Ruud Vermeulen - Academia.edu (original) (raw)
Papers by Ruud Vermeulen
Fatigue: Biomedicine, Health & Behavior, Oct 1, 2020
Background:Past research has found high rates of hyperventilation in patients with Myalgic Enceph... more Background:Past research has found high rates of hyperventilation in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), but hyperventilation can be influenced by psychological factors. Clinical respiratory rates have been less frequently assessed.Aim:This study aimed to identify the predictors of rapid respiratory rates in patients referred to an outpatient clinic specializing in ME/CFS.Methods:Adults (n = 216) referred to an outpatient clinic specializing in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) participated in a two-day cardiopulmonary exercise test. As part of that evaluation, subjects had resting respiratory rates measured on two consecutive days. The current study used questionnaires to assess the relationship between tachypnea (rapid respiratory rates) and a variety of domains including post-exertional malaise (PEM), a common complaint in patients with ME/CFS, and psychiatric/somatic symptoms, using hierarchical logistic regression analysis.Results:PEM was a significant predictor of tachypnea, while psychological/somatic assessments and sedentary behaviors were not significantly predictive of tachypnea.Conclusions:These findings suggest that respiratory rate may be useful as an objective clinical metric of PEM, and potentially ME/CFS.
PubMed, Oct 1, 2003
Objective: To compare symptoms of women with silicone gel breast implants and women with chronic ... more Objective: To compare symptoms of women with silicone gel breast implants and women with chronic fatigue syndrome (CFS), and to study the effect of rupture of the silicone implant. Methods: Five hundred readers of the Dutch silicone breast implant support group magazine were asked to respond if they had been informed by the surgeon about the silicone implant status at operation, and to answer questions about symptoms of CFS. Their complaints were compared with those of 100 female patients with CFS and 40 female controls. Results: The questionnaires were returned by 319 women. Of these, 227 had symptoms of debilitating chronic fatigue. The patterns of symptoms differed from those in patients with CFS. An analysis of the relation between integrity of the implants and the symptoms could be carried out in 176 women, and 74% of these latter women reported ruptured implants. Significantly more women with ruptured implants than those with intact implants had debilitating chronic fatigue (75% vs 51%), postexertional malaise > 24 h (77% vs 51%), impaired short term memory (58% vs 38%), and multi-joint pain (77% vs 60%). Conclusion: Women with silicone breast implants often report severe pain and chronic fatigue. Rupture of the implant is associated with an increase in symptoms of pain and chronic fatigue.
Journal of Translational Medicine, Jun 1, 2006
Background: CFS is a clinical state with defined symptoms, but undefined cause. The patients may ... more Background: CFS is a clinical state with defined symptoms, but undefined cause. The patients may show a chronic state of immune activation and treatment with an antibiotic in this subgroup has been suggested. Methods: In a retrospective study, the response of CFS patients to azithromycin, an antibiotic and immunomodulating drug, has been scored from the patients records and compared with clinical and laboratory data. Azithromycin was not the first choice therapy, but offered when the effect of counseling and L-carnitine was considered insufficient by the patient and the clinician. Results: Of the 99 patients investigated, 58 reported a decrease in the symptoms by the use of azithromycin. These responding patients had lower levels of plasma acetylcarnitine. Conclusion: The efficacy of azithromycin in the responsive patients could be explained by the modulating effect on a chronic primed state of the immune cells of the brain, or the activated peripheral immune system. Their lower acetylcarnitine levels may reflect a decreased antioxidant defense and/or an increased consumption of acetylcarnitine caused by oxidative stress.
Journal of Psychosomatic Research, Feb 1, 2004
The study was undertaken to determine if ambulant female patients with the chronic fatigue syndro... more The study was undertaken to determine if ambulant female patients with the chronic fatigue syndrome (CFS) report problems with their sexual functioning. We studied 35 female CFS patients and 36 healthy female controls. The severity of CFS was measured with a fatigue questionnaire and the presence and severity of sexual dysfunction with a questionnaire about sexual functioning. The mean fatigue score was 24.8 in the CFS patients and 11.9 in the controls (P=.000). No increase in sexual dysfunction was found in the CFS group. The control group showed negative correlations between the score of the fatigue questionnaire and the frequency of "sexual fantasies," "(desire for) sexual contact" and "satisfaction with sex life." Such correlations were absent in the CFS group. The satisfaction with sex life was similar in patients and controls. The results suggest that patients and controls have a different perception of fatigue.
