Comparison of tonic spinal cord stimulation, high-frequency and burst stimulation in patients with complex regional pain syndrome: a double-blind, randomised placebo controlled trial

BACKGROUND: Complex Regional Pain Syndrome (CRPS) is a disabling disease that is sometimes difficult to treat. Although spinal cord stimulation (SCS) can reduce pain in most patients with CRPS, some do not achieve the desired reduction in pain. Moreover, the pain reduction can diminish over time even after an initially successful period of SCS. Pain reduction can be regained by increasing the SCS frequency, but this has not been investigated in a prospective trial. This study compares pain reduction using five SCS frequencies (standard 40 Hz, 500 Hz, 1200 Hz, burst and placebo stimulation) in patients with CRPS to determine which of the modalities is most effective. DESIGN: All patients with a confirmed CRPS diagnosis that have unsuccessfully tried all other therapies and are eligible for SCS, can enroll in this trial (primary implantation group). CRPS patients that already receive SCS therapy, or those previously treated with SCS but with loss of therapeutic effect over time, can also participate (re-implantation group). Once all inclusion criteria are met and written informed consent obtained, patients will undergo a baseline assessment (T0). A 2-week trial with SCS is performed and, if successful, a rechargeable internal pulse generator (IPG) is implanted. For the following 3 months the patient will have standard 40 Hz stimulation therapy before a follow-up assessment (T1) is performed. Those who have completed the T1 assessment will enroll in a 10-week crossover period in which the five SCS frequencies are tested in five periods, each frequency lasting for 2 weeks. At the end of the crossover period, the patient will choose which frequency is to be used for stimulation for an additional 3 months, until the T2 assessment. DISCUSSION: Currently no trials are available that systematically investigate the importance of variation in frequency during SCS in patients with CRPS. Data from this trial will provide better insight as to whether SCS with a higher frequency, or with burst stimulation, results in more effective pain relief. TRIAL REGISTRATION: Current Controlled Trials ISRCTN3665525

The reliability of side to side measurements of upper extremity activity levels in healthy subjects

<p>Abstract</p> <p>Background</p> <p>In both clinical and occupational settings, ambulatory sensors are becoming common for assessing all day measurements of arm motion. In order for the motion of a healthy, contralateral side to be used as a control for the involved side, the inherent side to side differences in arm usage must be minimal. The goal of the present study was to determine the reliability of side to side measurements of upper extremity activity levels in healthy subjects.</p> <p>Methods</p> <p>Thirty two subjects with no upper extremity pathologies were studied. Each subject wore a triaxial accelerometer on both arms for three and a half hours. Motion was assessed using parameters previously reported in the literature. Side to side differences were compared with the intraclass correlation coefficient, standard error of the mean, minimal detectable change scores and a projected sample size analysis.</p> <p>Results</p> <p>The variables were ranked based on their percentage of minimal detectable change scores and sample sizes needed for paired t-tests. The order of these rankings was found to be identical and the top ranked parameters were activity counts per hour (MDC% = 9.5, n = 5), jerk time (MDC% = 15.8, n = 8) and percent time above 30 degrees (MDC% = 34.7, n = 9).</p> <p>Conclusions</p> <p>In general, the mean activity levels during daily activities were very similar between dominant and non-dominant arms. Specifically, activity counts per hour, jerk time, and percent time above 30 degrees were found to be the variables most likely to reveal significant difference or changes in both individuals and groups of subjects. The use of ambulatory measurements of upper extremity activity has very broad uses for occupational assessments, musculoskeletal injuries of the shoulder, elbow, wrist and hand as well as neurological pathologies.</p

Cancer-ID:Toward Identification of Cancer by Tumor-Derived Extracellular Vesicles in Blood

Extracellular vesicles (EVs) have great potential as biomarkers since their composition and concentration in biofluids are disease state dependent and their cargo can contain disease-related information. Large tumor-derived EVs (tdEVs, >1μm) in blood from cancer patients are associated with poor outcome, and changes in their number can be used to monitor therapy effectiveness. Whereas, small tumor-derived EVs (<1μm) are likely to outnumber their larger counterparts, thereby offering better statistical significance, identification and quantification of small tdEVs are more challenging. In the blood of cancer patients, a subpopulation of EVs originate from tumor cells, but these EVs are outnumbered by non-EV particles and EVs from other origin. In the Dutch NWO Perspectief Cancer-ID program, we developed and evaluated detection and characterization techniques to distinguish EVs from non-EV particles and other EVs. Despite low signal amplitudes, we identified characteristics of these small tdEVs that may enable the enumeration of small tdEVs and extract relevant information. The insights obtained from Cancer-ID can help to explore the full potential of tdEVs in the clinic

Surface Plasmon Resonance Sensing Detection of Mercury and Lead Ions Based on Conducting Polymer Composite

