Effect of Co-Morbid Conditions on Persistent Neuropathic Pain after Brachial Plexus Injury in Adult Patients

Pulsed radiofrequency to stellate ganglion for brachial plexus injury-induced complex regional pain syndrome: A case series

Brachial plexus injury (BPI) occurs commonly in young adults following trauma. This may result in the development of complex regional pain syndrome (CRPS) following injury, which is difficult to treat. We present a group of patients with CRPS secondary to BPI. These patients were managed with neuromodulation of the stellate ganglion (SG) with pulsed radiofrequency (PRF) and followed up for a period of 3 months to assess for pain relief and a decrease in the intake of medications after the intervention. PRF to SG was found to have significant pain relief lasting around three months.

Comparison of Different In Vivo Animal Models of Brachial Plexus Avulsion and Its Application in Pain Study

Brachial plexus injuries (BPIs) are high-energy trauma that can result in serious functional problems in the affected upper extremities, and brachial plexus avulsion (BPA) could be considered the most severe type of them. The booming occurrence rate of BPA brings up devastating impact on patients' life. Complications of muscle atrophy, neuropathic pain, and denervation-associated psychological disorders are major challenges in the treatment of BPA. Animal models of BPA are good vehicles for this kind of research. Full understanding of the current in vivo BPA models, which could be classified into anterior approach avulsion, posterior approach avulsion, and closed approach avulsion groups, could help researchers select the appropriate type of models for their studies. Each group of the BPA model has its distinct merits and demerits. An ideal BPA model that can inherit the advantages and make up for the disadvantages is still required for further exploration.

"Pill Pushers and CBD Oil"-A Thematic Analysis of Social Media Interactions About Pain After Traumatic Brachial Plexus Injury

Purpose

Brachial plexus injury (BPI) patients use on-line groups for peer support, often seeking information from Facebook groups devoted to BPI. We hypothesized that a qualitative thematic analysis of posts from BPI Facebook groups would demonstrate the areas in which patients were seeking information regarding treatment of BPI and reveal potential sources of misinformation that patients may encounter.

Methods

We identified the 2 most popular public Facebook groups for BPI by searching key words “traumatic brachial plexus injury.” We selected posts containing comments regarding BPI from November 1, 2018 through October 31, 2019. We excluded posts regarding brachial plexus birth injury. We used iterative inductive and deductive thematic analysis for the qualitative data to identify recurring topics, knowledge gaps, potential roles of patient educational interventions, and patient interaction dynamics. Two investigators independently coded all posts and resolved discrepancies by discussion.

Results

A total of 7,694 posts from 2 leading Facebook support groups were analyzed. Three themes emerged: (1) When discussing pain management, there was recurring anti-opioid sentiment. Posters who currently used opioids or supported those who did discussed perceived effects of the opioid epidemic on their treatment, on their relationships with care providers, and on availability of the medication. (2) Posters advocated for alternatives to traditional approaches to pain management, referring to prescribers as pill pushers and touting cannabinoids as a safer and more effective replacement. (3) There was strong anti-gabapentinoid sentiment owing to reported adverse effects and a perceived lack of efficacy, despite its role as a first-line treatment for neuropathic pain.

Conclusions

Examination of posts from Facebook support groups for BPI revealed recurring themes, questions, misinformation, and opinions from posters with regard to treatment of neuropathic pain. These findings can help clinicians who care for BPI patients identify areas to focus on during patient encounters to address neuropathic pain that commonly occurs with BPI.

Clinical relevance

Brachial plexus injury surgeons should be aware of information, misinformation, and opinions on social media, because these may influence patient–surgeon interactions.

Management of CRPS secondary to preganglionic C8 nerve root avulsion: A case report and literature review

Background:

Cervical nerve root avulsion is a well-documented result of high-velocity motor vehicle accidents (MVAs). In up to 21% of cases, preganglionic cervical root avulsion can result in a complex regional pain syndrome (CRPS) impacting the quality of life for patients already impaired by motor, sensory, and autonomic dysfunction. The optimal treatment strategies include repeated stellate ganglion blocks (SBGs).

Case Description:

A 43-year-old male sustained a high-velocity MVA resulting in the left C8 nerve root avulsion. This resulted in weakness in the C8 distribution, tactile allodynia, and dysesthesias. The magnetic resonance imaging demonstrated an abnormal signal ventral to the C8–T1 level. As the patient was not considered a candidate for surgical intervention secondary to the attendant brachial plexus injury, a C7–C8 epidural steroid injection was performed; this did not provide improvement. Before placing a spinal cord stimulator, the patient underwent a series of six ultrasound-guided SBGs performed 2 weeks apart; there was 75% improvement in pain and strength. Six years later, the patient continues to do well while receiving SBGs 4 times a year.

Conclusion:

A preganglionic cervical nerve root avulsion should not be a contraindication for a stellate ganglion block in a patient with established CRPS.

The Case for Comorbid Myofascial Pain-A Qualitative Review

Myofascial pain syndrome is widely considered to be among the most prevalent pain conditions, both in the community and in specialized pain clinics. While myofascial pain often arises in otherwise healthy individuals, evidence is mounting that its prevalence may be even higher in individuals with various comorbidities. Comorbid myofascial pain has been observed in a wide variety of medical conditions, including malignant tumors, osteoarthritis, neurological conditions, and mental health conditions. Here, we review the evidence of comorbid myofascial pain and discuss the diagnostic and therapeutic implications of its recognition.

Sex differences in measures of central sensitization and pain sensitivity to experimental sleep disruption: implications for sex differences in chronic pain

Study Objectives

Females demonstrate heightened central sensitization (CS), a risk factor for chronic pain characterized by enhanced responsivity of central nervous system nociceptors to normal or subthreshold input. Sleep disruption increases pain sensitivity, but sex has rarely been evaluated as a moderator and few experiments have measured CS. We evaluated whether two nights of sleep disruption alter CS measures of secondary hyperalgesia and mechanical temporal summation in a sex-dependent manner. We also evaluated differences in measures of pain sensitivity.

