Unraveling upper extremity performance in Duchenne muscular dystrophy: A biophysical model

This study aimed to identify critical physiological outcome variables underlying reduced upper extremity task performance in Duchenne muscular dystrophy (DMD). These critical variables were used to propose an explanatory biophysical model of the upper extremity working mechanisms in DMD. Twenty-three DMD patients (8–21 years) participated in this study. Correlations with Brooke scale and Performance of Upper Limb (PUL) score were very high for maximal active joint angle, high for maximal muscle torque and maximal surface electromyography amplitude, and moderate for mean echogenicity and maximal passive joint angle. Multivariable regression analysis showed that maximal active joint angle and maximal muscle torque were significantly associated with Brooke score (R² = 0.91). Maximal active joint angle, maximal passive joint angle, and maximal muscle torque were significantly associated with PUL score (R² = 0.94). Based on the most critical physiological outcome variables, we constructed an exploratory biophysical model of the working mechanisms leading to limitations in upper extremity task performance. Better insights in these working mechanisms could support clinical management of upper extremity limitations and facilitate the development of interventions. In addition, the model could form the basis for new multi-layered outcome measures for clinical trials.     

Assessment of locomotor function in young boys with Duchenne muscular dystrophy

Thirty-three young boys (mean age 3.42 years) with Duchenne muscular dystrophy (DMD) and 21 normal control boys (mean age 3.51 years) were studied prospectively to determine whether it is possible to objectively assess locomotor function in young boys with DMD so that they can be included in treatment trials. An initial reproducibility study using a hand-held myometer demonstrated that this method was not useful. The Hammersmith Motor Ability Score demonstrated an increase in developmental abilities with age which was markedly different from normal. The locomotor quotient of the Griffiths' Scales demonstrated a deterioration of quotient scores and is a useful method of assessment that could be used in treatment trials involving young boys with DMD. Sample size planning for treatment trials is discussed.     

Ambulatory capacity in Japanese patients with Duchenne muscular dystrophy

Introduction

Few long-term cohort studies have addressed changes in the ambulatory capacity of patients with Duchenne muscular dystrophy (DMD), and no reports have evaluated the factors associated with ambulatory capacity in Japanese.

Men with Duchenne muscular dystrophy and end of life planning

There is very limited evidence about the views of men with Duchenne muscular dystrophy (DMD) and end of life issues including death and dying. Studies have shown the physiological and psychological benefits of talking about and planning for end of life. Despite policy documents and guidance in the UK about end of life planning, there is consensus on the need for improvement. The study reported here is a qualitative one with 15 men with DMD (aged 20–45 years). Participants could not recall any significant conversations with clinicians about end of life and assumed that clinicians were reluctant to discuss the issue. The men in the study wanted to be given proactive cues that they could bring up topics such as death and dying and wanted to have these conversations with clinicians who combined expert knowledge about the condition as well as good listening skills. Topics of interest to participants included likely nature and place of death; practical planning for funerals and wills; and sources of information and support. Emotional or psychological support to think about end of life was not routinely offered and participants found it very difficult to discuss these issues with family members. The study suggests that more could be done to encourage clinicians, men with Duchenne, family members and the wider NMD community to pay attention to end of life planning issues and the associated need for emotional support and high quality interactions between patients and clinicians.     

Ventilation function changes in patients with Duchenne muscular dystrophy under and over 12 years of age Analysis of 65 cases

