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

A Reversible Etiology of Progressive Motor Decline in a Previously Healthy Child

We describe the clinical presentation and evaluation of a 10-year-old boy who presented to our medical center with years of progressive proximal muscle weakness, muscle atrophy, and weight loss. In addition to a myopathic phenotype, he was found to have tachycardia, tremor, and learning difficulties. Electromyography revealed chronic myopathic changes and laboratory screening was notable for undetectable thyroid stimulating hormone. Follow-up testing revealed elevated thyroid peroxidase antibodies and thyroid stimulating immunoglobulins. Ultrasound examination revealed an enlarged heterogeneous thyroid gland. Four weeks after treatment with atenolol and methimazole, his strength and cognition began to improve. This case highlights the importance of evaluating for potentially reversible toxic-metabolic etiologies in children presenting with any progressive neurologic symptoms.

Reading skills over time among children with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is an X-linked progressive neuromuscular disorder with a distinct cognitive profile including decreased verbal span. Children with DMD are also at risk for lower scores on academic achievement tests and increased behavioral problems. Longitudinal analyses generally reveal a stable intellectual profile, although attention and behavioral problems may negatively impact longitudinal IQ scores. To date, no study has reported on reading over time in DMD. Reading performance was assessed longitudinally in children with DMD, examining for potential contributions to the trajectory. Retrospective data analysis on assessments completed at baseline, year 2, and year 4 on 26 boys with DMD and 27 unaffected sibling controls (age at baseline: DMD 8 ± 1.4, controls 9 ± 2.6) indicated that children with DMD performed slightly, yet significantly, worse than controls on reading skills, but the longitudinal trajectory of reading skills for children with DMD and controls was not significantly different. Verbal span at time 1 was uniquely associated with later reading skills in children with DMD. Behavior was not associated with declines. The results confirm that children with DMD underperform on reading tasks and align with previous research suggesting that cognitive skills in DMD are stable over time.

Dmd mdx mice have defective oligodendrogenesis, delayed myelin compaction and persistent hypomyelination

Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene, resulting in the loss of dystrophin, a large cytosolic protein that links the cytoskeleton to extracellular matrix receptors in skeletal muscle. Aside from progressive muscle damage, many patients with DMD also have neurological deficits of unknown etiology. To investigate potential mechanisms for DMD neurological deficits, we assessed postnatal oligodendrogenesis and myelination in the Dmdmdx mouse model. In the ventricular-subventricular zone (V-SVZ) stem cell niche, we found that oligodendrocyte progenitor cell (OPC) production was deficient, with reduced OPC densities and proliferation, despite a normal stem cell niche organization. In the Dmdmdx corpus callosum, a large white matter tract adjacent to the V-SVZ, we also observed reduced OPC proliferation and fewer oligodendrocytes. Transmission electron microscopy further revealed significantly thinner myelin, an increased number of abnormal myelin structures and delayed myelin compaction, with hypomyelination persisting into adulthood. Our findings reveal alterations in oligodendrocyte development and myelination that support the hypothesis that changes in diffusion tensor imaging seen in patients with DMD reflect developmental changes in myelin architecture.

Neurocognitive functioning among children and young people with Duchenne Muscular Dystrophy: A systematic review and meta-analysis

Objective: The neurocognitive aspects of DMD have received less attention than the physiological sequalae. This study conducted a systematic review and meta-analysis of available literature on the neurocognitive profile of children and young people with DMD. Method: Five databases (EMBASE, Medline, PsycInfo, Scopus and Web of Science) and the grey literature was searched on 27th January 2023. Eligible articles were available in English and reported neurocognitive outcomes. Neurocognitive domains reported in a comparable way across a minimum of three studies were included. The neurocognitive domains of Full-Scale IQ (FSIQ), Verbal IQ (VIQ), Performance IQ (PIQ) and Working memory (WMI) derived from Wechsler scales and receptive vocabulary ability derived from the Peabody Picture Verbal Test (PPVT) were included. A single mean meta-analysis was completed. Results: Relevant data was extracted and presented for 38 eligible studies; 2 of which are from grey literature. Results suggest children with DMD perform around 1SD below non-clinical norms for FSIQ, PIQ, VIQ and WMI. Unlike VIQ, scores derived from the PPVT were within the non-clinical norms. Studies were of moderate - high quality, there was significant heterogeneity and no publication bias. Conclusion: A systematic review of working memory has not previously been completed, it appears that children with DMD perform around 1SD below the mean, like FSIQ, PIQVIQ and WMI. The PPVT is a measure of receptive verbal ability and caution is recommended around the interchangeability of PPVT scores and the wider construct of verbal intelligence.

