Quantitative Foot Muscle Magnetic Resonance Imaging Reliably Measures Disease Progression in Children and Adolescents with Charcot-Marie-Tooth Disease Type 1A.

Quantitative muscle fat fraction (FF) responsiveness is lower in younger Charcot-Marie-Tooth disease type 1A (CMT1A) patients with lower baseline calf-level FF. We investigated the practicality, validity, and responsiveness of foot-level FF in this cohort involving 22 CMT1A patients and 14 controls. The mean baseline foot-level FF was 25.9 ± 20.3% in CMT1A patients, and the 365-day FF (n = 15) increased by 2.0 ± 2.4% (p < 0.001 vs controls). Intrinsic foot-level FF demonstrated large responsiveness (12-month standardized response mean (SRM) of 0.86) and correlated with the CMT examination score (ρ = 0.58, P = 0.01). Intrinsic foot-level FF has the potential to be used as a biomarker in future clinical trials involving younger CMT1A patients. ANN NEUROL 2024;96:170-174.

Patient-Reported Impact of Symptoms in Fibromyalgia (PRISM-FM).

OBJECTIVE: To identify the frequency and relative importance of symptoms experienced by adults with fibromyalgia (FM) and determine factors associated with a higher disease burden. METHODS: We conducted semistructured interviews with 15 participants with FM, collecting 1479 quotes regarding the symptomatic burden of FM. We then performed an international cross-sectional study involving 1085 participants with FM to determine the prevalence and relative importance (scale 0-4) of 149 symptoms representing 14 symptomatic themes. We performed subgroup analysis to determine how age, sex, disease duration, medication use, employment status, change in employment status, missing work due to FM, and ability level are related to symptomatic theme prevalence. RESULTS: The symptomatic themes with the highest prevalence in FM were pain (99.8%), muscle tenderness (99.8%), and fatigue (99.3%). The symptomatic themes that had the greatest effect on patients' lives were related to fatigue (2.88), pain (2.85), muscle tenderness (2.79), and impaired sleep and daytime sleepiness (2.70). Symptomatic theme prevalence was most strongly associated with the modified Rankin Scale level of disability, disability status, and change in employment status (on disability vs not on disability). CONCLUSION: Participants with FM identify a variety of symptoms that significantly affect their daily lives. Many of these symptoms, such as fatigue, sleep disturbance, and activity limitation, are life-altering and not related to traditional diagnostic criteria. Symptom prevalence in this population varies across subgroups based on demographic categories and disability status.

A longitudinal study of disease progression in facioscapulohumeral muscular dystrophy (FSHD).

INTRODUCTION/AIMS: In preparation for clinical trials, it is important to better understand how disease burden changes over time in facioscapulohumeral muscular dystrophy (FSHD) and to assess the capability of select metrics to detect these changes. This study aims to evaluate FSHD disease progression over 1 year and to examine the sensitivity of several outcome measures in detecting changes during this interval. METHODS: We conducted a 12-month prospective observational study of 41 participants with FSHD. Participants were evaluated at baseline, 6 months, and 12 months with serial strength testing (manual muscle testing or MMT and maximum voluntary isometric contraction testing or MVICT), functional testing (FSHD-Composite Outcome Measure or FSHD-COM, FSHD Clinical Severity Score or CSS, and FSHD Evaluation Score or FES), sleep and fatigue assessments, lean body mass measurements, respiratory testing, and the FSHD-Health Index patient-reported outcome. Changes in these outcome measures were assessed over the 12-month period. Associations between changes in outcome measures and both age and sex were also examined. RESULTS: In a 12-month period, FSHD participant function remained largely stable with a mild worsening of strength, measured by MMT and standardized MVICT scores, and a mild loss in lean body mass. DISCUSSION: The abilities and disease burden of adults with FSHD are largely static over a 12-month period with participants demonstrating a mild average reduction in some measures of strength. Selection of patients, outcome measures, and trial duration should be carefully considered during the design and implementation of future clinical studies involving FSHD patients.

Patient- and caregiver-reported impact of symptoms in Duchenne muscular dystrophy.

