Background Progressive lung function decline, resulting in respiratory failure, is an important c... more Background Progressive lung function decline, resulting in respiratory failure, is an important complication of spinal muscular atrophy (SMA). The ability to predict the need for mechanical ventilation is important. We assessed longitudinal patterns of lung function prior to chronic respiratory failure in a national cohort of treatment-naïve children and adults with SMA, hypothesizing an accelerated decline prior to chronic respiratory failure. Methods We included treatment-naïve SMA patients participating in a prospective national cohort study if they required mechanical ventilation because of chronic respiratory failure and if lung function test results were available from the years prior to initiation of ventilation. We analyzed Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV1), Peak Expiratory Flow (PEF) and Maximum Expiratory Pressure (PEmax). We studied the longitudinal course using linear mixed-effects models. Results We analyzed 1171 lung function test...
Introduction Spirometry plays an important role in the assessment of possible respiratory failure... more Introduction Spirometry plays an important role in the assessment of possible respiratory failure in children with neuromuscular disorders (NMDs). However, obtaining reliable spirometry results is a major challenge. We studied the relation between Forced Oscillation Technique (FOT) and spirometry results. FOT is an easy, non-invasive method to measure respiratory mechanics, i.e. respiratory resistance R and respiratory reactance X. We hypothesized an increased resistance R and reduced reactance X in patients with more reduced lung function. Methods In this prospective single center study we included all children with NMDs able to perform spirometry. We consecutively measured respiratory resistance R and reactance X at 5, 11 and 19 Hz and (Forced) Vital Capacity, Peak Expiratory Flow. Spearman correlation coefficients were calculated and regression curves were estimated. Results We included 148 patients, with a median age of 13 years (IQR 8-16). All correlation coefficients were stat...
Introduction Understanding the impact of scoliosis surgery on lung function is important for coun... more Introduction Understanding the impact of scoliosis surgery on lung function is important for counseling patients about risks and benefits of surgery. We prospectively compared the trends in lung function test (LFT) results prior to and after scoliosis surgery in children with neuromuscular diseases, or dysmorphic syndromes. We hypothesized a stabilization. Methods We prospectively included children with neuromuscular or syndromic scoliosis able to perform LFTs. We studied (Forced) Vital Capacity ((F)VC), the ratio of Forced Expiratory Volume in 1 second (FEV1) and FVC, and Peak Expiratory Flow (PEF). Preoperative LFT results were compared with results 3-4 months after surgery. The mean monthly change in LFT results up to 2 years after surgery was compared with the preoperative natural history using linear mixed effects models. Results We included 43 patients. No significant change was observed in absolute values of (F)VC, FEV1/FVC and PEF prior to and after surgery. Median standardi...
Background Spinal Muscular Atrophy (SMA) is characterized by progressive and predominantly proxim... more Background Spinal Muscular Atrophy (SMA) is characterized by progressive and predominantly proximal and axial muscle atrophy and weakness. Respiratory muscle weakness results in impaired cough with recurrent respiratory tract infections, nocturnal hypoventilation, and may ultimately lead to fatal respiratory failure in the most severely affected patients. Treatment strategies to either slow down the decline or improve respiratory muscle function are wanting. Objective The aim of this study is to assess the feasibility and efficacy of respiratory muscle training (RMT) in patients with SMA and respiratory muscle weakness. Methods The effect of RMT in patients with SMA, aged ≥ 8 years with respiratory muscle weakness (maximum inspiratory mouth pressure [PImax] ≤ 80 Centimeters of Water Column [cmH2O]), will be investigated with a single blinded randomized sham-controlled trial consisting of a 4-month training period followed by an 8-month open label extension phase. Intervention The RM...
Objective The purpose of the present study was to investigate the association between cardiorespi... more Objective The purpose of the present study was to investigate the association between cardiorespiratory fitness (CRF) measured as peak oxygen uptake (VO2peak, expressed in mL/min) and body mass index (BMI) in a large cohort of apparently healthy subjects. Methods BMI and VO2peak were measured in a cross-sectional study of 8470 apparently healthy adults. VO2peak (mL/min) was determined by an incremental cycle ergometer test to exhaustion. Linear regression analyses were performed to identify predictors of CRF. Results There was no difference in CRF between adults with a normal weight (BMI between 18.5–24.9 kg/m2) and those who were overweight (BMI 25.0–29.9 kg/m2). Subjects who were underweight (BMI < 18.5 kg/m2) as well as females who were obese (BMI ≥ 30.0 kg/m2) showed a reduced CRF compared to the normal and overweight groups. Age, height, and gender were significant predictors of CRF (R2 = 0.467, P < 0.0001); BMI did not add significantly to this relationship. Conclusion O...