Duchenne Muscular Dystrophy-Associated Neurobehavioral Difficulties: Insights from Clinical Practice

Background

Emerging evidence underscores the high prevalence of neurobehavioral difficulties like ADHD, ASD and OCD, in patients with Duchenne muscular dystrophy (DMD). The substantial impact of these complex behavioral challenges in addition to motor function decline on the well-being of affected individuals and their families is increasingly evident. However, a uniform approach for effective screening, assessment and management of the neurobehavioral symptoms remains elusive.

Objective

We explored strategies used by healthcare professionals with clinical expertise in DMD to address neurobehavioral symptoms, in order to uncover diverse practices and to identify potential directions for clinical approaches in managing DMD neurobehavioral symptoms.

Methods and results

Twenty-eight respondents from 16 different countries completed an online survey. Only 35% of the centers systematically screened for neurobehavioral difficulties in their DMD population. Predominant screening methods included history taking and clinical observation. Common neurobehavioral difficulties encompassed learning challenges, dependency from adults, anxiety, concentration difficulties, and social deficits. The participating centers frequently employed parental counseling and liaison with psychosocial healthcare professionals for psychosocial intervention.

Conclusion

This study underscores the complex behavioral landscape in DMD, highlighting the need for validated screening, assessment and management strategies and collaborative efforts in implementing these. We advocate for international consensus recommendations for screening, assessment and management of neurobehavioral difficulties in DMD to enhance patient care and communication across healthcare settings.

Development and Pilot Validation of the DuMAND Checklist to Screen for Duchenne Muscular Dystrophy-Associated Neurobehavioral Difficulties (DuMAND)

Background

Patients with Duchenne muscular dystrophy (DMD) face a higher risk of neurobehavioral problems, yet an international consensus on screening, assessing, and managing these difficulties is lacking.

Objective

This report introduces the term Duchenne Muscular Dystrophy-Associated Neurobehavioral Difficulties (DuMAND) to comprehensively cover the spectrum of neurobehavioral issues in DMD patients, including behavior, psychiatric disorders, and various cognitive, academic, and psychosocial deficits. To facilitate screening, the DuMAND Checklist, a 43-item tool with five subscales, was developed.

Methods and results

DuMAND categories were derived through literature review, parent (48 mothers and 37 fathers), and expert (n = 28) input and feedback. The DuMAND Checklist subscales were developed iteratively, incorporating item selection, expert panel (n = 10) assessment for face validity, comprehensiveness, and a pilot validation study in a DMD sample (n = 20). DuMAND encompasses five categories: cognition and learning, social responsiveness, emotion regulation, externalizing behavior, and eating and sleeping. Preliminary validation of the DuMAND Checklist indicates acceptable-to-excellent internal consistency and construct validity.

Conclusion

By introducing the DuMAND concept, this study seeks to inspire a consensus approach for screening, assessing, and managing neurobehavioral issues in DMD. Incorporating screening, using the DuMAND Checklist, in addition to medical follow-up will facilitate early intervention, addressing a critical gap in identification of neurobehavioral disorders in DMD. Future research is needed to further evaluate psychometric properties of the DuMAND Checklist and investigate the natural course of DuMAND.

Comparison of two corticosteroid regimens on brain volumetrics in patients with Duchenne muscular dystrophy

OBJECTIVE

Duchenne muscular dystrophy (DMD) is a neuromuscular disorder in which many patients also have neurobehavioral problems. Corticosteroids, the primary pharmacological treatment for DMD, have been shown to affect brain morphology in other conditions, but data in DMD are lacking. This study aimed to investigate the impact of two corticosteroid regimens on brain volumetrics in DMD using magnetic resonance imaging (MRI).

