http://repub.eur.nl/res/aut/13877/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/37661/ 2012-09-17T00:00:00Z http://repub.eur.nl/res/pub/33865/ 2011-06-01T00:00:00Z Purpose: Peripheral nerve injury of the upper extremity frequently causes changes in the thermoregulatory system of the hands and fingers and leads to reports of cold intolerance. In this study, we aimed to measure the influence of median or ulnar nerve injury on cold-induced vasodilatation (CIVD) during prolonged cooling at low temperatures. Methods: We tested 12 patients with a median (n = 6) or ulnar (n = 6) injury 4 to 76 months after nerve repair. The palmar sides of both hands were cooled continuously using a cold plate at 5°C. We measured the skin temperature of the fingers using videothermography and plotted graphs of the temperature changes of the nailbed. The presence of a CIVD reaction was defined as a minimum increase in temperature of 2.5°C starting at the distal phalanx. Furthermore, we measured self-reported symptoms of cold intolerance using the Cold Intolerance Severity Scale questionnaire. Results: A CIVD reaction was absent in the affected digits of 4 patients (follow-up, 637 mo), whereas the CIVD reaction in the uninjured hand was present. The CIVD was present in 6 patients after 50 months' follow-up (range, 2476 mo). Two patients had no CIVD reaction in the injured or uninjured fingers. All patients with a CIVD response had at least diminished protective sensation. Presence of the CIVD reaction did not exclude self-reported symptoms of cold intolerance. Conclusions: After peripheral nerve injury, it is possible to recover the CIVD reaction. This might be an indication of nerve recovery. However, a positive CIVD reaction does not exclude subjective symptoms of posttraumatic cold intolerance. Type of study/level of evidence: Diagnostic III. http://repub.eur.nl/res/pub/21293/ 2010-10-01T00:00:00Z Cold induced vasoconstriction (CIVC) is a way for mammals to reduce heat loss in an effort to maintain body core temperature. As blood flow to a cooled extremity is reduced, the amount of body heat lost at the cooled location is minimised. However, when the extremity temperature gets below a certain threshold, Cold induced vasodilatation (CIVD) occurs, a phenomenon that is believed to reduce the risk of local cold injuries.Many theories explaining the mechanism of the CIVD reaction have been postulated, but no consensus has been found. One of these theories is that the CIVD reaction is controlled neurally. To study the effect of neural influence on the vascularisation and rewarming patterns a new experimental set-up was designed. This set-up is able to measure responses in both hind paws simultaneously, creating the opportunity to study the effect of nerve injury on one limb and use the contralateral limb as a control.Ten rats received a sciatic nerve transection and repair of either the left (n=5) or the right (n=5) hind limb. Measurements were performed, 1 day pre-operatively, directly post-operatively, and at days 1, 7, 14, 21, 35 and 49 post-operatively.Although results are not significant, there is a tendency for the CIVD reaction to be reduced in the nerve injured paw until the nerve is regenerated around day 35.Further investigation of neural influence on the CIVD reaction will be necessary; this set-up may prove to be useful in future experiments to elucidate the mechanism of the CIVD reaction. http://repub.eur.nl/res/pub/27379/ 2010-02-01T00:00:00Z Background: Anastomotic leakage and stricture formation remain an important surgical challenge after esophagectomy with gastric tube reconstruction for cancer of the esophagus. The perfusion of the anastomotic site at the proximal site of the gastric tube depends exclusively on the microcirculation, making it susceptible to hypoperfusion. We hypothesized that increasing the perfusion pressure would improve blood flow at the anastomotic site of the gastric tube. Methods: A gastric tube was reconstructed in 9 pigs. Laser speckle imaging and thermographic imaging were used to measure blood flow and temperature, respectively, at the base, medial part, future anastomotic site, and top of the gastric tube. Measurements were repeated at every stepwise increase of mean arterial blood pressure (MAP) from 50 to 110 mm Hg. Results: Besides MAP, global hemodynamics did not change throughout the experiment. The blood flow in the top of the gastric tube was significantly lower than the flow in the base and medial part of the gastric tube at all levels of MAP. Increasing MAP did not have a significant effect on blood flow at any location in the gastric tube. Distribution of temperature was similar to distribution of flow for the different locations. Increases in MAP did not change temperature values at any location of the gastric tube. CONCLUSION: Blood flow in the upper part of the gastric tube is decreased compared with more proximal sites. Gastric tissue blood flow does not increase with increased perfusion pressure. Therefore, it is not recommended to increase MAP to