Methods

Seventy-nine healthy adults (female n = 46) participated in a randomized crossover experiment comparing two consecutive nights of eight pseudorandomly distributed forced awakenings (FA [-200 min sleep time]) against two nights of undisturbed sleep (US). We conducted sensory testing the mornings following Night 2; the heat-capsaicin pain model was used to induce secondary hyperalgesia.

Results

FA reduced total sleep time (REM and NREM Stage 3) more profoundly in males. We observed divergent, sex-dependent effects of FA on secondary hyperalgesia and temporal summation. FA significantly increased secondary hyperalgesia in males and significantly increased temporal summation in females. Sex differences were not attributable to differential sleep loss in males. FA also significantly reduced heat-pain threshold and cold pressor pain tolerance, independently of sex.

Conclusions

Sleep disruption enhances different pain facilitatory measures of CS in males and females suggesting that sleep disturbance may increase risk for chronic pain in males and females via distinct pathways. Findings have implications for understanding sex differences in chronic pain and investigating sleep in chronic pain prevention efforts.

Acupuncture Induces Reduction in Limbic-Cortical Feedback of a Neuralgia Rat Model: A Dynamic Causal Modeling Study

Background

Neuropathic pain after brachial plexus avulsion remained prevalent and intractable currently. However, the neuroimaging study about neural mechanisms or etiology was limited and blurred.

Objective

This study is aimed at investigating the effect of electroacupuncture on effective connectivity and neural response in corticolimbic circuitries during implicit processing of nociceptive stimulus in rats with brachial plexus pain.

Methods

An fMRI scan was performed in a total of 16 rats with brachial plexus pain, which was equally distributed into the model group and the electroacupuncture group. The analysis of task-dependent data determined pain-related activation in each group. Based on those results, several regions including AMY, S1, and h were recruited as ROI in dynamic causal modeling (DCM) analysis comparing evidence for different neuronal hypotheses describing the propagation of noxious stimuli in regions of interest and horizontal comparison of effective connections between the model and electroacupuncture groups.

Results

In both groups, DCM revealed that noxious stimuli were most likely driven by the somatosensory cortex, with bidirectional propagation with the hypothalamus and amygdala and the interactions in them. Also, the 3-month intervention of acupuncture reduced effective connections of h-S1 and AMY-S1.

Conclusions

We showed an evidence that a full connection model within the brain network of brachial plexus pain and electroacupuncture intervention reduces effective connectivity from h and AMY to S1. Our study for the first time explored the relationship of involved brain regions with dynamic causal modeling. It provided novel evidence for the feature of the organization of the cortical-limbic network and the alteration caused by acupuncture.

A Comparative Study of Two Modalities in Pain Management of Patients Presenting with Chronic Brachial Neuralgia

Objectives: The study aims to assess, evaluate, and compare the efficacy of acupressure and hypnotherapy in the management of pain in patients presenting with chronic brachial neuralgia (CBN). Design: Randomized controlled trial. Settings/location: Department of Orthopaedic Surgery, University Malaya Medical Centre, Kuala Lumpur, Malaysia. Subjects: Forty patients with CBN following traumatic brachial plexus injury from 2012 to 2017. Intervention: Therapy for a duration of 1 month in two groups; subjects in the hypnotherapy group received a weekly session of clinical hypnotherapy (total of four times) using a standardized protocol, while subjects in the acupressure group were guided by an acupuncturist during the initial session, received 2 month take home supply of acupressure patches, and were reviewed fortnightly. Outcome measures: The Visual Analog Scale, the Brief Pain Inventory, and the SF-36v2^® Health Survey were recorded at different time points; 1 month pretreatment (week 0), pretreatment (week 4), post-treatment (week 8), and 4 months post-treatment (week 20). Results: There was a statistically significant improvement in the average pain intensity from pretreatment to post-treatment score in both groups. The pain intensity increased 4 months later; however, the pain intensity was still significantly reduced in comparison with pretreatment scores. The study suggests that both treatment outcomes are effective in terms of alleviating pain and improving quality of life in subjects with CBN, to a different degree. Conclusion: Overall, both therapies were able to improve the pain intensity and quality of life significantly during the treatment period. Hypnotherapy was observed to have a better carryover effect compared to acupressure, especially in terms of improving quality of life and the mental component score.

AAPT Diagnostic Criteria for Peripheral Neuropathic Pain: Focal and Segmental Disorders

Peripheral neuropathic pain is among the most prevalent types of neuropathic pain. No comprehensive peripheral neuropathic pain classification system that incorporates contemporary clinical, diagnostic, biological, and psychological information exists. To address this need, this article covers the taxonomy for 4 focal or segmental peripheral neuropathic pain disorders, as part of the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership and the American Pain Society (APS) collaborative to develop a standardized, evidence-based taxonomy initiative: the ACTTION-APS Pain Taxonomy (AAPT). The disorders-postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia-were selected because of their clinical and clinical research relevance. The multidimensional features of the taxonomy are suitable for clinical trials and can also facilitate hypothesis-driven case-control and cohort epidemiologic studies. PERSPECTIVE: The AAPT peripheral neuropathic pain taxonomy subdivides the peripheral neuropathic pain disorders into those that are generalized and symmetric and those that are focal or segmental and asymmetric. In this article, we cover the focal and segmental disorders: postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia. The taxonomy is evidence-based and multidimensional, with the following dimensions: 1) core diagnostic criteria; 2) common features; 3) common medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors.