BACKGROUND: Complex regional pain syndrome (CRPS) is a clinical disorder that can develop following surgery or trauma. Based on the most prominent underlying pathophysiological mechanisms, CRPS can be classified into different subtypes, namely inflammatory, nociplastic/neuropathic, vasomotor, and motor. Depending on the subtype, personalized treatment can be applied. If conservative treatments are insufficient or ineffective, more invasive treatments may be recommended. This article provides an overview of the most recent insights into CRPS and discusses the most common invasive treatments.
METHODS: The literature regarding interventional treatments for CRPS has been systematically reviewed and summarized.
RESULTS: Bisphosphonates are effective in treating the inflammatory subtype, while ketamine can provide pain relief for the nociplastic/neuropathic subtype. Sympathetic blocks are effective in addressing vasomotor disturbances. For patients with refractory symptoms, neurostimulation is a viable option due to its multimechanistic properties for all subtypes. End-of-line motor disturbances may benefit from intrathecal baclofen.
CONCLUSIONS: CRPS is a debilitating condition with an unpredictable course. The effectiveness of treatment varies from patient to patient. When conservative approaches prove insufficient, gradual progression to invasive treatments based on the underlying subtype is recommended.

Complex Regional Pain Syndrome is characterized by regional pain that is disproportionate to the triggering event, with no distribution to dermatomes, a tendency towards chronicity, and dysfunction. This narrative review proposes an update of criteria for diagnosis and management of the syndrome, providing information on epidemiology, etiology, and pathophysiology. We base our information on systematic and narrative reviews, as well as guidelines published in recent years, aiming to facilitate diagnostic suspicion and provide a broad overview of therapeutic possibilities.

Background: Complex regional pain syndrome (CRPS) presents as persistent regional pain, both spontaneous and triggered. The demand persists for innovative treatments that patients can endure with minimal adverse effects. Hyperbaric oxygen therapy (HBOT) emerges as a possible intervention in this regard. Methods: The main objective of this work is to retrospectively analyse a case series of patients diagnosed with CRPS treated in the Centre of Hyperbaric Medicine Ostrava over two years (period 2018-2019). The HBOT was applied at 2.0-2.4 absolute atmosphere (ATA) once a day. Results: A total of 83 patients with CRPS were treated with HBOT. 98% of cases reported pain, 92% reported limitation of movement of the affected limb, 87% had swelling of the limb, 41% had lividity and 70% had sensory problems. The mean number of HBOT exposures was 22.0 ± 7.1. At the end of HBOT treatment, 86% of cases had symptoms relief. The mean VAS value of pain at rest before the start of HBOT was 3.2±3.0, after treatment it was 1.6±1.9 (p<0.001). In a pain at activity it was 6.1±2.4 and 3.7±2.4 (p<0.001), respectively, at the end of HBOT. The value of the functional assessment of the limb was 7.0±2.0 and 4.3±2.4 (p<0.001), respectively, at the end of treatment. 79 cases were included in the end-of-treatment assessment. 23 cases (29%) were evaluated as large clinically significant response, 48 cases (61%) were evaluated as partial response with minimally important difference. The results showed larger clinical HBOT effect in cases of disease duration up to 3 and 6 months (p=0.029). Conclusions: The majority of patients improved pain and functional state of the affected limb. Our data also suggests the sooner after diagnosis of CRPS is HBOT started, the treatment has larger clinical effect. There was no serious HBOT-related complication or injury.

UNASSIGNED: Complex regional pain syndrome (CRPS) is characterized by chronic pain disproportional to any inciting event, and is associated with poor quality of life, and large clinical, healthcare, and societal costs. A CRPS diagnosis is challenging due to the lack of biomarkers and objective laboratory and radiographic tests. CRPS is currently diagnosed according to the IASP clinical diagnostic criteria, and it is not a radiological diagnosis. We report a case of acrometastasis to the hand that was initially thought to be CRPS. The purpose of this publication is to reinforce the importance of CRPS to be a diagnosis of exclusion.
UNASSIGNED: A woman in her 70s presented to a primary care facility with moderate pain in the dorsum of her right wrist and hand that began approximately two weeks prior without trauma. The initial reading of the white blood cell scan and three-phase bone scan (TPBS) were suggested to be compatible with CRPS; however, a pain medicine specialist did not confirm the diagnosis. The patient was later diagnosed with acrometastasis as a result of a bone biopsy demonstrating metastatic lung adenocarcinoma.
UNASSIGNED: CRPS shares clinical indications with various inflammatory diseases. Imaging techniques cannot be solely utilized to diagnose CRPS due to nonuniform findings and not only low but varying sensitivity and specificity. The WBC scan, laboratory results, and the three-phase bone scan did not properly demonstrate CRPS. Our case demonstrates the importance of excluding all conditions with similar presentations prior to determining a CRPS diagnosis and understanding the importance of interpreting a TPBS.

