Lumbar Sympathetic Block to Treat CRPS in an 18-Month-Old Girl: A Breaking Barriers Case Report and Review of Literature.

BACKGROUND: Children under the age of 3 years have been diagnosed with complex regional pain syndrome (CRPS). They were found to be functionally disadvantaged and psychologically distressed in relation to children with other painful conditions. CASE PRESENTATION: An 18-month-old baby girl was referred to the pain clinic with a history of severe right lower limb pain that had begun 2 months earlier. The parents were unable to recall any trauma before the painful situation. Pain and allodynia were severe and extended from the toes to the gluteus area. She was low weight for her age (6700 g). The patient was on the maximum doses of gabapentin and amitriptyline accepted for her body weight and did not have the possibility to start rehabilitation due to severe pain and allodynia. After discussing the risks and potential benefits of a planned lumbar sympathetic block (LSB), the parents approved the interventional procedure. This is the first case report describing the LSB technique at such a young age. METHOD: A lumbar sympathetic block was carried on at the third lumbar vertebral level, fluoroscopy-guided, and under general anesthesia (GA) initiated with ketamine iv. A 4-cm needle was introduced using a tunneled vision approach in an oblique view at the L3 level until adequate depth was confirmed in the lateral position. Safety considerations were taken in relation to the radiation dose and all drugs injected with dose adjustment to her body weight. The block was successful (the skin temperature increased by 2.8 °C) and was uneventful. Pain and allodynia were completely alleviated in the recovery room. At the follow-up after 3 and 8 weeks, the parents reported an 80% improvement in pain and allodynia, a 70% improvement in sleep, a weight gain of 900 g, and that she had started rehabilitation. CONCLUSIONS: Lumbar sympathetic blocks can be considered at a very young age to treat CRPS if other non-invasive measures fail.

Intravenous Magnesium for the Management of Chronic Pain:An Updated Review of the Literature.

Background: Available therapeutic options are currently limited by their modest efficacy. As a result, novel pharmacotherapeutic treatments with different mechanisms have recently attracted empirical attention. Magnesium, a divalent cation, is postulated to provide analgesic and anti-nociceptive effect through its action at the N-methyl-D-aspartate (NMDA) receptor. Objective: Considering the evidence surrounding magnesium's potential as a therapeutic modality for chronic pain, we conducted a narrative review on the evidence of magnesium's therapeutic effects in chronic pain. Methods: A review of the PubMed, and Google scholar databases was undertaken in May 2022 to identify completed studies that investigated the effectiveness of magnesium in the treatment of chronic pain from database inception to May 2022. Results: A total of 33 studies were included in the narrative review, out of which 26 were randomized controlled trials. Findings on available studies suggest that intravenous infusion of magnesium is an emerging and promising option that may alleviate pain in some clinical populations. Our narrative synthesis showed that evidence for intravenous magnesium is currently equivocal for a variety of chronic pain syndrome. Findings indicate that evidence for efficacy is poor or equivocal for: CRPS, neuropathic pain, chronic low back pain, and migraine prophylaxis. However, there is good evidence supporting the efficacy of intravenous magnesium for treating renal colic pain and pelvic pain related to endometriosis. Conclusion: Magnesium may be a promising pharmacologic solution for chronic pain. Future investigation is warranted on elucidating the neurobiological mechanisms of magnesium in attenuating pain signaling pathways.

Case Report: Rescue of Relapsed Pain in a Patient with Complex Regional Pain Syndrome Type II by Adding Another Dorsal Root Ganglion Lead.

We present on a patient with complex regional pain syndrome (CRPS) following ankle surgery. Pain was refractory to both conservative and surgical measures including neurotomies, ankle fusion, hardware removal, and spinal cord stimulation (SCS) trial. A dorsal root ganglion (DRG) stimulation trial with lead placements at L4, L5, and S1 provided significant pain and functional improvement. However, during the implantation, we were able to place only two DRG leads at L4 and L5 and not S1 due to difficulties with advancing the lead to the desired location. Nonetheless, the two DRG leads provided 90% pain relief and 75% functional improvement for 9 months. However, the patient experienced pain symptoms similar to that of pre-implant without a clear trigger after 9 months despite no DRG stimulator hardware malfunction or lead migration. A decision was made to re-try implanting the S1 DRG lead, which was successful and provided significant pain relief.