INTRODUCTION/AIMS: To better understand the disease burden faced by individuals with Duchenne muscular dystrophy (DMD) of all ages and elucidate potential targets for therapeutics, this study determined the prevalence and relative importance of symptoms experienced by individuals with DMD and identified factors associated with a higher disease burden. METHODS: We conducted qualitative interviews with individuals with DMD and caregivers of individuals with DMD to identify potential symptoms of importance to those living with DMD. We subsequently performed a cross-sectional study to assess which symptoms have the highest prevalence and importance in DMD and to determine which factors are associated with a higher disease burden. RESULTS: Thirty-nine individuals, aged 11 years and above, provided 3262 quotes regarding the symptomatic burden of DMD. Two hundred participants (87 individuals with DMD and 113 caregivers) participated in a subsequent cross-sectional study. Individuals with DMD identified limitations with mobility or walking (100%), inability to do activities (98.9%), trouble getting around (97.6%), and leg weakness (97.6%) as the most prevalent and life altering symptomatic themes in DMD. The symptomatic themes with the highest prevalence, as reported by caregivers on behalf of those with DMD for whom they care, were limitations with mobility or walking (90.3%), leg weakness (89.2%), and emotional issues (79.6%). Steroid/glucocorticoid use (e.g., prednisone or deflazacort) was associated with a lower level of disease burden in DMD. DISCUSSION: There are many symptomatic themes that contribute to disease burden in individuals with DMD. These symptoms are identified by both individuals with DMD and their caregivers and have a variable level of importance and prevalence in the DMD population.

The Crohn's Disease-Health Index: Development and Evaluation of a Novel Outcome Measure.

OBJECTIVE: We sought to develop and validate the Crohn's Disease-Health Index (CD-HI), a disease-specific, patient-reported outcome measure that serially measures Crohn's disease (CD) symptomatic burden in adults with CD. BACKGROUND: As therapeutic interventions are tested among patients with CD, responsive outcome measures are needed to track disease progression and therapeutic gain during clinical trials. PATIENTS AND METHODS: We conducted a national cross-sectional study of individuals with CD to identify the most prevalent and impactful symptoms of CD. The most relevant symptoms were included in the CD-HI. We used factor analysis, qualitative patient interviews, test-retest reliability evaluation, and known group validity testing to evaluate and optimize the CD-HI. RESULTS: The CD-HI contains 12 subscales that comprehensively measure CD burden using the patient's perspective. Fifteen adults with CD beta tested the CD-HI and found the instrument to be clear, easy to use, and relevant to them. Twenty-three adults with CD participated in an assessment of test-retest reliability, which indicated high reliability of individual questions, subscales, and the full instrument (intraclass correlation coefficient = 0.84 for the full instrument). The CD-HI and its subscales demonstrated a high internal consistency (Cronbach α = 0.98 for the full instrument). The CD-HI distinguished between groups of individuals with CD known to differ in disease severity. CONCLUSIONS: This research supports the use of the CD-HI as a valid, sensitive, reliable, and relevant patient-reported outcome to determine the multifactorial disease burden of those with CD, assess the relevance and merit of future CD therapies, and support drug labeling claims.

The Facioscapulohumeral Muscular Dystrophy-Health Index: Development and evaluation of a disease-specific outcome measure.

