Risdiplam in types 2 and 3 spinal muscular atrophy: A randomised, placebo-controlled, dose-finding trial followed by 24 months of treatment.

BACKGROUND AND PURPOSE: Spinal muscular atrophy (SMA) is caused by reduced levels of survival of motor neuron (SMN) protein due to deletions and/or mutations in the SMN1 gene. Risdiplam is an orally administered molecule that modifies SMN2 pre-mRNA splicing to increase functional SMN protein. METHODS: SUNFISH Part 1 was a dose-finding study conducted in 51 individuals with types 2 and 3 SMA aged 2-25 years. A dose-escalation method was used to identify the appropriate dose for the subsequent pivotal Part 2. Individuals were randomized (2:1) to risdiplam or placebo at escalating dose levels for a minimum 12-week, double-blind, placebo-controlled period, followed by treatment for 24 months. The dose selection for Part 2 was based on safety, tolerability, pharmacokinetic, and pharmacodynamic data. Exploratory efficacy was also measured. RESULTS: There was no difference in safety findings for all assessed dose levels. A dose-dependent increase in blood SMN protein was observed; a median twofold increase was obtained within 4 weeks of treatment initiation at the highest dose level. The increase in SMN protein was sustained over 24 months of treatment. Exploratory efficacy showed improvement or stabilization in motor function. The pivotal dose selected for Part 2 was 5 mg for patients with a body weight ≥20 kg or 0.25 mg/kg for patients with a body weight <20 kg. CONCLUSIONS: SUNFISH Part 1 demonstrated a twofold increase in SMN protein after treatment with risdiplam. The observed safety profile supported the initiation of the pivotal Part 2 study. The long-term efficacy and safety of risdiplam are being assessed with ongoing treatment.

Use of MFM-20 to monitor SMA types 1 and 2 patients treated with nusinersen.

OBJECTIVE: To evaluate sensitivity to change and discriminant validity of the 20-item Motor Function Measure (MFM-20) in 2-7-year-old patients with spinal muscular atrophy types 1 (SMA1) or 2 (SMA2) treated with nusinersen. METHODS: Children aged 2 to 7 years old with SMA1 or SMA2 treated with nusinersen were assessed at least three times using the MFM-20 over an average follow-up time of 17 months. Evolution of 4-month-standardized MFM-20 scores was calculated for each MFM-20 domain (D1 standing and transfers, D2 axial and proximal, D3 distal) and for the total score (TS). RESULTS: Included in the study were 22 SMA1 subjects and 19 SMA2 subjects. Baseline MFM scores were significantly lower in patients with SMA1 than SMA2 (TS 29.5% vs. 48.3%, D1 4.5% vs. 10.6%, D2 43.6% vs. 72.6%, D3 51.2% vs. 75.0%). When considering the mean change during nusinersen treatment, standardized over a 4-month period, TS was improved for both SMA1 (+ 4.1%, SRM 1.5) and SMA2 (+ 2.8%, SRM 0.89) patients. For SMA1 patients, considerable changes were observed in D2 (+ 6.2%, SRM 0.89) and D3 (+ 6.0%, SRM 0.72), whereas the change in D1 was small (+ 0.5%, SRM 0.44). In SMA2 2 subjects, D3 was improved to a larger extent (+ 4.2%, SRM 0.53) than D1 (+ 1.8% SRM 0.63) or D2 (+ 3.2%, SRM 0.69). CONCLUSION: Our results validate use of MFM-20 to monitor function of young SMA1 and SMA2 subjects treated with nusinersen. Significant motor function improvements following treatment were observed in both SMA1 and SMA2 patients.

Confirmatory validation of the french version of the Duchenne Muscular Dystrophy module of the pediatric quality of life inventory (PedsQLTM3.0DMDfv).