Breaking the Cycle of Pain: The Role of Graded Motor Imagery and Mirror Therapy in Complex Regional Pain Syndrome.

Background: Complex Regional Pain Syndrome (CRPS) is a chronic condition characterized by severe pain and functional impairment. Graded Motor Imagery (GMI) and Mirror Therapy (MT) have emerged as potential non-invasive treatments; this review evaluates the effectiveness of these therapies in reducing pain, improving function, and managing swelling in CRPS patients. Methods: A systematic review was conducted including randomized controlled trials (RCTs) that investigated GMI and MT in CRPS patients. This review was registered in PROSPERO (CRD42024535972) to ensure transparency and adherence to protocols. This review included searches of PubMed, Cochrane, SCOPUS, and Web of Science databases. Out of 81 studies initially screened, 6 were included in the final review. Studies were assessed for quality using the PEDro and RoB-2 scales. The primary outcomes were pain reduction, functional improvement, and swelling reduction. Results: Graded Motor Imagery (GMI) and Mirror Therapy (MT) reduced pain by an average of 20 points on the Neuropathic Pain Scale (NPS) and resulted in functional improvements as measured by the Task-Specific Numeric Rating Scale (NRS). GMI also contributed to some reduction in swelling. MT, particularly in post-stroke CRPS patients, showed significant pain reduction and functional improvements, with additional benefits in reducing swelling in certain studies. However, the included studies had small sample sizes and mixed designs, which limit the generalizability of the findings. The studies varied in sample size and design, with some risk of bias noted. Conclusions: Graded Motor Imagery (GMI) and Mirror Therapy (MT) have proven to be effective interventions for managing Complex Regional Pain Syndrome (CRPS), with significant improvements in pain reduction and functional recovery. These non-invasive treatments hold potential for integration into standard rehabilitation protocols. However, the small sample sizes and variability in study designs limit the generalizability of these findings. Future research should focus on larger, more homogeneous trials to validate the long-term effectiveness of GMI and MT, ensuring more robust clinical application.

Bioinformatic and Phenotypic Analysis of AtPCP-Ba Crucial for Silique Development in Arabidopsis.

Silique development exerts significant impacts on crop yield. CRPs (Cysteine-rich peptides) can mediate cell-cell communication during plant reproduction and development. However, the functional characterization and regulatory mechanisms of CRPs in silique development remain unclear. In this study, we identified many CRP genes downstream of the CRP gene TPD1 (TAPETUM DETERMINANT1) during silique development using a microarray assay. The novel Arabidopsis thaliana pollen-borne CRPs, the PCP-Bs (for pollen coat protein B-class) gene AtPCP-Ba, along with TPD1, are essential for silique development. The AtPCP-Ba was significantly down-regulated in tpd1 flower buds but up-regulated in OE-TPD1 flower buds and siliques. The silencing of AtPCP-Ba compromised the wider silique of OE-TPD1 plants and inhibited the morphology of OE-TPD1 siliques to the size observed in the wild type. A total of 258 CRPs were identified with the bioinformatic analysis in Arabidopsis, Brassica napus, Glycine max, Oryza sativa, Sorghum bicolor, and Zea mays. Based on the evolutionary tree classification, all CRP members can be categorized into five subgroups. Notably, 107 CRP genes were predicted to exhibit abundant expression in flowers and fruits. Most cysteine-rich peptides exhibited high expression levels in Arabidopsis and Brassica napus. These findings suggested the involvement of the CRP AtPCP-Ba in the TPD1 signaling pathway, thereby regulating silique development in Arabidopsis.

A surgical approach to complex regional pain syndrome with neurogenic thoracic outlet syndrome in a reoperation patient.

Thoracic outlet syndrome (TOS) and complex regional pain syndrome (CRPS) are two etiologies of chronic pain. TOS is a group of conditions that occur due to compression of the neurovascular structures of the upper extremity while CRPS is a disorder characterized by chronic and unremitting pain. This case highlights the experience of a 22-year-old female who presented following a traumatic injury to her left arm and was initially diagnosed with neurogenic TOS and later CRPS. Over a 10-year-period, she underwent a total of four operations to try and address her debilitating pain. In our third-time reoperation, symptoms of both pathologies nearly completely resolved with extensive neurolysis of the left brachial plexus and application of a scar tissue barrier.