BACKGROUND：Previous studies indicate that vital capacity in patients with Duchenne muscular dystrophy increases with age when they are under 12 years old, and decreases from 13 or 14 years of age; however, recent studies indicate that the vital capacity in patients with Duchenne muscular dystrophy begins to decrease even before 12 years of age. OBJECTIVE： To verify if the vital capacity in patients with Duchenne muscular dystrophy decreases before the age of 12 years and to observe the effect of rehabilitation exercise on vital capacity. DESIGN, TIME AND SETTING： The case analysis was performed at the Department of Neurology, The First Affiliated Hospital of Sun Yat-Sen University （Guangzhou, Guangdong Province, China） from December 2004 to January 2006. PARTICIPANTS： Sixty-five male patients diagnosed as having Duchenne muscular dystrophy and who underwent pulmonary ventilation function examination at the Department of Neurology, The First Affiliated Hospital of Sun Yat-Sen University （Guangzhou, Guangdong Province, China） from December 2004 to January 2006; ages ranged from 6 to 22 years old. METHODS： The ventilation function of 65 patients was determined using a Sensor Medics 2100 pulmonary function test apparatus （USA）, and the data obtained were subjected to statistical analysis comparing patients under 12 years of age and those above 13 years of age, and comparing those who performed rehabilitation exercise with those who did not. MAIN OUTCOME MEASURES： Forced vital capacity （FVC）; forced expiratory volume in one second （FEV1）; maximal voluntary ventilation （MMV）; the ratio of forced expiratory volume in one second and forced vital capacity （FEV1/FVC）; each measured value as a percentage of the corresponding predicted value. RESULTS： There were no significant differences in FVC, FEV1 and MMV between patients under 12 years of age and those above 13 years of age （P 〉 0.05）. The FVC, FEV1 and MMV values, as percentages of the predicted values, were, in patients     

A mitochondrial DNA mutation in a patient with an extensive family history of Duchenne muscular dystrophy

One challenge in the molecular diagnosis of mitochondrial DNA (mtDNA) disorders is detection of a low percentage of mutant heteroplasmy. We report a patient who had a delayed molecular diagnosis of mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome due to the complication of an extensive family history of another neuromuscular disease, Duchenne muscular dystrophy, and the failure to detect a low proportion of mutant A3243G mtDNA with a polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP)/ethidium bromide detection method. Using an improved, more sensitive allele-specific oligonucleotide (ASO) radioactive dot-blot hybridization method, a low degree of A3243G heteroplasmy was detected in several tissues from this patient. This case underscores the importance of a sensitive mutation detection method and the need for a search for mtDNA mutations if the patient's clinical symptoms suggest a mitochondrial disorder despite the family background of another neuromuscular disease.     

Influence of a two-year steroid treatment on body composition as measured by dual X-ray absorptiometry in boys with Duchenne muscular dystrophy

Steroids are nowadays routinely used as a long-term treatment in Duchenne muscular dystrophy (DMD). Their effects on body composition were assessed using dual X-ray absorptiometry. The study followed over 2 years 29 genetically confirmed DMD patients: 21 in the steroid-treated group and 8 in the steroid-naïve group. After 2 years of steroid treatment, the lean tissue mass values increased significantly (p < 0.0001), the percentage of body fat mass remained practically constant (p = 0.94) in comparison with the initial visit. In the steroid-naïve patients, there were no significant increases in the lean tissue mass but deterioration in body composition confirmed by a significant increase in the percentage of body fat mass. Besides, significant negative correlations were found between the percentage of body fat mass and the MFM total score (R = −0.79, n = 76, p < 0.0001). A 2-year steroid treatment improves significantly body composition of boys with DMD through a significant increase in lean tissue mass. We suggest that a thorough check of body composition should be carried out before steroid treatment discontinuation in case of overweight gain.     

Perioperative complications of scoliosis surgery in patients with Duchenne muscular dystrophy and spinal muscular atrophy,focussing on wound healing disorders

Purpose: Patients with Duchenne muscular dystrophy (DMD) or spinal muscular atrophy (SMA), both neuromuscular diseases, sustain spinal scoliosis in the course of their disease. To reduce the concomitant major morbidity and to improve their quality of life, patients require surgical spine stabilization. This can lead to complications like respiratory, cardiac or neurological complications or wound healing disorders (WHD). To find out the different complexities and risk factors increasing the chance to develop a WHD, the inpatient database was analyzed. Methods: We performed a retrospective statistical study. Therefore, we analyzed the inpatient database of 180 patients (142 DMD and 38 SMA patients). The focus was on WHD. To figure out the risk factors leading to WHD, we conducted a logistic regression. Results: Cardiac complications occurred most frequently, followed by pulmonary complications and neurological lesions. Fifty-seven out of 180 patients developed a WHD. In 23 cases the WHD was aseptic, in the other 34 cases dermal organisms, Pseudomonas species and intestinal organisms were responsible. By means of the logistic regression, we were able to identify two more risk factors, in addition to diagnosis and gender, for developing a WHD in our patients: the year of surgery and the direction of pelvic tilt. Conclusions: Most common complications following scoliosis surgery are respiratory and cardiac complications. WHD is a severe complication that implies a prolonged therapy. Some risk factors for developing WHD could be identified in this analysis. Specifically, these were the date of surgery and the direction of pelvic tilt.     

