Psychiatric and neurodevelopmental aspects of Becker muscular dystrophy

Social cognition in two brothers with Becker muscular dystrophy: an exploratory study revealing divergent behavioral phenotypes

BACKGROUND AND OBJECTIVE

Only few studies investigated social cognition in Becker muscular dystrophy (BMD). However, brain dystrophin deficiency could be a neural substrate for cognitive, emotional, and neuropsychological features in BMD.

METHODS

We compared interoceptive accuracy and interpersonal comfort distance in two brothers with BMD presenting with the same genetic deletion and a healthy control. When possible, we collected neuropsychological and psychopathological assessments.

RESULTS

Our BMD patients were significantly different in interoceptive accuracy, with patient 1 being extremely accurate and patient 2 being significantly less accurate than his brother but more accurate than the control. Interestingly, they presented opposite patterns of interpersonal distance. Patient 1 was comfortable with very short interpersonal distance (≤50 cm from the confederate/object) vs the control and patient 2. By contrast, patient 2 preferred larger distance vs the control and patient 1. Patient 1 also presented difficulties in social and emotional skills on the psychopathological assessment.

CONCLUSIONS

We are aware this is a small sample; nonetheless, this is also the first description of such aspects in BMD and the first report ever of such divergent behavioral pattern. As impaired social cognition affects the quality of life and social relationship, further studies are needed for a closer understanding of involved mechanisms.

Prevalence of Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder in Individuals With Dystrophinopathy at a Tertiary Care Center in Chicago

OBJECTIVE

To study the prevalence of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in individuals with dystrophinopathy compared with the general population.

METHODS

Retrospective chart review to examine the prevalence of ADHD and ASD, diagnosed both formally and informally, in individuals with dystrophinopathy receiving care in the multidisciplinary neuromuscular clinic at the Ann and Robert H. Lurie Children's Hospital of Chicago.

RESULTS

Our results demonstrate an ADHD prevalence of 18.40% and ASD prevalence of 12.73%, both significantly higher than those reported for the general population. Our results revealed a significant association between ADHD diagnosis and a positive family history but did not show a statistically significant association between prevalence of ADHD and the use of steroids.

CONCLUSION

Based on our current study results, we plan to further evaluate the prevalence, in a prospective cross-sectional manner, using validated screens for both ADHD and ASD.

Social difficulties and care burden of adult Duchenne muscular dystrophy in Japan: a questionnaire survey based on the Japanese Registry of Muscular Dystrophy (Remudy)

BACKGROUND

Little is known about the social difficulties and health care needs of adult Duchenne muscular dystrophy (DMD) patients in Japan, as well as the financial and physical stress experienced by their caregivers. This study aimed to clarify the social circumstances surrounding adult DMD patients and assess the degree of involvement of family members in their care and the associated economic burden of the disorder in Japan.

METHODS

Adult DMD patients were identified through the Registry of Muscular Dystrophy (Remudy) in Japan and invited to complete a questionnaire together with a caregiver. Data on health care use, quality of life, work status, informal care, and household expenses were collected to estimate the costs associated with DMD from social and caregiver household perspectives.

RESULTS

In total, 234 (63.7%) of 367 adult DMD patients (mean age, 27.4 ± 6.0; range, 20-48 years) completed the questionnaire. Of these, 38 (21%) had developmental disorders (mental retardation, autism, and learning disorders), 57 (33%) experienced bullying in school, and 44 (77%) indicated the reason for bullying to be their physical handicap. Employment histories were noted by 72 (31%), although 23 (10%) lost their jobs mainly due to physical difficulties. Of the 234 patients, 164 (74%) lived with their relatives, and 78% of care time was supplied by family members, in particular, their mothers. The mean rate of care work provided by family members was 81%. Household income of families with an adult DMD patient was lower, whereas the rate of living with parent(s) and grandparent(s) was higher, in comparison with the general Japanese population.

CONCLUSIONS

Adult DMD patients in Japan experience many social difficulties from childhood up to adulthood. As adults, many DMD patients experience bullying and workplace difficulties. Families were found to provide most of the care and financial support for DMD patients. Our results suggest the need to improve public patient care systems, including financial support, to address the physical and economic burdens of care for adult DMD patients in Japan.

