Neurodevelopmental, behavioral, and emotional symptoms common in Duchenne muscular dystrophy.

INTRODUCTION: We studied neurodevelopmental and behavioral/emotional symptoms in patients with Duchenne muscular dystrophy (DMD). METHODS: Retrospective case series of neurodevelopmental and behavioral/emotional symptoms obtained through review of systems of 700 DMD patients in relation to dystrophin gene mutations. RESULTS: The most common symptoms encountered were emotional/behavioral dysregulation (38.7%), inattention/hyperactive features (31.4%), obsessive and compulsive features (25.0%), and language/speech delays (24.4%). Most patients (72.7%) had at least one symptom. Patients with mutations near the 3' end of the dystrophin gene were at higher risk for developing inattention/hyperactive features, language/speech delays, and global intellectual delays. Those with mutations between exon 31 and 79 had higher risk of clustering of symptoms when compared with those upstream of exon 30. DISCUSSION: Neurodevelopmental, emotional, and behavioral symptoms are common comorbidities in DMD. There is higher prevalence of inattention/hyperactive features, language/speech delays, and global intellectual delays in genotypes affecting the 3' end of the dystrophin gene.

Neurodevelopmental, behavioral, and emotional symptoms in Becker muscular dystrophy.

INTRODUCTION: Becker muscular dystrophy (BMD) results in decreased dystrophin with implications for mental health. METHODS: This is a retrospective case series of neurodevelopmental, behavioral, and emotional symptoms and respective pharmacotherapies of 70 patients with BMD. RESULTS: Fifty-four (77.1%) patients exhibited at least one symptom, and 19 (27.1%) patients exhibited four or more symptoms. The most prevalent symptoms were specific learning disabilities or special education needs (31.4%), inattention/hyperactivity (35.7%), language/speech delays (35.7%), and emotional or behavioral dysregulation (38.6%). Fisher's exact tests indicated that anxiety was more prevalent with mutations upstream of exon 30 (P = .049), but the prevalence of other symptoms did not differ with respect to mutation sites. Similarly, the number of symptoms individual patients with BMD exhibited did not differ with respect to mutation sites. Seventeen (24.3%) patients required pharmacotherapy to manage symptoms. DISCUSSION: Neurodevelopmental, behavioral, and emotional symptoms are prevalent in patients with BMD regardless of dystrophin gene mutation site.

Comparison of Pulmonary Function Decline in Steroid-Treated and Steroid-Naïve Patients with Duchenne Muscular Dystrophy.

OBJECTIVE: To describe and compare the lung function decline in patients with Duchenne muscular dystrophy on glucocorticoid therapy in contrast with glucocorticoid-naïve patients, and to define the deciles of pulmonary decline in glucocorticoid-treated patients. STUDY DESIGN: This retrospective study examined lung function of patients with Duchenne muscular dystrophy over 6 years of age followed between 2001 and 2015 at 2 centers-glucocorticoid-treated patients in Cincinnati, Ohio, and glucocorticoid-naïve patients in Paris, France. Forced vital capacity (FVC, FVC%), forced expiratory volume in 1 second, maximal inspiratory pressure, maximal expiratory pressure, and peak expiratory flow data were analyzed. Only FVC data were available for the French cohort. RESULTS: There were 170 glucocorticoid-treated patients (92%), 5 patients (2.7%) with past glucocorticoid use, and 50 French glucocorticoid-naïve patients. The peak absolute FVC was higher and was achieved at earlier ages in glucocorticoid-treated compared with glucocorticoid-naïve patients (peak FVC, 2.4 ± 0.6 L vs 1.9 ± 0.7 L; P < .0001; ages 13.5 ± 3.0 years vs 14.3 ± 2.8 years; P = .03). The peak FVC% was also higher and was achieved at earlier ages in glucocorticoid-treated patients (peak FVC%, 105.1 ± 25.1% vs 56 ± 20.9%; P < .0001; ages 11.9 ± 2.9 years vs 13.6 ± 3.2 years; P = .002). Rates of decline for both groups varied with age. Maximal rates of decline were 5.0 ± 0.26% per year (12-20 years) for glucocorticoid-treated and 5.1 ± 0.39% per year for glucocorticoid-naïve patients (11-20 years; P = .2). Deciles of FVC% decline in glucocorticoid-treated patients show that patients experience accelerated decline at variable ages. CONCLUSIONS: These data describe nonlinear rates of decline of pulmonary function in patients with Duchenne muscular dystrophy, with improved function in glucocorticoid-treated patients. FVC% deciles may be a useful tool for clinical and research use.