INTRODUCTION Spirometry plays an important role in the assessment of possible respiratory failure... more INTRODUCTION Spirometry plays an important role in the assessment of possible respiratory failure in children with neuromuscular diseases (NMDs). However, obtaining reliable spirometry results is a major challenge. We studied the relation between oscillometry and spirometry results. Oscillometry is an easy, non-invasive method to measure respiratory resistance R and reactance X. We hypothesized an increased R and reduced X in patients with more reduced lung function. METHODS In this prospective single center study we included all children with NMDs able to perform spirometry. We consecutively measured R and X at 5, 11 and 19 Hz and (Forced) Vital Capacity, Peak Expiratory Flow. Spearman correlation coefficients and positive and negative predictive values were calculated. Regression curves were estimated. RESULTS We included 148 patients, median age 13 years (IQR 8-16). A negative correlation was found between R and spirometry outcomes (spearman correlation coefficient (ρ) -0.5 to -0.6, p < 0.001). A positive correlation was found between X (i.e. less negative outcomes) and spirometry outcomes (ρ 0.4 to 0.6, p < 0.001). Highest correlation was found at lower frequencies. Regression analysis showed a non-linear relation. Measurement of inspiratory and expiratory R and X did not provide added value. Positive predictive values of 80-85% were found for z-scores of R measured at 5 Hz versus (F)VC≤ 60%. CONCLUSION We found a non-linear relation between oscillometry and spirometry results with increased R and reduced X in patients with more restrictive lung function decline. Given the difficulties with performing spirometry, oscillometry may be a promising substitute. This article is protected by copyright. All rights reserved.
Background: Exercise intolerance is an important impairment in patients with SMA, but little is k... more Background: Exercise intolerance is an important impairment in patients with SMA, but little is known about the mechanisms underlying this symptom. Objective: To investigate if reduced motor unit- and capillary recruitment capacity in patients with SMA contribute to exercise intolerance. Methods: Adolescent and adult patients with SMA types 3 and 4 (n = 15) and age- and gender matched controls (n = 15) performed a maximal upper body exercise test. We applied respiratory gas analyses, non-invasive surface electromyography (sEMG) and continuous wave near-infrared spectroscopy (CW-NIRS) to study oxygen consumption, arm muscle motor unit- and capillary recruitment, respectively. Results: Maximal exercise duration was twofold lower (p < 0.001) and work of breathing and ventilation was 1.6- and 1.8-fold higher (p < 0.05) in patients compared to controls, respectively. Regarding motor unit recruitment, we found higher normalized RMS amplitude onset values of sEMG signals from all m...
Little is known about how play affects the development of children with a chronic condition. Stud... more Little is known about how play affects the development of children with a chronic condition. Studying play poses major methodological challenges in measuring differences in play behaviour, which results in a relative scarcity of research on this subject. This pilot study seeks to provide novel directions for research in this area. The effectiveness of a play- and sports-based cognitive behavioural programme for children (8–12 years) with a chronic condition was studied. The children and parents completed a battery of measurement tools before and after the programme. Moreover, the application of automated computer analyses of behaviour was piloted. Behaviour (Child Behavior Checklist) seemed to be positively affected by the programme. An increase in psychological well-being was observed (KIDSCREEN). Perceived competence (Self-Perception Profile for Children) and actual motor competence (Canadian Agility and Movement Skill Assessment) did not show any positive trends. These results of...
Background: Conflicting results are available of effect of surgical correction of scoliosis on pu... more Background: Conflicting results are available of effect of surgical correction of scoliosis on pulmonary function. In children with a severely decreased respiratory function even limited improvement of respiratory function after scoliosis surgery could be of major clinical relevance. Aim: This study aimed to evaluate the short-term effect of scoliosis surgery on pulmonary function in children diagnosed with non-idiopathic scoliosis by comparing pre-operative spirometry results to results three months after surgery. Methods: This prospective, single-centre, observational study included children, diagnosed with non-idiopathic scoliosis, able to perform spirometry. Wilcoxon signed-rank test was used to compare spirometry results. Results: 28 children were included with median age of 13 years (interquartile rang (IQR) 10-15). Half were children with neuromuscular disease. There was a statistically significant higher relative expiratory forced vital capacity prior (median 58%, IQR 43-76%) compared to 3 months after surgery (55%, IQR 32-78%), p=0.001). No statistically significant difference of both absolute and relative values of peak expiratory flow and maximal vital capacity were seen prior and after surgery. A trend towards higher relative peak expiratory flow 3 months after surgery was observed (median 60%, IQR 42-77%) versus 50%, IQR 40-88%, p=0.053). Results were similar in the most severely affected children. Conclusion: Spirometry results 3 months after surgery for non-idiopathic scoliosis showed no statistically significant difference compared to results prior to surgery. Even a decline of relative expiratory forced vital capacity was observed.