Journal of Translational Medicine, 2014
Background: The insufficient metabolic adaptation to exercise in Chronic Fatigue Syndrome (CFS) i... more Background: The insufficient metabolic adaptation to exercise in Chronic Fatigue Syndrome (CFS) is still being debated and poorly understood. Methods: We analysed the cardiopulmonary exercise tests of CFS patients, idiopathic chronic fatigue (CFI) patients and healthy visitors. Continuous non-invasive measurement of the cardiac output by Nexfin ® (BMEYE B.V. Amsterdam, the Netherlands) was added to the cardiopulmonary exercise tests. The peak oxygen extraction by muscle cells and the increase of cardiac output relative to the increase of oxygen uptake (ΔQ'/ΔV'O 2) were measured, calculated from the cardiac output and the oxygen uptake during incremental exercise. Results: The peak oxygen extraction by muscle cells was 10.83 ± 2.80 ml/100ml in 178 CFS women, 11.62 ± 2.90 ml/ 100 ml in 172 CFI, and 13.45 ± 2.72 ml/100 ml in 11 healthy women (ANOVA: P=0.001), 13.66 ± 3.31 ml/100 ml in 25 CFS men, 14.63 ± 4.38 ml/100 ml in 51 CFI, and 19.52 ± 6.53 ml/100 ml in 7 healthy men (ANOVA: P=0.008). The ΔQ'/ΔV'O 2 was > 6 L/L (normal ΔQ'/ΔV'O 2 ≈ 5 L/L) in 70% of the patients and in 22% of the healthy group. Conclusion: Low oxygen uptake by muscle cells causes exercise intolerance in a majority of CFS patients, indicating insufficient metabolic adaptation to incremental exercise. The high increase of the cardiac output relative to the increase of oxygen uptake argues against deconditioning as a cause for physical impairment in these patients.
Population Health Metrics, Oct 18, 2006
Background: In a study by Wagner et al., the CDC Symptom Inventory was validated in a population ... more Background: In a study by Wagner et al., the CDC Symptom Inventory was validated in a population selected from the inhabitants of a city in the USA, and proofed reliable for the assessment of the accompanying symptoms of CFS. The Dutch translation of the CDC Symptom Inventory is compared to the original and the psychometric properties are presented for patients in a tertiary care setting. Methods: One hundred thirty-nine consecutive patients who visited the CFS Center Amsterdam for the first time were asked to complete the CDC Symptom Inventory in the Dutch Language Version (DLV) together with the usual set of questionnaires. Sixty-one patients had Chronic Fatigue (CF) and 78 patients fulfilled the criteria for CFS. Forty-three healthy accompanying persons completed the CDC Symptom Inventory DLV, the Physical Functioning scale of the Medical Outcome Survey Short Form-36 DLV, and the Fatigue and Concentration scales of the Checklist Individual Strength (CIS-20). Results: The healthy controls group contained fewer women and was overall older than the patient groups. The influence of gender on the CDC Symptom Inventory DLV was significant but the effect of age was not. The Dutch version had a good internal consistency and convergent validity. The results were comparable to the original English version, but the sex-related difference needs further study. Conclusion: The Dutch version of the CDC Symptom Inventory is a reliable tool for the assessment of the secondary criteria for CFS. The results show that it is comparable to the outcome of studies in English speaking countries.
Psychosomatic Medicine, Mar 1, 2004
We compared the effects of acetylcarnitine, propionylcarnitine and both compounds on the symptoms... more We compared the effects of acetylcarnitine, propionylcarnitine and both compounds on the symptoms of chronic fatigue syndrome (CFS). In an open, randomized fashion we compared 2 g/d acetyl-L-carnitine, 2 g/d propionyl-L-carnitine, and its combination in 3 groups of 30 CFS patients during 24 weeks. Effects were rated by clinical global impression of change. Secondary endpoints were the Multidimensional Fatigue Inventory, McGill Pain Questionnaire, and the Stroop attention concentration test. Scores were assessed 8 weeks before treatment; at randomization; after 8, 16, and 24 weeks of treatment; and 2 weeks later. Clinical global impression of change after treatment showed considerable improvement in 59% of the patients in the acetylcarnitine group and 63% in the propionylcarnitine group, but less in the acetylcarnitine plus propionylcarnitine group (37%). Acetylcarnitine significantly improved mental fatigue (p =.015) and propionylcarnitine improved general fatigue (p =.004). Attention concentration improved in all groups, whereas pain complaints did not decrease in any group. Two weeks after treatment, worsening of fatigue was experienced by 52%, 50%, and 37% in the acetylcarnitine, propionylcarnitine, and combined group, respectively. In the acetylcarnitine group, but not in the other groups, the changes in plasma carnitine levels correlated with clinical improvement. Acetylcarnitine and propionylcarnitine showed beneficial effect on fatigue and attention concentration. Less improvement was found by the combined treatment. Acetylcarnitine had main effect on mental fatigue and propionylcarnitine on general fatigue.
