OBJECTIVE: The objective of treatment of complex regional pain syndrome is to relieve pain and restore function in the affected limb. The aim of this study is to evaluate spinal cord stimulation as a therapy for patients diagnosed with complex regional pain syndrome, for whom adequate pain control could not be achieved with other previous treatments.
METHODS: A prospective study was conducted from 2018 to 2020. We included patients diagnosed with complex regional pain syndrome refractory to other treatments or techniques, classified by demographic data. Efficacy, functionality and opioid dependence in each patient were subsequently monitored for one year.
RESULTS: Seven of the 13 patients (53.84%) included in the study achieved significant pain relief with spinal cord stimulation. Improvements in pain and functionality were obtained, and both were statistically significant (p < 0.001 and p = 0.003, respectively). Improvement in the Oswestry Disability Index/Neck Disability Index (ODI/NDI) was significantly associated with body mass index (BMI) (p = 0.011) and was lower as BMI increased.
CONCLUSIONS: The results suggest that spinal cord stimulation is an effective therapeutic option for patients with CRPS refractory to other treatments. BMI and ODI/NDI also showed a significant correlation.
BACKGROUND: Estimulación medular en el síndrome de dolor regional complejo refractario. Un estudio prospectivo.
Introducción y objetivos. En el tratamiento del síndrome de dolor regional complejo se pretende aliviar el dolor y restaurar la función de la extremidad afectada. El objetivo de este estudio es evaluar la estimulación de la médula espinal como terapia para pacientes a quienes se les diagnosticó síndrome de dolor regional complejo, en los que no se ha podido conseguir un control adecuado del dolor con otros tratamientos previos. Pacientes y métodos. Se realizó un estudio prospectivo de 2018 a 2020. Se incluyó a pacientes diagnosticados de síndrome de dolor regional complejo refractario a otros tratamientos o técnicas, clasificados por datos demográficos. Posteriormente, se hizo seguimiento de la eficacia, la funcionalidad y la dependencia de opioides de cada paciente durante un año. Resultados. Siete de los 13 (53,84%) pacientes incluidos en el estudio consiguieron un alivio significativo de su dolor con la estimulación medular. Se obtuvo mejoría del dolor y de la funcionalidad, y ambas fueron estadísticamente significativas (p < 0,001 y p = 0,003, respectivamente). La mejoría en el Oswestry Disability Index/Neck Disability Index (ODI/NDI) se asoció significativamente con el índice de masa corporal (IMC) (p = 0,011) y fue menor cuanto mayor era el IMC. Conclusiones. Los resultados sugieren que la estimulación de la médula espinal es una opción terapéutica eficaz para pacientes con SDRC refractario a otros tratamientos. Además, el IMC y el ODI/NDI mostraron una correlación significativa.

UNASSIGNED: Complex regional pain syndrome (CRPS) presents postinjury with disproportionate pain and neuropathic, autonomic, motor symptoms, and skin texture affection. However, the origin of these multiplex changes is unclear. Skin biopsies offer a window to analyze the somatosensory and vascular system as well as skin trophicity with their protecting barriers. In previous studies, barrier-protective exosomal microRNAs were altered in CRPS. We here postulated that tissue architecture and barrier proteins are already altered at the beginning of CRPS. We analyzed ipsilateral and contralateral skin biopsies of 20 fully phenotyped early CRPS patients compared with 20 age- and sex-matched healthy controls. We established several automated unbiased methods to comprehensively analyze microvessels and somatosensory receptors as well as barrier proteins, including claudin-1, claudin-5, and claudin-19. Meissner corpuscles in the skin were bilaterally reduced in acute CRPS patients with some of them lacking these completely. The number of Merkel cells and the intraepidermal nerve fiber density were not different between the groups. Dermal papillary microvessels were bilaterally less abundant in CRPS, especially in patients with allodynia. Barrier proteins in keratinocytes, perineurium of dermal nerves, Schwann cells, and papillary microvessels were not affected in early CRPS. Bilateral changes in the tissue architecture in early CRPS might indicate a predisposition for CRPS that manifests after injury. Further studies should evaluate whether these changes might be used to identify risk patients for CRPS after trauma and as biomarkers for outcome.

