronic databases. The key search terms used were COVID-19, long COVID, and signs and symptoms of pain syndrome. A review of current literature data has shown that close study and dynamic monitoring of patients who had COVID-19 can contribute to further deciphering the pathophysiological mechanisms of the development of its long-term consequences and provide answers to questions on the prevention and treatment of chronic pain syndrome in this patient cohort.

Use of Antiandrogens as Therapeutic Agents in COVID-19 Patients

COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), is estimated to have caused over 6.5 million deaths worldwide. The emergence of fast-evolving SARS-CoV-2 variants of concern alongside increased transmissibility and/or virulence, as well as immune and vaccine escape capabilities, highlight the urgent need for more effective antivirals to combat the disease in the long run along with regularly updated vaccine boosters. One of the early risk factors identified during the COVID-19 pandemic was that men are more likely to become infected by the virus, more likely to develop severe disease and exhibit a higher likelihood of hospitalisation and mortality rates compared to women. An association exists between SARS-CoV-2 infectiveness and disease severity with sex steroid hormones and, in particular, androgens. Several studies underlined the importance of the androgen-mediated regulation of the host protease TMPRSS2 and the cell entry protein ACE2, as well as the key role of these factors in the entry of the virus into target cells. In this context, modulating androgen signalling is a promising strategy to block viral infection, and antiandrogens could be used as a preventative measure at the pre- or early hospitalisation stage of COVID-19 disease. Different antiandrogens, including commercial drugs used to treat metastatic castration-sensitive prostate cancer and other conditions, have been tested as antivirals with varying success. In this review, we summarise the most recent updates concerning the use of antiandrogens as prophylactic and therapeutic options for COVID-19.

Long COVID: The latest manifestations, mechanisms, and potential therapeutic interventions

COVID-19 caused by SARS-CoV-2 infection affects humans not only during the acute phase of the infection, but also several weeks to 2 years after the recovery. SARS-CoV-2 infects a variety of cells in the human body, including lung cells, intestinal cells, vascular endothelial cells, olfactory epithelial cells, etc. The damages caused by the infections of these cells and enduring immune response are the basis of long COVID. Notably, the changes in gene expression caused by viral infection can also indirectly contribute to long COVID. We summarized the occurrences of both common and uncommon long COVID, including damages to lung and respiratory system, olfactory and taste deficiency, damages to myocardial, renal, muscle, and enduring inflammation. Moreover, we provided potential treatments for long COVID symptoms manifested in different organs and systems, which were based on the pathogenesis and the associations between symptoms in different organs. Importantly, we compared the differences in symptoms and frequency of long COVID caused by breakthrough infection after vaccination and infection with different variants of concern, in order to provide a comprehensive understanding of the characteristics of long COVID and propose improvement for tackling COVID-19.

Data-Driven Path Analytic Modeling to Understand Underlying Mechanisms in COVID-19 Survivors Suffering from Long-Term Post-COVID Pain: A Spanish Cohort Study

Pain can be present in up to 50% of people with post-COVID-19 condition. Understanding the complexity of post-COVID pain can help with better phenotyping of this post-COVID symptom. The aim of this study is to describe the complex associations between sensory-related, psychological, and cognitive variables in previously hospitalized COVID-19 survivors with post-COVID pain, recruited from three hospitals in Madrid (Spain) by using data-driven path analytic modeling. Demographic (i.e., age, height, and weight), sensory-related (intensity or duration of pain, central sensitization-associated symptoms, and neuropathic pain features), psychological (anxiety and depressive levels, and sleep quality), and cognitive (catastrophizing and kinesiophobia) variables were collected in a sample of 149 subjects with post-COVID pain. A Bayesian network was used for structural learning, and the structural model was fitted using structural equation modeling (SEM). The SEM model fit was excellent: RMSEA < 0.001, CFI = 1.000, SRMR = 0.063, and NNFI = 1.008. The only significant predictor of post-COVID pain was the level of depressive symptoms (β=0.241, p = 0.001). Higher levels of anxiety were associated with greater central sensitization-associated symptoms by a magnitude of β=0.406 (p = 0.008). Males reported less severe neuropathic pain symptoms (−1.50 SD S-LANSS score, p < 0.001) than females. A higher level of depressive symptoms was associated with worse sleep quality (β=0.406, p < 0.001), and greater levels of catastrophizing (β=0.345, p < 0.001). This study presents a model for post-COVID pain where psychological factors were related to central sensitization-associated symptoms and sleep quality. Further, maladaptive cognitions, such as catastrophizing, were also associated with depression. Finally, females reported more neuropathic pain features than males. Our data-driven model could be leveraged in clinical trials investigating treatment approaches in COVID-19 survivors with post-COVID pain and can represent a first step for the development of a theoretical/conceptual framework for post-COVID pain.