Clinical Neurophysiology, 2021
In chronic fatigue patients, muscle conduction increases abnormally with force. Surface EMG can e... more In chronic fatigue patients, muscle conduction increases abnormally with force. Surface EMG can elicit abnormalities in both fibromyalgia and chronic fatigue. The surface EMG abnormalities in fibromyalgia and chronic fatigue differ. a b s t r a c t Objective: Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are disorders of unknown etiology and unclear pathophysiology, with overlapping symptoms of-especially muscular-fatigue and pain. Studies have shown increased muscle fiber conduction velocity (CV) in the non-painful muscles of FM patients. We investigated whether CFS patients also show CV abnormalities. Methods: Females with CFS (n = 25), with FM (n = 22), and healthy controls (n = 21) underwent surface electromyography of the biceps brachii, loaded up to 20% of maximum strength, during short static contractions. The mean CV and motor unit potential (MUP) velocities with their statistical distribution were measured. Results: The CV changes with force differed between CFS-group and both FM-group and controls (P = 0.01). The CV of the CFS-group increased excessively with force (P < 0.001), whereas that of the controls increased only slightly and non-significantly, and that of the FM-group did not increase at all. In the CFS-group, the number of MUPs conveying very high conduction velocities increased abundantly with force and the MUPs narrowed. Conclusion: Our results suggest disturbed muscle membrane function in CFS patients, in their motor units involved in low force generation. Central neural deregulation may contribute to this disturbance. Significance: These findings help to detangle the underlying mechanisms of CFS.
Netherlands Heart Journal, 2016
Objective In chronic fatigue syndrome (CFS), only a few imaging and histopathological studies hav... more Objective In chronic fatigue syndrome (CFS), only a few imaging and histopathological studies have previously assessed either cardiac dimensions/function or myocardial tissue, suggesting smaller left ventricular (LV) dimensions, LV wall motion abnormalities and occasionally viral persistence that may lead to cardiomyopathy. The present study with cardiac magnetic resonance (CMR) imaging is the first to use a contrast-enhanced approach to assess cardiac involvement, including tissue characterisation of the LV wall. Methods CMR measurements of 12 female CFS patients were compared with data of 36 age-matched, healthy female controls. With cine imaging, LV volumes, ejection fraction (EF), mass, and wall motion abnormalities were assessed. T2-weighted images were analysed for increased signal intensity, reflecting oedema (i. e. inflammation). In addition, the presence of contrast enhancement, reflecting fibrosis (i. e. myocardial damage), was analysed. Results When comparing CFS patients and healthy controls, LVEF (57.9 ± 4.3 % vs. 63.7 ± 3.7 %; p < 0.01), end-C. von Birgelen
Patients with chronic fatigue syndrome performed worse than controls in a controlled repeated exe... more Patients with chronic fatigue syndrome performed worse than controls in a controlled repeated exercise study despite a normal oxidative phosphorylation capacity
which permits unrestricted use, distribution, and reproduction in any medium, provided the origin... more which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: In a study by Wagner et al., the CDC Symptom Inventory was validated in a population selected from the inhabitants of a city in the USA, and proofed reliable for the assessment of the accompanying symptoms of CFS. The Dutch translation of the CDC Symptom Inventory is compared to the original and the psychometric properties are presented for patients in a tertiary care setting. Methods: One hundred thirty-nine consecutive patients who visited the CFS Center Amsterdam for the first time were asked to complete the CDC Symptom Inventory in the Dutch Language Version (DLV) together with the usual set of questionnaires. Sixty-one patients had Chronic Fatigue (CF) and 78 patients fulfilled the criteria for CFS. Forty-three healthy accompanying persons completed the CDC Symptom Inventory DLV, the Physical Functioning scale of the Medical Outcome Survey Shor...
Journal of Translational Medicine, 2010
The Journal of rheumatology, 2003
OBJECTIVE To compare symptoms of women with silicone gel breast implants and women with chronic f... more OBJECTIVE To compare symptoms of women with silicone gel breast implants and women with chronic fatigue syndrome (CFS), and to study the effect of rupture of the silicone implant. METHODS Five hundred readers of the Dutch silicone breast implant support group magazine were asked to respond if they had been informed by the surgeon about the silicone implant status at operation, and to answer questions about symptoms of CFS. Their complaints were compared with those of 100 female patients with CFS and 40 female controls. RESULTS The questionnaires were returned by 319 women. Of these, 227 had symptoms of debilitating chronic fatigue. The patterns of symptoms differed from those in patients with CFS. An analysis of the relation between integrity of the implants and the symptoms could be carried out in 176 women, and 74% of these latter women reported ruptured implants. Significantly more women with ruptured implants than those with intact implants had debilitating chronic fatigue (75% ...
Fatigue: Biomedicine, Health & Behavior
Population health metrics, 2006
In a study by Wagner et al., the CDC Symptom Inventory was validated in a population selected fro... more In a study by Wagner et al., the CDC Symptom Inventory was validated in a population selected from the inhabitants of a city in the USA, and proofed reliable for the assessment of the accompanying symptoms of CFS. The Dutch translation of the CDC Symptom Inventory is compared to the original and the psychometric properties are presented for patients in a tertiary care setting. One hundred thirty-nine consecutive patients who visited the CFS Center Amsterdam for the first time were asked to complete the CDC Symptom Inventory in the Dutch Language Version (DLV) together with the usual set of questionnaires. Sixty-one patients had Chronic Fatigue (CF) and 78 patients fulfilled the criteria for CFS. Forty-three healthy accompanying persons completed the CDC Symptom Inventory DLV, the Physical Functioning scale of the Medical Outcome Survey Short Form-36 DLV, and the Fatigue and Concentration scales of the Checklist Individual Strength (CIS-20). The healthy controls group contained fewer...