Duchenne Muscular Dystrophy (DMD) is a neuromuscular disease that inevitably leads to total loss of autonomy. The new therapeutic strategies aim to both improve survival and optimise quality of life. Evaluating quality of life is nevertheless a major challenge. No DMD-specific quality of life scale to exists in French. We therefore produced a French translation of the English Duchenne Muscular Dystrophy module of the Pediatric Quality of Life Inventory (PedsQLTMDMD) following international recommendations. The study objective was to carry out a confirmatory validation of the French version of the PedsQLTMDMD for paediatric patients with DMD, using French multicentre descriptive cross-sectional data. The sample consisted of 107 patients. Internal consistency was acceptable for proxy-assessments, with Cronbach's alpha coefficients above 0.70, except for the Treatment dimension. For self-assessments, internal consistency was acceptable only for the Daily Activities dimension. Our results showed poor metric qualities for the French version of the PedsQLTMDMD based on a sample of about 100 children, but these results remained consistent with those of the original validation. This confirms the interest of its use in clinical practice.

Early Intensive Bimanual Stimulation Program (BB-Bim) for Infants at Risk of Unilateral Cerebral Palsy: A Randomized, Multiple-Baseline, Single-Case Study.

IMPORTANCE: Clinical practice guidelines for infants at high risk of cerebral palsy (CP) emphasize the importance of very early and intensive intervention. OBJECTIVE: To determine the feasibility of a new, home-based, early intensive bimanual stimulation program (BB-Bim) and its impact on hand function in infants at risk of unilateral CP. DESIGN: Single case experimental design, multiple baseline across subjects, lasting from 12 to 15 wk, including a 4- to 7-wk randomized baseline, followed by 8 wk of BB-Bim. SETTING: Home. PARTICIPANTS: Infants (ages 3-12 mo) with suspected unilateral CP, whose parents agreed to participate in the stimulation program. INTERVENTION: Parent-provided bimanual stimulation 20 min/day, 6×/wk, with weekly occupational therapist coaching visits. MEASURES: Weekly repeated measures were the Hand Assessment in Infants (HAI) and Goal Attainment Scaling (GAS). Feasibility and relevance were assessed with a logbook and a parental report, including 10 continuous 0-10 scaled questions. RESULTS: Six infants were included (2 with left and 4 with right brain lesions). Parents provided a mean 3.4 to 6.2 stimulation sessions/wk. Feasibility and relevance were highly rated (Ms = 8.2-9.6, SDs = 0.2-1.3). Stimulation significantly improved HAI bimanual and total scores for all infants, with no impact on HAI unilateral scores. GAS scores improved with stimulation (significant for 3 infants). CONCLUSIONS AND RELEVANCE: BB-Bim was feasible and tended to improve bimanual function in infants at risk of unilateral CP. What This Article Adds: Parent-provided daily bimanual stimulation at home is feasible when parents are coached weekly by an occupational therapist. Bimanual stimulation seems to improve functional interactions between the hands among infants at high risk of unilateral CP.

Scoring People With Spinal Muscular Atrophy on the Motor Function Measure Using the Microsoft Kinect.

PURPOSE: Assess the ability of the Kinect to capture movement and posture of people with spinal muscular atrophy (SMA) during completion of 14 items of the Motor Function Measure, a validated functional rating scale for people with neuromuscular diseases. METHODS: Multicenter feasibility study in which Motor Function Measure items were scored as usual by the participant's therapist during the completion (Score-T) while another therapist scored items based only on the visualization of digital data collected using the Kinect (Score-D). Agreement and disagreement were investigated. RESULTS: Twenty people with SMA type 2 or 3 were participants; 142 items were recorded and analyzed. There was 31.7% agreement between Score-T and Score-D for participants with SMA type 2, and 76.2% for those with SMA type 3. CONCLUSIONS: The results prevent us from considering the use of Kinect capture to deduce an automated scoring, but this device may be of interest to highlight potential compensations.

Determining the Interrater Reliability of the SOFMER Activity Score (version 2) for Individuals in Rehabilitation Centers.