A new sensing area for a sensor based on surface plasmon resonance (SPR) was fabricated to detect trace amounts of mercury and lead ions. The gold surface used for SPR measurements were modified with polypyrrole-chitosan (PPy-CHI) conducting polymer composite. The polymer layer was deposited on the gold surface by electrodeposition. This optical sensor was used for monitoring toxic metal ions with and without sensitivity enhancement by chitosan in water samples. The higher amounts of resonance angle unit (ΔRU) were obtained for PPy-CHI film due to a specific binding of chitosan with Pb2+ and Hg2+ ions. The Pb2+ ion bind to the polymer films most strongly, and the sensor was more sensitive to Pb2+ compared to Hg2+. The concentrations of ions in the parts per million range produced the changes in the SPR angle minimum in the region of 0.03 to 0.07. Data analysis was done by Matlab software using Fresnel formula for multilayer system

Economische en ecologische perspectieven van een dubbele dijk langs de Eems-Dollard : waarderen en verzilveren van ecosysteemdiensten en versterken van biodiversiteit bij een Multifunctionele Dubbele Keringzone voor de dijkversterking Eemshaven – Delfzijl

Dit rapport gaat in op het waarderen en verzilveren van ecosysteemdiensten en biodiversiteit in de verkenning van de haalbaarheid van een Multifunctionele Dubbele Keringzone als alternatief bij de Dijkversterking Eemshaven – Delfzijl. Het project richt zich op het waarderen van ecosysteemdiensten die worden geleverd door de voorgestelde een ‘natuurinclusieve’ dijk en de meerwaarde hiervan in termen van biodiversiteit

German translation and external validation of the Radboud Skills Questionnaire in patients suffering from Complex Regional Pain Syndrome 1

BACKGROUND: Patients suffering from Complex Regional Pain Syndrome commonly complain of substantial limitations in their activities of daily living. The Radboud Skills Questionnaire measures alterations in the level of disability of patients with Complex Regional Pain Syndrome, but this instrument is currently not available in German. The goals of our study were to translate the Dutch Radboud Skills Questionnaire into German and to assess its external criterion validity with the German version of the Disabilities of the Arm, Shoulder and Hand Questionnaire. METHODS: We translated the Radboud Skills Questionnaire according to published guidelines. Demographic data and validity were assessed in 57 consecutive patients with Complex Regional Pain Syndrome 1 of the upper extremity. Information on age, duration of symptoms, type of Complex Regional Pain Syndrome 1 and type of initiating event was obtained. We assessed the external criterion validity by comparing the German Radboud Skills Questionnaire and the German Disabilities of the Arm, Shoulder and Hand Questionnaire and calculated the prediction intervals. RESULTS: Score values ranged from 55.4 +/- 22.0 for the Disabilities of the Arm, Shoulder and Hand Questionnaire score and 140.1 +/- 39.2 for the Radboud Skills Questionnaire. We found a high correlation between the Radboud Skills Questionnaire and the Disabilities of the Arm, Shoulder and Hand Questionnaire (R2 = 0.83). CONCLUSION: This validation of the Radboud Skills Questionnaire demonstrates that this German version is a simple and accurate instrument to assess and quantify disabilities of patients suffering from Complex Regional Pain Syndrome 1 of the upper extremity for clinical and research purposes

An updated evaluation of the implementation of the sigmoid take-off landmark 1 year after the official introduction in the Netherlands

PURPOSE: The definition of rectal cancer based on the sigmoid take-off (STO) was incorporated into the Dutch guideline in 2019, and became mandatory in the national audit from December 2020. This study aimed to evaluate the use of the STO in clinical practice and the added value of online training, stratified for the period before (group A, historical cohort) and after (group B, current cohort) incorporation into the national audit.METHODS: Participants, including radiologists, surgeons, surgical and radiological residents, interns, PhD students, and physician assistants, were asked to complete an online training program, consisting of questionnaires, 20 MRI cases, and a training document. Outcomes were agreement with the expert reference, inter-rater variability, and accuracy before and after the training.RESULTS: Group A consisted of 86 participants and group B consisted of 114 participants. Familiarity with the STO was higher in group B (76% vs 88%, p = 0.027). Its use in multidisciplinary meetings was not significantly higher (50% vs 67%, p = 0.237). Agreement with the expert reference was similar for both groups before (79% vs 80%, p = 0.423) and after the training (87% vs 87%, p = 0.848). Training resulted in significant improvement for both groups in classifying tumors located around the STO (group A, 69-79%; group B, 67-79%, p &lt; 0.001).CONCLUSIONS: The results of this study show that after the inclusion of the STO in the mandatory Dutch national audit, the STO was consequently used in only 67% of the represented hospitals. Online training has the potential to improve implementation and unambiguous assessment.</p