Role of affective instability on suicidal risk in complex regional pain syndrome: a diary approach (preliminary report)

CXCL13 contributes to chronic pain of a mouse model of CRPS-I via CXCR5-mediated NF-κB activation and pro-inflammatory cytokine production in spinal cord dorsal horn

BACKGROUND

Complex regional pain syndrome type-I (CRPS-I) causes excruciating pain that affect patients' life quality. However, the mechanisms underlying CRPS-I are incompletely understood, which hampers the development of target specific therapeutics.

METHODS

The mouse chronic post-ischemic pain (CPIP) model was established to mimic CRPS-I. qPCR, Western blot, immunostaining, behavioral assay and pharmacological methods were used to study mechanisms underlying neuroinflammation and chronic pain in spinal cord dorsal horn (SCDH) of CPIP mice.

RESULTS

CPIP mice developed robust and long-lasting mechanical allodynia in bilateral hindpaws. The expression of inflammatory chemokine CXCL13 and its receptor CXCR5 was significantly upregulated in ipsilateral SCDH of CPIP mice. Immunostaining revealed CXCL13 and CXCR5 was predominantly expressed in spinal neurons. Neutralization of spinal CXCL13 or genetic deletion of Cxcr5 (Cxcr5^-/-) significantly reduced mechanical allodynia, as well as spinal glial cell overactivation and c-Fos activation in SCDH of CPIP mice. Mechanical pain causes affective disorder in CPIP mice, which was attenuated in Cxcr5^-/- mice. Phosphorylated STAT3 co-expressed with CXCL13 in SCDH neurons and contributed to CXCL13 upregulation and mechanical allodynia in CPIP mice. CXCR5 coupled with NF-κB signaling in SCDH neurons to trigger pro-inflammatory cytokine gene Il6 upregulation, contributing to mechanical allodynia. Intrathecal CXCL13 injection produced mechanical allodynia via CXCR5-dependent NF-κB activation. Specific overexpression of CXCL13 in SCDH neurons is sufficient to induce persistent mechanical allodynia in naïve mice.

CONCLUSIONS

These results demonstrated a previously unidentified role of CXCL13/CXCR5 signaling in mediating spinal neuroinflammation and mechanical pain in an animal model of CRPS-I. Our work suggests that targeting CXCL13/CXCR5 pathway may lead to novel therapeutic approaches for CRPS-I.

Evaluation of YouTube videos as sources of information about complex regional pain syndrome

Background

As the internet usage becomes easily accessible, the patients are more frequently searching about diseases and medical/non-medical treatments. Considering that complex regional pain syndrome (CRPS) is a debilitating disease, it is important to check the information that patients are accessing. Therefore, this study aimed to investigate the reliability, sufficiency, and accuracy of the YouTube videos about CRPS.

Methods

This study is a descriptive research which is derived by searching videos using the keyword ‘complex regional pain syndrome’ on YouTube. Relevance-based sequencing was used to sort the videos. Sources and video parameters were documented. To evaluate the accuracy, reliability and content quality of the videos, Global Quality Score, Journal of American Medical Association Benchmark Criteria and Modified DISCERN Questionnaire scales were used.

Results

A total of 167 videos were included in this study. The majority of the videos originated from USA (80.2%, n = 134). The median number of views was 639 and the viewing rate was 73.3. Most of the videos had partially sufficient data and the interaction index viewing rate parameters for videos with high content quality were greater than videos with low content quality (P = 0.010, P = 0.014).

Conclusions

Our results showed that videos about CRPS on YouTube mostly had partially sufficient data and include intermediate-high quality contents. Moreover, high-content quality videos had higher viewing rates, interaction indexes, number of likes, longer durations, as well as better reliability and accuracy scores. Videos with high quality and reliable content are needed to reduce misinformation about CRPS.

What do I need to know? Essential educational concepts for complex regional pain syndrome

Background

Methods

Results

Conclusion

Significance

Impact of coronavirus disease 2019 on patients with chronic pain: multicenter study in Korea

Background

The coronavirus disease 2019 (COVID-19) pandemic has caused significant changes. This study aimed to investigate the impact of COVID-19 on patients with chronic pain.

Methods

Patients with chronic pain from 23 university hospitals in South Korea participated in this study. The anonymous survey questionnaire consisted of 25 questions regarding the following demographic data, diagnosis, hospital visit frequency, exercise duration, time outside, sleep duration, weight change, nervousness and anxiety, depression, interest or pleasure, fatigue, daily life difficulties, and self-harm thoughts. Depression severity was evaluated using the Patient Health Questionnaire-9 (PHQ-9). Logistic regression analysis was used to investigate the relationship between increased pain and patient factors.

Results

A total of 914 patients completed the survey, 35.9% of whom had decreased their number of visits to the hospital, mostly due to COVID-19. The pain level of 200 patients has worsened since the COVID-19 outbreak, which was more prominent in complex regional pain syndrome (CRPS). Noticeable post-COVID-19 changes such as exercise duration, time spent outside, sleep patterns, mood, and weight affected patients with chronic pain. Depression severity was more significant in patients with CRPS. The total PHQ-9 average score of patients with CRPS was 15.5, corresponding to major depressive orders. The patients’ decreased exercise duration, decreased sleep duration, and increased depression were significantly associated with increased pain.

Conclusions

COVID-19 has caused several changes in patients with chronic pain. During the pandemic, decreased exercise and sleep duration and increased depression were associated with patients’ increasing pain.

A Korean nationwide investigation of the national trend of complex regional pain syndrome vis-à-vis age-structural transformations

Background

The present study employed National Health Insurance Data to explore complex regional pain syndrome (CRPS) updated epidemiology in a Korean context.

Methods

A CRPS cohort for the period 2009-2016 was created based on Korean Standard Classification of Diseases codes alongside the national registry. The general CRPS incidence rate and the yearly incidence rate trend for every CRPS type were respectively the primary and secondary outcomes. Among the analyzed risk factors were age, sex, region, and hospital level for the yearly trend of the incidence rate for every CRPS. Statistical analysis was performed via the chi-square test and the linear and logistic linear regression tests.

Results

Over the research period, the number of registered patients was 122,210. The general CRPS incidence rate was 15.83 per 100,000, with 19.5 for type 1 and 12.1 for type 2. The condition exhibited a declining trend according to its overall occurrence, particularly in the case of type 2 (P < 0.001). On the other hand, registration was more pervasive among type 1 compared to type 2 patients (61.7% vs. 38.3%), while both types affected female individuals to a greater extent. Regarding age, individuals older than 60 years of age were associated with the highest prevalence in both types, regardless of sex (P < 0.001).

Conclusions

CRPS displayed an overall incidence of 15.83 per 100,000 in Korea and a declining trend for every age group which showed a negative association with the aging shift phenomenon.