OBJECTIVE: To assess the interrater reliability of the SOFMER Activity Score (SAS) (version 2 [v2], an 8-item [4 motor and 4 cognitive] and 5-level scale) and improve its scoring system before conducting further validation steps. DESIGN: Cross-sectional, prospective, observational, noninterventional, and multicentric study. SETTING: The study was conducted between November 2018 and September 2019 in 4 French rehabilitation centers (2 public university hospitals for adults and 2 private not-for-profit rehabilitation centers for children). PARTICIPANTS: The study included 101 participants (N=101; mean age, 44.5±25.4 years; 28.7% younger than 18 and 18.8% older than 65 years). The female/male sex ratio was 0.6. The causes for admission to the center were mainly neurologic (65%) or orthopedic (24%). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Activity limitation was rated with the SAS the same day by 2 independent multidisciplinary teams. The interrater reliabilities of the score items were assessed using weighted kappa coefficients. RESULTS: All weighted kappa coefficients ranged between 0.83 and 0.92, indicating "good" to "excellent" interrater reliability. Interteam score disagreements occurred in 227 of 808 scores (28%). The reason for most disagreements was unnoticed human or material aid during the observation period. CONCLUSIONS: The results demonstrate the high interrater reliability of the SASv2 and allow carrying out further validation steps after minor changes to item scoring instructions and clearer definitions of some items that help improving scoring standardization. The SASv2 may then become a consistent measure of activity level for clinical research or burden of care investigations.

Perceived impact of lockdown on daily life in children with physical disabilities and their families during the COVID-19 pandemic.

BACKGROUND: The first lockdown during COVID-19 pandemic in France led to an abrupt change in children's daily lives. For children with physical disabilities and their families, activities were limited, access to healthcare and therapy was disrupted, and family organization was altered. The objective was to report the impact of the lockdown on daily life activities and well-being of children with physical disabilities as perceived by caregivers. METHODS: Two online national surveys were addressed to the parents of children with physical disabilities (ECHO survey: 6 April to 11 May 2020) and without disabilities (E-COPAIN survey: 24 April to 11 May 2020), confined at home during the lockdown. A lockdown impact score was calculated from difficulties related to children's well-being (morale, behaviour and social interaction) and daily life activities (schooling and physical activity) and compared between groups. Data on family environment, parental stress and concerns were collected. RESULTS: One thousand three hundred seventy-six children (9.45 ± 4.78 years, 54% girls) in ECHO survey and 367 children (7.3 ± 4.4 years, 48% girls) in E-COPAIN survey were included. A negative impact of lockdown was found on 81% of children with physical disabilities. Behavioural problems were significantly more frequent (59.5% vs. 47.4%, P < .005) and parental stress was higher (6.1 ± 3.33 vs. 5.3 ± 3.01, P = .005) in the ECHO group. Associated impairments (odds ratio [OR] = 1.45 [1.30-1.62], P < .001), parental stress (OR = 1.09 [1.06-1.12], P < .001) and continuation of rehabilitation (OR = 0.80 [0.72-0.89], P < .001) were determinants of the level of difficulty experienced. CONCLUSIONS: The lockdown had a considerable, negative impact on the daily life of children with disabilities and their families. Guiding policymakers with the essential daily life activities and the services to provide for children with physical disabilities would offer valuable insights to manage such a sanitary crisis and allow to identify the most vulnerable population.

Understanding the relationship between the 32-item motor function measure and daily activities from an individual with spinal muscular atrophy and their caregivers' perspective: a two-part study.

BACKGROUND: The 32-item Motor Function Measure (MFM32) is a clinician-reported outcome measure used to assess the functional abilities of individuals with neuromuscular diseases, including those with spinal muscular atrophy (SMA). This two-part study explored the relationship between the functional abilities assessed in the MFM32 and activities of daily living (ADLs) from the perspective of individuals with Type 2 and Type 3 (non-ambulant and ambulant) SMA and their caregivers through qualitative interviews and a quantitative online survey. METHODS: In-depth, semi-structured, qualitative interviews were conducted with individuals with SMA and caregivers from the US. Subsequently, a quantitative online survey was completed by individuals with SMA or their caregivers from France, Germany, Italy, Poland, Spain, Canada, the United States (US) and the UK. In both parts of the study, participants were asked to describe the ADLs considered to be related to the functional abilities assessed in the MFM32. Results from the qualitative interviews informed the content of the quantitative online survey. RESULTS: Qualitative interviews were conducted with 15 adult participants, and 217 participants completed the quantitative online survey. From the qualitative interviews, all of the functional abilities assessed in the patient-friendly MFM32 were deemed as related to one or more ADL. The specific ADLs that participants considered related to the patient-friendly MFM32 items could be grouped into 10 key ADL domains: dressing, mobility/transferring, self-care, self-feeding, reaching, picking up and holding objects, physical activity, writing and technology use, social contact/engagement, toileting and performing work/school activities. These results were confirmed by the quantitative online survey whereby the ADLs reported to be related to each patient-friendly MFM32 item were consistent and could be grouped into the same 10 ADL domains. CONCLUSION: This study provides in-depth evidence from the patient/caregiver perspective supporting the relevance of the patient-friendly MFM32 items to the ADLs of individuals with Type 2 and Type 3 SMA.