INTRODUCTION/AIMS: As promising therapeutic interventions are tested among patients with facioscapulohumeral muscular dystrophy (FSHD), there is a clear need for valid and reliable outcome tools to track disease progression and therapeutic gain in clinical trials and for clinical monitoring. Our aim was to develop and validate the Facioscapulohumeral Muscular Dystrophy-Health Index (FSHD-HI) as a multifaceted patient-reported outcome measure (PRO) designed to measure disease burden in adults with FSHD. METHODS: Through initial interviews with 20 individuals and a national cross-sectional study with 328 individuals with FSHD, we identified the most prevalent and impactful symptoms in FSHD. The most relevant symptoms were included in the FSHD-HI. We used patient interviews, test-retest reliability evaluation, known groups validity testing, and factor analysis to evaluate and optimize the FSHD-HI. RESULTS: The FSHD-HI contains 14 subscales that measure FSHD disease burden from the patient's perspective. Fourteen adults with FSHD participated in semistructured beta interviews and found the FSHD-HI to be clear, usable, and relevant to them. Thirty-two adults with FSHD participated in test-retest reliability assessments, which demonstrated the high reliability of the FSHD-HI total score (intraclass correlation coefficient = 0.924). The final FSHD-HI and its subscales also demonstrated a high internal consistency (Cronbach α = 0.988). DISCUSSION: The FSHD-HI provides researchers and clinicians with a reliable and valid mechanism to measure multifaceted disease burden in patients with FSHD. The FSHD-HI may facilitate quantification of therapeutic effectiveness, as demonstrated by its use as a secondary and exploratory measure in several clinical trials.

Assessing Prevalence and Characteristics of Oro-bulbar Involvement in Children and Adults with SMA Type 2 and 3 Using a Multimodal Approach.

Bulbar and jaw muscles are impaired in patients with Spinal Muscular Atrophy (SMA) but the assessment of their severity and progression are limited by the lack of age-appropriate and disease-specific measures. We investigated mastication and swallowing in children and adults with SMA, sitters and walkers. In a 2-year multicentre cross-sectional prospective study, lip and tongue strength (Iowa Oral Performance Instrument), chewing and swallowing (Test of Masticating and Swallowing Solids), active mouth opening (aMMO) were compared to age-appropriate normative data. The perceived burden of oro-bulbar involvement (SMA-Health Index) was recorded. 78 patients were included, 45 children (median age 7.4 years),22 adults (median age 26.8 years) on nusinersen and 11 untreated (median age 32.7 years). Forty-three percent children had reduced mouth opening, 50% had prolonged total time to eat. These issues were more prominent in sitters than in walkers (p = 0.019, p = 0.014). Sixty-six percent needed increased swallows for bolus clearance. Nusinersen treated adults had median aMMO, tongue strength and total time at TOMASS values within normal range (z score: -1.40, -1.22, -1.32, respectively) whereas untreated adults had reduced aMMO (z score: -2.68) and tongue strength (z score: -2.20). Only a minority of children (2/17) and treated adults (5/21) reported burden in swallowing or mastication compared to all untreated adults (5/5). After 16 months, mastication and swallowing were stable in treated children and adults, whether sitters or walkers. The reported multimodal approach to assess oro-bulbar functions demonstrate that swallowing and mastication are impaired in SMA despite patients' perception. These results suggest a trend towards stabilization of oro-bulbar function in patients on long-term treatment with nusinersen.

Patient-Reported Impact of Symptoms in Crohn's Disease.

INTRODUCTION: Patients with Crohn's disease (CD) experience a variety of symptoms that significantly affect their lives. In this study, we (i) ascertain the most prevalent and impactful symptoms in CD and (ii) identify modifying factors that are associated with a higher disease burden in CD. METHODS: We conducted semistructured interviews with adult participants with CD to determine what issues have the greatest impact on their lives. Next, we conducted a large cross-sectional study of individuals with CD to determine the prevalence and relative importance of those symptoms and themes and to identify the demographic features that are associated with a higher disease burden. RESULTS: Sixteen individuals with CD provided 792 direct quotes regarding their symptomatic burden. Four hundred three people with CD participated in our cross-sectional study. The symptomatic themes with the highest prevalence in CD were gastrointestinal issues (93.0%), fatigue (86.4%), dietary restrictions (77.9%), and impaired sleep or daytime sleepiness (75.6%). The symptomatic themes that had the greatest impact on patients' lives (0-4 scale) related to fatigue (1.82), impaired sleep or daytime sleepiness (1.71), gastrointestinal issues (1.66), and dietary restrictions (1.61). Symptomatic theme prevalence was strongly associated with a higher number of soft stools per day, greater number of bowel movements per day, missed work, employment and disability status, and having perianal disease. DISCUSSION: Patients with CD experience numerous symptoms that affect their daily life. These symptoms, some underrecognized, vary based on disease and demographic characteristics and represent potential targets for future therapeutic interventions.