Phenotyping Post-COVID Pain as a Nociceptive, Neuropathic, or Nociplastic Pain Condition

Pain after an acute Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) condition (post-COVID pain) is becoming a new healthcare emergency. Precision medicine refers to an evidence-based method of grouping patients based on their diagnostic/symptom presentation and then tailoring specific treatments accordingly. Evidence suggests that post-COVID pain can be categorized as nociceptive (i.e., pain attributable to the activation of the peripheral receptive terminals of primary afferent neurons in response to noxious chemical, mechanical, or thermal stimuli), neuropathic (i.e., pain associated with a lesion or disease of the somatosensory nervous system and limited to a "neuroanatomically plausible" distribution of the system), nociplastic (i.e., pain arising from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nociceptors or evidence for disease or lesion of the somatosensory system causing the pain), or mixed type (when two pain phenotypes co-exist). Each of these pain phenotypes may require a different treatment approach to maximize treatment effectiveness. Accordingly, the ability to classify post-COVID pain patients into one of these phenotypes would likely be critical for producing successful treatment outcomes. The 2021 International Association for the Study of Pain (IASP) clinical criteria and grading system provide a framework for classifying pain within a precision pain medicine approach. Here we present data supporting the possibility of grouping patients with post-COVID pain into pain phenotypes, using the 2021 IASP classification criteria, with a specific focus on nociplastic pain, which is probably the primary mechanism involved in post-COVID pain. Nociplastic pain, which is usually associated with comorbid symptomology (e.g., poor sleep quality, fatigue, cognitive-emotional disturbances, etc.) and is considered to be more difficult to treat than other pain types, may require a more nuanced multimodal treatment approach to achieve better treatment outcomes.

Sequelae of COVID-19 among previously hospitalized patients up to 1 year after discharge: a systematic review and meta-analysis

OBJECTIVE

Although complications and clinical symptoms of COVID-19 have been elucidated, the prevalence of long-term sequelae of COVID-19 is less clear in previously hospitalized COVID-19 patients. This review and meta-analysis present the occurrence of different symptoms up to 1 year of follow-up for previously hospitalized patients.

METHODS

We performed a systematic review from PubMed and Web of Science using keywords such as "COVID-19", "SARS-CoV-2", "sequelae", "long-term effect" and included studies with at least 3-month of follow-up. Meta-analyses using random-effects models were performed to estimate the pooled prevalence for different sequelae. Subgroup analyses were conducted by different follow-up time, regions, age and ICU admission.

RESULTS

72 articles were included in the meta-analyses after screening 11,620 articles, identifying a total of 167 sequelae related to COVID-19 from 88,769 patients. Commonly reported sequelae included fatigue (27.5%, 95% CI 22.4-33.3%, range 1.5-84.9%), somnipathy (20.1%, 95% CI 14.7-26.9%, range 1.2-64.8%), anxiety (18.0%, 95% CI 13.8-23.1%, range 0.6-47.8%), dyspnea (15.5%, 95% CI 11.3-20.9%, range 0.8-58.4%), PTSD (14.6%, 95% CI 11.3-18.7%, range 1.2-32.0%), hypomnesia (13.4%, 95% CI 8.4-20.7%, range 0.6-53.8%), arthralgia (12.9%, 95% CI 8.4-19.2%, range 0.0-47.8%), depression (12.7%, 95% CI 9.3-17.2%, range 0.6-37.5%), alopecia (11.2%, 95% CI 6.9-17.6%, range 0.0-47.0%) over 3-13.2 months of follow-up. The prevalence of most symptoms reduced after > 9 months of follow-up, but fatigue and somnipathy persisted in 26.2% and 15.1%, respectively, of the patients over a year. COVID-19 patients from Asia reported a lower prevalence than those from other regions.

CONCLUSIONS

This review identified a wide spectrum of COVID-19 sequelae in previously hospitalized COVID-19 patients, with some symptoms persisting up to 1 year. Management and rehabilitation strategies targeting these symptoms may improve quality of life of recovered patients.

