Investigating the impact of developmental coordination difficulties across home, school, and community settings: Findings from the Australian Impact for DCD survey.

AIM: To evaluate the participation difficulties experienced by children with developmental coordination disorder (DCD) in home, school, and community environments. METHODS: The Impact for DCD survey was completed by primary caregivers of 4-18-year-old children with DCD (or synonymous diagnosis) (n = 429). OUTCOMES AND RESULTS: The greatest participation difficulties experienced at home included dressing, eating with utensils, self-care tasks and drawing/writing reported by over 70% of families. At school, fine motor difficulties were also frequently reported, with additional difficulties keeping up or completing tasks, and not feeling supported at school. Socialisation challenges and bullying were also commonly reported (34.9%). As a result of participation difficulties at school, 5.4% were home schooled. Many children engaged in community activity, with 72.0% currently engaged in at least one organised sports-based activity. CONCLUSIONS AND IMPLICATIONS: Increased recognition of the widespread impact of DCD in a child's life is crucial at an individual and societal level. Parents reported their children experiencing significant participation restrictions and difficulties. The findings of this large-scale study have revealed that most children with DCD are not receiving the support they need to thrive, especially at school. This largely reflects a lack of understanding and recognition of the condition and its associated challenges.

Psychosocial wellbeing, parental concerns, and familial impact of children with developmental coordination disorder.

BACKGROUND: Developmental Coordination Disorder (DCD) is a neurodevelopmental condition impacting motor skill acquisition and competence. While previous studies have identified adverse psychosocial outcomes in DCD, they are limited by small or population-screened, community-based samples. AIMS: To understand the psychosocial difficulties, parental concerns, and familial impacts of childhood DCD in a large population-based sample. METHODS AND PROCEDURES: Parents of 310 children aged 4 - 18 years with a diagnosis of DCD (or synonymous term) completed the Impact for DCD survey. Parent-rated measures of emotional problems, peer problems, and prosocial behaviour were compared to normative data. Parental concerns for the impact of DCD on participation, interaction, emotional well-being, and the family system were examined. OUTCOMES AND RESULTS: Compared to typically developing children, children with DCD were rated significantly higher for emotional and peer problems, and significantly lower for prosocial behaviours. Parents most commonly reported concerns for their child's future and withdrawal from physical activity. The presence of one or more co-occurring disorders did not significantly influence outcomes. CONCLUSION AND IMPLICATIONS: Findings highlight the poor psychosocial outcomes for children with DCD. Crucially, poor psychosocial outcomes were just as likely in those with a single diagnosis of DCD as those with DCD and multiple co-occurring diagnoses. Parents reported concerns for their child (i.e., non-participation and social withdrawal) that are not targeted in existing DCD intervention modalities and emphasised the impact of DCD on the whole family unit. WHAT THIS PAPER ADDS: This paper presents data from the largest parent-reported survey of children with a known diagnosis of DCD (or synonymous labels). It highlights the significant impact of DCD on psychosocial outcomes in children across age groups. The children in this study were rated by their parents to have significantly higher levels of emotional and peer problems, and lower prosocial behaviours, than similarly aged Australian children without DCD. It also challenges the misconception that poor psychosocial outcomes in DCD are the result of co-occurring disorders, with outcomes observed to be as poor in children with a sole diagnosis of DCD in this sample. Furthermore, findings highlighted the significant worry and concern that parents with DCD face, particularly around their child's participation and their emotional health. Finally, parents reported on the considerable impact that DCD had on their family unit, regularly causing worry and concern, influencing their choice of activities, and causing financial strain. These concerns and impacts are not addressed in current intervention models for DCD and highlight the need for support mechanisms moving forward.

Motor problems in autism: Co-occurrence or feature?

Motor features of autism have long been acknowledged by clinicians, researchers, and community stakeholders. Current DSM-5 and ICD-11 guidelines allow clinicians to assign a co-occurring diagnosis of developmental [motor] coordination disorder (DCD) for autistic individuals with significant motor problems. DCD is characterized by poor motor proficiency with an onset of symptoms in early development. Studies have shown considerable overlap in the behavioral motor features observed in autism and DCD. However, others indicate that motor problems in autism and DCD may stem from different underlying sensorimotor mechanisms. Regardless of whether autism has a unique motor phenotype or an overlap with DCD, changes need to be made in the clinical pipeline to address motor problems in autism at the stages of recognition, assessment, diagnosis, and intervention. Consensus is needed to address unmet needs in research on the etiology of motor problems in autism and their overlap with DCD, to optimize clinical practice guidelines. The development of screening and assessment tools for motor problems that are valid and reliable for use with autistic individuals is essential, and an evidence-based clinical pipeline for motor problems in autism is urgently needed. WHAT THIS PAPER ADDS: Motor problems in autism are highly prevalent, yet underdiagnosed and poorly managed. An evidence-based clinical pipeline for motor problems in autism is urgently needed.