American Journal of Obstetrics and Gynecology, Jan 12, 1985
Placentas after uneventful pregnancies were perfused under physiologic pressure in the fetal vess... more Placentas after uneventful pregnancies were perfused under physiologic pressure in the fetal vessels, expanded to their predelivery volume, fixated with 4% formaldehyde, and compared to their ultrasound images in pregnancy. The placentas showed a side arrangement of the fetal cotyledons in contact with the basal plate. The centers of the cotyledons showed an empty space in which the spiral arteries ended. These spaces in the placenta corresponded with transonic areas of ultrasound. The central spaces were surrounded by a relatively dense shell of villi containing the more or less fibrotic stem villi. This explained the areas of increased echo-density, as seen by ultrasound during the last trimester of pregnancy. The fetal cotyledons, composed of a central cavity and a dense villous shell, were separated by a reticular area. The veins ended at the basal plate in these intercotyledonary areas. (AM J OssrET GvNECOL 1985;153:806-10.)
Journal of translational medicine, 2006
CFS is a clinical state with defined symptoms, but undefined cause. The patients may show a chron... more CFS is a clinical state with defined symptoms, but undefined cause. The patients may show a chronic state of immune activation and treatment with an antibiotic in this subgroup has been suggested. In a retrospective study, the response of CFS patients to azithromycin, an antibiotic and immunomodulating drug, has been scored from the patients records and compared with clinical and laboratory data. Azithromycin was not the first choice therapy, but offered when the effect of counseling and L-carnitine was considered insufficient by the patient and the clinician. Of the 99 patients investigated, 58 reported a decrease in the symptoms by the use of azithromycin. These responding patients had lower levels of plasma acetylcarnitine. The efficacy of azithromycin in the responsive patients could be explained by the modulating effect on a chronic primed state of the immune cells of the brain, or the activated peripheral immune system. Their lower acetylcarnitine levels may reflect a decrease...
Psychosomatic medicine
We compared the effects of acetylcarnitine, propionylcarnitine and both compounds on the symptoms... more We compared the effects of acetylcarnitine, propionylcarnitine and both compounds on the symptoms of chronic fatigue syndrome (CFS). In an open, randomized fashion we compared 2 g/d acetyl-L-carnitine, 2 g/d propionyl-L-carnitine, and its combination in 3 groups of 30 CFS patients during 24 weeks. Effects were rated by clinical global impression of change. Secondary endpoints were the Multidimensional Fatigue Inventory, McGill Pain Questionnaire, and the Stroop attention concentration test. Scores were assessed 8 weeks before treatment; at randomization; after 8, 16, and 24 weeks of treatment; and 2 weeks later. Clinical global impression of change after treatment showed considerable improvement in 59% of the patients in the acetylcarnitine group and 63% in the propionylcarnitine group, but less in the acetylcarnitine plus propionylcarnitine group (37%). Acetylcarnitine significantly improved mental fatigue (p =.015) and propionylcarnitine improved general fatigue (p =.004). Attenti...
The Journal of rheumatology, 2003
To compare symptoms of women with silicone gel breast implants and women with chronic fatigue syn... more To compare symptoms of women with silicone gel breast implants and women with chronic fatigue syndrome (CFS), and to study the effect of rupture of the silicone implant. Five hundred readers of the Dutch silicone breast implant support group magazine were asked to respond if they had been informed by the surgeon about the silicone implant status at operation, and to answer questions about symptoms of CFS. Their complaints were compared with those of 100 female patients with CFS and 40 female controls. The questionnaires were returned by 319 women. Of these, 227 had symptoms of debilitating chronic fatigue. The patterns of symptoms differed from those in patients with CFS. An analysis of the relation between integrity of the implants and the symptoms could be carried out in 176 women, and 74% of these latter women reported ruptured implants. Significantly more women with ruptured implants than those with intact implants had debilitating chronic fatigue (75% vs 51%), postexertional ma...
American journal of obstetrics and gynecology, 1985
Placentas after uneventful pregnancies were perfused under physiologic pressure in the fetal vess... more Placentas after uneventful pregnancies were perfused under physiologic pressure in the fetal vessels, expanded to their predelivery volume, fixated with 4% formaldehyde, and compared to their ultrasound images in pregnancy. The placentas showed a side arrangement of the fetal cotyledons in contact with the basal plate. The centers of the cotyledons showed an empty space in which the spiral arteries ended. These spaces in the placenta corresponded with transsonic areas of ultrasound. The central spaces were surrounded by a relatively dense shell of villi containing the more or less fibrotic stem villi. This explained the areas of increased echo-density, as seen by ultrasound during the last trimester of pregnancy. The fetal cotyledons, composed of a central cavity and a dense villous shell, were separated by a reticular area. The veins ended at the basal plate in these intercotyledonary areas.