The Importance of a PM&R Consultation for Becker Muscular Dystrophy Patients Admitted with Cardiomyopathy

Becker muscular dystrophy (BMD) is a rare genetic disorder that is associated with significant cardiac compromise, including heart failure and cardiomyopathy. Given the significant cardiac impact of the disease, patients are commonly hospitalized under the care of cardiologists. While it is imperative to address the acute cardiac challenges these patients face, it is crucial to not disregard the musculoskeletal derangement that occurs from this underlying disease and how acute hospitalization can exacerbate these issues. While literature focuses heavily on providing management protocols to address these acute cardiac complications, it is also important for providers to feel supported in addressing the functional implications that hospitalized BMD patients may face. An early PM&R consultation in the inpatient setting can be useful in identifying and addressing the functional impairments and subsequent comorbidities of BMD patients. PM&R teams can provide oversight from multiple avenues including the psychosocial, neurocognitive, durable medical equipment, and pain management perspectives and assist with transition of care to the postacute rehabilitation setting. The ultimate goal of the PM&R provider is to work alongside the primary service and patient in order to assist with retaining independence, improving patient satisfaction, and most importantly improving quality of life both inside and outside of the hospital setting.

Brain Abnormalities in Becker Muscular Dystrophy: Evaluation by Voxel-Based DTI and Morphometric Analysis

BACKGROUND AND PURPOSE

Although various neuropsychological problems in Becker muscular dystrophy have attracted attention, there have been few related neuroimaging studies. We investigated brain abnormalities in patients with Becker muscular dystrophy using 3D T1WI and DTI.

MATERIALS AND METHODS

MR images were obtained for 30 male patients and 30 age-matched healthy male controls. We classified patients into Dp140+ and Dp140- subgroups based on their predicted dystrophin Dp140 isoform expression and performed voxel-based comparisons of gray and white matter volumes and DTI metrics among the patients, patient subgroups, and controls. ROI-based DTI analyses were also performed.

RESULTS

Significantly decreased fractional anisotropy was observed in the left planum temporale and right superior parietal lobule compared between the Becker muscular dystrophy and control groups. In the Dp140- subgroup, decreased fractional anisotropy was observed in the left planum temporale, but no significant changes were seen in the Dp140+ subgroup. The ROI-based analysis obtained the same results. No significant differences were evident in the gray or white matter volumes or the DTI metrics other than fractional anisotropy between the groups.

CONCLUSIONS

A DTI metric analysis is useful to detect white-matter microstructural abnormalities in Becker muscular dystrophy that may be affected by the Dp140 isoform expression.

Diagnosis and management of Becker muscular dystrophy: the French guidelines

Becker muscular dystrophy (BMD) is one of the most frequent among neuromuscular diseases, affecting approximately 1 in 18,000 male births. It is linked to a genetic mutation on the X chromosome. In contrast to Duchenne muscular dystrophy, for which improved care and management have changed the prognosis and life expectancy of patients, few guidelines have been published for management of BMD. Many clinicians are inexperienced in managing the complications of this disease. In France, a committee of experts from a wide range of disciplines met in 2019 to establish recommendations, with the goal of improving care of patients with BMD. Here, we present the tools to provide diagnosis of BMD as quickly as possible and for differential diagnoses. Then, we describe the multidisciplinary approach essential for optimum management of BMD. We give recommendations for the initial assessment and follow-up of the neurological, respiratory, cardiac, and orthopedic consequences of males who present with BMD. Finally, we describe the optimal therapeutic management of these complications. We also provide guidance on cardiac management for female carriers.

Impairments and comorbidities in adults with cerebral palsy and spina bifida: a meta-analysis

Introduction

Aging with a childhood-onset disability, such as cerebral palsy (CP), spina bifida (SB), and muscular diseases (MD), comes along with significant impairments and comorbidities. Despite the increasing evidence an overall picture is lacking. This study aimed to review the literature about adults with CP/SB/MD and impairments and comorbidities to perform a meta-analysis.