supranormal levels to increase anastomotic tissue blood flow and reduce postoperative complications. http://repub.eur.nl/res/pub/24436/ 2009-09-01T00:00:00Z The microcirculation appears to be impaired in cold chronic complex regional pain syndrome (CRPS). This double-blind, placebo-controlled, randomized trial investigated the effect of the nitric oxide (NO) donor isosorbide dinitrate (ISDN) on the peripheral blood flow in patients with chronic CRPS. Twenty-four patients received 1% ISDN in Vaseline®or a placebo ointment applied to the dorsum of the affected hand four times daily for 10 weeks. The patients participated in a physical therapy program to improve activity. The primary outcome measure was blood distribution in the affected extremity, which was determined by measuring the skin temperature using videothermography. We also measured NO and endothelin-1 concentrations in blister fluid, pain using the visual analog scale, and activity limitations using an upper limb activity monitor and the Disabilities of Arm Shoulder and Hand Questionnaire. ISDN failed to produce a significant improvement in temperature asymmetry in chronic cold CRPS patients, and it did not result in the expected reduction in pain and increase in activity compared with placebo either. There may be other central or peripheral factors contributing to the disturbed vasodynamics in cold chronic CRPS that are not influenced by NO substitution. This study does not show an improvement of the regional blood distribution by ISDN in the involved extremity of patients with cold-type CRPS. http://repub.eur.nl/res/pub/25260/ 2009-07-27T00:00:00Z Background. Surgical stress triggers an inflammatory response and releases mediators into human plasma such as interleukins (ILs). Awake craniotomy and craniotomy performed under general anesthesia may be associated with different levels of stress. Our aim was to investigate whether those procedures cause different inflammatory responses. Methods. Twenty patients undergoing craniotomy under general anesthesia and 20 patients undergoing awake function-controlled craniotomy were included in this prospective, observational, two-armed study. Circulating levels of IL-6, IL-8, and IL-10 were determined pre-, peri-, and postoperatively in both patient groups. VAS scores for pain, anxiety, and stress were taken at four moments pre- and postoperatively to evaluate physical pain and mental duress. Results. Plasma IL-6 level significantly increased with time similarly in both groups. No significant plasma IL-8 and IL-10 change was observed in both experimental groups. The VAS pain score was significantly lower in the awake group compared to the anesthesia group at 12 hours postoperative. Postoperative anxiety and stress declined similarly in both groups. Conclusion. This study suggests that awake function-controlled craniotomy does not cause a significantly different inflammatory response than craniotomy performed under general anesthesia. It is also likely that function-controlled craniotomy does not cause a greater emotional challenge than tumor resection under general anesthesia. Copyright http://repub.eur.nl/res/pub/25050/ 2009-01-01T00:00:00Z Purpose: Posttraumatic cold intolerance (CI) is a frequent and important sequel after peripheral nerve injury. In this study, it is hypothesized that altered rewarming patterns after peripheral nerve injury are related to the degree of posttraumatic CI. This hypothesis is tested by quantitatively comparing rewarming patterns of the digits in controls and in median or ulnar nerve injury patients and by investigating relationships between rewarming patterns, sensory recovery, and CI. Methods: Twelve median or ulnar nerve injury patients with a follow-up of 4 to 76 months after nerve repair and 13 control subjects had isolated cold stress testing of the hands. Video thermography was used to analyze and compare rewarming patterns of the injured and uninjured digits after cold stress testing. Temperature curves were analyzed by calculating the Q value as an indicator of heat transfer (temperature added during the first 10 minutes after start of active rewarming) and the maximum slope. Results: Test-retest reliability was 0.64 and 0.79, respectively, for the Q value and maximum slope. High Q values and maximum slopes were interpreted as the presence of active rewarming. Patients with return of active rewarming had better sensory recovery and lower Blond McIndoe Cold Intolerance Severity Scale (CISS) scores. Better sensory recovery was correlated with lower CISS scores. Conclusions: Test-retest reliability of cold stress testing was good, and we found a difference in rewarming patterns between nerve injury patients and controls. The presence of active rewarming in the nerve injury patients was related to sensory recovery and fewer complaints of posttraumatic CI. http://repub.eur.nl/res/pub/30328/ 2008-11-06T00:00:00Z Background. This double-blind, randomized, controlled trial investigated the effect of the phosphodiesterase-5 inhibitor tadalafil on the