Fatigue: Biomedicine, Health & Behavior, Oct 1, 2020
Background:Past research has found high rates of hyperventilation in patients with Myalgic Enceph... more Background:Past research has found high rates of hyperventilation in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), but hyperventilation can be influenced by psychological factors. Clinical respiratory rates have been less frequently assessed.Aim:This study aimed to identify the predictors of rapid respiratory rates in patients referred to an outpatient clinic specializing in ME/CFS.Methods:Adults (n = 216) referred to an outpatient clinic specializing in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) participated in a two-day cardiopulmonary exercise test. As part of that evaluation, subjects had resting respiratory rates measured on two consecutive days. The current study used questionnaires to assess the relationship between tachypnea (rapid respiratory rates) and a variety of domains including post-exertional malaise (PEM), a common complaint in patients with ME/CFS, and psychiatric/somatic symptoms, using hierarchical logistic regression analysis.Results:PEM was a significant predictor of tachypnea, while psychological/somatic assessments and sedentary behaviors were not significantly predictive of tachypnea.Conclusions:These findings suggest that respiratory rate may be useful as an objective clinical metric of PEM, and potentially ME/CFS.
PubMed, Oct 1, 2003
Objective: To compare symptoms of women with silicone gel breast implants and women with chronic ... more Objective: To compare symptoms of women with silicone gel breast implants and women with chronic fatigue syndrome (CFS), and to study the effect of rupture of the silicone implant. Methods: Five hundred readers of the Dutch silicone breast implant support group magazine were asked to respond if they had been informed by the surgeon about the silicone implant status at operation, and to answer questions about symptoms of CFS. Their complaints were compared with those of 100 female patients with CFS and 40 female controls. Results: The questionnaires were returned by 319 women. Of these, 227 had symptoms of debilitating chronic fatigue. The patterns of symptoms differed from those in patients with CFS. An analysis of the relation between integrity of the implants and the symptoms could be carried out in 176 women, and 74% of these latter women reported ruptured implants. Significantly more women with ruptured implants than those with intact implants had debilitating chronic fatigue (75% vs 51%), postexertional malaise > 24 h (77% vs 51%), impaired short term memory (58% vs 38%), and multi-joint pain (77% vs 60%). Conclusion: Women with silicone breast implants often report severe pain and chronic fatigue. Rupture of the implant is associated with an increase in symptoms of pain and chronic fatigue.
Journal of Translational Medicine, Jun 1, 2006
Background: CFS is a clinical state with defined symptoms, but undefined cause. The patients may ... more Background: CFS is a clinical state with defined symptoms, but undefined cause. The patients may show a chronic state of immune activation and treatment with an antibiotic in this subgroup has been suggested. Methods: In a retrospective study, the response of CFS patients to azithromycin, an antibiotic and immunomodulating drug, has been scored from the patients records and compared with clinical and laboratory data. Azithromycin was not the first choice therapy, but offered when the effect of counseling and L-carnitine was considered insufficient by the patient and the clinician. Results: Of the 99 patients investigated, 58 reported a decrease in the symptoms by the use of azithromycin. These responding patients had lower levels of plasma acetylcarnitine. Conclusion: The efficacy of azithromycin in the responsive patients could be explained by the modulating effect on a chronic primed state of the immune cells of the brain, or the activated peripheral immune system. Their lower acetylcarnitine levels may reflect a decreased antioxidant defense and/or an increased consumption of acetylcarnitine caused by oxidative stress.
Journal of Psychosomatic Research, Feb 1, 2004
The study was undertaken to determine if ambulant female patients with the chronic fatigue syndro... more The study was undertaken to determine if ambulant female patients with the chronic fatigue syndrome (CFS) report problems with their sexual functioning. We studied 35 female CFS patients and 36 healthy female controls. The severity of CFS was measured with a fatigue questionnaire and the presence and severity of sexual dysfunction with a questionnaire about sexual functioning. The mean fatigue score was 24.8 in the CFS patients and 11.9 in the controls (P=.000). No increase in sexual dysfunction was found in the CFS group. The control group showed negative correlations between the score of the fatigue questionnaire and the frequency of &amp;amp;amp;amp;amp;quot;sexual fantasies,&amp;amp;amp;amp;amp;quot; &amp;amp;amp;amp;amp;quot;(desire for) sexual contact&amp;amp;amp;amp;amp;quot; and &amp;amp;amp;amp;amp;quot;satisfaction with sex life.&amp;amp;amp;amp;amp;quot; Such correlations were absent in the CFS group. The satisfaction with sex life was similar in patients and controls. The results suggest that patients and controls have a different perception of fatigue.