A longitudinal examination of perinatal testosterone, estradiol and vitamin D as predictors of handedness outcomes in childhood and adolescence.

The developmental origins of handedness remain elusive, though very early emergence suggests individual differences manifesting in utero could play an important role. Prenatal testosterone and Vitamin D exposure are considered, yet findings and interpretations remain equivocal. We examined n = 767 offspring from a population-based pregnancy cohort (The Raine Study) for whom early biological data and childhood/adolescent handedness data were available. We tested whether 18-week maternal circulatory Vitamin D (25[OH]D), and testosterone and estradiol from umbilical cord blood sampled at birth predicted variance in direction of hand preference (right/left), along with right- and left-hand speed, and the strength and direction of relative hand skill as measured by a finger-tapping task completed at 10 (Y10) and/or 16 (Y16) years. Although higher concentrations of Vitamin D predicted more leftward and less lateralized (regardless of direction) relative hand skill profiles, taken as a whole, statistically significant findings typically did not replicate across time-point (Y10/Y16) or sex (male/female) and were rarely detected across different (bivariate/multivariate) levels of analysis. Considering the number of statistical tests and generally inconsistent findings, our results suggest that perinatal testosterone and estradiol contribute minimally, if at all, to subsequent variance in handedness. Vitamin D, however, may be of interest in future studies.

Characterising the Early Presentation of Motor Difficulties in Autistic Children.

This study aimed to explore the rates of motor difficulties in children from the Australian Autism Biobank, and how early motor concerns impacted on children functionally. Children with autism aged 2-7 years, including 441 with a Vineland Adaptive Behavior Scale (VABS-II) motor subscale and 385 with a Mullen Scales of Early Learning (MSEL) fine motor subscale were included (n total = 514; 80% male). Approximately 60% of children on the MSEL and ~ 25% on the VABS-II had clinically significant motor impairments. More children with delayed sitting and walking motor milestones had early childhood parent reported motor difficulties (p < 0.001). Early motor delays or concerns may assist identifying individuals who will likely benefit from early ongoing developmental monitoring and early support.

Repetitive transcranial magnetic stimulation (rTMS) in autism spectrum disorder: protocol for a multicentre randomised controlled clinical trial.

INTRODUCTION: There are no well-established biomedical treatments for the core symptoms of autism spectrum disorder (ASD). A small number of studies suggest that repetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation technique, may improve clinical and cognitive outcomes in ASD. We describe here the protocol for a funded multicentre randomised controlled clinical trial to investigate whether a course of rTMS to the right temporoparietal junction (rTPJ), which has demonstrated abnormal brain activation in ASD, can improve social communication in adolescents and young adults with ASD. METHODS AND ANALYSIS: This study will evaluate the safety and efficacy of a 4-week course of intermittent theta burst stimulation (iTBS, a variant of rTMS) in ASD. Participants meeting criteria for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition ASD (n=150, aged 14-40 years) will receive 20 sessions of either active iTBS (600 pulses) or sham iTBS (in which a sham coil mimics the sensation of iTBS, but no active stimulation is delivered) to the rTPJ. Participants will undergo a range of clinical, cognitive, epi/genetic, and neurophysiological assessments before and at multiple time points up to 6 months after iTBS. Safety will be assessed via a structured questionnaire and adverse event reporting. The study will be conducted from November 2020 to October 2024. ETHICS AND DISSEMINATION: The study was approved by the Human Research Ethics Committee of Monash Health (Melbourne, Australia) under Australia's National Mutual Acceptance scheme. The trial will be conducted according to Good Clinical Practice, and findings will be written up for scholarly publication. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12620000890932).

The course and prognostic capability of motor difficulties in infants showing early signs of autism.