A case report of a patient with severe & debilitating arm pain: Neurogenic thoracic outlet syndrome and complex regional pain syndrome are two disorders with the potential to cause severe and debilitating long-term pain, typically in an arm or leg. These two disorders are hard to diagnose, and patients can have variable responses to treatment. This case discussed a young woman who has severe pain of her left arm which eventually progress to the point that she had lost all meaningful use of the arm. After 8 years of treatments and four surgeries, she improved and began to regain her arm function.

Secure PUF-Based Authentication Systems.

The Internet of Things faces significant security challenges, particularly in device authentication. Traditional methods of PUF-based authentication protocols do not fully address IoT's unique security needs and resource constraints. Existing solutions like Identity-Based Encryption with Physically Unclonable Functions enhance security but still struggle with protecting data during transmission. We show a new protocol that leverages PUFs for device authentication by utilizing Paillier homomorphic encryption or the plaintext equality test to enhance security. Our approach involves encrypting both the challenge-response pairs (CRPs) using Paillier homomorphic encryption scheme or ElGamal encryption for plaintext equality testing scheme. The verifier does not need access to the plaintext CRPs to ensure that sensitive data remain encrypted at all times and our approach reduces the computational load on IoT devices. The encryption ensures that neither the challenge nor the response can be deciphered by potential adversaries who obtain them during the transmission. The homomorphic property of the Paillier scheme or plaintext equality testing scheme allows a verifier to verify device authenticity without decrypting the CRPs, preserving privacy and reducing the computational load on IoT devices. Such an approach to encrypting both elements of the CRP provides resistance against CRP disclosure, machine learning attacks, and impersonation attacks. We validate the scheme through security analysis against various attacks and evaluate its performance by analyzing the computational overhead and the communication overhead. Comparison of average computational and communication time demonstrates Paillier scheme achieves approximately 99% reduction while the plaintext equality test achieves approximately 94% reduction between them.

The Treatment of Chronic Complex Regional Pain Syndrome with Novel Neuromodulatory Sound Waves: A Case Report.

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.

The emerging role of cysteine-rich peptides in pollen-pistil interaction.

Unlike early land plants, flowering plants have evolved a pollen tube that transport a pair of non-motile sperm cells to the female gametophyte. This process, known as siphonogamy, was first observed in gymnosperms and later become prevalent in angiosperms. However, the precise molecular mechanisms underlying the male-female interactions remain enigmatic. From the pollen grain's landing on the stigma to gametes fusion, the male part needs to pass various tests: How does the stigma distinguish between compatible and incompatible pollen? What mechanisms guide pollen tube towards the ovule? What factors trigger pollen tube rupture? How is polyspermy prevented? And how does the sperm cell ultimately reach the egg? Successful male-female communications is essential for surmounting these challenges, with cysteine-rich peptides (CRPs) playing a pivotal role in these dialogues. In this review, we summarize the characteristics of four distinct classes of CRPs and then we systematically review the recent progresses of the role of CRPs in four crucial stages of pollination and fertilization. Finally, we conclude by considering the potential applications of this knowledge in crop breeding, and suggesting avenues for future research.

Temperature difference between the affected and unaffected limbs in complex regional pain syndrome.

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.

Aftereffects of visuomanual prism adaptation in auditory modality: Review and perspectives.

Visuomanual prism adaptation (PA), which consists of pointing to visual targets while wearing prisms that shift the visual field, is one of the oldest experimental paradigms used to investigate sensorimotor plasticity. Since the 2000's, a growing scientific interest emerged for the expansion of PA to cognitive functions in several sensory modalities. The present work focused on the aftereffects of PA within the auditory modality. Recent studies showed changes in mental representation of auditory frequencies and a shift of divided auditory attention following PA. Moreover, one study demonstrated benefits of PA in a patient suffering from tinnitus. According to these results, we tried to shed light on the following question: How could this be possible to modulate audition by inducing sensorimotor plasticity with glasses? Based on the literature, we suggest a bottom-up attentional mechanism involving cerebellar, parietal, and temporal structures to explain crossmodal aftereffects of PA. This review opens promising new avenues of research about aftereffects of PA in audition and its implication in the therapeutic field of auditory troubles.

Bone Turnover Markers and Wnt Signaling Modulators in Early Complex Regional Pain Syndrome. A Pre-specified Observational Study.