Materials and methods

Embase, PubMed, Cinahl, and Google Scholar were searched (2000-2020). Search terms included adults with one of the aforementioned disabilities combined with impairments and comorbidities. If specific impairments or comorbidities were reported by at least four studies, these were included in the study. Pooled prevalence (95% Confidence Interval) of impairments/comorbidities were calculated.

Results

The search yielded 7,054 studies of which 95 were included in the meta-analysis (64 CP, 31 SB, 0 MD). In total estimates were calculated for 26 (CP) and 11 (SB) outcomes. In adults with CP, pain [56.4% (95%CI 48.8-63.8)], deformities [44.2% (95%CI 12.9-78.4)], intellectual disability [37.2% (95%CI 26.7-48.3)], and fatigue [36.9% (95%CI 24.6-50.1)] were most prevalent; renal disease [3.0% (95%CI 2.1-4.2)] and stroke/rheumatic diseases {4.8% (95%CI 3.4-6.5; 4.8% (95%CI 1.5-9.9)] respectively} were least prevalent. For adults with SB, bladder incontinence [60.0% (95%CI 50.5-69.2)], bowel incontinence [49.2% (95%CI 34.5-64.0)], pain [44.1% (95%CI 27.4-61.5)], and sleeping problems [30.3% (95%CI 4.7-65.8)] were most prevalent; diabetes [4.8% (95%CI 2.8-7.3)] and renal disease [8.7% (95%CI 2.0-19.9)] were least prevalent. The included studies showed large heterogeneity.

Conclusions

More research is needed to study health issues in adults with MD. Adults with CP or SB deal with a variety of health issues. More attention for the mental health of these adults is needed. There also is a need for accessible and adequate screening, preventive measures and clinical follow-up.

Dystrophin Genotype and Risk of Neuropsychiatric Disorders in Dystrophinopathies: A Systematic Review and Meta-Analysis

BACKGROUND

Dystrophinopathies are associated with neuropsychiatric disorders due to alterations in dystrophin/DMD expression.

OBJECTIVE

The objective was to estimate the association of developmental disorders, autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), depression, anxiety disorders, and obsessive-compulsive disorder with the dystrophin/DMD genotype in population with dystrophinopathies.

METHODS

Systematic searches of Medline, Scopus, Web of Science, and Cochrane Library were performed from inception to September 2022. We included observational studies in the population with Becker or Duchenne muscular dystrophies (BMD, DMD) that estimated the prevalence of these disorders according to Dp140 and/or Dp71 genotype. Meta-analysis of the prevalence ratio (PR) of genotype comparisons was conducted for each disorder.

RESULTS

Ten studies were included in the systematic review. In BMD, Dp140+ vs. Dp140- and Dp71+ vs. Dp71- were associated with developmental disorders with a PR of 0.11 (0.04, 0.34) and 0.22 (0.07, 0.67), respectively. In DMD, Dp140+/Dp71+ vs. Dp140- /Dp71- had a PR of 0.40 (0.28, 0.57), and Dp71+ vs. Dp71- had a PR of 0.47 (0.36, 0.63) for ADHD. However, there was no association of genotype with ASD, only a trend was observed for Dp71+ vs. Dp71-, with a PR of 0.61 (0.35, 1.06). Moreover, the data showed no association of these isoforms with emotional-related disorders.

CONCLUSIONS

In BMD, Dp140 and Dp71 could be associated with developmental disorders, while ADHD might be associated with the Dp71 genotype in DMD. Further research is needed regarding Dp140 and Dp71, especially in DMD for ASD.

Prevalence of Neuropsychiatric Disorders in Duchenne and Becker Muscular Dystrophies: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate the prevalence of neuropsychiatric disorders, including autism spectrum disorders (ASDs), attention-deficit hyperactivity disorder (ADHD), depression, anxiety disorders, and obsessive-compulsive disorder (OCD), in populations with Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD).

DATA SOURCES

MEDLINE (via PubMed), Scopus, Web of Science, and Cochrane Library from inception to November 2021.

