Dimethyl fumarate modulates the dystrophic disease program following short-term treatment.

New medicines are urgently required to treat the fatal neuromuscular disease Duchenne muscular dystrophy (DMD). Dimethyl fumarate (DMF) is a potent immunomodulatory small molecule nuclear erythroid 2-related factor 2 activator with current clinical utility in the treatment of multiple sclerosis and psoriasis that could be effective for DMD and rapidly translatable. Here, we tested 2 weeks of daily 100 mg/kg DMF versus 5 mg/kg standard-care prednisone (PRED) treatment in juvenile mdx mice with early symptomatic DMD. Both drugs modulated seed genes driving the DMD disease program and improved force production in fast-twitch muscle. However, only DMF showed pro-mitochondrial effects, protected contracting muscles from fatigue, improved histopathology, and augmented clinically compatible muscle function tests. DMF may be a more selective modulator of the DMD disease program than PRED, warranting follow-up longitudinal studies to evaluate disease-modifying impact.

Safety and efficacy of tamoxifen in boys with Duchenne muscular dystrophy (TAMDMD): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Drug repurposing could provide novel treatment options for Duchenne muscular dystrophy. Because tamoxifen-an oestrogen receptor regulator-reduced signs of muscular pathology in a Duchenne muscular dystrophy mouse model, we aimed to assess the safety and efficacy of tamoxifen in humans as an adjunct to corticosteroid therapy over a period of 48 weeks. METHODS: We did a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial at 12 study centres in seven European countries. We enrolled ambulant boys aged 6·5-12·0 years with a genetically confirmed diagnosis of Duchenne muscular dystrophy and who were on stable corticosteroid treatment for more than 6 months. Exclusion criteria included ophthalmological disorders, including cataracts, and haematological disorders. We randomly assigned (1:1) participants using an online randomisation tool to either 20 mg tamoxifen orally per day or matched placebo, stratified by centre and corticosteroid intake. Participants, caregivers, and clinical investigators were masked to treatment assignments. Tamoxifen was taken in addition to standard care with corticosteroids, and participants attended study visits for examinations every 12 weeks. The primary efficacy outcome was the change from baseline to week 48 in scores on the D1 domain of the Motor Function Measure in the intention-to-treat population (defined as all patients who fulfilled the inclusion criteria and began treatment). This study is registered with ClinicalTrials.gov (NCT03354039) and is completed. FINDINGS: Between May 24, 2018, and Oct 14, 2020, 95 boys were screened for inclusion, and 82 met inclusion criteria and were initially enrolled into the study. Three boys were excluded after initial screening due to cataract diagnosis or revoked consent directly after screening, but before randomisation. A further boy assigned to the placebo group did not begin treatment. Therefore, 40 individuals assigned tamoxifen and 38 allocated placebo were included in the intention-to-treat population. The primary efficacy outcome did not differ significantly between tamoxifen (-3·05%, 95% CI -7·02 to 0·91) and placebo (-6·15%, -9·19 to -3·11; 2·90% difference, -3·02 to 8·82, p=0·33). Severe adverse events occurred in two participants: one participant who received tamoxifen had a fall, and one who received placebo suffered a panic attack. No deaths or life-threatening serious adverse events occurred. Viral infections were the most common adverse events. INTERPRETATION: Tamoxifen was safe and well tolerated, but no difference between groups was reported for the primary efficacy endpoint. Slower disease progression, defined by loss of motor function over time, was indicated in the tamoxifen group compared with the placebo group, but differences in outcome measures were neither clinically nor statistically significant. Currently, we cannot recommend the use of tamoxifen in daily clinical practice as a treatment option for boys with Duchenne muscular dystrophy due to insufficient clinical evidence. FUNDING: Thomi Hopf Foundation, ERA-Net, Swiss National Science Foundation, Duchenne UK, Joining Jack, Duchenne Parent Project, Duchenne Parent Project Spain, Fondation Suisse de Recherche sur les Maladies Musculaires, Association Monegasque contre les Myopathies.

Metabolic markers of short and long-term exogenous DL-beta-hydroxybutyrate supplementation in episodic migraine patients: an exploratory analysis of a randomized-controlled-trial.