Assessing perspectives of disease burden and clinically meaningful changes using the Spinal Muscular Atrophy Health Index in adolescents and young adults.

INTRODUCTION/AIMS: Spinal muscular atrophy (SMA) treatment may increase survival and improve physical function among adolescents and young adults. Validated patient-reported outcome measures are needed to understand which treatment benefits are clinically meaningful and to develop targeted resources for this population. To date, use of the SMA Health Index (SMA-HI) in pediatric and young adult populations has been limited. Here, we report results from a survey of adolescents and young adults with SMA to quantifiably understand individuals' perceptions of disease burden. METHODS: Participants aged 12-25 y with a self-reported diagnosis of SMA completed an online survey containing demographic questions and the SMA-HI, a patient-reported outcome measure that assesses individuals' perceptions of disease burden in 15 symptomatic areas. RESULTS: Eighty-eight participants completed the survey. Total SMA-HI scores and SMA-HI subscale scores including shoulder and arm function; back, chest, and abdominal function; activity participation; hand and finger strength; swallowing function; gastrointestinal function; respiratory function; mobility and ambulation, and total disease burden were significantly higher (greater disease burden) in patients with poorer motor function and severe SMA. SMA-HI total and subscale scores were generally lower in adolescents (12-17 y old) versus adults (18-25 y old), suggesting a possible progression of symptomatic disease burden over time. DISCUSSION: This study demonstrates the utility of the SMA-HI for measuring clinically relevant disease burden in adolescents and young adults with SMA. This study demonstrates how disease burden varies by age, SMA type, and other demographics.

P047 The Crohn's Disease-Health Index (CD-HI): Development and Validation of a Novel, Disease-Specific Patient Reported Outcome Measure for Clinical Trials.

BACKGROUND: In preparation for upcoming clinical trials involving patients with Crohn's disease (CD), we examine the validity, reliability and usability of the Crohn's Disease-Health Index (CD-HI). The CD-HI is a multifaceted, disease-specific patient reported outcome measure (PROM) designed to measure CD symptomatic disease burden during clinical trials. As promising therapeutic interventions are being tested among CD patients, there is a clear need for researchers to have access to a valid, sensitive, and reliable patient reported outcome tool to track disease burden. This research describes the development and validation of the CD-HI as an efficient mechanism to quantify how CD patients both feel and function. METHODS: We conducted semi-structured, qualitative interviews with CD patients to identify potential symptoms of importance in CD. We then conducted a large, cross-sectional survey study with CD patients to identify the prevalence and importance of symptoms identified during the prior interviews. Symptom questions in the first version of the CD-HI were selected based on overall frequency and impact in a large population of CD patients, generalizability, and potential to respond to therapeutic intervention. Questions which measured a similar concept were grouped into subscales using factor analysis. The first version of the CD-HI was beta tested to explore the usability and relevance of the instrument to patients. We then performed test-retest reliability of each question and subscale. Lastly, we determined the internal consistency for each subscale and the overall instrument. The CD-HI is now finalized and available for use in upcoming clinical trials. RESULTS: Sixteen adults with CD participated in semi-structured qualitative interviews, providing 792 quotes regarding the symptomatic burden of CD. Four hundred and three adults with CD completed an online survey to determine the prevalence and relative importance of 148 patient identified symptoms. Questions were selected for the CD-HI based on their prevalence and relative importance to CD patients. Sixteen adults with CD participated in beta interview testing to address the usability and relevance of the instrument. Patients found the CD-HI to be clear, highly relevant, and easy to use. Test-retest reliability was conducted with twenty-three adults with CD, where participants completed the CD-HI at baseline and fourteen days later. One question was removed to optimize the overall reliability of the instrument. The final version of the CD-HI contains subscales that measure the following granular areas of CD health: 1) fatigue; 2) dietary restrictions; 3) gastrointestinal health; 4) sleep and daytime sleepiness; 5) bowel and bladder function; 6) emotional health; 7) joint health; 8) pain; 9) neck and back health; 10) activity participation; 11) social health; and 12) skin health. Total CD disease burden is measured using a weighted composite of these subscale scores. CONCLUSION: This research successfully demonstrates the ability of the CD-HI to report valid, reliable, and patient-relevant data as a disease-specific PROM. The CD-HI provides researchers and clinicians with an optimal mechanism to record relevant changes in CD health using the patient's perspective.