Elementary visuospatial perception deficit in children with neurodevelopmental disorders.

AIM: To assess the prevalence of elementary visuospatial perception (EVSP) deficit in children with neurodevelopmental disorders. METHOD: Using a screening test designed and validated to measure dorsal EVSP ability, 168 children (122 males, 46 females; mean age 10y [SD 1y 10mo], range 4y 8mo-16y 4mo) diagnosed with developmental coordination disorder (DCD), specific learning disorder (SLD), attention-deficit/hyperactivity disorder (ADHD), and/or oral language disorder were compared with a group of 184 typically developing children. We also tested 14 children with binocular vision dysfunction and no neurodevelopmental disorder. RESULTS: Children with SLD scored below the interquartile range of typically developing children as frequently (59%) as children with DCD, but only 5% were severely impaired (i.e. scored as outliers). Children with DCD were the most severely impaired (22% of outliers), even more so when they exhibited a co-occuring disorder. Children with language disorder and those with binocular vision dysfunction scored similarly to the group of typically developing children. INTERPRETATION: These results confirm the importance of assessing EVSP in the clinical evaluation of children with neurodevelopmental disorders, in particular those presenting with DCD or SLD. What this paper adds More than half of children with developmental coordination disorder (DCD) scored below the normal interquartile range on the elementary visuospatial perception (EVSP) test. More than half of children with specific learning disorder (SLD) scored below the normal interquartile range on the EVSP test. Twenty-two percent of children with DCD performed as outliers on the EVSP test. Children with language disorder and those with binocular vision dysfunction scored similarly to typically developing children.

Responsiveness and Minimal Clinically Important Difference of the Motor Function Measure in Collagen VI-Related Dystrophies and Laminin Alpha2-Related Muscular Dystrophy.

OBJECTIVES: To investigate the responsiveness of the motor function measure (MFM) and determine the minimal clinically important difference (MCID) in individuals with 2 common types of congenital muscular dystrophy (CMD). DESIGN: Observational, prospective, single center, cohort study. SETTING: National Institute of Neurological Disorders and Stroke (NINDS) of the National Institutes of Health (NIH). PARTICIPANTS: Individuals (N=44) with collagen VI-related dystrophies (COL6-RD, n=23) and 21 individuals laminin alpha2-related muscular dystrophy (LAMA2-RD, n=21) enrolled in a 4-year longitudinal natural history study. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Responsiveness of the MFM-32 and the Rasch-scaled MFM-25 and the MCID of the MFM-32 determined from a patient-reported anchor with 2 different methods, within-patient and between-patient. RESULTS: The original MFM-32 and Rasch-scaled MFM-25 performed similarly overall in both the COL6-RD and LAMA2-RD populations, with all subscores (D1, standing and transfers; D2, axial and proximal; D3, distal) showing a significant decrease over time, except MFM D1 and D3 for LAMA2-RD. The MFM D1 subscore was the most sensitive to change for ambulant individuals, whereas the MFM D2 subscore was the most sensitive to change for nonambulant individuals. The MCID for the MFM-32 total score was calculated as 2.5 and 3.9 percentage points according to 2 different methods. CONCLUSIONS: The MFM showed strong responsiveness in individuals with LAMA2-RD and COL6-RD. Because a floor effect was identified more prominently with the Rasch-Scaled MFM-25, the use of the original MFM-32 as a quantitative variable with the assumption of scale linearity appears to be a good compromise. When designing clinical trials in congenital muscular dystrophies, the use of MCID for MFM should be considered to determine if a given intervention effects show not only a statistically significant change but also a clinically meaningful change.