STUDY SELECTION

Observational studies of individuals with DMD or BMD that estimated the prevalence of ASDs, ADHD, depression, anxiety disorders, and OCD in each population.

DATA EXTRACTION

A random-effects meta-analysis was performed on each outcome and each population (ie, DMD, BMD).

DATA SYNTHESIS

Twenty-three studies were included in the meta-analysis. In DMD, there was a prevalence of 7.0% of ASDs, 18.0% of ADHD, 11.0% of depression, 24.0% of anxiety disorders, and 12.0% of OCD. Furthermore, in BMD, there was a prevalence of 6.0% of ASDs, 28.0% of ADHD, 7.0% of depression, 25.0% of anxiety disorders, and 7.0% of OCD.

CONCLUSIONS

The prevalence of these neuropsychiatric disorders is higher among patients with DMD or BMD than among the general population, and the presence of these disorders may negatively influence optimal medical management.

Global prevalence of intellectual developmental disorder in dystrophinopathies: A systematic review and meta-analysis

AIM

To estimate the global prevalence of intellectual developmental disorder (IDD) and the IDD prevalence-genotype association in Becker muscular dystrophy (BMD) or Duchenne muscular dystrophy (DMD) according to the affected isoforms of the DMD gene: Dp427, Dp140, Dp71.

METHOD

Systematic searches in MEDLINE, Scopus, Web of Science, and the Cochrane Library were conducted from inception of each database to March 2022. Observational studies that determined the prevalence of IDD in the population with BMD or DMD were included. Meta-analyses of IDD prevalence and prevalence ratios of the IDD-genotype association were conducted.

RESULTS

Forty-nine studies were included. The prevalence of IDD in BMD was 8.0% (95% confidence interval 5.0-11.0), and in DMD it was 22.0% (18.0-27.0). Meta-analyses of IDD-genotype association showed a deleterious association between IDD and the number of isoforms affected in DMD, with a prevalence ratio = 0.43 (0.28-0.64) and 0.17 (0.09-0.34) for Dp140⁺ /Dp71⁺ versus Dp140^- /Dp71⁺ and Dp140⁺ /Dp71⁺ versus Dp140^- /Dp71^- comparisons respectively. However, in BMD, there was no association for Dp140⁺ /Dp71⁺ versus Dp140^- /Dp71⁺ .

INTERPRETATION

There is a high prevalence of IDD in BMD and DMD. Moreover, the number of isoforms affected is strongly and negatively associated with the prevalence of IDD in DMD.

Wechsler Scale Intelligence Testing in Males with Dystrophinopathies: A Review and Meta-Analysis

BACKGROUND

Intelligence scores in males with Duchenne Muscular Dystrophy (DMD) and Becker Muscular Dystrophy (BMD) remain a major issue in clinical practice. We performed a literature review and meta-analysis to further delineate the intellectual functioning of dystrophinopathies.

METHOD

Published, peer-reviewed articles assessing intelligence, using Wechsler Scales, of males with DMD or BMD were searched from 1960 to 2022. Meta-analysis with random-effects models was conducted, assessing weighted, mean effect sizes of full-scale IQ (FSIQ) scores relative to normative data (Mean = 100, Standard Deviation = 15). Post hoc we analysed differences between performance and verbal intelligence scores.

RESULTS

43 studies were included, reporting data on 1472 males with dystrophinopathies; with FSIQ scores available for 1234 DMD (k = 32) and 101 BMD (k = 7). DMD males score, on average, one standard deviation below average (FSIQ = 84.76) and significantly lower than BMD (FSIQ = 92.11). Compared to a previous meta-analysis published in 2001, we find, on average, significantly higher FSIQ scores in DMD.

CONCLUSION

Males with Duchenne have, on average, significantly lower FSIQ scores than BMD males and the general population. Clinicians must consider lower intelligence in dystrophinopathies to ensure good clinical practice.

Cognitive profile and neuropsychiatric disorders in Becker muscular dystrophy: A systematic review of literature

BACKGROUND

Brain co-morbidities in DMD are well-documented, less is known about the cognitive, behavioral and psychosocial functioning of patients with BMD.