A patient-focused survey to assess the effects of the COVID-19 pandemic and social guidelines on people with muscular dystrophy.

INTRODUCTION/AIMS: In this study, we examined the social and health impacts of the coronavirus disease 2019 (COVID-19) pandemic and social guidelines on people with muscular dystrophies. METHODS: A prospective de-identified electronic survey was distributed to adults with self-reported facioscapulohumeral muscular dystrophy (FSHD), myotonic dystrophy (DM), and limb-girdle muscular dystrophy (LGMD) enrolled in national registries or with patient advocacy groups. The COVID-19 Impact Survey was developed by muscular dystrophy experts in association with patient collaborators and advocacy groups. The Perceived Stress Scale was used to measure perceived stress. RESULTS: Respondents (n = 774: 56% FSHD; 35% DM, and 9% LGMD) were mostly women and middle-aged (range 19-87 y). Rates of COVID-19 infections were low (<1%), compliance with local social distancing guidelines and policies high (98%). Major challenges reported during the pandemic included: obtaining treatment (40%), managing stress (37%), social distancing (36%), and obtaining essentials (34%). The majority reported a slight worsening in their disease state. Respondents reported moderate stress levels (stress score = 15.4; range = 0-35), with higher stress levels reported by women and those under age 30 y. Three-quarters of participants who participated in telemedicine visits were satisfied with the encounters; however, most reported a preference for in-person visits. DISCUSSION: People with muscular dystrophy reported moderate stress and challenges during the COVID-19 pandemic. Interventions such as exercise and stress-coping strategies, including strategies specific to women or individuals <30 y, may be important. Further investigation is needed into the role of telemedicine in the care of individuals with muscular dystrophy.

The Spinal Muscular Atrophy Health Index: A novel outcome for measuring how a patient feels and functions.

INTRODUCTION: The Spinal Muscular Atrophy Health Index (SMA-HI) is a multifaceted, disease-specific, patient-reported outcome to measure an SMA patient's perception of their disease burden. In preparation for upcoming therapeutic trials, we examine the validity, reliability, and usability of the SMA-HI in adults, teenagers, and children with SMA. METHODS: Using data from a cross-sectional study of 359 international adult patients with SMA, we identified the most relevant symptoms to include in the SMA-HI. We utilized factor analysis, patient interviews with adults and minors (age 8-15 years), known-group validity testing, and test-retest reliability assessments to evaluate and refine the SMA-HI. RESULTS: The SMA-HI measures overall disease burden and 15 areas of SMA health. Fifteen adult patients and five patients, age 8 to 15 years, participated in semistructured qualitative interviews and found the SMA-HI to be comprehensive, easily completed, and to have clear meaning. The final SMA-HI and its subscales demonstrated good internal consistency (Cronbach α = 0.77-0.96), high test-retest reliability (intraclass correlation coefficient = 0.60-0.96), and an ability to differentiate between SMA groups with different disease severities affecting areas such as employment and ambulation (P < .0001 for both). DISCUSSION: This research provides evidence that the SMA-HI is a valid, relevant, and reliable outcome measure to assess multifaceted patient-reported disease burden in older children, teenagers, and adults with SMA. The SMA-HI provides an opportunity for researchers and clinicians to measure a SMA patient's perception of their health and determine relevant changes in response to therapeutic intervention or disease progression.

Validation of the Italian version of the Charcot-Marie-Tooth Health Index.