Congenital Titinopathy: Comprehensive characterization and pathogenic insights.

OBJECTIVE: Comprehensive clinical characterization of congenital titinopathy to facilitate diagnosis and management of this important emerging disorder. METHODS: Using massively parallel sequencing we identified 30 patients from 27 families with 2 pathogenic nonsense, frameshift and/or splice site TTN mutations in trans. We then undertook a detailed analysis of the clinical, histopathological and imaging features of these patients. RESULTS: All patients had prenatal or early onset hypotonia and/or congenital contractures. None had ophthalmoplegia. Scoliosis and respiratory insufficiency typically developed early and progressed rapidly, whereas limb weakness was often slowly progressive, and usually did not prevent independent walking. Cardiac involvement was present in 46% of patients. Relatives of 2 patients had dilated cardiomyopathy. Creatine kinase levels were normal to moderately elevated. Increased fiber size variation, internalized nuclei and cores were common histopathological abnormalities. Cap-like regions, whorled or ring fibers, and mitochondrial accumulations were also observed. Muscle magnetic resonance imaging showed gluteal, hamstring and calf muscle involvement. Western blot analysis showed a near-normal sized titin protein in all samples. The presence of 2 mutations predicted to impact both N2BA and N2B cardiac isoforms appeared to be associated with greatest risk of cardiac involvement. One-third of patients had 1 mutation predicted to impact exons present in fetal skeletal muscle, but not included within the mature skeletal muscle isoform transcript. This strongly suggests developmental isoforms are involved in the pathogenesis of this congenital/early onset disorder. INTERPRETATION: This detailed clinical reference dataset will greatly facilitate diagnostic confirmation and management of patients, and has provided important insights into disease pathogenesis. Ann Neurol 2018;83:1105-1124.

Motor function performance in individuals with RYR1-related myopathies.

INTRODUCTION: The objective of this study was to obtain a 6-month natural history of motor function performance in individuals with RYR1- related myopathy (RYR1-RM) by using the Motor Function Measure-32 (MFM-32) and graded functional tests (GFT) while facilitating preparation for interventional trials. METHODS: In total, 34 participants completed the MFM-32 and GFTs at baseline and 6-month visits. RESULTS: Motor deficits according to MFM-32 were primarily observed in the standing and transfers domain (D1; mean 71%). Among the GFTs, participants required the most time to ascend/descend stairs (>7.5 s). Functional movement, determined by GFT grades, was strongly correlated with MFM-32 (D1; r ≥ 0.770, P < 0.001). Motor Function Measure-32 and GFT scores did not reflect any change in performance between baseline and 6-month visits. DISCUSSION: The MFM-32 and GFTs detected motor impairment in RYR1-RM, which remained stable over 6 months. Thus, these measures may be suitable for assessing change in motor function in response to therapeutic intervention. Muscle Nerve 60: 80-87, 2019.

Mathematical Disease Progression Modeling in Type 2/3 Spinal Muscular Atrophy.

INTRODUCTION: We propose a mathematical model to empirically describe spinal muscular atrophy (SMA) progression assessed by the 3 domains of the motor function measure (MFM) scale. The model implements development and deterioration of muscle function. METHODS: Nonlinear mixed-effects modeling was applied to data from 2 observational studies and 1 prospective clinical efficacy study comprising 190 healthy participants and 277 patients with type 2/3 SMA. RESULTS: The model evidenced correlations between parameter estimates for different MFM domains. Slower development in MFM domain D1 (standing and transfers) was associated with faster deterioration for MFM domains D2 (proximal and axial motricity) and D3 (distal motor function). DISCUSSION: The model describes all individual data well, although sparseness and variability of observational data prevented numerically stable estimation of parameters. Treatment duration in clinical studies was too limited to determine a proper drug-effect model that could differentiate between symptomatic and disease modifying effects. Muscle Nerve 58: 528-535, 2018.