Muscle function and age are associated with loss of bone mineral density in Duchenne muscular dystrophy

Introduction: Patients with Duchenne muscular dystrophy (DMD) demonstrate decreased bone mineral density (BD). It is not clear which factors exert the greatest impact on BD loss in these patients. Methods: In 63 patients with DMD, serum cytokines (interleukin [IL]-1, IL-6, and tumor necrosis factor-beta [TNF-β]), C-reactive protein (CRP), creatine kinase (CK), muscle function (by Vignos scale), body composition, and total BD (the latter 2 measured by dual-energy X-ray absorptiometry, or DEXA) were determined. Results: The main factors associated with BD loss were muscle function (34.0%; β = −0.139; P < 0.023) and age (36.7%; β = −0.151; P = 0.004). Cytokines, CRP, body fat mass, and CK did not contribute to BD loss. Discussion: Muscle function and age contribute to BD loss in DMD. We propose that a cut-off of at least 6 points for the Vignos scale and at least 10.5 years of age predict a Z-score of less than or equal to −2.0. Muscle Nerve 59:417–421, 2019     

Respiratory and upper limb function as outcome measures in ambulant and non-ambulant subjects with Duchenne muscular dystrophy: A prospective multicentre study

The field of translational research in Duchenne muscular dystrophy (DMD) has been transformed in the last decade by a number of therapeutic targets, mostly studied in ambulant patients. A paucity of studies focus on measures that capture the non-ambulant stage of the disease, and the transition between the ambulant and non-ambulant phase. In this prospective natural history study, we report the results of a comprehensive assessment of respiratory, upper limb function and upper limb muscle strength in a group of 89 DMD boys followed in 3 European countries, 81 receiving corticosteroids, spanning a wide age range (5–18 years) and functional abilities, from ambulant (n?=?60) to non-ambulant (n?=?29). Respiratory decline could be detected in the early ambulatory phase using Peak Expiratory Flow percentage predicted (PEF%), despite glucocorticoid use (mean annual decline: 4.08, 95% CI [?7.44,?0.72], p?=?0.02 in ambulant; 4.81, 95% CI [?6.79,?2.82], p < 0.001 in non-ambulant). FVC% captured disease progression in non-ambulant DMD subjects, with an annual loss of 5.47% (95% CI [?6.48,?4.45], p < 0.001). Upper limb function measured with the Performance of Upper Limb (PUL 1.2) showed an annual loss of 4.13 points (95% CI [?4.79,3.47], p < 0.001) in the non-ambulant cohort. Measures of upper limb strength (MyoGrip and MyoPinch) showed a continuous decline independent of the ambulatory status, when reported as percentage predicted (grip force ?5.51%, 95% CI [?6.54,?4.48], p < 0.001 in ambulant and a slower decline ?2.86%; 95% CI ?3.29,?2.43, p < 0.001, in non-ambulant; pinch force: ?2.66%, 95% CI [?3.82,?1.51], p < 0.001 in ambulant and ?2.23%, 95% CI [?2.92,?1.53], p < 0.001 in non-ambulant). Furthermore, we also explored the novel concept of a composite endpoint by combining respiratory, upper limb function and force domains: we were able to identify clear clinical progression in patients in whom an isolated measurement of only one of these domains failed to appreciate the yearly change. Our study contributes to the field of natural history of DMD, linking the ambulant and non-ambulant phases of the disease, and suggests that composite scores should be explored further.     