Background: Emerging findings propose that the pathophysiology of migraine may be associated with dysfunctional metabolic mechanisms. Recent findings suggest that migraine attacks are a response to the cerebral energy deficit, and ingestion of ketone bodies stabilizes the generation of a migraine attack. Based on these findings, ketone body supplementation is postulated as a prophylactic treatment approach to restore cerebral metabolism deficiency. Metabolic markers are unexplored after exogenous ketone body supplementation in episodic migraineurs. Therefore, the present single-arm uncontrolled explorative analysis evaluated blood ketone body and glucose concentration after short and long-term 6 g exogenous DL-Mg-Ca-beta-hydroxybutyrate (DL-ßHB) supplementation. Methods: The presented data are part of the MigraKet randomized-control cross-over clinical trial of 41 episodic migraineurs (Number NCT03132233). Patients were given a single dose of 6 g DL-ßHB. Ketone body and glucose blood concentration were assessed before intake, 20, and 40 min after DL-ßHB intake. Ketone body, glucose concentration and glycated hemoglobin values were evaluated after 12 weeks of 18 g DL-ßHB ingestion (total dose), taken three times daily (6g/dose; 3x/day). Linear models explored the association between the ketone body and glucose levels. Results: Ketone body concentration increased within-group to a mean of 0.46 (0.30) mmol/L after 40 min post- DL-ßHB supplementation [estimate = 0.24 mmol/L, CI = (0.20.0.27), p < 0.01]. This within-group increase of ketone body concentration did not change after repeated daily intake of DL-ßHB supplementation over 12 weeks [estimate = 0.00 mmol/L, CI = (-0.03.0.04), p = 0.794]. DL-ßHB intake significantly reduced blood glucose concentration within-group from a mean baseline of 4.91 (0.42) mmol/L to 4.75 (0.47) mmol/L 40 min post-DL-ßHB supplementation [estimate = -0.16 mmol/L, CI = (-0.15, 0.03), p < 0.01]. Repeated DL-ßHB supplementation for 12 weeks showed no change within-group in acute ketone bodies concentration [estimate = 0.00 mmol/L, CI = (-0.03.0.04), p = 0.794] and in the HbA1c value [estimate = 0.02, CI = (-0.07.0.11), p = 0.69]. Conclusion: A single dose of 6 g DL-ßHB significantly elevated blood ketone bodies and decreased blood glucose concentration within-group in episodic migraineurs. Long-term DL-ßHB supplementation for 12 weeks showed no effect within-group on acute ketone body concentration and had not impact on HbA1c. The elevation of the ketone body concentration was moderate, indicating that nutritional ketosis was not reached. Therefore, a dose higher than 6 g of DL-ßHB is required to reach the nutritional level of ketosis. ClinicalTrials.gov Identifier: NCT03132233.

Stable-Isotope Dilution GC-MS Measurement of Metformin in Human Serum and Urine after Derivatization with Pentafluoropropionic Anhydride and Its Application in Becker Muscular Dystrophy Patients Administered with Metformin, l-Citrulline, or Their Combination.

Metformin (N,N-dimethylguanylguanidine) is one of the most prescribed drugs with pleiotropic, exerted in part by not fully elucidated mechanisms of action. We developed and validated a gas chromatography-mass spectrometry (GC-MS) method for the quantitative analysis of metformin (metformin-d0) in 10-µL aliquots of human serum and urine using N,N-[dimethylo-2H6]guanylguanidine (metformin-d6) as the internal standard. The method involves evaporation of the samples to dryness, derivatization with pentafluoropropionic (PFP) anhydride in ethyl acetate (30 min, 65 °C), and extraction into toluene. The negative-ion chemical ionization GC-MS spectra of the PFP derivatives contain a single intense ion with mass-to-charge (m/z) ratios of m/z 383 for metformin-d0 and m/z 389 for metformin-d6. Our results suggest that all amine/imine groups of metformin-d0 and metformin-d6 are converted to their N,N,N-tripentafluoropropionyl derivatives, which cyclize to form a symmetric triazine derivative, of which the non-ring amine group is amidated. Quantification was performed by selected-ion monitoring (SIM) of m/z 383 and m/z 389. Upon validation, the method was applied to determine serum and urine metformin concentrations in 19 patients with Becker muscular dystrophy (BMD). Serum and urine samples were collected at baseline (Visit I), after six weeks of supplementation (Visit II) with metformin (3 × 500 mg/d; metformin group; n = 10) or l-citrulline (3 × 1500 mg/d; citrulline group; n = 9) followed by a six-week supplementation with 3 × 500 mg/d of metformin plus 3 × 1500 mg/d l-citrulline. At Visit I, the metformin concentration in the serum and urine was very low in both groups. The metformin concentrations in the serum and urine of the patients who first took metformin (MET group) were higher at Visit II and Visit III. The metformin concentration in the serum and urine samples of the patients who first took l-citrulline (CITR group) were higher at Visit III. The serum and urine concentrations of metformin were insignificantly lower in the CITR group at Visit III. The mean fractional excretion (FE) rate of metformin was 307% (Visit II) and 322% (Visit III) in the MET group, and 290% in the CITR group (Visit III). This observation suggests the accumulation of metformin in the kidney and its secretion in the urine. The GC-MS is suitable to measure reliably circulating and excretory metformin in clinical settings.