Electrical impedance myography in individuals with collagen 6 and laminin α-2 congenital muscular dystrophy: a cross-sectional and 2-year analysis.

INTRODUCTION: Electrical impedance myography (EIM) is a noninvasive electrophysiological technique that characterizes muscle properties through bioimpedance. We compared EIM measurements to function, strength, and disease severity in a population with congenital muscular dystrophy (CMD). METHODS: Forty-one patients with CMD, either collagen 6 related disorders (COL6-RD; n = 21) or laminin α-2-related disorders (LAMA2-RD; n = 20), and 21 healthy pediatric controls underwent 2 yearly EIM exams. In the CMD cohorts, EIM was compared with functional and strength measurements. RESULTS: Both CMD cohorts exhibited change over time and had correlation with disease severity. The 50-kHZ phase correlated well with function and strength in the COL6-RD cohort but not in the LAMA2-RD cohort. DISCUSSION: EIM is a potentially useful measure in clinical studies with CMD because of its sensitivity to change over a 1-year period and correlation with disease severity. For COL6-RD, there were also functional and strength correlations. Muscle Nerve 57: 54-60, 2018.

Corticosteroids in Duchenne muscular dystrophy: impact on the motor function measure sensitivity to change and implications for clinical trials.

AIM: To monitor the evolution of the motor function of ambulatory patients with Duchenne muscular dystrophy (DMD) treated by corticosteroids for 2 years in comparison with untreated patients. METHOD: This observational, multicentre cohort study explores the evolution of the motor function measure (MFM) over a 24-month period for 29 ambulant corticosteroids-treated and 45 ambulant untreated patients with DMD. RESULTS: Significant differences were found between mean MFM scores in corticosteroids-treated and untreated groups for domain 1 of the MFM (standing position and transfers; D1), domain 2 of the MFM (axial and proximal motor function; D2), and domain 3 of the MFM (distal motor function; D3). Subscores were between 0 months and 6 months, and 0 months and 24 months. For the D1 subscore specifically, there was a significant increase in the corticosteroids-treated group (mean±standard deviation [SD] slope of change=12.6±15.5%/y), while a decrease was observed in the untreated group (-17.8±17.7%/y) between 0 months and 6 months (p<0.001). Sensitivity to change as assessed by standardized response means was high between 12 months and 24 months for D1 of both corticosteroids-treated and untreated groups (1.0 and 1.2 respectively), and low for D2 and D3 of both treated and untreated groups. INTERPRETATION: Patients with DMD treated by corticosteroids present a different course of the disease as assessed by MFM, confirming the sensitivity to change of the MFM in this population. WHAT THIS PAPER ADDS: Corticosteroids have a quantitative impact on muscle strength 6 to 24 months after starting treatment. Motor function measure is a valid outcome measure in Duchenne muscular dystrophy patients under corticosteroid treatment.

Is Going Beyond Rasch Analysis Necessary to Assess the Construct Validity of a Motor Function Scale?

OBJECTIVE: To examine whether a Rasch analysis is sufficient to establish the construct validity of the Motor Function Measure (MFM) and discuss whether weighting the MFM item scores would improve the MFM construct validity. DESIGN: Observational cross-sectional multicenter study. SETTING: Twenty-three physical medicine departments, neurology departments, or reference centers for neuromuscular diseases. PARTICIPANTS: Patients (N=911) aged 6 to 60 years with Charcot-Marie-Tooth disease (CMT), facioscapulohumeral dystrophy (FSHD), or myotonic dystrophy type 1 (DM1). INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): Comparison of the goodness-of-fit of the confirmatory factor analysis (CFA) model vs that of a modified multidimensional Rasch model on MFM item scores in each considered disease. RESULTS: The CFA model showed good fit to the data and significantly better goodness of fit than the modified multidimensional Rasch model regardless of the disease (P<.001). Statistically significant differences in item standardized factor loadings were found between DM1, CMT, and FSHD in only 6 of 32 items (items 6, 27, 2, 7, 9 and 17). CONCLUSIONS: For multidimensional scales designed to measure patient abilities in various diseases, a Rasch analysis might not be the most convenient, whereas a CFA is able to establish the scale construct validity and provide weights to adapt the item scores to a specific disease.