Background Progressive lung function decline, resulting in respiratory failure, is an important c... more Background Progressive lung function decline, resulting in respiratory failure, is an important complication of spinal muscular atrophy (SMA). The ability to predict the need for mechanical ventilation is important. We assessed longitudinal patterns of lung function prior to chronic respiratory failure in a national cohort of treatment-naïve children and adults with SMA, hypothesizing an accelerated decline prior to chronic respiratory failure. Methods We included treatment-naïve SMA patients participating in a prospective national cohort study if they required mechanical ventilation because of chronic respiratory failure and if lung function test results were available from the years prior to initiation of ventilation. We analyzed Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV1), Peak Expiratory Flow (PEF) and Maximum Expiratory Pressure (PEmax). We studied the longitudinal course using linear mixed-effects models. Results We analyzed 1171 lung function test...
Introduction Spirometry plays an important role in the assessment of possible respiratory failure... more Introduction Spirometry plays an important role in the assessment of possible respiratory failure in children with neuromuscular disorders (NMDs). However, obtaining reliable spirometry results is a major challenge. We studied the relation between Forced Oscillation Technique (FOT) and spirometry results. FOT is an easy, non-invasive method to measure respiratory mechanics, i.e. respiratory resistance R and respiratory reactance X. We hypothesized an increased resistance R and reduced reactance X in patients with more reduced lung function. Methods In this prospective single center study we included all children with NMDs able to perform spirometry. We consecutively measured respiratory resistance R and reactance X at 5, 11 and 19 Hz and (Forced) Vital Capacity, Peak Expiratory Flow. Spearman correlation coefficients were calculated and regression curves were estimated. Results We included 148 patients, with a median age of 13 years (IQR 8-16). All correlation coefficients were stat...
Introduction Understanding the impact of scoliosis surgery on lung function is important for coun... more Introduction Understanding the impact of scoliosis surgery on lung function is important for counseling patients about risks and benefits of surgery. We prospectively compared the trends in lung function test (LFT) results prior to and after scoliosis surgery in children with neuromuscular diseases, or dysmorphic syndromes. We hypothesized a stabilization. Methods We prospectively included children with neuromuscular or syndromic scoliosis able to perform LFTs. We studied (Forced) Vital Capacity ((F)VC), the ratio of Forced Expiratory Volume in 1 second (FEV1) and FVC, and Peak Expiratory Flow (PEF). Preoperative LFT results were compared with results 3-4 months after surgery. The mean monthly change in LFT results up to 2 years after surgery was compared with the preoperative natural history using linear mixed effects models. Results We included 43 patients. No significant change was observed in absolute values of (F)VC, FEV1/FVC and PEF prior to and after surgery. Median standardi...
Background Spinal Muscular Atrophy (SMA) is characterized by progressive and predominantly proxim... more Background Spinal Muscular Atrophy (SMA) is characterized by progressive and predominantly proximal and axial muscle atrophy and weakness. Respiratory muscle weakness results in impaired cough with recurrent respiratory tract infections, nocturnal hypoventilation, and may ultimately lead to fatal respiratory failure in the most severely affected patients. Treatment strategies to either slow down the decline or improve respiratory muscle function are wanting. Objective The aim of this study is to assess the feasibility and efficacy of respiratory muscle training (RMT) in patients with SMA and respiratory muscle weakness. Methods The effect of RMT in patients with SMA, aged ≥ 8 years with respiratory muscle weakness (maximum inspiratory mouth pressure [PImax] ≤ 80 Centimeters of Water Column [cmH2O]), will be investigated with a single blinded randomized sham-controlled trial consisting of a 4-month training period followed by an 8-month open label extension phase. Intervention The RM...
Objective The purpose of the present study was to investigate the association between cardiorespi... more Objective The purpose of the present study was to investigate the association between cardiorespiratory fitness (CRF) measured as peak oxygen uptake (VO2peak, expressed in mL/min) and body mass index (BMI) in a large cohort of apparently healthy subjects. Methods BMI and VO2peak were measured in a cross-sectional study of 8470 apparently healthy adults. VO2peak (mL/min) was determined by an incremental cycle ergometer test to exhaustion. Linear regression analyses were performed to identify predictors of CRF. Results There was no difference in CRF between adults with a normal weight (BMI between 18.5–24.9 kg/m2) and those who were overweight (BMI 25.0–29.9 kg/m2). Subjects who were underweight (BMI < 18.5 kg/m2) as well as females who were obese (BMI ≥ 30.0 kg/m2) showed a reduced CRF compared to the normal and overweight groups. Age, height, and gender were significant predictors of CRF (R2 = 0.467, P < 0.0001); BMI did not add significantly to this relationship. Conclusion O...