Delays within the motor domain are often overlooked as an early surveillance marker for autism. The present study evaluated motor difficulties and its potential as an early predictive marker for later autism likelihood in a cohort of infants (N = 96) showing early behavioral signs of autism aged 9-14 months. The motor domain was evaluated using the motor subscales of the Mullen Scales of Early Learning at baseline, and at a 6-month follow-up. The Autism Diagnostic Observation Schedule - Toddler Module (ADOS-T) was completed at follow-up as a measure of autism likelihood. Motor difficulties were common at baseline, with 63/96 (65.6%) infants scoring very low or below average in the gross motor domain and 29/96 (30.2%) in the fine motor domain. At follow-up, gross motor difficulties had resolved for many, with 23/63 (36.5%) infants maintaining these difficulties. Fine motor difficulties resolved in fewer infants, with 20/29 (69.0%) continuing to present with fine motor delays at follow-up. Adjusted linear regression models suggested that fine motor scores at baseline (ß = -0.12, SE = 0.04) and follow-up (ß = -0.17, SE = 0.05) were associated with higher ADOS-T scores; with difficulties across both timepoints (ß = 5.60, SE = 1.35) the strongest (largest in magnitude) association with ADOS-T scores of the predictors examined. Motor difficulties are prominent in children displaying emerging signs of autism, with persistent fine motor difficulties predictive of the developing autism phenotype. The findings indicate the potential clinical value of including evaluation of motor skills within early autism surveillance measures. LAY SUMMARY: This prospective study evaluated motor development over a 6-month period in infants showing early behavioral signs of autism. Atypical motor development was a common feature of infants showing early signs of autism and persistent fine motor difficulties were predictive of the emerging autism phenotype.

The unmet clinical needs of children with developmental coordination disorder.

BACKGROUND: The aim of this study was to understand the challenges experienced by families obtaining a diagnosis and therapy for developmental coordination disorder (DCD). METHODS: Parents of 435 children aged 4-18 years with persistent motor difficulties consistent with a diagnosis of DCD completed an online survey. Diagnostic timeline and diagnostic label/s received were examined, along with therapies accessed. RESULTS: There was inconsistent diagnostic terminology (nine separate terms) with more children diagnosed with dyspraxia (64.7%) than DCD (48.8%). Even though most parents (87.0%) reported that receiving a diagnosis was helpful, children did not receive a diagnosis until years after seeking help (mean 2.8 ± 2.3 years). Many children were diagnosed with at least one co-occurring neurodevelopmental, language or learning disorder (70.0%). Almost all families had accessed therapy for their child's movement difficulties (93.9%), but more than half did not have access to funding to support therapy costs (57.8%) and reported that the costs caused financial strain (52.6%). Two out of every three families reported that they did not feel the current level of therapy was sufficient. CONCLUSIONS: This critical advocacy research highlights inconsistent and incorrect terminology and the challenges families experience in obtaining a diagnosis and adequate access to therapy for their child's movement difficulties. IMPACT: This is the first comprehensive study to examine the challenges families experience gaining a diagnosis and therapy for their child with DCD. Families regularly experienced prolonged diagnosis; 45% waited between 2 and 4 years. There is no clear diagnostic pathway, with children more likely to be diagnosed with dyspraxia than the correct clinical diagnosis of DCD. More extensive implementation of the diagnostic guidelines into clinical practice is needed.

Investigating associations between birth order and autism diagnostic phenotypes.

BACKGROUND: Birth order effects have been linked to variability in intelligence, educational attainment and sexual orientation. First- and later-born children have been linked to an increased likelihood of an Autism Spectrum Disorder (ASD) diagnosis, with a smaller body of evidence implicating decreases in cognitive functioning with increased birth order. The present study investigated the potential association between birth order and ASD diagnostic phenotypes in a large and representative population sample. METHODS: Data were obtained from an ongoing prospective diagnostic registry, collected between 1999 and 2017, including children (1-18 years of age, n = 5,404) diagnosed with ASD in the state of Western Australia. Children with ASD were ranked relative to sibling's birth to establish birth order within families at time of ASD diagnosis. Information reported to the registry by health professionals at the time of diagnostic evaluation included demographic and family characteristics, functional abilities and intellectual capacity. RESULTS: Adaptive functioning and intelligence scores decreased with increasing birth order, with later-born children more likely to have an intellectual disability. Compared to first-born children with siblings, first-born children without siblings at the time of diagnosis also exhibited decreased cognitive functioning. CONCLUSIONS: These findings demonstrate for the first time an association between increasing birth order and variability in ASD clinical phenotypes at diagnosis, with potential evidence of reproductive curtailment in children without siblings. Taken together, these findings have significant implications for advancing understanding about the potential mechanisms that contribute to heterogeneity in ASD clinical presentations as a function of birth order and family size.

Exploring associations between neuromuscular performance, hypermobility, and children's motor competence.