Thigh Ultrasound Monitoring Identifies Decreases in Quadriceps Femoris Thickness as a Frequent Observation in Critically Ill Children.

OBJECTIVES: Significant muscle wasting develops in critically ill adults, with subsequent worse outcomes. In the pediatric setting, occurrence and effects of muscle wasting are undescribed; this is in part due to a lack of validated, objective methods for assessing muscle wasting. A single measurement of quadriceps femoris thickness has failed to show consistent reproducibility. We hypothesized that averaging repeated measurements could afford good reproducibility to allow for quadriceps femoris thickness decline detection and monitoring. DESIGN: A prospective bedside observational study. SETTING: Two PICUs. PATIENTS: Mechanically ventilated critically ill children were 15 years and younger. INTERVENTIONS: Transverse and longitudinal axis measurements of quadriceps femoris anterior thickness were undertaken using bedside ultrasound. The average of four measurement values was recorded. The location of measurement was marked for consistency within subsequent measurements by the same or another trained operator, to assess intra- and interoperator repeatability and reproducibility of the technique. Where feasible, serial measurements were undertaken until the time of extubation in a group of children with prolonged PICU stay (> 5 d). MEASUREMENTS AND MAIN RESULTS: Seventy-three children were enrolled to assess intra- and interoperator ultrasound reliability. Their median (25-75 interquartile range) age and weight were 30 months (4.5-96) and 10 kg (5-23.5). In the intraoperator repeatability study, mean relative difference in quadriceps femoris muscle thickness was 0.36% ± 2.5% (lower and upper limits of agreement: -4.5/+5.2%). In the interoperator reproducibility study, intraclass correlation coefficient was 0.998. In the 17 children monitored over their PICU stay, quadriceps femoris thickness significantly decreased at day 5 by 9.8% (p = 0.006) and by 13.3% (< 0.001) at the last performed measurement. CONCLUSIONS: Quadriceps femoris thickness decrease, proposed as a surrogate for muscle mass, is an early, frequent, and intense phenomenon in PICU. Quadriceps femoris ultrasonography is a reliable technique to monitor this process and in future could help to guide rehabilitation and nutrition interventions.

Rasch analysis of the motor function measure in patients with congenital muscle dystrophy and congenital myopathy.

OBJECTIVES: To monitor treatment effects in patients with congenital myopathies and congenital muscular dystrophies, valid outcome measures are necessary. The Motor Function Measure (MFM) was examined for robustness, and changes are proposed for better adequacy. DESIGN: Observational study based on data previously collected from several cohorts. SETTING: Nineteen departments of physical medicine or neuromuscular consultation in France, Belgium, and the United States. PARTICIPANTS: Patients (N=289) aged 5 to 77 years. INTERVENTIONS: None. MAIN OUTCOME MEASURES: A Rasch analysis examined the robustness of the MFM across the disease spectrum. The 3 domains of the scale (standing position and transfers, axial and proximal motor function, and distal motor function) were independently examined with a partial credit model. RESULTS: The original 32-item MFM did not sufficiently fit the Rasch model expectations in either of its domains. Switching from a 4- to a 3-category response scale in 18 items restored response order in 16. Various additional checks suggested the removal of 7 items. The resulting Rasch-scaled Motor Function Measure with 25 items for congenital disorders of the muscle (Rs-MFM25(CDM)) demonstrated a good fit to the Rasch model. Domain 1 was well targeted to the whole severity spectrum-close mean locations for items and persons (0 vs 0.316)-whereas domains 2 and 3 were better targeted to severe cases. The reliability coefficients of the Rs-MFM25(CDM) suggested sufficient ability for each summed score to distinguish between patient groups (0.9, 0.8, and 0.7 for domains 1, 2, and 3, respectively). A sufficient agreement was found between results of the Rasch analysis and physical therapists' opinions. CONCLUSIONS: The Rs-MFM25(CDM) can be considered a clinically relevant linear scale in each of its 3 domains and may be soon reliably used for assessment in congenital disorders of the muscle.