Spinal cord gray matter atrophy is associated with functional decline in post-polio syndrome.

OBJECTIVE: To determine if patients with post-polio syndrome (PPS) show spinal cord gray matter (SCGM) atrophy and to assess associations between SCGM atrophy, muscle strength and patient-reported functional decline. METHODS: Twenty patients diagnosed with PPS (March of Dimes criteria) and 20 age- and sex-matched healthy controls (HC) underwent 3T axial 2D-rAMIRA magnetic resonance imaging at the intervertebral disc levels C2/C3-C6/C7, T9/T10 and the lumbar enlargement level (Tmax ) (0.5 × 0.5 mm2 in-plane resolution). SCGM areas were segmented manually by two independent raters. Muscle strength, self-reported fatigue, depression and pain measures were assessed. RESULTS: Post-polio syndrome patients showed significantly and preferentially reduced SCGM areas at C2/C3 (p = 0.048), C3/C4 (p = 0.001), C4/C5 (p < 0.001), C5/C6 (p = 0.004) and Tmax (p = 0.041) compared to HC. SCGM areas were significantly associated with muscle strength in corresponding myotomes even after adjustment for fatigue, pain and depression. SCGM areaTmax together with age and sex explained 68% of ankle dorsiflexion strength variance. No associations were found with age at or time since infection. Patients reporting PPS-related decline in arm function showed significant cervical SCGM atrophy compared to stable patients adjusted for initial disease severity. CONCLUSIONS: Patients with PPS show significant SCGM atrophy that correlates with muscle strength and is associated with PPS-related functional decline. Our findings suggest a secondary neurodegenerative process underlying SCGM atrophy in PPS that is not explained by aging or residua of the initial infection alone. Confirmation by longitudinal studies is needed. The described imaging methodology is promising for developing novel imaging surrogates for SCGM diseases.

Efficacy and safety of exogenous beta-hydroxybutyrate for preventive treatment in episodic migraine: A single-centred, randomised, placebo-controlled, double-blind crossover trial.

BACKGROUND: Several studies propose that brain energy deficit might be partially involved in the pathophysiology of migraine. Previously, studies demonstrated that ketogenic diet causes a substantial reduction in migraine frequency. Since the ketogenic diet is restricting and its adherence is difficult, we proposed to supplement ketone bodies exogenously to provide a prophylactic effect in migraineurs. AIM: To evaluate the prophylactic effect of exogenous DL-beta-hydroxybutyrate supplementation in episodic migraineurs. METHODS: A double-blind, placebo-controlled, randomised crossover trial was conducted, involving 41 patients with episodic migraine. Patients were randomised 1:1 into placebo or beta-hydroxybutyrate group before entering the first treatment period. Each treatment period was 12 weeks long, followed by four weeks of washout phase and four weeks of run-in phase before entering into the corresponding second treatment period. The primary endpoint was the number of migraine days in the last four weeks of treatment, adjusted for baseline. RESULTS: We observed no clinically significant amelioration of migraine frequency or intensity under DL-beta-hydroxybutyrate treatment as compared to placebo regarding number of migraine days (mean difference [95% CI]: -1.1[-5.07, 2.85]), migraine intensity (0-10 VAS: 1.5[-0.8, 3.7]). CONCLUSION: The selected dose of supplemented exogenous DL-beta-hydroxybutyrate did not demonstrate efficacy in episodic migraineurs.ClinicalTrials.gov Identifier: NCT03132233.

Implementation of Motor Function Measure score percentile curves - Predicting motor function loss in Duchenne muscular dystrophy.

The Motor Function Measure is a standardized scoring system to evaluate motor function and monitor disease progression in neuromuscular diseases such as Duchenne muscular dystrophy. There are no available reference percentile curves for this measure. The aim of this analysis was to generate Motor Function Measure percentile curves for ambulant and non-ambulant patients affected by Duchenne Muscular Dystrophy, providing the opportunity to better evaluate the status and progression of an individual patient compared to other patients in the same age group. Data of patients aged between 6 and 15 years (819 measurements) was obtained from the international Motor Function Measure database. Age-dependent percentile curves were estimated using a "Generalized additive model for location, scale and shape" as suggested by the World Health Organisation Multicentre Growth Reference Study Group. Percentile curves for the Motor Function Measure total score and its sub-scores for patients with and without treatment with glucocorticoids are presented. Mean scores decline with age. Patients treated with glucocorticoids have higher mean values compared to glucocorticoid-naïve patients at the same age. The percentile curves with the online tool extend the clinical utility of the Motor Function Measure by facilitating the interpretation of individual standing and disease progression.