BACKGROUND: The efficacy of spinal cord stimulation (SCS) in chronic pain studies is traditionally assessed by pain scores, which do not reflect the multidimensional nature of pain perception. Despite the evidence of SCS\'s influence on emotional functioning comprehensive assessments of its effect remain lacking.
OBJECTIVE: To assess changes in emotional and psychosocial functioning in patients who underwent SCS implantation for chronic pain.
METHODS: Ovid MEDLINE, EMBASE, PsychINFO, Cochrane CENTRAL and Scopus databases were searched for original peer-reviewed publications reporting emotional functioning after SCS. The primary outcomes were a pooled mean difference (MD) in anxiety, depression, global functioning, mental well-being and pain catastrophizing at 12 months. The Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) was used to determine the quality of evidence.
RESULTS: Thirty-two studies were included in the primary analysis. Statistically significant improvements were observed in anxiety (MD -2.16; 95% CI -2.84 to -1.49; p<0.001), depression (MD -4.66; 95% CI -6.26 to -3.06; p<0.001), global functioning (MD 20.30; 95% CI 14.69 to 25.90; p<0.001), mental well-being (MD 4.95; 95% CI 3.60 to 6.31; p<0.001), and pain catastrophizing (MD -12.09; 95% CI -14.94 to -9.23; p<0.001). Subgroup analyses revealed differences in Global Assessment of Functioning and mental well-being based on study design and in depression based on waveform paradigm.
CONCLUSIONS: The results highlight the statistically and clinically significant improvements in emotional and psychosocial outcomes in patients with chronic pain undergoing SCS therapy. However, these results need to be interpreted with caution due to the very low certainty of evidence per the GRADE criteria.
UNASSIGNED: CRD42023446326.

Objective  Complex regional pain syndrome (CRPS) requires further understanding. Thus, the present study aimed to analyze if pre- and intraoperative factors may be related to the development of CRPS in the postoperative period. Methods  We reviewed 1,183 medical records of patients undergoing forearm and hand surgeries from 2015 to 2021. The data of interest, that is, diagnosis, incisions, synthesis material, and anesthesia, were collected, tabulated, and statistically analyzed, with subsequent calculation of the odds ratios. Results  Most patients were female, aged between 30 and 59 years, and sought the service electively (67% of the cases). The diagnoses included soft tissue trauma (43%), bone trauma (31.6%), and compressive syndromes (25.5%). During this period, 45 (3.8%) subjects developed CRPS. The statistical analysis showed that the chance of developing CRPS is twice as high in patients with compressive syndrome, especially carpal tunnel syndrome (CTS), which represented most surgeries performed in our service (24%). Two or more incisions occurred in 7.6% of the cases, which tripled the chance of developing postoperative CRPS. Gender, age, use pf synthetic material, type of anesthesia type did not statistically increase the risk of developing postoperative CRPS. Conclusion  In short, the incidence of CRPS is low; however, it is critical to know and recognize the risk factors for prevention and active screening in the postoperative period.

BACKGROUND: Chronic pelvic pain syndrome is a complex multifactorial condition with an increasing prevalence probably due to a rising awareness. Chronic pelvic pain syndrome is pain in the pelvic area and often accompanied with complaints in other organ systems of the lesser pelvis. Patients with chronic pelvic pain syndrome who present at our center are evaluated in a standardized care pathway with an integrated multidisciplinary consultation. The team works in a single center and consists of gynecologists, pain specialists, urologists, a pelvic floor physiotherapist and a psychologist. The aim of this interview study is to evaluate the value of the multidisciplinary consultation from the patient\'s perspectives.
METHODS: In a qualitative study, we evaluated the experiences and perspectives of patients with chronic pelvic pain syndrome concerning the multidisciplinary consultation at the Radboud University Medical Center. Semistructured interviews were conducted with patients with chronic pelvic pain syndrome who attended a multidisciplinary consultation between 2019 and 2022. All interviews were transcribed verbatim, coded and analyzed via ATLAS.ti with the conventional content analysis.
RESULTS: Data saturation was reached after seven interviews, followed by three confirmative interviews. In total, 10 patients (22-76 years) participated in the study. Three relevant themes were identified in the interviews: the deleterious effects of pain on overall health, the importance of the design of the multidisciplinary consultation, and the performance of healthcare professionals (knowledge, skills and interaction with patients and colleagues). Participants suggested that although the consultation did not improve their pain experience, there was value in having a comprehensive assessment of their disease. Patients preferred the consultation to occur at the beginning of the care. Additionally, they acknowledged the performance of healthcare providers and having their complaints recognized. However, some participants suggested the need for additional attention to mental health issues during the multidisciplinary consultation.
CONCLUSIONS: Even though patients did not perceive the multidisciplinary consultation to improve their pain experience, they appreciated the sense of recognition by this team.
CONCLUSIONS: A multidisciplinary consultation is of value from the patients\' perspective. A suggestion for improvement emerged where the multidisciplinary consultation should occur at the beginning of the patient journey.

OBJECTIVE: 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.

