Case report: Long-standing complex regional pain syndrome relieved by a cephalosporin antibiotic

A case of truncal complex regional pain syndrome: literature review

Introduction and importance

Complex regional pain syndrome is a rare and chronic pain disorder characterized by an abnormal level of pain disproportionate to the initiating cause, often manifesting well after the triggering event.

Case presentation

The authors present a free past medical history 33-year-old female, employed as a nurse in an intensive care unit, presented with a 9-year history of diffuse back pain. Her symptoms initially emerged at the neck with muscle spasms and restricted neck mobility, eventually progressing along the spine. Notably, the pain became episodic and intensified over time, significantly impeding her daily activities. Analgesic (non-steroidal anti-inflammatory drugs) treatments proved ineffective, and a distinct feature emerged-a change in skin colour to dark purple spots on her back, accompanied by hyperhidrosis and extreme tenderness. Despite an exhaustive evaluation involving bloodwork, inflammatory markers, serological tests, and radiographic imaging, a definitive diagnosis remained elusive until she responded positively to Pregabilin.

Clinical discussion

Although typically associated with extremities, this case challenges the conventional understanding of complex regional pain syndrome by showcasing its manifestation in the truncal region. The patient's clinical history, examination findings, and diagnostic journey are detailed herein, shedding light on the complexity and diagnostic considerations associated with this condition.

Conclusion

The case underscores the importance of a comprehensive approach and prompts a reevaluation of the existing guidelines to encompass such atypical presentations.

Microbiota-Accessible Boron-Containing Compounds in Complex Regional Pain Syndrome

The microbiota-gut-brain axis has garnered increasing attention in recent years for its role in various health conditions, including neuroinflammatory disorders like complex regional pain syndrome (CRPS). CRPS is a debilitating condition characterized by chronic neuropathic pain, and its etiology and pathophysiology remain elusive. Emerging research suggests that alterations in the gut microbiota composition and function could play a significant role in CRPS development and progression. Our paper explores the implications of microbiota in CRPS and the potential therapeutic role of boron (B). Studies have demonstrated that individuals with CRPS often exhibit dysbiosis, with imbalances in beneficial and pathogenic gut bacteria. Dysbiosis can lead to increased gut permeability and systemic inflammation, contributing to the chronic pain experienced in CRPS. B, an essential trace element, has shown promise in modulating the gut microbiome positively and exerting anti-inflammatory effects. Recent preclinical and clinical studies suggest that B supplementation may alleviate neuropathic pain and improve CRPS symptoms by restoring microbiota balance and reducing inflammation. Our review highlights the complex interplay between microbiota, inflammation, and neuropathic pain in CRPS and underscores the potential of B as a novel therapeutic approach to target the microbiota-gut-brain axis, offering hope for improved management of this challenging condition.

A role for the microbiota in complex regional pain syndrome?

Complex regional pain syndrome (CRPS) is a debilitating neuroinflammatory condition of unknown etiology. Symptoms include excruciating pain and trophic changes in the limbs as defined by the Budapest criteria. The severity and functional recovery of CRPS, unlike most pain conditions, is quantifiable using a variation of the Budapest criteria known as the CRPS severity score. Like many chronic pain conditions, CRPS is difficult to treat once pain has been present for more than 12 months. However, previous work has demonstrated that a subset of patients with new-onset CRPS (~50%) improve if treated within one year, while the rest have minimal to no symptom improvement. Unfortunately, this leads to permanent disability and often requires invasive and costly treatments such as spinal cord stimulation or long-term opioid therapy. Because the etiology is unknown, treatment is multimodal, and often supportive. Biomarkers that predict severity or resolution of symptoms would significantly change treatment but have not yet been identified. Interestingly, there are case reports of remission or resolution of CRPS symptoms with the use of antibiotics known to affect the gut flora. Mouse studies have demonstrated that modulation of the gut microbiome is anti-nociceptive in visceral, inflammatory and neuropathic pain models. We hypothesize that the variable clinical potential for recovery and response to therapy in CRPS may be secondary to or reflected in changes in the gut microbiota. We suggest that the microbiota may mediate or reflect clinical status via the metabolome, activation of the immune system and/or microglial activation. We hypothesize that the gut microbiome is a potential mediator in development and persistence of CRPS symptoms and propose that the clinical condition of CRPS could provide a unique opportunity to identify biomarkers of the microbiota and potential therapies to prevent pain chronification.

Ceftriaxone and clavulanic acid induce antiallodynia and anti-inflammatory effects in rats using the carrageenan model

Introduction

Ceftriaxone (CFX) and clavulanic acid (CA) are 2 β-lactam molecules widely used as antibiotics. However, several reports of their antiallodynic properties have been published in recent years. Although this effect has been considered mostly due to a GLT1 overexpression, these molecules have also been proven to induce direct immunomodulation. In this work, we determine the acute analgesic effect of CFX and CA in an inflammatory pain model and assess if their administration may induce anti-inflammatory effects.

Methods

The carrageenan (Carr) test was used as an inflammatory pain model. Both mechanical and thermal responses were analyzed after CFX and CA administration at different times. A plethysmometer was used to determine inflammation. Also, TNF-α and IL-10 serum concentrations were determined by enzyme-linked immunosorbent assay.

Results

Both CFX and CA induced a significant thermal antiallodynic effect 3 and 24 h after administration. Furthermore, CA induced a mechanical antiallodynic effect 30, 60, and 90 min after administration. Moreover, a significant anti-inflammatory effect was found for both molecules 24 h after Carr injection. Also, both CA and CFX modulated TNF-α and IL-10 serum concentrations at different times.

Conclusion

Our results provide evidence that both CFX and CA cause an analgesic effect on a Carr inflammatory pain model and that said analgesic effect differs between each β-lactam molecule. Furthermore, this effect may be related to an anti-inflammatory effect of both molecules and a direct TNF-α and IL-10 serum concentration modulation.

Identification and Treatment of New Inflammatory Triggers for Complex Regional Pain Syndrome: Small Intestinal Bacterial Overgrowth and Obstructive Sleep Apnea

Complex regional pain syndrome (CRPS) is evoked by conditions that may be associated with local and/or systemic inflammation. We present a case of long-standing CRPS in a patient with Ehlers-Danlos syndrome in which prolonged remission was attained by directing therapy toward concomitant small intestinal bacterial overgrowth, obstructive sleep apnea, and potential increased microglia activity. We theorize that cytokine production produced by small intestinal bacterial overgrowth and obstructive sleep apnea may act as stimuli for ongoing CRPS symptoms. CRPS may also benefit from the properties of low-dose naltrexone that blocks microglia Toll-like receptors and induces production of endorphins that regulate and reduce inflammation.