Treatment with L-Citrulline in patients with post-polio syndrome: A single center, randomized, double blind, placebo-controlled trial.

This single-centered, randomized, double-blind, placebo-controlled study reports the results of L-Citrulline treatment for 24 weeks in patients with post-polio syndrome (PPS). Twenty-nine patients were randomized and assigned into receiving a treatment of 15 g L-Citrulline or placebo. The primary endpoint was the change of the 6 min walking distance test. Secondary endpoints included motor function measure, quantitative muscle strength, quantitative MRI and self-reported impairment questionnaires. Patients receiving L-Citrulline walked 17.5 longer in the 6 min walking distance test when compared to placebo group, however not statistically significant (95% CI = -14.69; 49.68, p = 0.298). None of the secondary endpoints showed a statistically significant change in the L-Citrulline group when compared to placebo group. The motor function measure showed a change of -0.78 (95% CI= [-3.39; 1.83] p = 0.563). Muscle degeneration of leg muscles assessed with quantitative MRI indicated no significant change (estimate= -0.01, 95% CI =-0.13; 0.11, p = 0.869). L-Citrulline was safe and well tolerated. In conclusion, administration of 15 g L-Citrulline daily for 24 weeks to patients with PPS showed no beneficial treatment effect in timed muscle function.

Standard of care versus new-wave corticosteroids in the treatment of Duchenne muscular dystrophy: Can we do better?

BACKGROUND: Pharmacological corticosteroid therapy is the standard of care in Duchenne Muscular Dystrophy (DMD) that aims to control symptoms and slow disease progression through potent anti-inflammatory action. However, a major concern is the significant adverse effects associated with long term-use. MAIN: This review discusses the pros and cons of standard of care treatment for DMD and compares it to novel data generated with the new-wave dissociative corticosteroid, vamorolone. The current status of experimental anti-inflammatory pharmaceuticals is also reviewed, with insights regarding alternative drugs that could provide therapeutic advantage. CONCLUSIONS: Although novel dissociative steroids may be superior substitutes to corticosteroids, other potential therapeutics should be explored. Repurposing or developing novel pharmacological therapies capable of addressing the many pathogenic features of DMD in addition to anti-inflammation could elicit greater therapeutic advantages.

Health-related quality of life, self-reported impairments and activities of daily living in relation to muscle function in post-polio syndrome.

BACKGROUND: The symptoms of post-polio syndrome (PPS) and its resulting disabilities can affect quality of life and the ability to perform daily activities. No study has comprehensively analysed how various patient-reported outcome measures (PROMs) are associated with objectively assessed physical function in patients with PPS. AIM: To investigate health-related quality of life (HRQOL), self-reported impairments and activities of daily living during 6 months and evaluate their association with clinical muscle function outcomes in individuals with PPS. METHODS: Twenty-seven patients with PPS were included in the study. At baseline and 6 months, patients were administered PROMs measuring HRQOL (WHOQOL-BREF), self-reported impairments related to PPS (SIPP-RS) and activities of daily living (IBM-FRS). Clinical muscle function outcomes included 6 min walking distance (6MWD) and motor function measure (MFM). RESULTS: There were no changes in self-reported impairments (25.52 to 24.93, p = 0.40), activities of daily living (33.89 to 33.30, p = 0.20), 6MWD (391.52 to 401.85, p = 0.30) and MFM (83.87 to 85.46, p = 0.14) during 6 months, while the HRQOL psychological health decreased during this period (76.85 to 72.38, p = 0.05). A strong association was found between activities of daily living and clinical muscle function outcomes (6MWD: ß = 0.02, 95% CI: 0.02;0.03, t = 6.88, p < 0.01; MFM: ß = 0.25, 95% CI: 0.17;0.33, t = 6.69, p < 0.01). Self-reported impairments and HRQOL domains were not associated with the clinical muscle outcomes. CONCLUSIONS: Study findings indicate that objectively measured walking and motor abilities do not reflect patient's perspectives of their HRQOL and impairment due to PPS. More research is needed to assess changes over time and capture clinically meaningful changes in individuals with PPS and to increase the understanding of how the patient's perspective of disability measured by PROMs is related to objectively measured walking and motor abilities. TRIAL REGISTRATION: ClinicalTrials.gov Identifier ( NCT02801071 ) registered June 15, 2016.