Journal of Translational Medicine, 2014
Background: The insufficient metabolic adaptation to exercise in Chronic Fatigue Syndrome (CFS) i... more Background: The insufficient metabolic adaptation to exercise in Chronic Fatigue Syndrome (CFS) is still being debated and poorly understood. Methods: We analysed the cardiopulmonary exercise tests of CFS patients, idiopathic chronic fatigue (CFI) patients and healthy visitors. Continuous non-invasive measurement of the cardiac output by Nexfin ® (BMEYE B.V. Amsterdam, the Netherlands) was added to the cardiopulmonary exercise tests. The peak oxygen extraction by muscle cells and the increase of cardiac output relative to the increase of oxygen uptake (ΔQ'/ΔV'O 2) were measured, calculated from the cardiac output and the oxygen uptake during incremental exercise. Results: The peak oxygen extraction by muscle cells was 10.83 ± 2.80 ml/100ml in 178 CFS women, 11.62 ± 2.90 ml/ 100 ml in 172 CFI, and 13.45 ± 2.72 ml/100 ml in 11 healthy women (ANOVA: P=0.001), 13.66 ± 3.31 ml/100 ml in 25 CFS men, 14.63 ± 4.38 ml/100 ml in 51 CFI, and 19.52 ± 6.53 ml/100 ml in 7 healthy men (ANOVA: P=0.008). The ΔQ'/ΔV'O 2 was > 6 L/L (normal ΔQ'/ΔV'O 2 ≈ 5 L/L) in 70% of the patients and in 22% of the healthy group. Conclusion: Low oxygen uptake by muscle cells causes exercise intolerance in a majority of CFS patients, indicating insufficient metabolic adaptation to incremental exercise. The high increase of the cardiac output relative to the increase of oxygen uptake argues against deconditioning as a cause for physical impairment in these patients.
Population Health Metrics, Oct 18, 2006
Background: In a study by Wagner et al., the CDC Symptom Inventory was validated in a population ... more Background: In a study by Wagner et al., the CDC Symptom Inventory was validated in a population selected from the inhabitants of a city in the USA, and proofed reliable for the assessment of the accompanying symptoms of CFS. The Dutch translation of the CDC Symptom Inventory is compared to the original and the psychometric properties are presented for patients in a tertiary care setting. Methods: One hundred thirty-nine consecutive patients who visited the CFS Center Amsterdam for the first time were asked to complete the CDC Symptom Inventory in the Dutch Language Version (DLV) together with the usual set of questionnaires. Sixty-one patients had Chronic Fatigue (CF) and 78 patients fulfilled the criteria for CFS. Forty-three healthy accompanying persons completed the CDC Symptom Inventory DLV, the Physical Functioning scale of the Medical Outcome Survey Short Form-36 DLV, and the Fatigue and Concentration scales of the Checklist Individual Strength (CIS-20). Results: The healthy controls group contained fewer women and was overall older than the patient groups. The influence of gender on the CDC Symptom Inventory DLV was significant but the effect of age was not. The Dutch version had a good internal consistency and convergent validity. The results were comparable to the original English version, but the sex-related difference needs further study. Conclusion: The Dutch version of the CDC Symptom Inventory is a reliable tool for the assessment of the secondary criteria for CFS. The results show that it is comparable to the outcome of studies in English speaking countries.
Psychosomatic Medicine, Mar 1, 2004
We compared the effects of acetylcarnitine, propionylcarnitine and both compounds on the symptoms... more We compared the effects of acetylcarnitine, propionylcarnitine and both compounds on the symptoms of chronic fatigue syndrome (CFS). In an open, randomized fashion we compared 2 g/d acetyl-L-carnitine, 2 g/d propionyl-L-carnitine, and its combination in 3 groups of 30 CFS patients during 24 weeks. Effects were rated by clinical global impression of change. Secondary endpoints were the Multidimensional Fatigue Inventory, McGill Pain Questionnaire, and the Stroop attention concentration test. Scores were assessed 8 weeks before treatment; at randomization; after 8, 16, and 24 weeks of treatment; and 2 weeks later. Clinical global impression of change after treatment showed considerable improvement in 59% of the patients in the acetylcarnitine group and 63% in the propionylcarnitine group, but less in the acetylcarnitine plus propionylcarnitine group (37%). Acetylcarnitine significantly improved mental fatigue (p =.015) and propionylcarnitine improved general fatigue (p =.004). Attention concentration improved in all groups, whereas pain complaints did not decrease in any group. Two weeks after treatment, worsening of fatigue was experienced by 52%, 50%, and 37% in the acetylcarnitine, propionylcarnitine, and combined group, respectively. In the acetylcarnitine group, but not in the other groups, the changes in plasma carnitine levels correlated with clinical improvement. Acetylcarnitine and propionylcarnitine showed beneficial effect on fatigue and attention concentration. Less improvement was found by the combined treatment. Acetylcarnitine had main effect on mental fatigue and propionylcarnitine on general fatigue.