METHODS

In a cross-sectional, two-center study, T1-weighted MRI scans were obtained from three age-matched groups (9-18 years): DMD patients treated daily with deflazacort (DMDd, n = 20, scan site: Leuven), DMD patients treated intermittently with prednisone (DMDi, n = 20, scan site: Leiden), and healthy controls (n = 40, both scan sites). FSL was used to perform voxel-based morphometry analyses and to calculate intracranial, total brain, gray matter, white matter, and cerebrospinal fluid volumes. A MANCOVA was employed to compare global volumetrics between groups, with site as covariate.

RESULTS

Both patient groups displayed regional differences in gray matter volumes compared to the control group. The DMDd group showed a wider extent of brain regions affected and a greater difference overall. This was substantiated by the global volume quantification: the DMDd group, but not the DMDi group, showed significant differences in gray matter, white matter, and cerebrospinal fluid volumes compared to the control group, after correction for intracranial volume.

INTERPRETATION

Volumetric differences in the brain are considered part of the DMD phenotype. This study suggests an additional impact of corticosteroid treatment showing a contrast between pronounced alterations seen in patients receiving daily corticosteroid treatment and more subtle differences in those treated intermittently.

Effect of transcutaneous electrical acupoint stimulation on postoperative pain in pediatric orthopedic surgery with the enhanced recovery after surgery protocol: a prospective, randomized controlled trial

STUDY OBJECTIVE

To evaluate the safety and effectiveness of transcutaneous electrical acupoint stimulation (TEAS) in postoperative analgesia following pediatric orthopedic surgery with the enhanced recovery after surgery (ERAS) protocol.

DESIGN

Prospective randomized controlled trial.

SETTING

The Seventh Medical Center of the Chinese People's Liberation Army General Hospital.

PARTICIPANTS

Eligible participants were children aged 3-15 years who were scheduled to undergo orthopedic surgery of the lower extremities under general anesthesia.

INTERVENTIONS

A total of 58 children were randomly allocated into two groups: TEAS (n = 29) and sham-TEAS (n = 29). The ERAS protocol was used in both groups. In the TEAS group, the bilateral Hegu (LI4) and Neiguan (PC6) acupoints were stimulated starting from 10 min before anesthetic induction until the completion of surgery. In the sham-TEAS group, the electric stimulator was also connected to the participants; however, electrical stimulation was not applied.

MEASURES

The primary outcome was the severity of pain before leaving the post-anesthesia care unit (PACU) and at postoperative 2 h, 24 h, and 48 h. Pain intensity was measured with the Faces Pain Scale-Revised (FPS-R).

RESULTS

None of the participants had any TEAS-related adverse reactions. In comparison with the sham-TEAS group, FPS-R scores in the TEAS group were significantly decreased before leaving the PACU and at postoperative 2 h and 24 h (p < 0.05). The incidence of emergence agitation, intraoperative consumption of remifentanil, and time to extubation were significantly reduced in the TEAS group. Furthermore, the time to first press of the patient-controlled intravenous analgesia (PCIA) pump was significantly longer, the pressing times of the PCIA pump in 48 h after surgery was significantly decreased, and parental satisfaction was significantly improved (all p < 0.05).

CONCLUSION

TEAS may safely and effectively relieve postoperative pain and reduce the consumption of perioperative analgesia in children following orthopedic surgery with the ERAS protocol.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2200059577), registered on May 4, 2022.

Psychological test usage in duchenne muscular dystrophy: An EU multi-centre study

AIM

During the last two decades brain related comorbidities of Duchenne have received growing scientific and clinical interest and therefore systematic assessment of cognition, behaviour and learning is important. This study aims to describe the instruments currently being used in five neuromuscular clinics in Europe as well as the diagnoses being made in these clinics.

METHOD

A Delphi based procedure was developed by which a questionnaire was sent to the psychologist in five of the seven participating clinics of the Brain Involvement In Dystrophinopathy (BIND) study. Instruments and diagnoses being used were inventoried for three domains of functioning (cognition, behaviour and academics) and three age groups (3-5 years, 6-18 years and adulthood 18+ years).

RESULTS

Data show wide diversity of tests being used in the five centres at different age groups and different domains. For the intelligence testing there is consensus in using the Wechsler scales, but all other domains such as memory, attention, behavioural problems and reading are tested in very different ways by different instruments in the participating centres.

CONCLUSION

The heterogeneity of tests and diagnoses being used in current clinical practice underlines the importance for developing a Standard Operating Procedure (SOP) to improve both clinical practice and scientific research over different countries and improve comparative work.