Longitudinal reliability of outcome measures in patients with Duchenne muscular dystrophy.

INTRODUCTION: The definition of reliable outcome measures is of increasing interest in patients with Duchenne muscular dystrophy (DMD). METHODS: In this retrospective study, we analyzed the longitudinal reliability of clinical and radiological endpoints in 29 ambulant patients with DMD. Clinical outcome measures included motor function measure (MFM) and timed function tests, while quantitative MRI data were mean fat fraction (MFF) and T2 relaxation time of thigh muscles. Statistical analysis was based on 3-, 6-, and 12-month follow-up data. RESULTS: Quantitative MRI using the MFF was the most sensitive and powerful marker of disease progression with a sample size of four at 1-year follow-up, followed by the D1 domain of MFM (standing and transfer function) with a sample size of 12. DISCUSSION: Our data support the longitudinal design of clinical trials over at least 12 months and the combinational use of clinical and radiological surrogate outcome measures.

Tamoxifen in Duchenne muscular dystrophy (TAMDMD): study protocol for a multicenter, randomized, placebo-controlled, double-blind phase 3 trial.

BACKGROUND: Duchenne muscular dystrophy (DMD) is an inherited neuromuscular disorder of childhood with a devastating disease course. Several targeted gene therapies and molecular approaches have been or are currently being tested in clinical trials; however, a causative therapy is still not available and best supportive care is limited to oral glucocorticoids with numerous long-term side effects. Tamoxifen is a selective estrogen receptor regulator, and shows antioxidant actions and regulatory roles in the calcium homeostasis besides its antitumor activity. In a mouse model of DMD, oral tamoxifen significantly improved muscle strength and reduced muscle fatigue. This multicenter, randomized, double-blind, placebo-controlled phase III trial aims to demonstrate safety and efficacy of tamoxifen over placebo in pediatric patients with DMD. After completion of the double-blind phase, an open-label extension of the study will be offered to all participants. METHODS/DESIGN: At least 71 ambulant and up to 20 nonambulant patients with DMD are planned to be enrolled at multiple European sites. Patients will be randomly assigned to receive either tamoxifen 20 mg or placebo daily over 48 weeks. In the open-label extension phase, all patients will be offered tamoxifen for a further 48 weeks. The primary endpoint of the double-blind phase is defined as the change of the D1 domain of the motor function measure in ambulant patients or a change of the D2 domain in nonambulant patients under tamoxifen compared to placebo. Secondary outcome measures include change in timed function tests, quantitative muscle testing, and quantitative magnetic resonance imaging of thigh muscles. Laboratory analyses including biomarkers of tamoxifen metabolism and muscle dystrophy will also be assessed. DISCUSSION: The aim of the study is to investigate whether tamoxifen can reduce disease progression in ambulant and nonambulant patients with DMD over 48 weeks. Motor function measures comprise the primary endpoint, whereas further clinical and radiological assessments and laboratory biomarkers are performed to provide more data on safety and efficacy. An adjacent open-label extension phase is planned to test if earlier initiation of the treatment with tamoxifen (verum arm of double-blind phase) compared to a delayed start can reduce disease progression more efficiently. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03354039. Registered on 27 November 2017.

Effect of Combination l-Citrulline and Metformin Treatment on Motor Function in Patients With Duchenne Muscular Dystrophy: A Randomized Clinical Trial.