Lumbar sympathetic ganglion neurolysis (LSGN) has been used for long-term pain relief in patients with complex regional pain syndrome (CRPS). However, the actual effect duration of LSGN has not been accurately measured. This prospective observational study measured the effect duration of LSGN in CRPS patients and investigated the relationship between temperature change and pain relief. After performing LSGN, the skin temperatures of both the maximum pain site and the plantar area in the affected and unaffected limbs were measured by infrared thermography, and pain intensity was assessed before and at 2 weeks, 1 month, and 3 months. The median time to return to baseline temperature was calculated using survival analysis. The skin temperature increased significantly at all-time points relative to baseline in both regions (maximum pain site: 1.4 °C ± 1.0 °C, plantar region: 1.28 °C ± 0.8 °C, all P < 0.001). The median time to return to baseline temperature was 12 weeks (95% confidence interval [CI] 7.7-16.3) at the maximum pain site and 12 weeks (95% CI 9.4-14.6) at the plantar area. Pain intensity decreased significantly relative to baseline, at all-time points after LSGN. In conclusion, the median duration of the LSGN is estimated to be 12 weeks.

BACKGROUND: Complex regional pain syndrome (CRPS) can profoundly affect many aspects of everyday life. Spinal cord stimulation (SCS) is a potential therapeutic option. This retrospective, single-site evaluation explored health-related quality of life (HRQoL) in individuals with CRPS treated with SCS in our Pain Service.
METHODS: All patients aged ≥18 years with fully implanted SCS for CRPS between June 2013 and January 2023 were identified from hospital records. The following data were collected: sex, age, chronic pain diagnosis, CRPS type (I or II), location of CRPS (upper or lower limb), years of CRPS before first SCS implant, SCS system, preimplant and follow-up scores for HRQoL (euroqol 5 dimensions 3 levels [EQ-5D-3L] index score), average pain, worst pain and the influence of pain on aspects of everyday life (all numerical rating scale [NRS]), patient and clinician global impression of change at follow-up, and the occurrence and reasons for revisions and explants. An intention-to-treat approach was used and data statistically analyzed.
RESULTS: The final cohort comprised 83 patients (46 women), with a median (minimum, maximum) follow-up duration of 29 months (seven, 72). There were statistically and clinically significant improvements in HRQoL, despite relatively low pain response rates. The pain response rate was 34% (reduction of ≥30% in average pain NRS); the pain remission rate was 13% (average pain score ≤3 NRS), and all patients had preimplant EQ-5D-3L index values below the population norm of 0.82. However, 60% of patients reported EQ-5D-3L index scores greater than the published minimally important difference of 0.074, and scores were better at follow-up than at preimplant (p < 0.001); 44% of patients and 41% of clinicians reported improved symptoms at the most recent follow-up. Explants occurred in eight of 83 patients (10%).
CONCLUSIONS: Patients had meaningful improvements in HRQoL, which is a key outcome in ascertaining the overall outcome of SCS in CRPS. Randomized controlled clinical trials should build on the findings to improve understanding of the benefits and risks of treating CRPS with SCS.

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.
OBJECTIVE: 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.
METHODS: Prospective, open label, single arm, multi-center study.
METHODS: 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.
CONCLUSIONS: 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.

BACKGROUND: Sympathetic ganglion block (SGB) technique is becoming increasingly prevalent in the treatment of complex regional pain syndromes (CRPS). Given the varied reported effectiveness of these techniques and the heterogeneity of treatment regimens, there is an urgent need for consistent and high-quality evidence on the efficacy and safety of such procedures.
OBJECTIVE: This study aimed to compare the efficacy of SGB therapy for CRPS-related pain.
METHODS: A meta-analysis of randomized controlled trials (RCTs).
METHODS: PubMed, EMBASE, Web of Science, CINAHL, US National Institutes of Health Clinical Trials Registry, Google Scholar, and Cochrane Library Databases were systematically searched between January 1967 and April 2023. A meta-analysis of the included RCTs on SGB was conducted to evaluate the effectiveness and risk of bias (ROBs) of SGB.
RESULTS: After screening 8523 records, 12 RCTs were included in this meta-analysis. Compared with controls, the visual analog pain score decreased by a weighted mean difference (WMD) of -6.24 mm (95% CI, -11.45, -1.03; P = 0.019) in the random-effects model, and the numerical scale score was reduced by a WMD of -1.17 mm (95% CI, -2.42, 0.08; P = 0.067) in the fixed-effects model, indicating a pain relief. The methodological quality of the included RCTs was high, with an average PEDro score of 7.0 (range: 5-9).
CONCLUSIONS: The number of included trials was limited.
CONCLUSIONS: SGB therapy can reduce pain intensity in patients with CRPS with few adverse events. However, owing to the relatively high heterogeneity of the included RCTs, a larger sample of high-quality RCTs is needed to further confirm this conclusion.