OBJECTIVE: Complex regional pain syndrome (CRPS) is a debilitating chronic condition characterized by severe, nociplastic pain along with various other symptoms. Neuromodulation, particularly electrical stimulation of the dorsal root ganglion (DRG), has emerged as a promising intervention for patients with CRPS unresponsive to conventional treatments. However, little is known about the anatomical characteristics of DRGs in patients with CRPS. This study aimed to assess DRG size in patients with CRPS compared with healthy controls.
METHODS: A retrospective pilot study was conducted in 12 patients with unilateral lower extremity CRPS who have a history of lumbar magnetic resonance imaging, and evaluated DRG sizes bilaterally. Patients were age-, race-, and sex-matched to patients in the control group who were asymptomatic at matched spinal level. DRG sizes were evaluated by a neuroradiologist. Statistical analyses including paired t-tests were performed to compare the difference in DRG size in contralateral sides in patients with CRPS and their matched controls.
RESULTS: Patients with CRPS exhibited a statistically significant reduction in DRG size on the affected side compared with the unaffected side (4.4 mm-4.8 mm, respectively). This difference was significant when compared with the difference observed in healthy controls (4.9 mm-5.0 mm, respectively). In addition, the mean DRG size difference between the affected and unaffected side showed a greater difference in DRG size in patients with CRPS (0.6 mm difference) than in control patients (0.2 mm difference).
CONCLUSIONS: The findings suggest that CRPS is associated with a smaller DRG size in affected dermatomes, potentially indicating neuronal atrophy. Importantly, the study offers insights for DRG stimulation therapy especially among concerns for DRG compression after placement. This pilot study reveals a significant size difference in DRGs between affected and unaffected sides in patients with CRPS compared with controls, highlighting potential implications for treating CRPS. Further research is warranted to validate these findings and explore implications for clinical practice, including optimized neuromodulation strategies.

This paper presents a case of a 35-year-old female patient diagnosed with Complex Regional Pain Syndrome (CRPS) type I and treated over a two-month period with a novel low-frequency sound-transduced focal pulsed stimulus. The patient received 21 treatments consisting of focally applied sound sweeps in the 15-100 Hz range. Outcome measures included the Visual Analogue Scale for pain, five physical assessment parameters, medication, and the Pain Catastrophizing Scale. A follow-up was conducted at six months. The results show that the patient\'s low-back pain level was substantially reduced after treatment and after six months. CRPS-related peripheral pain was strongly reduced but had some rebound after six months. The low-frequency sound-transduced focal pulsed stimulus shows potential as a non-invasive treatment for CRPS and deserves controlled clinical trials.

BACKGROUND: Social support is a multidimensional construct encompassing emotional support as well as pain-focused care and attention, also known as solicitous support. One the one hand, social support is widely believed to positively influence pain symptoms, their intensity, and the ability to cope and influence pain. On the other hand, social support can be negative if it conflicts with the patient\'s needs or even causes discomfort. How different types of social support influence pain is not very well understood especially because most of the present research originates from laboratory studies, raising uncertainties about its generalizability to the everyday life of individuals with chronic pain.
METHODS: Here, we tested the effects of emotional, solicitous, and negative social support on pain intensity cross-sectionally in everyday life. We collected data from 20 patients with acute complex regional pain syndrome using a smartphone-based Ecological Momentary Assessment with up to 30 survey prompts over a period of five consecutive days.
RESULTS: Our results showed that solicitous social support decreased pain, in particular in male patients. Emotional support was beneficial on pain in women but not in men.
CONCLUSIONS: Taken together, these findings highlight the differential effects of social support in every-day life on chronic pain.