METHODS

The systematic review was carried out on two databases (Pubmed and Scopus) according to the PRISMA guidelines. We included all research articles specific to BMD written after 1995.

RESULTS

Studies examining neuropsychological and neurobehavioral functioning in BMD are few and have several methods limitations. BMD population is characterized by high rates of cognitive impairment, with specific involvement of different cognitive areas. Unlike DMD, verbal skills are better preserved. Neurodevelopmental and emotional/behavioral disorders have great importance in BMD, due to their high prevalence. Lack of Dp140 or Dp71 can cause intellectual disability, these isoforms are probably responsible for the other brain-related comorbidities as well.

DISCUSSION

The results suggest that cognitive and neuropsychiatric comorbid symptoms may affect a significant proportion of BMD patients therefore it is important to mental health and neuropsychological screening. Finding tools for an adequate assessment is a priority in order to include brain outcome measures in clinical trials.

Deficiency of Glycosylated α-Dystroglycan in Ventral Hippocampus Bridges the Destabilization of Gamma-Aminobutyric Acid Type A Receptors With the Depressive-like Behaviors of Male Mice

BACKGROUND

Depression is a common psychiatric disorder associated with defects in GABAergic (gamma-aminobutyric acidergic) neurotransmission. α-Dystroglycan (α-DG), a cell adhesion molecule known to be essential for skeletal muscle integrity, is also present at inhibitory synapses in the central nervous system and forms a structural element in certain synapses. However, the role of α-DG in the regulation of depressive-like behaviors remains largely unknown.

METHODS

Depressive-like behaviors were induced by chronic social defeat stress in adult male mice. Surface protein was extracted by a biotin kit, and the expression of protein was detected by Western blotting. Intrahippocampal microinjection of the lentivirus or adeno-associated virus or agrin intervention was carried out using a stereotaxic instrument and followed by behavioral tests. Miniature inhibitory postsynaptic currents were recorded by whole-cell patch-clamp techniques.

RESULTS

The expression of α-DG and glycosylated α-DG in the ventral hippocampus was significantly lower in chronic social defeat stress-susceptible male mice than in control mice, accompanied by a decreased surface expression of GABA_A receptor γ2 subunit and reduced GABAergic neurotransmission. RNA interference-mediated knockdown of Dag1 increased the susceptibility of mice to subthreshold stress. Both in vivo administration of agrin and overexpression of like-acetylglucosaminyltransferase ameliorated depressive-like behaviors and restored the decrease in surface expression of GABA_A receptor γ2 subunit and the amplitude of miniature inhibitory postsynaptic currents in chronic social defeat stress-exposed mice.

CONCLUSIONS

Our findings demonstrate that glycosylated α-DG plays a role in the pathophysiological process of depressive-like behaviors by regulating the surface expression of GABA_A receptor γ2 subunit and GABAergic neurotransmission in the ventral hippocampus.

A case of delayed diagnosis of Becker muscular dystrophy due to underlying developmental disorders

BACKGROUND

Developmental disorders associated with Becker muscular dystrophy (BMD), possibly resulting from a lack of dystrophin in the brain, have been reported, but their importance is not fully understood. We report a case of a BMD patient who had been socially withdrawn due to mental retardation and autism spectrum disorder and could not receive appropriate medical services, resulting in delayed detection of severe cardiomyopathy and embolic strokes which developed as complications of BMD.

CASE REPORT

The case is a 41-year-old male. In elementary school, he was the slowest runner in his class and had poor grades. He started missing school due to bullying in junior high school and had been socially withdrawn for 24 years. He developed difficulty walking due to progressive muscle weakness in the extremities and lost ambulation at age 36. At age 41, he was referred to our hospital by public health support services to address his social withdrawal. Muscle biopsy led to the diagnosis of BMD. Psychological examination revealed mild mental retardation and autism spectrum disorder, which may have resulted in social isolation. He had severe cardiomyopathy and asymptomatic cerebral infarction due to heart failure.

CONCLUSION

In BMD patients, developmental disorders can potentially hinder access to appropriate medical treatment. BMD is an important differential diagnosis for physically disabled children with developmental disorders. Early intellectual and psychological interventions and evaluation of complications are important for improving patient prognosis and quality of life.