Clinical Neurophysiology, 2021
In chronic fatigue patients, muscle conduction increases abnormally with force. Surface EMG can e... more In chronic fatigue patients, muscle conduction increases abnormally with force. Surface EMG can elicit abnormalities in both fibromyalgia and chronic fatigue. The surface EMG abnormalities in fibromyalgia and chronic fatigue differ. a b s t r a c t Objective: Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are disorders of unknown etiology and unclear pathophysiology, with overlapping symptoms of-especially muscular-fatigue and pain. Studies have shown increased muscle fiber conduction velocity (CV) in the non-painful muscles of FM patients. We investigated whether CFS patients also show CV abnormalities. Methods: Females with CFS (n = 25), with FM (n = 22), and healthy controls (n = 21) underwent surface electromyography of the biceps brachii, loaded up to 20% of maximum strength, during short static contractions. The mean CV and motor unit potential (MUP) velocities with their statistical distribution were measured. Results: The CV changes with force differed between CFS-group and both FM-group and controls (P = 0.01). The CV of the CFS-group increased excessively with force (P < 0.001), whereas that of the controls increased only slightly and non-significantly, and that of the FM-group did not increase at all. In the CFS-group, the number of MUPs conveying very high conduction velocities increased abundantly with force and the MUPs narrowed. Conclusion: Our results suggest disturbed muscle membrane function in CFS patients, in their motor units involved in low force generation. Central neural deregulation may contribute to this disturbance. Significance: These findings help to detangle the underlying mechanisms of CFS.
Netherlands Heart Journal, 2016
Objective In chronic fatigue syndrome (CFS), only a few imaging and histopathological studies hav... more Objective In chronic fatigue syndrome (CFS), only a few imaging and histopathological studies have previously assessed either cardiac dimensions/function or myocardial tissue, suggesting smaller left ventricular (LV) dimensions, LV wall motion abnormalities and occasionally viral persistence that may lead to cardiomyopathy. The present study with cardiac magnetic resonance (CMR) imaging is the first to use a contrast-enhanced approach to assess cardiac involvement, including tissue characterisation of the LV wall. Methods CMR measurements of 12 female CFS patients were compared with data of 36 age-matched, healthy female controls. With cine imaging, LV volumes, ejection fraction (EF), mass, and wall motion abnormalities were assessed. T2-weighted images were analysed for increased signal intensity, reflecting oedema (i. e. inflammation). In addition, the presence of contrast enhancement, reflecting fibrosis (i. e. myocardial damage), was analysed. Results When comparing CFS patients and healthy controls, LVEF (57.9 ± 4.3 % vs. 63.7 ± 3.7 %; p < 0.01), end-C. von Birgelen
Patients with chronic fatigue syndrome performed worse than controls in a controlled repeated exe... more Patients with chronic fatigue syndrome performed worse than controls in a controlled repeated exercise study despite a normal oxidative phosphorylation capacity
which permits unrestricted use, distribution, and reproduction in any medium, provided the origin... more which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: In a study by Wagner et al., the CDC Symptom Inventory was validated in a population selected from the inhabitants of a city in the USA, and proofed reliable for the assessment of the accompanying symptoms of CFS. The Dutch translation of the CDC Symptom Inventory is compared to the original and the psychometric properties are presented for patients in a tertiary care setting. Methods: One hundred thirty-nine consecutive patients who visited the CFS Center Amsterdam for the first time were asked to complete the CDC Symptom Inventory in the Dutch Language Version (DLV) together with the usual set of questionnaires. Sixty-one patients had Chronic Fatigue (CF) and 78 patients fulfilled the criteria for CFS. Forty-three healthy accompanying persons completed the CDC Symptom Inventory DLV, the Physical Functioning scale of the Medical Outcome Survey Shor...
Journal of Translational Medicine, 2010
The Journal of rheumatology, 2003
OBJECTIVE To compare symptoms of women with silicone gel breast implants and women with chronic f... more OBJECTIVE To compare symptoms of women with silicone gel breast implants and women with chronic fatigue syndrome (CFS), and to study the effect of rupture of the silicone implant. METHODS Five hundred readers of the Dutch silicone breast implant support group magazine were asked to respond if they had been informed by the surgeon about the silicone implant status at operation, and to answer questions about symptoms of CFS. Their complaints were compared with those of 100 female patients with CFS and 40 female controls. RESULTS The questionnaires were returned by 319 women. Of these, 227 had symptoms of debilitating chronic fatigue. The patterns of symptoms differed from those in patients with CFS. An analysis of the relation between integrity of the implants and the symptoms could be carried out in 176 women, and 74% of these latter women reported ruptured implants. Significantly more women with ruptured implants than those with intact implants had debilitating chronic fatigue (75% ...
Fatigue: Biomedicine, Health & Behavior
Population health metrics, 2006
In a study by Wagner et al., the CDC Symptom Inventory was validated in a population selected fro... more In a study by Wagner et al., the CDC Symptom Inventory was validated in a population selected from the inhabitants of a city in the USA, and proofed reliable for the assessment of the accompanying symptoms of CFS. The Dutch translation of the CDC Symptom Inventory is compared to the original and the psychometric properties are presented for patients in a tertiary care setting. One hundred thirty-nine consecutive patients who visited the CFS Center Amsterdam for the first time were asked to complete the CDC Symptom Inventory in the Dutch Language Version (DLV) together with the usual set of questionnaires. Sixty-one patients had Chronic Fatigue (CF) and 78 patients fulfilled the criteria for CFS. Forty-three healthy accompanying persons completed the CDC Symptom Inventory DLV, the Physical Functioning scale of the Medical Outcome Survey Short Form-36 DLV, and the Fatigue and Concentration scales of the Checklist Individual Strength (CIS-20). The healthy controls group contained fewer...