Background: Complex regional pain syndrome (CRPS) is classified into two subtypes based on clinical presentation: warm or cold.Methods: We examined the distribution of warm and cold subtypes in CRPS patients before they received lumbar sympathetic block. We retrospectively analyzed 81 prelumbar sympathetic block Forward Looking InfraRed images obtained from 30 patients to study temperature asymmetry between affected and unaffected limbs.Results: In 23 of the 30 patients (77%), the temperature difference between the affected and affected limbs was within the normal range (<0.6°C difference). Of the remaining seven cases, six (20%) were diagnosed with cold-CRPS and one (3%) with warm-CRPS. During subsequent interventions, 74% of the patients maintained a temperature difference within the normal range (<0.6°C difference).Conclusion: Retrospective analysis of Forward Looking InfraRed thermal camera images in CRPS patients showed that 77% of patients did not exhibit significant temperature asymmetry (<0.6°C difference) between affected and unaffected limbs.
What is the article about? The article discusses a condition called complex regional pain syndrome (CRPS), a type of chronic pain that affects arms or legs. CRPS can potentially make the affected limb colder or warmer compared with the other limb. This study investigated temperature differences between the affected and nonaffected limbs in CRPS patients to be treated with a procedure called lumbar sympathetic nerve blocks. Researchers used an infrared thermal camera to take pictures of the patients’ feet to measure these temperature differences.What were the results? The study found that 77% of the patients, who were about to have their initial nerve block treatments, did not show a significant (greater than 0.6°C) temperature difference between their affected and nonaffected limbs.What do the results mean? The study suggests that most CRPS patients demonstrated only a small temperature difference between their affected and nonaffected limbs. This result is different from earlier studies, which suggested that warm CRPS occurs in about 70% and cold CRPS in about 30% of cases at the time of diagnosis.

UNASSIGNED: Automated manual lymphatic drainage therapy (AMLDT) is available for home use in the form of a pneumatic mat of 16 pressurized air channels that inflate and deflate to mimic the stretch and release action of manual lymphatic drainage therapy. Four cases (a patient with complex regional pain syndrome and lymphedema, a healthy patient, a breast cancer survivor with chronic pain, and a patient with a history of abdominal surgery) underwent near-infrared fluorescence lymphatic imaging (NIRFLI) with AMLDT to evaluate the effect of AMLDT on lymphatic pumping and pain.
UNASSIGNED: Each patient received 32-36 injections of 25 μg indocyanine green (ICG) on the anterior and posterior sides of their body and underwent 1 h of NIRFLI to assess the drainage of ICG laden lymph toward regional nodal basins at baseline. Each patient lay supine on the mat for 1 h of AMLDT with NIRFLI to assess lymphatic flow during treatment. A final NIFRFLI assessment was done 30-60 min posttreatment with the patient in the supine and prone position. Patients reported baseline and posttreatment pain using the Visual Analogue Scale. An imager analyzed NIRFLI images using ImageJ (US National Institutes of Health). Using time stamps of the first and last images to determine time lapsed and the number of pulses observed in a timeframe, pulsing frequency (pulses/min) was obtained to assess lymphatic function.
UNASSIGNED: All 4 cases completed the NIRFLI and AMLDT without complications; all 3 patients with baseline pain reported reduced pain posttreatment. AMLDT appeared to alter lymphatic contractility, with both increased and decreased pulsing frequencies observed, including in nonaffected limbs. Pulsing frequencies were very heterogeneous among patients and varied within anatomic regions of the same patient.
UNASSIGNED: This proof-of-concept study suggests that AMLDT may impact lymphatic contractility. Further research on its effect on lymphatic function is warranted.

Complex regional pain syndrome (CRPS) is an uncommon neuropathic pain illness characterized by extreme discomfort, muscular weakness, limb edema, and hyperhidrosis. Fracture, surgery, stroke, and spinal cord damage are all potential risk factors. This case report study provides a detailed description of no-traumatic CRPS, a complex pain illness characterized by sensory, vasomotor, sudomotor, motor, trophic, and edematous changes and persistent discomfort. We reported a case of a 39-year-old male with a seven-year history of severe right shoulder-hand pain. He presented with recurrent hand and shoulder pain characterized by burning sensations and weakness, despite not having experienced this before, and he denied any history of trauma or fracture. Surgical procedure and pharmaceutical therapy were provided, but there was no outcome, as evidenced by the patient\'s clinical condition and the medical records. Despite extensive investigation, no imaging or laboratory tests have been developed for diagnosis, necessitating further research for a comprehensive understanding and diagnosis.