Epileptic disorders in Becker and Duchenne muscular dystrophies: a systematic review and meta-analysis

Dystrophin alterations in the brain have been associated with an increased risk of epilepsy in Becker and Duchenne muscular dystrophies (BMD and DMD). Moreover, an association between the mutation site and the risk of epilepsy is not ruled out. The aim of this systematic review and meta-analysis was to estimate the prevalence of epilepsy in BMD and DMD populations and to establish a possible association between the site of mutation in the dystrophin gene and the risk of epilepsy. Systematic searches of Medline, Scopus, Web of Science, and Cochrane Library were conducted to identify relevant studies published from inception to January 2022. Observational studies of participants with BMD/DMD estimating the prevalence of epilepsy were included. The main outcome was the prevalence of epilepsy, and the secondary outcome was the prevalence ratio considering genotype. A random effects meta-analysis was performed for the prevalence of epilepsy. Eight studies were included in the systematic review and meta-analysis. The prevalence of epilepsy was 7% (95% CI 3-11%) in BMD, 5% (95% CI 2-8%) in DMD, and 5% (95% CI 3-7%) in the overall estimate. No association was observed between mutation site and the prevalence of epilepsy. BMD/DMD is strongly associated with the prevalence of epilepsy, with a higher prevalence in BMD/DMD populations than in the general population, probably owing to alterations in Dp427. The current evidence does not support the hypothesis that Dp140 or Dp71 affect epilepsy risk.

Extra-muscular manifestations in GNE myopathy patients: A nationwide repository questionnaire survey in Japan

OBJECTIVE

GNE myopathy is a rare autosomal recessive adult-onset distal myopathy caused by biallelic pathogenic variants in GNE. Although some extra-muscular manifestations associated with GNE myopathy have been reported, little is known about whether they are disease-specific and how often they present. This study aimed to characterize extra-muscular manifestations of GNE myopathy.

METHODS

We conducted a questionnaire survey of GNE myopathy patients registered in a national registry in Japan. The questionnaire requested information regarding idiopathic thrombocytopenia, cardiac involvement, respiratory involvement, sleep apnea syndrome (SAS), and psychiatric diseases.

RESULTS

The response rate was 62.4% (126/198), yielding a total of 51 male and 75 female participants. Of the participants, 4.1% (5/123) had a diagnosis of idiopathic thrombocytopenia, and 16.3% (8/49) of males and 6.6% of females (5/76) had a diagnosis of SAS. In total, 0.8% (1/126) of participants had pervasive developmental disabilities and 14.7% (16/109) had a psychiatric disease.

CONCLUSION

The frequencies of idiopathic thrombocytopenia and SAS among Japanese GNE myopathy patients were higher than those observed in the general Japanese population. Routine blood tests and evaluation of sleep-disordered breathing should be considered in order to better manage GNE myopathy patients.

The effects of 12 weeks' resistance training on psychological parameters and quality of life in adults with Facioscapulohumeral, Becker, and Limb-girdle dystrophies

PURPOSE

Investigate the impact of 12-weeks' moderate-intensity resistance training on psychological parameters in ambulatory adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophy.

METHODS

Seventeen adults with Facioscapulohumeral (n = 6), Limb-girdle (n = 6; types 2A, 2B, 2L, and 2I), or Becker (n = 5) muscular dystrophy took part. Participants were tested at baseline (PRE), after a 12-week control period (PRE2), and after a 12-week supervised resistance training programme (POST). Training included multi-joint and single-joint resistance exercises. Outcomes from self-report questionnaires were health-related quality of life, depressive symptoms, trait anxiety, self-esteem, and physical self-worth.

RESULTS

No difference in outcome measures, except depressive symptoms, was found in the control period (PRE to PRE2). Symptoms of depression were reduced by 9% from PRE to PRE2 (p < 0.05) and by a further 19% from PRE2 to POST (p < 0.05). Other changes from PRE2 to POST were that trait anxiety reduced by 10%, self-esteem increased by 10%, physical self-worth increased by 20%, and quality of life improved in 8 domains (p < 0.05).