American Journal of Obstetrics and Gynecology, Jan 12, 1985
Placentas after uneventful pregnancies were perfused under physiologic pressure in the fetal vess... more Placentas after uneventful pregnancies were perfused under physiologic pressure in the fetal vessels, expanded to their predelivery volume, fixated with 4% formaldehyde, and compared to their ultrasound images in pregnancy. The placentas showed a side arrangement of the fetal cotyledons in contact with the basal plate. The centers of the cotyledons showed an empty space in which the spiral arteries ended. These spaces in the placenta corresponded with transonic areas of ultrasound. The central spaces were surrounded by a relatively dense shell of villi containing the more or less fibrotic stem villi. This explained the areas of increased echo-density, as seen by ultrasound during the last trimester of pregnancy. The fetal cotyledons, composed of a central cavity and a dense villous shell, were separated by a reticular area. The veins ended at the basal plate in these intercotyledonary areas. (AM J OssrET GvNECOL 1985;153:806-10.)
Journal of translational medicine, 2006
CFS is a clinical state with defined symptoms, but undefined cause. The patients may show a chron... more CFS is a clinical state with defined symptoms, but undefined cause. The patients may show a chronic state of immune activation and treatment with an antibiotic in this subgroup has been suggested. In a retrospective study, the response of CFS patients to azithromycin, an antibiotic and immunomodulating drug, has been scored from the patients records and compared with clinical and laboratory data. Azithromycin was not the first choice therapy, but offered when the effect of counseling and L-carnitine was considered insufficient by the patient and the clinician. Of the 99 patients investigated, 58 reported a decrease in the symptoms by the use of azithromycin. These responding patients had lower levels of plasma acetylcarnitine. The efficacy of azithromycin in the responsive patients could be explained by the modulating effect on a chronic primed state of the immune cells of the brain, or the activated peripheral immune system. Their lower acetylcarnitine levels may reflect a decrease...
Psychosomatic medicine
We compared the effects of acetylcarnitine, propionylcarnitine and both compounds on the symptoms... more We compared the effects of acetylcarnitine, propionylcarnitine and both compounds on the symptoms of chronic fatigue syndrome (CFS). In an open, randomized fashion we compared 2 g/d acetyl-L-carnitine, 2 g/d propionyl-L-carnitine, and its combination in 3 groups of 30 CFS patients during 24 weeks. Effects were rated by clinical global impression of change. Secondary endpoints were the Multidimensional Fatigue Inventory, McGill Pain Questionnaire, and the Stroop attention concentration test. Scores were assessed 8 weeks before treatment; at randomization; after 8, 16, and 24 weeks of treatment; and 2 weeks later. Clinical global impression of change after treatment showed considerable improvement in 59% of the patients in the acetylcarnitine group and 63% in the propionylcarnitine group, but less in the acetylcarnitine plus propionylcarnitine group (37%). Acetylcarnitine significantly improved mental fatigue (p =.015) and propionylcarnitine improved general fatigue (p =.004). Attenti...
The Journal of rheumatology, 2003
To compare symptoms of women with silicone gel breast implants and women with chronic fatigue syn... more To compare symptoms of women with silicone gel breast implants and women with chronic fatigue syndrome (CFS), and to study the effect of rupture of the silicone implant. Five hundred readers of the Dutch silicone breast implant support group magazine were asked to respond if they had been informed by the surgeon about the silicone implant status at operation, and to answer questions about symptoms of CFS. Their complaints were compared with those of 100 female patients with CFS and 40 female controls. The questionnaires were returned by 319 women. Of these, 227 had symptoms of debilitating chronic fatigue. The patterns of symptoms differed from those in patients with CFS. An analysis of the relation between integrity of the implants and the symptoms could be carried out in 176 women, and 74% of these latter women reported ruptured implants. Significantly more women with ruptured implants than those with intact implants had debilitating chronic fatigue (75% vs 51%), postexertional ma...
American journal of obstetrics and gynecology, 1985
Placentas after uneventful pregnancies were perfused under physiologic pressure in the fetal vess... more Placentas after uneventful pregnancies were perfused under physiologic pressure in the fetal vessels, expanded to their predelivery volume, fixated with 4% formaldehyde, and compared to their ultrasound images in pregnancy. The placentas showed a side arrangement of the fetal cotyledons in contact with the basal plate. The centers of the cotyledons showed an empty space in which the spiral arteries ended. These spaces in the placenta corresponded with transsonic areas of ultrasound. The central spaces were surrounded by a relatively dense shell of villi containing the more or less fibrotic stem villi. This explained the areas of increased echo-density, as seen by ultrasound during the last trimester of pregnancy. The fetal cotyledons, composed of a central cavity and a dense villous shell, were separated by a reticular area. The veins ended at the basal plate in these intercotyledonary areas.