Importance: Nitric oxide precursors, such as the amino acid l-arginine and the biguanide antidiabetic drug metformin, have been associated with metabolism and muscle function in patients with Duchenne muscular dystrophy (DMD). The treatment of DMD remains an unmet medical need. Objective: To evaluate the benefits and harms of a combination of l-citrulline and metformin treatment among patients with DMD. Design, Setting, and Participants: A single-center randomized double-blind placebo-controlled parallel-group clinical trial was conducted between December 12, 2013, and March 30, 2016, at the University Children's Hospital Basel in Switzerland. A total of 47 ambulant male patients aged 6.5 to 10 years with genetically confirmed DMD were recruited locally and from the patient registries of Switzerland, Germany, Austria, and France. Data were analyzed from April 6, 2016, to September 5, 2019. Interventions: Patients in the treatment group received 2500 mg of l-citrulline and 250 mg of metformin (combination therapy) 3 times a day for 26 weeks compared with patients in the control group, who received placebo. Main Outcomes and Measures: The primary end point was the change in transfer and standing posture, as assessed by the first dimension of the Motor Function Measure, version 32, from baseline to week 26. Secondary end points included assessments of timed function, quantitative muscle force, biomarkers for muscle necrosis, and adverse events. The 2 prespecified subgroups comprised patients who were able to walk 350 m or more in 6 minutes (stable subgroup) and patients who were not able to walk 350 m in 6 minutes (unstable subgroup) at baseline. Results: Among 49 ambulant male children with DMD who were screened for eligibility, 47 patients with a mean (SD) age of 8.2 (1.1) years were randomized to a treatment group receiving combination therapy (n = 23) or a control group receiving placebo (n = 24), and 45 patients completed the study. No significant differences between groups were found in the results of timed function and muscle force tests for overall, proximal and axial, and distal motor function. Among patients receiving combination therapy, the Motor Function Measure first dimension subscore decrease was 5.5% greater than that of patients receiving placebo (95% CI, -1.0% to 12.1%; P = .09). The administration of combination therapy had significantly favorable effects on the first dimension subscore decrease among the 29 patients in the stable subgroup (6.7%; 95% CI, 0.9%-12.6%; P = .03) but not among the 15 patients in the unstable subgroup (3.9%; 95% CI, -13.2% to 20.9%; P = .63). Overall, the treatment was well tolerated with only mild adverse effects. Conclusions and Relevance: Treatment with combination therapy was not associated with an overall reduction in motor function decline among ambulant patients with DMD; however, a reduction in motor function decline was observed among the stable subgroup of patients treated with combination therapy. The statistically nonsignificant difference of distal motor function in favor of combination therapy and the reduced degeneration of muscle tissue appear to support the treatment concept, but the study may have lacked sufficient statistical power. Further research exploring this treatment option with a greater number of patients is warranted. Trial Registration: ClinicalTrials.gov identifier: NCT01995032.

Psychosocial adjustment and parental stress in Duchenne Muscular Dystrophy.

OBJECTIVE: This cross-sectional study aimed to assess psychosocial adjustment of children with Duchenne Muscular Dystrophy (DMD) and to explore its possible association to parental stress. METHODS: 34 children with DMD, 9-14.1 years of age, and their parents were included in the study. Caregivers completed the Child Behaviour Checklist (CBCL), the Psychosocial Adjustment and Role Skills Scale III (PARS-III) and the Parenting Stress Index-Short Form (PSI-SF). Patients older than 11 years completed the Youth Self Report (YSR). Regression analyses including parental stress, socio-demographic and disorder-related factors were performed to determine how these aspects influence the psychosocial adjustment in children with DMD. RESULTS: Depending on the measure, 15%-47% of children with DMD were found to be psychosocially "at risk" for emotional and behavioural problems. Age showed no association with psychosocial adjustment. Half of the caregivers experienced very high parenting stress. Moreover, the two aspects parent-child dysfunctional interaction and difficult child scores were associated to psychosocial adjustment. Regression analyses showed that both parental stress and participation in a DMD support group are related to the psychosocial adjustment. CONCLUSIONS: The PARS-III represents a more suitable instrument assessing psychosocial adjustment in DMD, since compared to the CBCL it excludes physiological symptoms regarding chronic diseases. Decreased parents' stress levels and participation in a DMD support group positively contributed to good psychosocial adjustment. A family-centered approach is crucial for interventions in order to improve the psychosocial adjustment of these children and their families even while living with the significant burdens associated with DMD.

Association Between Health-Related Quality of Life and Motor Function in Ambulant and Nonambulant Duchenne Muscular Dystrophy Patients.

This cross-sectional study assessed health-related quality of life (HRQOL) in ambulant and nonambulant patients with Duchenne muscular dystrophy, and explored the association between health-related quality of life and clinically assessed motor function. The Pediatric Quality of Life Inventory (PedsQL) Generic Core Scale and PedsQL Neuromuscular module were completed by 34 parent-child dyads. Association between PedsQL scores and overall motor abilities and the transfers and standing posture domain measured by the Motor Function Measure were examined. Child self-reported and parent proxy-reported mean PedsQL scores for children with Duchenne muscular dystrophy were lower than those for healthy children for the physical and psychosocial health-related quality of life. Fifty-six percent of patients reported clinically impaired psychosocial health-related quality of life scores. Several aspects of the generic and disease-specific health-related quality of life in patients with Duchenne muscular dystrophy were positively associated to overall motor function and transfers and standing posture domain. Associations remained stable when adjusted for age and corticosteroid use. The Motor Function Measure is clinically meaningful in the context of a patient's day-to-day life.