OBJECTIVES: To evaluate if neuromuscular performance and hypermobility are factors associated with children's motor competence. DESIGN: Cross-sectional observation study. METHODS: Data was collected on 60 children aged 6-12 years; motor competence was determined using the Movement Assessment Battery for Children-2 test, with children classified into 3 groups (Typically Developing n=30; 'At Risk' of low motor competence (LMC) n=9; LMC n=21). Neuromuscular performance was determined utilising the Resistance Training Skills Battery for Children (RTSBc), 5-repetition maximum (5RM) leg press and Biodex dynamometry to assess isometric and isokinetic peak torque of the knee flexors and extensors. Hypermobility was measured using the Beighton and Lower Limb Assessment Score. RESULTS: Between-groups MANCOVA revealed typically developing children scored significantly higher on the RTSBc than those 'at risk' of LMC (p=0.021) and those in the LMC group (p<0.001). 5RM scores also differed between groups, with typically developing children achieving significantly higher scores than the LMC group. No differences were found between groups for isometric or isokinetic measures of strength. Sequential regression analysis revealed neuromuscular performance variables explained 44.7% of the variance in motor competence, with RTSBc (p<0.001) and 5RM (p=0.019) emerging as positive significant predictors. Hypermobility failed to explain significant variance in motor competence beyond that explained by neuromuscular performance. CONCLUSIONS: Neuromuscular performance of children varies according to levels of motor competence, with those with LMC performing poorly on tasks requiring multi-joint movement. Furthermore, neuromuscular performance predicted almost half the variance observed in motor competence and highlights a novel intervention strategy.

A preliminary investigation of the effects of prenatal alcohol exposure on facial morphology in children with Autism Spectrum Disorder.

Alcohol exposure during pregnancy has been associated with altered brain development and facial dysmorphology. While Autism Spectrum Disorder (ASD) is not specifically related to distinct facial phenotypes, recent studies have suggested certain facial characteristics such as increased facial masculinity and asymmetry may be associated with ASD and its clinical presentations. In the present study, we conducted a preliminary investigation to examine facial morphology in autistic children with (n = 37; mean age = 8.21 years, SD = 2.72) and without (n = 100; mean age = 8.37 years, SD = 2.47) prenatal alcohol exposure. Using three-dimensional facial scans and principal component analysis, we identified a facial shape associated with prenatal alcohol exposure in autistic children. However, variations in the alcohol-related facial shape were generally not associated with behavioral and cognitive outcomes. These findings suggest that while early exposure to alcohol may influence the development of facial structures, it does not appear to be associated with ASD phenotypic variability. Importantly, although these findings do not implicate a role for prenatal alcohol exposure in the etiology of ASD, further research is warranted to investigate the link between prenatal alcohol exposure and facial morphology differences among neurodevelopmental conditions.

The effect of parental logistic support on physical activity in children with, or at risk of, movement difficulties.

OBJECTIVES: In a sample of children with, or at risk of, movement difficulties, (1) To test the direct effects of children's perceptions of parents' logistic support for physical activity on children's physical activity-related self-perceptions and on children's physical activity levels, and (2) To explore the indirect relationship between children's perceptions of parents' logistic support for physical activity and children's physical activity levels through children's physical activity-related self-perceptions. DESIGN: Cross-sectional observation study. METHODS: Data were collected from 120 children aged 6 to 12 years; movement proficiency levels were determined using the movement assessment battery for children-2 test. Children's perspectives of parental support for physical activity were captured using the Activity Support Scale for Multiple Groups child report. Children's self-perceptions towards physical activity were reported with the Children's Self- perceptions of Adequacy in and Predilections for physical activity, and time spent in physical activity were measured using accelerometers. RESULTS: There was no significant direct effect between perceived levels of parents' logistic support for physical activity and children's physical activity. A significant indirect relationship between these variables was discovered, with higher perceived levels of parent logistical support for physical activity predicting stronger perceptions of adequacy (i.e., confidence) toward physical activity participation among children, which in turn was associated with increased physical activity minutes. CONCLUSIONS: The results demonstrate that irrespective of a child's movement ability, children's perceptions of parents' logistic support for physical activity indirectly and positively predicts children's physical activity levels, via children's confidence for physical activity.

Prevalence of Motor Difficulties in Autism Spectrum Disorder: Analysis of a Population-Based Cohort.