CONCLUSION

These findings demonstrate the positive impact of moderate-intensity resistance training on psychological health and quality of life in adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophies.Implications for rehabilitationResistance training can have a positive impact on psychological health and quality of life in adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophy.Healthcare professionals should consider including moderate-intensity resistance training within the management and treatment programmes of adults with Facioscapulohumeral, Becker, and Limb-girdle muscular dystrophy.

Towards Central Nervous System Involvement in Adults with Hereditary Myopathies

There is increasing evidence of central nervous system involvement in numerous neuromuscular disorders primarily considered diseases of skeletal muscle. Our knowledge on cerebral affection in myopathies is expanding continuously due to a better understanding of the genetic background and underlying pathophysiological mechanisms. Intriguingly, there is a remarkable overlap of brain pathology in muscular diseases with pathomechanisms involved in neurodegenerative or neurodevelopmental disorders. A rapid progress in advanced neuroimaging techniques results in further detailed insight into structural and functional cerebral abnormalities. The spectrum of clinical manifestations is broad and includes movement disorders, neurovascular complications, paroxysmal neurological symptoms like migraine and epileptic seizures, but also behavioural abnormalities and cognitive dysfunction. Cerebral involvement implies a high socio-economic and personal burden in adult patients sometimes exceeding the everyday challenges associated with muscle weakness. It is especially important to clarify the nature and natural history of brain affection against the background of upcoming specific treatment regimen in hereditary myopathies that should address the brain as a secondary target. This review aims to highlight the character and extent of central nervous system involvement in patients with hereditary myopathies manifesting in adulthood, however also includes some childhood-onset diseases with brain abnormalities that transfer into adult neurological care.

Decision-Making And Selection Bias in Four Observational Studies on Duchenne and Becker Muscular Dystrophy

BACKGROUND

Natural history data are essential for trial design in Duchenne (DMD) and Becker muscular dystrophy (BMD), but recruitment for observational studies can be challenging.

OBJECTIVE

We reviewed reasons why patients or caregivers declined participation, and compared characteristics of participants and non-participants to assess possible selection bias in four observational studies, three on DMD and one on BMD.

METHODS

Three pediatric DMD studies focused on cross-sectional cognitive function and brain MRI (DMDbrain, n = 35 and DMDperfusion, n = 12), and on longitudinal upper extremity function and muscle MRI (DMDarm, n = 22). One adult BMD study assessed longitudinal functioning (n = 36). Considerations for non-participation were retrospectively reviewed from screening logs. Age, travel-time, DMD gene mutations and age at loss of ambulation (DMDarm and BMD study only), of participants and non-participants were derived from the Dutch Dystrophinopathy Database and compared using nonparametric tests (p < 0.05).

RESULTS

The perceived burden of the protocol (38.2%), use of MRI (30.4%), and travel-time to the study site (19.1%) were the most frequently reported considerations for non-participation. Only few patients reported lack of personal gain (0.0- 5.9%). Overall, participating patients were representative for the studied sub-populations, except for a younger age of DMDarm study participants and a complete lack of participants with a mutation beyond exon 63.

CONCLUSION

Optimizing patient involvement in protocol design, improving MRI experiences, and integrating research into clinics are important factors to decrease burden and facilitate participation. Nationwide registries are essential to compare participants and non-participants and ensure representative observational research. Specific effort is needed to include patients with distal mutations in cognitive studies.

Assessment of Weighted Gene Co-Expression Network Analysis to Explore Key Pathways and Novel Biomarkers in Muscular Dystrophy

Purpose

This study aimed to explore the key molecular pathways involved in Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) and thereby identify hub genes to be potentially used as novel biomarkers using a bioinformatics approach.

Methods

Raw GSE109178 data were collected from the Gene Expression Omnibus (GEO) database. Weighted gene co-expression network analysis (WGCNA) was conducted on the top 50% of altered genes. The key modules associated with the clinical features of DMD and BMD were identified. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using the DAVID website. A protein-protein interaction (PPI) network was constructed using the STRING website. MCODE, together with the Cytohubba plug-ins of Cytoscape, screened out the potential hub genes, which were subsequently verified via receiver operating characteristic (ROC) curves in other datasets.