Acquired neuromyotonia in children with CASPR2 and LGI1 antibodies.

Acquired neuromyotonia is a form of peripheral nerve hyperexcitability. In adults, pathogenic antibodies that target the extracellular domains of leucine-rich glioma-inactivated protein 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) have been reported. We describe three paediatric patients with acquired neuromyotonia and CASPR2 and LGI1 serum antibodies. They all presented with acute-onset myokymia and pain in the lower limbs; one patient also had muscle weakness. Electromyography was suggestive of peripheral nerve hyperexcitability. Two patients improved without immunotherapy; one treated patient remained immunotherapy-dependent. Although not fatal, acquired paediatric neuromyotonia can be disabling. It is amenable to symptomatic treatment or may undergo spontaneous recovery. More severe cases may require rational immunotherapy. WHAT THIS PAPER ADDS: The symptoms of neuromyotonia may resolve spontaneously or may require sodium channel blockers. Patients with debilitating symptoms who are refractory to symptomatic therapy may require immunotherapy.

NEUROMIOTONÍA ADQUIRIDA EN NIÑOS CON ANTICUERPOS CASPR2 Y LGI1: La neuromiotonía adquirida es una forma de hiperexcitabilidad de los nervios periféricos. En algunos adultos, se han notificado anticuerpos patógenos que se dirigen a los dominios extracelulares de la proteína 1 inactivada por glioma rico en leucina (LGI1) y la proteína 2 asociada a contactina (CASPR2). Describimos tres pacientes pediátricos con neuromiotonía adquirida y anticuerpos séricos CASPR2 y LGI1. Todos presentaban mioquimia de inicio agudo y dolor en las extremidades inferiores; un paciente también tenía debilidad muscular. La electromiografía sugirió hiperexcitabilidad del nervio periférico. Dos pacientes mejoraron sin inmunoterapia; un paciente tratado permaneció dependiente de la inmunoterapia. Aunque no es fatal, la neuromiotonía pediátrica adquirida puede ser incapacitante. Es susceptible de tratamiento sintomático o puede sufrir una recuperación espontánea. Los casos más graves pueden requerir inmunoterapia racional.

NEUROMIOTONIA ADQUIRIDA EM CRIANÇAS COM ANTICORPOS PRCAS2 E GIL1: A neuromiotonia adquirida é uma forma de hiperexcitabilidade nervosa periférica. Em alguns adultos, anticorpos patogênicos que visam os domínios extracelulares da proteína glioma-inativada rica em leucina1 (GIL1) e da proteína contactina-associada 2 (PRCAS2) foram reportados. Descrevemos três pacientes pediátricos com neuromiotonia adquirida e anticorpos séricos PRCAS2 e GIL1 CASPR2. Todos apresentaram miocimia de início agudo e dor nos membros inferiores; um paciente também teve fraqueza muscular. A eletromiografia foi sugestiva de hiperexcitabilidade nervosa periférica. Dois pacientes melhoraram sem imunoterapia; um paciente tratado permaneceu imunoterapia-dependente. Embora não seja fatal, a neuromiotomia pediátrica aguda pode ser incapacitante. É responsiva a tratamento sintomático e pode apresentar recuperação espontânea. Casos mais severaos podem requerer imunoterapia racional.

Measurements of Motor Function and Other Clinical Outcome Parameters in Ambulant Children with Duchenne Muscular Dystrophy.

While the number of new treatment options tested in patients with Duchenne muscular dystrophy (DMD) is increasing, there is still no defining of the most reliable assessments regarding therapeutic efficacy. We present clinical and radiological outcome measures used in ambulatory patients participating in our trial "Treatment with L-citrulline and metformin in Duchenne muscular dystrophy". The motor function measure is a validated test in patients with neuromuscular disorders that consists of 32 items and assesses all three dimensions of motor performance including standing and transfer (D1 subscore), axial and proximal motor function (D2 subscore), and distal motor function (D3 subscore). The test shows high intra- and inter-rater variability but only when strictly following guidelines of the materials, examination steps, and calculation of scores. The 6-minute walk test, timed 10-meter walk/run test, and supine-up time are commonly used timed functional tests that also sufficiently monitor changes in muscle function; however, they strongly depend on patient collaboration. Quantitative MRI is an objective and sensitive biomarker to detect subclinical changes, though the examination costs may be a reason for its limited use. In this study, a high correlation between all clinical assessments and quantitative MRI scans was found. The combinational use of these methods provides a better understanding about disease progression; however, longitudinal studies are needed to validate their reliability.