Post-acute COVID syndrome (long COVID): What should radiographers know and the potential impact for imaging services

OBJECTIVES

The COVID-19 pandemic caused an unprecedented health crisis resulting in over 6 million deaths worldwide, a figure, which continues to grow. In addition to the excess mortality, there are individuals who recovered from the acute stages, but suffered long-term changes in their health post COVID-19, commonly referred to as long COVID. It is estimated there are currently 1.8 million long COVID sufferers by May 2022 in the UK alone. The aim of this narrative literature review is to explore the signs, symptoms and diagnosis of long COVID and the potential impact on imaging services.

KEY FINDINGS

Long COVID is estimated to occur in 9.5% of those with two doses of vaccination and 14.6% if those with a single dose or no vaccination. Long COVID is defined by ongoing symptoms lasting for 12 or more weeks post acute infection. Symptoms are associated with reductions in the quality of daily life and may involve multisystem manifestations or present as a single symptom.

CONCLUSION

The full impact of long COVID on imaging services is yet to be realised, but there is likely to be significant increased demand for imaging, particularly in CT for the assessment of lung disease. Educators will need to include aspects related to long COVID pathophysiology and imaging presentations in curricula, underpinned by the rapidly evolving evidence base.

IMPLICATIONS FOR PRACTICE

Symptoms relating to long COVID are likely to become a common reason for imaging, with a particular burden on Computed Tomography services. Planning, education and updating protocols in line with a rapidly emerging evidence base is going to be essential.

Prevalence of Musculoskeletal Post-COVID Pain in Hospitalized COVID-19 Survivors Depending on Infection with the Historical, Alpha or Delta SARS-CoV-2 Variant

We compared the prevalence of musculoskeletal post-COVID pain between previously hospitalized COVID-19 survivors infected with the historical, Alpha or Delta SARS-CoV-2 variant. Data about musculoskeletal post-COVID pain were systematically collected through a telephone interview involving 201 patients who had survived the historical variant, 211 who had survived the Alpha variant and 202 who had survived the Delta variant six months after hospital discharge. Participants were recruited from non-vaccinated individuals hospitalized due to SARS-CoV-2 infection in one hospital of Madrid (Spain) during three different waves of the pandemic (historical, Alpha or Delta variant). Hospitalization and clinical data were collected from hospital medical records. In addition, anxiety/depressive levels and sleep quality were also assessed. The prevalence of musculoskeletal post-COVID pain was higher (p = 0.003) in patients infected with the historical variant (47.7%) than in those infected with the Alpha (38.3%) or Delta (41%) variants. A significantly (p = 0.002) higher proportion of individuals infected with the historical variant reported generalized pain (20.5%) when compared with those infected with the other variants. The prevalence of new-onset post-COVID musculoskeletal pain reached 80.1%, 75.2% and 79.5% of patients infected with the historical, Alpha or Delta variants, respectively. No specific risk factors for developing post-COVID pain were identified depending on the SARS-CoV-2 variant. In conclusion, this study found that musculoskeletal post-COVID pain is highly prevalent in COVID-19 survivors six months after hospital discharge, with the highest prevalence and most generalized pain symptoms in individuals infected with the historical variant. Approximately 50% developed “de novo” post-COVID musculoskeletal pain symptoms.

Pain Extent Is Not Associated with Sensory-Associated Symptoms, Cognitive or Psychological Variables in COVID-19 Survivors Suffering from Post-COVID Pain

We aimed to investigate the relationship between pain extent, as a sign of sensitization, and sensory-related, cognitive and psychological variables in hospitalized COVID-19 survivors with post-COVID pain. One hundred and forty-six (67 males, 79 females) previously hospitalized COVID-19 survivors with post-COVID pain completed demographic (age, sex, height, weight), sensory-related (Central Sensitization Inventory, Self-Report Leeds Assessment of Neuropathic Symptoms), cognitive (Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia) and psychological (Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index) variables. Pain extent and frequency maps were calculated from pain drawings using customized software. After conducting a correlation analysis to determine the relationships between variables, a stepwise linear regression model was performed to identify pain extent predictors, if available. Pain extent was significantly and weakly associated with pain intensity (r = -0.201, p = 0.014): the larger the pain extent, the lower the pain intensity. No other significant association was observed between pain extent and sensory-related, cognitive, or psychological variables in individuals with post-COVID pain. Females had higher pain intensity, more sensitization-associated symptoms, higher anxiety, lower sleep quality, and higher kinesiophobia levels than males. Sex differences correlation analyses revealed that pain extent was associated with pain intensity in males, but not in females. Pain extent was not associated with any of the measured variables and was also not related to the presence of sensitization-associated symptoms in our sample of COVID-19 survivors with long-term post-COVID pain.