The Charcot-Marie-Tooth Health Index (CMT-HI) is a disease-specific patient-reported outcome measure measuring overall disease burden in Charcot-Marie-Tooth (CMT) patients, designed for natural history studies and clinical trials in English-speaking affected individuals. We developed and validated its Italian Charcot-Marie-Tooth Health Index (I-CMT-HI) version. The questionnaire was translated and culturally adapted from source into Italian by two neurologists experienced in CMT and neuromuscular disorders (NMDs). The two translations were reviewed by a panel of seven experts in CMT and NMD. The provisional version was back-translated into English by a professional translator. The definitive Italian version was developed during a consensus teleconference by the panel and a patient representative from ACMT-Rete. A series of clinically and genetically characterized CMT patients completed the final questionnaire; 11 participated in a test-retest reliability assessment of the instrument. The I-CMT-HI was administered to 30 CMT patients (13 CMT1A, eight CMTX1, two CMT1B, two CMT1E, two CMT2I, one CMT2A, one CMT2N, one distal Hereditary Motor Neuropathy), with test-rest in 11:14 females and 16 males, aged (mean ± SD) 48.0 ± 16.4 years (range 18-81), with CMT Examination Score (CMTES) = 10.0 ± 4.4 (range 2-18). The I-CMT-HI mean total score was 29.4 ± 21.2 (range 0.1-60.3). The I-CMT-HI showed a high test-retest reliability: intraclass correlation coefficient = 0.95 (95% confidence interval, 0.84-0.99). No patient had difficulty in completing the questionnaire and none reported any problem with the questions' formulation. The total CMT-HI score was positively correlated with age and CMTES, with higher disease burden with increasing age and disease severity according to the CMTES. The I-CMT-HI is now ready for use in clinical studies in the Italian population.

The Charcot-Marie-Tooth Health Index: Evaluation of a Patient-Reported Outcome.

OBJECTIVE: The development of a disease-specific patient-reported outcome for Charcot-Marie-Tooth disease is an important step in the preparation for therapeutic trials. This study describes the development of the Charcot-Marie-Tooth Health Index (CMTHI). METHODS: Inherited Neuropathy Consortium Contact Registry participants were queried on the symptoms that most impacted their lives. The CMTHI was developed based on these responses. Factor analysis, assessment of test-retest reliability, known group validity, and patient interviews were utilized to refine the instrument. RESULTS: The final CMTHI contains 18 themes that capture Charcot-Marie-Tooth disease (CMT) burden. The CMTHI has a high internal consistency and test-retest reliability. The CMTHI was able to discriminate between patient groups expected to have different disease burden. The CMTHI was able to discriminate levels of disability as measured by the CMT examination score and the mobility-Disability Severity Index. INTERPRETATION: The CMTHI represents a valid and reliable outcome to assess patient-reported disease burden in CMT. Ann Neurol 2018;84:225-233.

Facioscapulohumeral muscular dystrophy functional composite outcome measure.

INTRODUCTION: We developed an evaluator-administered functional facioscapulohumeral muscular dystrophy composite outcome measure (FSHD-COM) comprising patient-identified areas of functional burden for future clinical trials. METHODS: We performed a prospective observational study of 41 patients with FSHD at 2 sites. The FSHD-COM includes functional assessment of the legs, shoulders and arms, trunk, hands, and balance/mobility. We determined the test-retest reliability and convergent validity compared to established FSHD disease metrics. RESULTS: The FSHD-COM demonstrated excellent test-retest reliability (intraclass correlation coefficient [ICC] 0.96; subscale ICC range, 0.90-0.94). Cross-sectional associations between the FSHD-COM and disease duration, clinical severity, and strength were moderate to strong (Pearson correlation coefficient range |0.51-0.92|). DISCUSSION: The FSHD-COM is a disease-relevant, functional composite outcome measure suitable for future FSHD clinical trials that shows excellent test-retest reliability and cross-sectional associations to disease measures. Future directions include determining multisite reliability, sensitivity to change, and the minimal clinically important change in the FSHD-COM. Muscle Nerve, 2018.

Myotonic dystrophy patient preferences in patient-reported outcome measures.