Long-Term Outcome of Interdisciplinary Management of Patients with Duchenne Muscular Dystrophy Receiving Daily Glucocorticoid Treatment.

OBJECTIVE: To evaluate clinical outcomes and steroid side effects in a cohort of patients with Duchenne muscular dystrophy (DMD) treated with long-term daily glucocorticoid therapy. Although daily glucocorticoid therapy has been shown to extend ambulatory function in DMD, less frequent dosing is often used because of side effect concerns. STUDY DESIGN: Retrospective study of 97 patients with DMD aged 10 to <16 years treated with daily glucocorticoid (89% on deflazacort) for a mean of 8.5 years. Outcome measures were motor, pulmonary, and cardiac function, and scoliosis. Side effects were growth failure and weight gain, facial fullness, blood pressure, bone health, cataracts, gastrointestinal symptoms, behavior, hypertrichosis, and need for medication interventions. RESULTS: For 13- to 16-year-old patients, 40% could rise from the floor and 50% could perform the 30-foot run test. Forced vital capacity for the entire cohort was well preserved. Thirteen percent of younger (10- to <13-year-old) and 21% of older patients had findings of left ventricle systolic dysfunction. Six percent (all aged 16 years) developed scoliosis (Cobb angle >20 degrees). Eighty-six percent had normal weight velocities; 30% had no increased facial fullness; 72% had short stature; and 19% had asymptomatic cataracts. Asymptomatic spine compression deformities were noted in 76% and long bone fractures in 30%. One patient stopped glucocorticoid because of behavioral concerns. CONCLUSIONS: With evidence for improved outcomes and manageable side effects, we recommend use of daily glucocorticoid therapy for patients with DMD with anticipatory management of side effects and a coordinated interdisciplinary care approach.

Appendicular lean mass index changes in patients with Duchenne muscular dystrophy and Becker muscular dystrophy.

INTRODUCTION: Mutations in the 79 exons of the dystrophin gene result in muscle wasting and weakness of varying clinical severity, ranging from severe/typical Duchenne muscular dystrophy (DMD) to intermediate DMD and mild Becker muscular dystrophy (BMD), depending on the frameshift of the mutation. We previously reported that males with DMD have progressively declining appendicular lean mass (ALM) and ALM index (ALMI) with age and worsening functional motor ability compared with healthy controls. These indices have not been studied in patients with intermediate DMD and BMD phenotypes and across DMD genotypes. In this study, we compared age-related trajectories of ALM and ALMI of patients who had (1) BMD without functional mobility deficits with patients who had DMD at different stages of disease and healthy controls; (2) a DMD intermediate phenotype with patients who had a typical DMD phenotype; and (3) DMD categorized by genotype. METHODS: We conducted a retrospective review of ALM and ALMI data from 499 patients (ages 5-23 years) with DMD (466 typical and 33 intermediate) and 46 patients (ages 5-21 years) with BMD (without functional mobility deficits and functional mobility score of 1). Patients were grouped according to age reflecting disease stage (ages 5 to <7, 7 to <10, 10 to <14, and 14 to <20 years) and genotype (mutations in exons 1-30, 31-44, 45-62, and 63-79). RESULTS: ALM and ALMI trajectories of patients with BMD paralleled those of healthy controls until adolescence, in contrast to patients with DMD. ALMI Z-scores of patients with BMD remained within ±2 SD without decline while those of patients with DMD fell below -2 SD around age 12 years. Patients with BMD had increasing ALM and ALMI with age, with peak accrual between ages 10 to <14 years. ALMI declined after age 14 years for those with intermediate DMD compared with 10 years for patients with typical DMD. Patients with mutations in exons 63-79 had a greater decline in ALMI as compared with those with other genotypes after age 10 years. CONCLUSIONS: Age-related changes in ALMI in patients with BMD and intermediate DMD differ from those with typical DMD, reflecting their clinical phenotypes. ALM and ALMI should be further studied in patients with BMD and DMD subtypes for their potential value as surrogate markers to characterize the severity of BMD and DMD and inform clinical care decisions and clinical trial designs.