The Self-Reported Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) and PainDETECT Questionnaires in COVID-19 Survivors with Post-COVID Pain

This study aimed to analyze correlations between Self-Report Leeds Assessment of Neuropathic Symptoms (S-LANSS) and PainDETECT with proxies of sensitization, pain-related, or psychological/cognitive variables in coronavirus disease, 2019 (COVID-19) survivors exhibiting post-COVID pain. Demographic, clinical, psychological, cognitive, sensitization-associated symptoms, and health-related quality of life were collected in 146 survivors with post-COVID pain. The PainDETECT and S-LANSS questionnaires were used for assessing neuropathic pain-related symptoms. Patients were assessed with a mean of 18.8 (SD 1.8) months after hospitalization. Both questionnaires were positively associated with pain intensity (p < 0.05), anxiety (PainDETECT p < 0.05; S-LANSS p < 0.01), sensitization-associated symptoms (p < 0.01), catastrophism (p < 0.01), and kinesiophobia (p < 0.01) and negatively associated with quality of life (PainDETECT p < 0.05; S-LANSS p < 0.01). Depressive levels were associated with S-LANSS (p < 0.05) but not with PainDETECT. The stepwise regression analyses revealed that 47.2% of S-LANSS was explained by PainDETECT (44.6%), post-COVID pain symptoms duration (1.7%), and weight (1.1%), whereas 51.2% of PainDETECT was explained by S-LANSS (44.6%), sensitization-associated symptoms (5.4%), and anxiety levels (1.2%). A good convergent association between S-LANSS and PainDETECT was found. Additionally, S-LANSS was associated with symptom duration and weight whereas PainDETECT was associated with sensitization-associated symptoms and anxiety levels, suggesting that the two questionnaires evaluate different aspects of the neuropathic pain spectrum in post-COVID pain patients.

Understanding Sensitization, Cognitive and Neuropathic Associated Mechanisms behind Post-COVID Pain: A Network Analysis

This study aimed to describe a network including demographic, sensory-related, psychological/cognitive and other variables in individuals with post-COVID pain after hospitalization. Demographic (i.e., age, height, weight, months with symptoms), sensory-related (Central Sensitization Inventory -CSI-, Self-Report Leeds Assessment of Neuropathic Symptoms -S-LANSS-, PainDETECT), psychological/cognitive (Hospital Anxiety and Depression Scale -HADS-A/HADS-D-, Pain Catastrophizing Scale -PCS-, Tampa Scale for Kinesiophobia -TSK-11-) and other (sleep quality and health-related quality of life -EQ/5D/5L) variables were collected in 146 COVID-19 survivors with post-COVID pain. A network analysis was conducted to quantify the adjusted correlations between the modelled variables, and to assess their centrality indices (i.e., the connectivity with other symptoms in the network and the importance in the system modelled as network). The network revealed associations between sensory-related and psychological/cognitive variables. PainDETECT was associated with S-LANSS (ρ: 0.388) and CSI (ρ: 0.207). Further, CSI was associated with HADS-A (ρ: 0.269), TSK-11 (ρ: 0.165) and female gender (ρ: 0.413). As expected, HADS-A was associated with HADS-D (ρ: 0.598) and TSK-11 with PCS (ρ: 0.405). The only negative association was between sleep quality and EQ-5D-5L (ρ: -0.162). Gender was the node showing the highest strength, closeness, and betweenness centralities. In addition, CSI was the node with the second highest closeness and betweenness centralities, whereas HADS-D was the node with the second highest strength centrality. This is the first study applying a network analysis for phenotyping post-COVID pain. Our findings support a model where sensitization-associated symptoms, neuropathic phenotype, and psychological aspects are connected, reflecting post-COVID pain as a nociplastic pain condition. In addition, post-COVID pain is gender dependent since female sex plays a relevant role. Clinical implications of current findings, e.g., developing treatments targeting these mechanisms, are discussed.