To explore serum levels of some bone turnover markers and the involvement of the Wnt signaling in CRPS-1. Query ID="Q1" Text="Please check and confirm whether the edit made to the article title is in order." We conducted an observational study on patients with early CRPS-1 recruited before any treatment. Clinical measures were assessed together with biochemical evaluation. Values of sclerostin, DKK1, CTX-I, and P1NP were compared with sex-age-matched healthy controls (HCs). We enrolled 34 patients diagnosed with CRPS-1 (mean age 59.3 ± 10.6 years, Male/Female 10/24), median disease duration = 2 weeks (IQR 1-5); median VAS score = 76 (IQR 68-80). Foot localization was slightly more frequent than hand localization (18/16). No statistically significant difference was found between CRPS-1 patients and HCs for CTX-I (0.3 ± 0.1 ng/ml vs 0.3 ± 0.1, p = 0.140), while mean serum values of P1NP were significantly higher in CRPS-1 patients compared to HCs (70.0 ± 38.8 ng/ml vs 50.1 ± 13.6, p = 0.005). Mean levels of sclerostin and DKK1 were lower in CRPS-1 patients vs HCs (sclerostin 28.4 ± 10.8 pmol/l vs 34.1 ± 11.6, p = 0.004; DKK1 12.9 ± 10.8 pmol/l vs 24.1 ± 11.9, p = 0.001). No statistically significant difference was found for all biochemical assessments in a subgroup of fracture-induced CRPS-1. No statistically significant differences were observed according to disease localization, disease duration, presence of hyperalgesia, allodynia, sudomotor alterations, and mild or moderate/severe swelling. No significant correlation emerged between sclerostin, DKK1 levels, baseline VAS score, or McGill Pain Questionnaire score. Bone involvement in early CRPS-1 does not seem to rely on increased osteoclast activity. Conversely, a serum marker of bone formation resulted increased. Both Sclerostin and DKK1 showed decreased values, probably suggesting a widespread osteocyte loss of function.Trial registration number: Eudract Number: 2014-001156-28.

Complex Regional Pain Syndrome in a Non-traumatic Case: A Case Report.

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.

Attention and Interoception Alter Perceptual and Neural Pain Signatures-A Case Study.

Introduction: Fluctuations of chronic pain levels are determined by a complex interplay of cognitive, emotional and perceptual variables. We introduce a pain tracking platform composed of wearable neurotechnology and a smartphone application to measure and predict chronic pain levels and its interplay with other dimensions of experience. Methods: Our method measures, dynamically and at home, pain strength, phenomenal and neural time series collected with an online tool and low-density EEG. Here we used data from a single participant who performed an attention task at home for a period of 20 days to investigate the role of attention to different bodily systems in chronic pain. Results: We show a relationship between emotions and pain strength while allocating attention to the heartbeat, the breathing, the affected or the unaffected limb. We found that pain was maximal when attending to the affected limb and decreased when the participant focused on his breathing or his heartbeat. These results provide interesting insights regarding the role of attention to interoceptive signals in chronic pain. We found power changes in the delta, theta, alpha and beta (but not in the gamma) band between the four attention conditions. However, there was no reliable association of these changes to pain intensity ratings. Theta power was higher when attention was directed to the unaffected limb compared to the others. Further, the pain ratings, when attending to unaffected limb, were associated with alpha and theta power band changes. Conclusion: Overall, we demonstrate that our neurophysiology and experience tracking platform can capture how body attention allocation alters the dynamics of subjective measures and its neural correlates. This research approach is proof of concept for the development of personalized clinical assessment tools and a testbed for behavioural, subjective and biomarkers characterization.

The role of fatigue in patients with complex regional pain syndrome.