INTRODUCTION Spirometry plays an important role in the assessment of possible respiratory failure... more INTRODUCTION Spirometry plays an important role in the assessment of possible respiratory failure in children with neuromuscular diseases (NMDs). However, obtaining reliable spirometry results is a major challenge. We studied the relation between oscillometry and spirometry results. Oscillometry is an easy, non-invasive method to measure respiratory resistance R and reactance X. We hypothesized an increased R and reduced X in patients with more reduced lung function. METHODS In this prospective single center study we included all children with NMDs able to perform spirometry. We consecutively measured R and X at 5, 11 and 19 Hz and (Forced) Vital Capacity, Peak Expiratory Flow. Spearman correlation coefficients and positive and negative predictive values were calculated. Regression curves were estimated. RESULTS We included 148 patients, median age 13 years (IQR 8-16). A negative correlation was found between R and spirometry outcomes (spearman correlation coefficient (ρ) -0.5 to -0.6, p < 0.001). A positive correlation was found between X (i.e. less negative outcomes) and spirometry outcomes (ρ 0.4 to 0.6, p < 0.001). Highest correlation was found at lower frequencies. Regression analysis showed a non-linear relation. Measurement of inspiratory and expiratory R and X did not provide added value. Positive predictive values of 80-85% were found for z-scores of R measured at 5 Hz versus (F)VC≤ 60%. CONCLUSION We found a non-linear relation between oscillometry and spirometry results with increased R and reduced X in patients with more restrictive lung function decline. Given the difficulties with performing spirometry, oscillometry may be a promising substitute. This article is protected by copyright. All rights reserved.
Background: Exercise intolerance is an important impairment in patients with SMA, but little is k... more Background: Exercise intolerance is an important impairment in patients with SMA, but little is known about the mechanisms underlying this symptom. Objective: To investigate if reduced motor unit- and capillary recruitment capacity in patients with SMA contribute to exercise intolerance. Methods: Adolescent and adult patients with SMA types 3 and 4 (n = 15) and age- and gender matched controls (n = 15) performed a maximal upper body exercise test. We applied respiratory gas analyses, non-invasive surface electromyography (sEMG) and continuous wave near-infrared spectroscopy (CW-NIRS) to study oxygen consumption, arm muscle motor unit- and capillary recruitment, respectively. Results: Maximal exercise duration was twofold lower (p < 0.001) and work of breathing and ventilation was 1.6- and 1.8-fold higher (p < 0.05) in patients compared to controls, respectively. Regarding motor unit recruitment, we found higher normalized RMS amplitude onset values of sEMG signals from all m...
Little is known about how play affects the development of children with a chronic condition. Stud... more Little is known about how play affects the development of children with a chronic condition. Studying play poses major methodological challenges in measuring differences in play behaviour, which results in a relative scarcity of research on this subject. This pilot study seeks to provide novel directions for research in this area. The effectiveness of a play- and sports-based cognitive behavioural programme for children (8–12 years) with a chronic condition was studied. The children and parents completed a battery of measurement tools before and after the programme. Moreover, the application of automated computer analyses of behaviour was piloted. Behaviour (Child Behavior Checklist) seemed to be positively affected by the programme. An increase in psychological well-being was observed (KIDSCREEN). Perceived competence (Self-Perception Profile for Children) and actual motor competence (Canadian Agility and Movement Skill Assessment) did not show any positive trends. These results of...
Background: Conflicting results are available of effect of surgical correction of scoliosis on pu... more Background: Conflicting results are available of effect of surgical correction of scoliosis on pulmonary function. In children with a severely decreased respiratory function even limited improvement of respiratory function after scoliosis surgery could be of major clinical relevance. Aim: This study aimed to evaluate the short-term effect of scoliosis surgery on pulmonary function in children diagnosed with non-idiopathic scoliosis by comparing pre-operative spirometry results to results three months after surgery. Methods: This prospective, single-centre, observational study included children, diagnosed with non-idiopathic scoliosis, able to perform spirometry. Wilcoxon signed-rank test was used to compare spirometry results. Results: 28 children were included with median age of 13 years (interquartile rang (IQR) 10-15). Half were children with neuromuscular disease. There was a statistically significant higher relative expiratory forced vital capacity prior (median 58%, IQR 43-76%) compared to 3 months after surgery (55%, IQR 32-78%), p=0.001). No statistically significant difference of both absolute and relative values of peak expiratory flow and maximal vital capacity were seen prior and after surgery. A trend towards higher relative peak expiratory flow 3 months after surgery was observed (median 60%, IQR 42-77%) versus 50%, IQR 40-88%, p=0.053). Results were similar in the most severely affected children. Conclusion: Spirometry results 3 months after surgery for non-idiopathic scoliosis showed no statistically significant difference compared to results prior to surgery. Even a decline of relative expiratory forced vital capacity was observed.
Uploads