Results

Among the 11 modules obtained, the black module was predominantly associated with pathology and DMD, whereas the light-green module was primarily related to age and BMD. Functional enrichment assessments indicated that the genes in the black module were primarily clustered in “immune response” and “phagosome,” whereas the ones in the light-green module were chiefly enriched in “protein polyubiquitination”. Eleven essential genes were eventually identified, including VCAM1, TYROBP, CD44, ITGB2, CSF1R, LCP2, C3AR1, CCL2, and ITGAM for DMD, along with UBA5 and UBR2 for BMD.

Conclusion

Overall, our findings may be useful for investigating the mechanisms underlying DMD and BMD. In addition, the hub genes discovered might serve as novel molecular markers correlated with dystrophinopathies.

The adult multidisciplinary respiratory neuromuscular clinic

Many neuromuscular disorders (NMD) are complicated by respiratory failure. These patients are best managed in a multidisciplinary outpatient clinic to provide timely access to the various disciplines they require. The key mainstay of treatment of respiratory failure in patients with NMD is noninvasive ventilation, supported by secretion clearance, speech and language therapy, optimisation of nutrition and the maintenance of mobility. Patients with specific conditions may also require cardiology, neurology, orthopaedics, urology and psychological services. The respiratory NMD multidisciplinary team should also provide access to palliative care, and caregiver health and wellbeing should also be reviewed at clinical reviews. The future of care for the respiratory NMD patient will increasingly involve home services and telehealth and the clinic should be equipped and resourced to deliver these. Although not all health systems will be able to provide all elements of the multidisciplinary team discussed here, this review provides the “ideal” recipe for the adult multidisciplinary team and the evidence base underpinning this from which a clinic can be developed.

Care for neuromuscular-related respiratory failure is complex and is best delivered in a multidisciplinary context. The future will increasingly involve home services and telehealth, and their burden needs to be considered when establishing this service.https://bit.ly/33fNsMT

The Neurocognitive and Behavioral Profiles of 3 Brothers With Becker Muscular Dystrophy

Becker muscular dystrophy patients generally carry in-frame mutations in the dystrophin gene, allowing the production of partially functional dystrophin protein. The presence of cognitive and behavioral comorbidities and the relation with the location of mutations has been scarcely investigated in Becker. This case report describes the neurocognitive and behavioral profiles of 3 brothers with Becker carrying an in-frame deletion of exons 45-48. The 3 cases underwent 2 consecutive neuropsychological assessments of which one assessment took place when they completed their primary education (age range of the cases: 11.2 -12.1 years). Intellectual abilities were normal to high and all cases had difficulties with processing speed and math. The brothers differed in intellectual abilities, executive functions, working memory, attention and reading abilities. Variability in cognitive development was noted as well. This report suggests that cognitive and behavioral functions in Becker vary regardless of gene mutation and exposer to similar environmental factors.

Rare intronic mutation between Exon 62 and 63 (c.9225-285A>G) of the dystrophin gene associated with atypical BMD phenotype

Dystrophinopathies are predominantly caused by deletions, duplications and point mutations in the coding regions of the dystrophin gene with less than 1% of all pathogenic mutations identified within intronic sequences. We describe a 17-year-old male with a Becker muscular dystrophy diagnosis and mental disability due to an intron mutation that led to aberrant splicing and formation of an additional exon. Histopathological analysis of muscle tissue revealed signs of muscular dystrophy and reduced signal for dystrophin, alpha-sarcoglycan, and alpha-dystroglycan. Multiplex ligation-dependent probe amplification screening and total sequencing of the dystrophin gene did not identify a mutation in the coding regions. However, next generation sequencing revealed an intron mutation between exons 62 and 63 of the dystrophin gene known for pseudoexon formation and disruption of the reading frame. We report a functional consequence of this mutation as an increased intracellular-weighted sodium signal (assessed by ²³Na-magnetic resonance imaging) in leg muscles.