microcirculation in patients with cold Complex Regional Pain Syndrome (CRPS) in one lower extremity. Methods. Twenty-four patients received 20 mg tadalafil or placebo daily for 12 weeks. The patients also participated in a physical therapy program. The primary outcome measure was temperature difference between the CRPS side and the contralateral side, determined by measuring the skin temperature with videothermography. Secondary outcomes were: pain measured on a Visual Analogue Scale, muscle force measured with a MicroFet 2 dynamometer, and level of activity measured with an Activity Monitor (AM) and walking tests. Results. At the end of the study period, the temperature asymmetry was not significantly reduced in the tadalafil group compared with the placebo group, but there was a significant and clinically relevant reduction of pain in the tadalafil group. Muscle force improved in both treatment groups and the AM revealed small, non-significant improvements in time spent standing, walking, and the number of short walking periods. Conclusion. Tadalafil may be a promising new treatment for patients that have chronic cold CRPS due to endothelial dysfunction, and deserves further investigation. Trial Registration. The registration number in the Dutch Trial Register is ISRCTN60226869. http://repub.eur.nl/res/pub/30070/ 2008-08-01T00:00:00Z It was previously shown in a group of 9 patients with complex regional pain syndrome type 1 (CRPS1) that levels of the proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) are higher in blister fluid from the involved side. We hypothesize that local inflammation is responsible for the characteristics of CRPS1. The aim of this study was to confirm the previous observation in a large group of CRPS1 patients, repeating the measurement of TNF-α and IL-6 in blister fluid. Furthermore, we sought to determine whether these cytokines are responsible for the characteristics of CRPS1 and characterize the relationship between cytokine levels and duration of the disease. Sixty-six patients with CRPS1 participated. Skin blisters were artificially induced for measurement of cytokines in both extremities. The following disease characteristics were assessed: pain and differences in temperature, volume, and mobility between the extremities. TNF-α and IL-6 levels were significantly higher in blister fluid from the involved side. However, cytokine levels did not correlate with the characteristics or duration of the disease. Our findings confirm the presence of local inflammation in a population of 66 patients in the first 2 years of CRPS1. Proinflammatory cytokines seem to be only partly involved in the pathophysiology of CRPS1, as indicated by the lack of coherence between TNF-α and IL-6 levels and the signs and symptoms of inflammation and disease duration. Other inflammatory mediators and mechanisms, such as central sensitization, are probably involved in the early stages of CRPS1. http://repub.eur.nl/res/pub/32532/ 2008-07-22T00:00:00Z In an earlier study, levels of the proinflammatory cytokines TNF-α and IL-6 are higher in blisters fluid from the complex regional pain syndrome type 1 (CRPS1) side obtained at 6 and 30 months (median) after the initial event. The aim of this follow-up study is to determine the involvement of these cytokines in long lasting CRPS1. Twelve CRPS1 patients, with median disease duration of 72 months, participated. The levels of TNF-α and IL-6 were measured in blister fluid; disease activity was reevaluated by measuring pain and differences in temperature, volume, and mobility between both extremities. Differences in levels of IL-6 and TNF-α and mobility between both sides were significantly decreased. Pain and differences in temperature and volume were not significantly altered. No correlation was found between the cytokines and the disease characteristics. These results indicate that IL-6 and TNF-α are only partially responsible for the signs and symptoms of CRPS1. Copyright http://repub.eur.nl/res/pub/29180/ 2008-01-01T00:00:00Z OBJECTIVE: In this study, we assessed the validity of skin surface temperature recordings, based on various calculation methods applied to the thermographic data, to diagnose acute complex regional pain syndrome type 1 (CRPS1) fracture patients. METHODS: Thermographic recordings of the palmar/plantar side and dorsal side of both hands or feet were made on CRPS1 patients and in control fracture patients with/without and without complaints similar to CRPS1 (total in the three subgroups = 120) just after removal of plaster. Various calculation methods applied to the thermographic data were compared using receiver operating characteristics analysis to obtain indicators of diagnostic value. RESULTS: There were no significant differences in demographic data and characteristics among the three subgroups. The most pronounced differences among the subgroups were vasomotor signs in the CRPS1 patients. The involved side in CRPS1 patients was often warmer compared with the noninvolved extremity. The difference in temperature