BACKGROUND AND PURPOSE: Fatigue affects patients across a variety of neurological diseases, including chronic pain syndromes such as complex regional pain syndrome (CRPS). In CRPS, fatigue is often underestimated, as the focus lies in the assessment and managing of pain and sensorimotor deficits. This study aimed to investigate the prevalence, characteristics, and influence of fatigue on CRPS severity and quality of life in these patients. Such insights could enhance the clinical management of this challenging condition. METHODS: In this prospective study, 181 CRPS patients and 141 age and gender-matched individuals with injury but without chronic pain were interviewed using the Fatigue Scale for Motor and Cognitive Function to assess fatigue. Depressive symptoms and quality of life (QoL) were also evaluated as additional outcome measures. Statistical analysis was performed to examine differences in fatigue prevalence between the groups, as well as associations with CRPS severity, pain levels, and clinical phenotype. In addition, best subsets regression was used to identify the primary factors influencing QoL. Fatigue was tested in a mediation analysis as a mediator between pain and depression. RESULTS: CRPS patients showed significantly higher fatigue levels compared to controls (CRPS: 75 [IQR: 57-85] vs. controls: 39 [IQR: 25-57]). Based on the FSMC, 44.2% in the control group experienced fatigue, while 85% of patients with CRPS experienced fatigue (p < 0.001), of which 6% were mild, 15% moderate, and 67% severe. In CRPS severe fatigue was associated with higher pain intensities compared to no fatigue (pain at rest: p = 0.003; pain during movement: p = 0.007) or moderate fatigue (pain during movement: p = 0.03). QoL in our cohort was mainly influenced by pain (pain during movement: adj.R2 = 0.38; p < 0.001, pain at rest: Δadj.R2 = 0.02, p = 0.007) and depressive symptoms (Δadj.R2 = 0.12, p < 0.001). Subsequent analyses indicated that pain and depressive symptoms primarily impact QoL in CPRS whereas fatigue may exert an indirect influence by mediating the connection between pain and depression (p < 0.001). CONCLUSIONS: This pioneering study investigates the prevalence of fatigue in CRPS patients and its relation to disease characteristics. Our results indicate a high prevalence of severe fatigue, strongly correlated with pain intensity, and its importance in the interaction between pain and depression in CRPS. These findings underscore the significant role of fatigue as a disease factor in CRPS. Therefore, the evaluation of CRPS-related disability should include a standardized assessment of fatigue for comprehensive clinical management.

Exploring Ascorbic Acid's Role in Orthopedic Practices: Present Theories, Innovative Approaches, and Prospects.

In the human body, ascorbic acid (AA) is known for its potent antioxidant and reducing properties and also plays a vital role in supporting the growth of bones and cartilage. It has been used extensively in orthopedic surgery. Ongoing studies under the umbrella of ascorbic acid research investigate its impact on bone and tendon physiology, as well as its influence on joint replacement and postoperative pain. The majority of both laboratory and human studies link the usage of ascorbic acid to enhanced bone health and improved tendon healing. Recent literature suggest that ascorbic acid administration may have a positive impact on the outcome of orthopedic procedures. On the other hand, controversy exists regarding the efficacy of ascorbic acid in reducing the incidence of complex regional pain syndrome. In brief, the effectiveness of ascorbic acid in enhancing orthopedic procedure outcomes remains a subject of ongoing investigation. Although certain studies have hinted at the potential positive influence of ascorbic acid on these outcomes, further research is required to validate its effectiveness and ascertain the ideal dosage and method of administration for maximizing its anticipated advantages. To establish the efficacy of ascorbic acid in improving orthopedic procedure outcomes, rigorous human trials of high quality are imperative. The aim of this review was to provide an overview of ascorbic acid's utilization in orthopedic practices and to pinpoint prospective areas for future research.

Targeted Nerve Root Stimulation Alleviates Intractable Chronic Limb Pain Associated with Complex Regional Pain Syndrome - A Prospective Multi-Center Feasibility Study.

BACKGROUND: There are limited therapeutic options to treat complex regional pain syndrome (CRPS). Spinal cord stimulation and dorsal root ganglion stimulation are proven therapies for treating chronic low limb pain in CRPS patients. There is limited evidence that stimulation of dorsal nerve roots can also provide relief of lower limb pain in these patients. OBJECTIVES: To demonstrate that electrical stimulation of dorsal nerve roots via epidural lead placement provides relief of chronic lower limb pain in patients suffering from CRPS. STUDY DESIGN: Prospective, open label, single arm, multi-center study. SETTING: The study was performed at the Center for Interventional Pain and Spine (Exton, PA), Millennium Pain Center (Bloomington, IL), and the Carolinas Pain Center (Huntersville, NC). It was approved by the Western Institutional Review Board-Copernicus Group Institutional Review Board and is registered at clinicaltrials.gov (NCT03954080). METHODS: Sixteen patients with intractable chronic severe lower limb pain associated with CRPS were enrolled in the study. A standard trial period to evaluate a patients' response to stimulation of the dorsal nerve roots was conducted over 3 to 10-days. Patients that obtained 50% or greater pain relief during the trial period underwent permanent implantation of a neurostimulation system. The primary outcome was the evaluated pain level after 3 months of device activation, based on NRS pain score relative to baseline. Patients were followed up for 6 months after activation of the permanently implanted system. RESULTS: At the primary endpoint, patients reported a significant (P = 0.0006) reduction in pain of 3.3 points, improvement in quality of life, improved neuropathic pain characteristics, improved satisfaction, and an overall perception of improvement with the therapy. Improvements were sustained throughout the duration of the study up to the final 6-month visit. LIMITATIONS: Due to the COVID-19 pandemic occurring during patient enrollment, only 16 patients were enrolled and trialed, with 12 being permanently implanted. Nine were able to complete the end of study evaluation at 6 months. CONCLUSIONS: The results of this short feasibility study confirm the functionality, effectiveness, and safety of intraspinal stimulation of dorsal nerve roots in patients with intractable chronic lower limb pain due to CRPS using commercially approved systems and conventional parameters.