Oral bisphosphonate treatment in patients with Duchenne muscular dystrophy on long term glucocorticoid therapy.

Osteoporosis is a major problem in patients with Duchenne muscular dystrophy (DMD), due to glucocorticoid therapy and muscle weakness. Evidence on which to base optimal prevention and treatment strategies, including bisphosphonate use, in DMD are limited. Our objective was to describe bone health outcomes of oral alendronate treatment in patients with DMD and glucocorticoid-induced osteoporosis. We retrospectively studied 54 patients treated between 2005 and 2017, and assessed changes in dual-energy x-ray absorptiometry (DXA) whole body and lumbar spine bone mineral density and content, and lateral distal femur bone mineral density. We also examined vertebral fracture development in a subset with serial spine radiographs. Pre-alendronate DXA Z-score trajectories decreased progressively. Over three years post-alendronate initiation, Z-score trajectories improved (p<0.01) at most sites compared with pre-alendronate trajectories. Height-adjusted Z-score trajectories for lumbar spine bone mineral density (p = 0.01) and whole body bone mineral content (p = 0.0004) also improved. The positive trajectories did not seem to be sustained long term in those treated up to 6 years. Radiographic vertebral findings in 43 patients appeared stable. In conclusion, oral bisphosphonate therapy using alendronate was associated with improvement of DXA bone health indices during the first three years of treatment, and may help mitigate progression of osteoporosis in glucocorticoid-treated patients with DMD.

MRI vastus lateralis fat fraction predicts loss of ambulation in Duchenne muscular dystrophy.

OBJECTIVE: We studied the potential of quantitative MRI (qMRI) as a surrogate endpoint in Duchenne muscular dystrophy by assessing the additive predictive value of vastus lateralis (VL) fat fraction (FF) to age on loss of ambulation (LoA). METHODS: VL FFs were determined on longitudinal Dixon MRI scans from 2 natural history studies in Leiden University Medical Center (LUMC) and Cincinnati Children's Hospital Medical Center (CCHMC). CCHMC included ambulant patients, while LUMC included a mixed ambulant and nonambulant population. We fitted longitudinal VL FF values to a sigmoidal curve using a mixed model with random slope to predict individual trajectories. The additive value of VL FF over age to predict LoA was calculated from a Cox model, yielding a hazard ratio. RESULTS: Eighty-nine MRIs of 19 LUMC and 15 CCHMC patients were included. At similar age, 6-minute walking test distances were smaller and VL FFs were correspondingly higher in LUMC compared to CCHMC patients. Hazard ratio of a percent-point increase in VL FF for the time to LoA was 1.15 for LUMC (95% confidence interval [CI] 1.05-1.26; p = 0.003) and 0.96 for CCHMC (95% CI 0.84-1.10; p = 0.569). CONCLUSIONS: The hazard ratio of 1.15 corresponds to a 4.11-fold increase of the instantaneous risk of LoA in patients with a 10% higher VL FF at any age. Although results should be confirmed in a larger cohort with prospective determination of the clinical endpoint, this added predictive value of VL FF to age on LoA supports the use of qMRI FF as an endpoint or stratification tool in clinical trials.