between the involved site and the noninvolved extremity in CRPS1 patients significantly differed from the difference in temperature between the contralateral extremities of the two control groups. The largest temperature difference between extremities was found in CRPS1 patients. The difference in temperature recordings comparing the palmar/plantar and dorsal recording was not significant in any group. The sensitivity and specificity varied considerably between the various calculation methods used to calculate temperature difference between extremities. The highest level of sensitivity was 71% and the highest specificity was 64%; the highest positive predictive value reached a value of 35% and the highest negative predictive 84%, with a moderate 0.60 ≥ area under the curve ≤ 0.65. CONCLUSION: The validity of skin surface temperature recordings under resting conditions to discriminate between acute CRPS1 fracture patients and control fracture patients with/without complaints is limited, and only useful as a supplementary diagnostic tool. http://repub.eur.nl/res/pub/29796/ 2008-01-01T00:00:00Z BACKGROUND: In complex regional pain syndrome type 1 (CRPS1) vascular changes occur from the initial, inflammatory event onto the trophic signs during chronicity of the disease, resulting in blood flow disturbances and marked temperature changes. Pharmacotherapeutic treatment is generally inadequate. AIM: To determine whether local application of the nitric oxide donor isosorbide dinitrate (ISDN) could cause vasodilation and thereby improve tissue blood distribution in the affected extremity. METHODS: In a pilot study, 5 female patients with CRPS1 in one hand were treated with ISDN ointment 4 times daily during 10 weeks. As a primary objective videothermography was used to monitor changes in blood distribution in both the involved and contralateral extremities. RESULTS: Patients treated with ISDN showed an increase of 4°C to 6°C in mean skin temperature of the cold CRPS1 hands, reaching values similar to that of the contralateral extremities within 2 to 4 weeks time, suggesting normalization of blood distribution. This was confirmed by an improvement in skin color. In 3 patients the Visual Analog Scale pain declined, whereas in the other 2 patients the Visual Analog Scale pain was unchanged over time. CONCLUSIONS: In this pilot study, topical application of ISDN seems to be beneficial to improve symptoms for patients with cold type CRPS1, but further study is needed. http://repub.eur.nl/res/pub/10704/ 2007-10-03T00:00:00Z In this thesis videothermography is developed and evaluated as a diagnostic and monitoring tool in Complex Regional Pain Syndrome type 1 (CRPS1). This work is conducted within four pre- set developmental phases: namely, the initial, potential, monitoring and diagnostic phases. Two main methods of measurement were developed and evaluated, namely: i) static videothermography: recording of a thermographic image of an extremity without application of any disturbing factors on temperature regulation and ii) dynamic videothermography: recordings of a sequence of thermographic images during application of various disturbing effects on temperature regulation of the human body. The recorded thermographic images were analysed by means of various mathematical methods and their additive value in the assessment of CRPS1 was studied. http://repub.eur.nl/res/pub/35558/ 2007-03-01T00:00:00Z http://repub.eur.nl/res/pub/14008/ 2006-05-12T00:00:00Z BACKGROUND: Complex Regional Pain Syndrome type 1 (CRPS1) is a clinical diagnosis based on criteria describing symptoms of the disease.The main aim of the present study was to compare the sensitivity and specificity of calculation methods used to assess thermographic images (infrared imaging) obtained during temperature provocation. The secondary objective was to obtain information about the involvement of the sympathetic system in CRPS1. METHODS: We studied 12 patients in whom CRPS1 was diagnosed according to the criteria of Bruehl. High and low whole body cooling and warming induced and reduced sympathetic vasoconstrictor activity. The degree of vasoconstrictor activity in both hands was monitored using a videothermograph. The sensitivity and specificity of the calculation methods used to assess the thermographic images were calculated. RESULTS: The temperature difference between the hands in the CRPS patients increases significantly when the sympathetic system is provoked. At both the maximum and minimum vasoconstriction no significant differences were found in fingertip temperatures between both hands. CONCLUSION: The majority of CRPS1 patients do not show maximal obtainable temperature differences between the involved and contralateral extremity at room temperature (static measurement). During cold and warm temperature challenges this temperature difference increases significantly. As a result a higher sensitivity and specificity could be achieved in the diagnosis of CRPS1. These findings suggest that the sympathetic efferent system is involved in CRPS1.