脐带间充质干细胞治疗Duchenne型肌营养不良3例报告

Due to their relative abundance,stable biological properties and excellent reproductive activity,umbilical cord mesenchymal stem cells have previously been utilized for the treatment of Duchenne muscular dystrophy,which is a muscular atrophy disease.Three patients who were clinically and pathologically diagnosed with Duchenne muscular dystrophy were transplanted with umbilical cord mesenchymal stem cells by intravenous infusion,in combination with multi-point intramuscular injection.They were followed up for 12 months after cell transplantation.Results showed that clinical symptoms significantly improved,daily living activity and muscle strength were enhanced,the sero-enzyme,electromyogram,and MRI scans showed improvement,and dystrophin was expressed in the muscle cell membrane.Hematoxylin-eosin staining of a muscle biopsy revealed that muscle fibers were well arranged,fibrous degeneration was alleviated,and fat infiltration was improved.These pieces of evidence suggest that umbilical cord mesenchymal stem cell transplantation can be considered as a new regimen for Duchenne muscular dystrophy.     

Sleep pattern and spectral analysis of caregiver-mothers of sons with Duchenne muscular dystrophy,and an examination of differences between carriers and non-carriers

ObjectivesSleep is essential for physical and mental well-being. However, poor sleep is a common complaint among caregivers. The aim of the present study was to determine sleep patterns of caregiver-mothers (CM group) of sons with Duchenne muscular dystrophy (DMD) and also to examine the differences between non-carriers and carriers of the gene related to DMD within the CM group.MethodsObservational case–control study.ParticipantsThe CM and control (CTRL) groups were matched for age, body mass index and social class. Polysomnography was conducted in a sleep laboratory for one night. The discrete fast Fourier transformation method was used to calculate the electroencephalogram (EEG) power spectrum for the entire night and sleep stages.ResultsThe CM group presented higher sleep latency and N3 sleep stage compared with the CTRL. When carrier and non-carrier CM subgroups were analyzed, increased sleep latency and time awake, as well as reduced sleep efficiency and N2, were observed in the carrier group. Regarding respiratory parameters, carriers demonstrated higher hypopnea index values compared with non-carriers. Spectral analysis showed that carriers compared with non-carrier DMD caregiver-mothers presented lower spectral power in fast waves, mainly beta, during REM sleep in some EEG derivations.ConclusionsThere was an impairment of sleep pattern in the CM group compared with CTRL mothers; this was possibly associated with difficulty in initiating sleep. Being a DMD gene carrying caregiver further compromised some aspects of sleep microstructure during REM sleep. The data demonstrated the importance of sleep evaluation in caregiver-mothers, and the relationship between sleep and being a carrier of the gene associated with DMD, which was demonstrated as possibly impacting sleep quality.     

Utility of real-time three-dimensional echocardiography for Duchenne muscular dystrophy with echocardiographic limitations

Duchenne muscular dystrophy (DMD) is strongly associated with a unique form of dilated cardiomyopathy. Cardiac complications are the leading cause of death in DMD; thus, longitudinal assessments and early intervention for cardiac dysfunction are necessary to improve prognosis. Two-dimensional echocardiography, which is routinely used for cardiac assessment, has some limitations for quantitative analyses in DMD patients with thoracic deformities and regional wall motion abnormalities in the left ventricle. Recently, real-time three-dimensional echocardiography has emerged as a feasible tool for cardiac assessment in various cardiac diseases. The aim of this study was to examine the utility of this technology in DMD. We evaluated left ventricular ejection fraction (LVEF), a major parameter of left ventricular function, in 17 male DMD patients. LVEF values measured by real-time three-dimensional echocardiography were compared with those determined by two established nuclear cardiology methods: “the first-pass method of radionuclide angiocardiography” and “quantitative electrocardiogram-gated single-photon emission computed tomography”. A good correlation was observed for LVEF values, particularly between real-time three-dimensional echocardiography and “the first-pass method of radionuclide angiocardiography” (r = 0.90, p < 0.05). Thus, real-time three-dimensional echocardiography can provide an accurate measurement of LVEF in DMD patients with echocardiographic limitations.