Electromyography and muscle biopsy in paediatric neuromuscular disorders - Evaluation of current practice and literature review.

The conduct and interpretation of electromyography in children is considered difficult and therefore often avoided. We assessed the diagnostic accuracy of the paediatric electromyography protocol used in our tertiary reference centre and compared it to muscle biopsy results and clinical diagnosis. Electromyography was performed in unsedated children with suspected neuromuscular diseases between January 2010 and September 2017 and was analysed quantitatively. Muscle pathology was classified into seven groups based on existing histopathology reports. The clinical diagnosis, including myopathic, neurogenic and non-neuromuscular categories was used as the gold standard. 171 children between the age of 12 days to 17.4 years were included in the analysis. 41 children (24%) were under the age of 2 years at the time of electromyography. 98 (57%) children were diagnosed with a myopathic disorder, 18 (11%) with a neurogenic disease and 55 (32%) as not having a primary neuromuscular disorder. In detecting myopathic disease, electromyography performed as well as muscle biopsy (sensitivity 87.8% for electromyography vs. 84.5% for muscle biopsy; specificity 75.7% vs. 86.4%). This also applied to children under the age of 2 years (sensitivity 81.8% vs. 86.4%). Quantitative analysis of a limited electromyography protocol performed in unsedated children is a very valuable diagnostic tool.

Effects of single and combined metformin and L-citrulline supplementation on L-arginine-related pathways in Becker muscular dystrophy patients: possible biochemical and clinical implications.

The L-arginine/nitric oxide synthase (NOS) pathway is considered to be altered in muscular dystrophy such as Becker muscular dystrophy (BMD). We investigated two pharmacological options aimed to increase nitric oxide (NO) synthesis in 20 male BMD patients (age range 21-44 years): (1) supplementation with L-citrulline (3 × 5 g/d), the precursor of L-arginine which is the substrate of neuronal NO synthase (nNOS); and (2) treatment with the antidiabetic drug metformin (3 × 500 mg/d) which activates nNOS in human skeletal muscle. We also investigated the combined use of L-citrulline (3 × 5 g/d) and metformin (3 × 500 mg/d). Before and after treatment, we measured in serum and urine samples the concentration of amino acids and metabolites of L-arginine-related pathways and the oxidative stress biomarker malondialdehyde (MDA). Compared to healthy subjects, BMD patients have altered NOS, arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT) pathways. Metformin treatment resulted in concentration decrease of arginine and MDA in serum, and of homoarginine (hArg) and guanidinoacetate (GAA) in serum and urine. L-Citrulline supplementation resulted in considerable increase of the concentrations of amino acids and creatinine in the serum, and in their urinary excretion rates. Combined use of metformin and L-citrulline attenuated the effects obtained from their single administrations. Metformin, L-citrulline or their combination did not alter serum nitrite and nitrate concentrations and their urinary excretion rates. In conclusion, metformin or L-citrulline supplementation to BMD patients results in remarkable antidromic changes of the AGAT and GAMT pathways. In combination, metformin and L-citrulline at the doses used in the present study seem to abolish the biochemical effects of the single drugs in slight favor of L-citrulline.

Timed function tests, motor function measure, and quantitative thigh muscle MRI in ambulant children with Duchenne muscular dystrophy: A cross-sectional analysis.

The development of new therapeutic agents for the treatment of Duchenne muscular dystrophy has put a focus on defining outcome measures most sensitive to capture treatment effects. This cross-sectional analysis investigates the relation between validated clinical assessments such as the 6-minute walk test, motor function measure and quantitative muscle MRI of thigh muscles in ambulant Duchenne muscular dystrophy patients, aged 6.5 to 10.8 years (mean 8.2, SD 1.1). Quantitative muscle MRI included the mean fat fraction using a 2-point Dixon technique, and transverse relaxation time (T2) measurements. All clinical assessments were highly significantly inter-correlated with p < 0.001. The strongest correlation with the motor function measure and its D1-subscore was shown by the 6-minute walk test. Clinical assessments showed no correlation with age. Importantly, quantitative muscle MRI values significantly correlated with all clinical assessments with the extensors showing the strongest correlation. In contrast to the clinical assessments, quantitative muscle MRI values were highly significantly correlated with age. In conclusion, the motor function measure and timed function tests measure disease severity in a highly comparable fashion and all tests correlated with quantitative muscle MRI values quantifying fatty muscle degeneration.