INTRODUCTION: When preparing for clinical trials in myotonic dystrophy type-1 (DM1), it is important that researchers develop and identify patient-reported outcome measures with good measurement properties. METHODS: Fifty-two DM1 patients enrolled in 2 clinical studies completed the Myotonic Dystrophy Health Index (MDHI), 36-Item Short Form Health Survey (version 2; SF-36v2), Individualized Neuromuscular Quality of Life questionnaire (INQoL), and a questionnaire comparing the relevance, usability, overall preference, and perceived responsiveness of each measure. The associations between instrument scores and physical function, genetic test results, and employment status were examined. RESULTS: The MDHI was preferred over the INQoL in 13 of 13 areas and was preferred over the SF-36v2 in 9 of 13 areas. The MDHI was the only score that was associated with participant employment status, CTG repeat length, and the 3 measurements of clinical function. DISCUSSION: The MDHI correlates well with physical function and is viewed favorably by participants in DM1 clinical studies. Muscle Nerve, 2018.

Electrical impedance myography in facioscapulohumeral muscular dystrophy: A 1-year follow-up study.

INTRODUCTION: Electrical impedance myography (EIM) is a noninvasive technique for measuring muscle composition and a potential physiological biomarker for facioscapulohumeral muscular dystrophy (FSHD). METHODS: Thirty-two participants with genetically confirmed and clinically affected FSHD underwent EIM in 7 muscles bilaterally. Correlations between EIM and baseline clinical measures were used to select EIM variables of interest in FSHD, and EIM and clinical measures were followed for 1 year. RESULTS: There were no significant changes in the EIM variables. Although 50-kHZ reactance correlated the strongest with clinical measures at baseline, the 50-211-kHZ phase ratio demonstrated lower within-subject 12-month variability, potentially offering sample size savings for FSHD clinical trial planning. DISCUSSION: EIM did not identify significant disease progression over 12 months. It is currently unclear whether this is because of limitations of the technology or the slow rate of disease progression in this cohort of FSHD patients over this period of time. Muscle Nerve 58: 213-218, 2018.

Electrical impedance myography in facioscapulohumeral muscular dystrophy.

INTRODUCTION: In this study we determined the reliability and validity of electrical impedance myography (EIM) in facioscapulohumeral muscular dystrophy (FSHD). METHODS: We performed a prospective study of EIM on 16 bilateral limb and trunk muscles in 35 genetically defined and clinically affected FSHD patients (reliability testing on 18 patients). Summary scores based on body region were derived. Reactance and phase (50 and 100 kHz) were compared with measures of strength, FSHD disease severity, and functional outcomes. RESULTS: Participants were mostly men, mean age 53.0 years, and included a full range of severity. Limb and trunk muscles showed good to excellent reliability [intraclass correlation coefficients (ICC) 0.72-0.99]. Summary scores for the arm, leg, and trunk showed excellent reliability (ICC 0.89-0.98). Reactance was the most sensitive EIM parameter to a broad range of FSHD disease metrics. CONCLUSIONS: EIM is a reliable measure of muscle composition in FSHD that offers the possibility to serially evaluate affected muscles. Muscle Nerve 54: 696-701, 2016.

Myotonic dystrophy health index: Correlations with clinical tests and patient function.

INTRODUCTION: The Myotonic Dystrophy Health Index (MDHI) is a disease-specific patient-reported outcome measure. Here, we examine the associations between the MDHI and other measures of disease burden in a cohort of individuals with myotonic dystrophy type-1 (DM1). METHODS: We conducted a cross-sectional study of 70 patients with DM1. We examined the associations between MDHI total and subscale scores and scores from other clinical tests. Participants completed assessments of strength, myotonia, motor and respiratory function, ambulation, and body composition. Participants also provided blood samples, underwent physician evaluations, and completed other patient-reported outcome measures. RESULTS: MDHI total and subscale scores were strongly associated with muscle strength, myotonia, motor function, and other clinical measures. CONCLUSIONS: Patient-reported health status, as measured by the MDHI, is associated with alternative measures of clinical health. These results support the use of the MDHI as a valid tool to measure disease burden in DM1 patients.