Complex Regional Pain Syndrome in Cancer Cases: Current Knowledge and Perspectives.

Background: Complex regional pain syndrome (CRPS) is a disabling painful disorder caused by many different and poorly understood mechanisms. It often affects the distal limbs and usually happens as consequence of a trauma. Its severity can remarkably affect patients' quality of life. When this painful complication happens in a cancer patient, the impact may be exponential. To date, there is limited knowledge of the surrounding circumstances of CRPS cases in this population. Methods: We present two clinical cases of patients diagnosed with cancer-related pain presenting with symptoms and signs compatible with CRPS. In one case, CRPS was attributed to direct tumor nerve compression, and it responded successfully to an interventional pain procedure. The second case was associated with a Zoster infection in an immunocompromised cancer patient. Patient responded to multidisciplinary pain management strategies. Additionally, we conducted a literature review to investigate the coexistence of cancer pain and CRPS and suggest some pathophysiology mechanisms of action. Results and Discussion: Literature reviewed and potential pathophysiology mechanisms are simultaneously explored in terms of classification, etiopathology, evidence, challenges, and future scientific directions. Conclusion: Comorbid CRPS can impact negatively in cases of cancer pain by affecting their diagnosis and treatment. Further studies are necessary to elucidate how these two conditions present together and how they can be better addressed.

Complex regional pain syndrome: diagnostic challenges and favorable response to prednisolone.

Complex regional pain syndrome (CRPS), characterized by severe and disproportionate pain, is a rare and debilitating condition. Due to its rarity, evidence-based treatment guidelines remain limited, creating a challenge for clinicians. We present the case of a 20-year-old female with CRPS type 1 of the right hand. Her pain, initially triggered by a minor trauma, had persisted for three months. The patient demonstrated severe pain, swelling, hyperesthesia, and restricted range of motion. Despite multiple hospital visits, her symptoms did not improve until she was diagnosed with CRPS and treated with oral prednisolone. A dosage of 40 mg daily led to a dramatic response within 10 days. Our report emphasizes the importance of recognizing CRPS and highlights the potential of prednisolone as a treatment option, particularly in resource-limited settings, where more specialized interventions may be unavailable. Further research is essential to establish a stronger evidence base for the use of steroids in CRPS management.

Sustained Relief of Complex Regional Pain Syndrome (CRPS) Pain Following a 60-Day Peripheral Nerve Stimulation: A Report of Three Cases.

Patients who present to pain clinics with complex regional pain syndrome (CRPS) typically have debilitating pain, including hyperalgesia and allodynia, and additional substantial quality-of-life concerns related to the motor and autonomic-related symptoms of CRPS. Present treatments for CRPS such as neuropathic pain medications and sympathetic blocks are often unsatisfactory for managing symptoms. The present cases highlight the use of a 60-day percutaneous peripheral nerve stimulation (PNS) treatment for three patients with CRPS Type I affecting the foot. In all three patients, the tibial and common peroneal nerves were targeted separately at the popliteal fossa with two percutaneous leads each placed a remote distance (~1 cm) from the target nerve under ultrasound guidance. All three patients reported substantial pain relief and resolution of autonomic symptoms (e.g., swelling, edema, erythema), with sustained relief lasting 8-10 months in two patients, and 34 months (as of this writing) in the third patient. There were no medical complications. These three cases suggest that 60-day PNS is a safe and efficacious treatment for CRPS.