Motor impairment is not currently included in the diagnostic criteria or evaluation of autism. This reflects the lack of large-scale studies demonstrating its prominence to advocate for change. We examined the prevalence of motor difficulties at the time of diagnosis in a large sample of children with autism utilizing standardized assessment, and the relationship between motor difficulties, core autism symptomology, and other prominent clinical features. Vineland Adaptive Behavior Scales were administered to children from the Western Australian Register for Autism Spectrum Disorders aged ≤6 years (N = 2,084; 81.2% males, 18.8% females). Prevalence of motor difficulties was quantified based on scores from the motor domain of the Vineland and then compared to other domains of functioning within the Vineland (communication, daily living, and socialization), the DSM criteria, intellectual level, age, and gender. Scores on the Vineland indicated that 35.4% of the sample met criteria for motor difficulties (standard score <70), a rate almost as common as intellectual impairment (37.7%). Motor difficulties were reported by diagnosing clinicians in only 1.34% of cases. Motor difficulties were common in those cases meeting diagnostic criteria for impairments in nonverbal behavior and the presence of restricted and repetitive behaviors. The prevalence of motor difficulties also increased with increasing age of diagnosis (P < 0.001). Findings from the present study highlight the need for further consideration of motor difficulties as a distinct specifier within the diagnostic criteria for ASD. Autism Res 2020, 13: 298-306. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: In this population-based cohort that included 2,084 children with autism aged ≤6 years, over one-third met the criteria for motor difficulties, a rate almost as common as intellectual disability. This study demonstrates that motor difficulties are a prominent feature of the autism phenotype requiring further consideration in both the diagnostic criteria and evaluation of autism.

Physiological characteristics, self-perceptions, and parental support of physical activity in children with, or at risk of, developmental coordination disorder.

Children with low movement proficiency have been identified as having poorer physiological and psychosocial outcomes; however, the varied measurement approaches used to assess these outcomes have varied resulting in conflicting evidence regarding the presence and magnitude of differences compared to Typically Developing (TD) children. Additionally, there has been limited research into the role of parental support for physical activity (PA) in this group. We compared children with varying levels of movement proficiency on physiological characteristics and self-perceptions regarding PA. In addition, these children's parents were compared on physiological characteristics and support of their children's PA. Children (N = 117) aged 6 to 12 years, along with their parent/guardian, participated in this study. Children were classified according to the Movement Assessment Battery for Children-2 test (Typically Developing (TD) = 60; At Risk = 19; Developmental Coordination Disorder (DCD) = 38). Children's PA, muscle strength, cardio-respiratory fitness (CRF), body composition, and self-perceptions regarding PA were assessed, with parents assessed on CRF, body composition, and PA support. Compared to TD children, children with DCD had lower PA (p = 0.036), predilection (p ≤0.001) and adequacy (p ≤0.001) regarding PA, higher body fat percentage (p = 0.019), and received less logistic support (i.e., transportation) from their parents (p = 0.012). TD children had increased muscle strength compared to the DCD (p ≤ 0.001) and At Risk (p ≤ 0.001) groups. Results indicated that, relative to TD children, children with DCD have multiple physiological deficits, receive less parental logistic support for PA involvement, and report lower scores on psychological constructs that are predictive of PA involvement.

Visual tracking behaviour of two-handed catching in boys with developmental coordination disorder.

BACKGROUND: Developmental coordination disorder (DCD) is a motor learning disability that affects coordination resulting in an inability to perform movement skills at an age appropriate level. One area suspected to contribute to the movement difficulties experienced are deficits in visuomotor control. AIMS: This study investigated visual tracking behaviour during catching in children with DCD. METHODS AND PROCEDURES: Twenty-four boys completed the study: 11 with DCD (9.43 years ±0.73) and 13 controls (9.16 years ± 0.68). Participants performed 10 central catching trials, with the best five used to evaluate tracking behaviour and motor responses. OUTCOMES AND RESULTS: Prior to ball release, the DCD group exhibited more fixations (p = 0.043) of lesser duration (p = 0.045). During flight, the DCD group took longer to initiate smooth pursuit (p = 0.003) however, once initiated, both groups were effectively able to maintain smooth pursuit. Despite initial delays, these had no impact on movement initiation time (p = 0.173), however, movement time was significantly slower in the DCD group (p = 0.031). CONCLUSIONS AND IMPLICATIONS: The results of this study demonstrate that catching performance in children with DCD likely reflect a combination of errors in attending to visual information and movement organisation.

Reduced relative volume in motor and attention regions in developmental coordination disorder: A voxel-based morphometry study.

BACKGROUND AND OBJECTIVES: Developmental coordination disorder (DCD) is a prevalent childhood movement disorder, impacting the ability to perform movement skills at an age appropriate level. Although differences in grey matter (GM) volumes have been found in related developmental disorders, no such evidence has been linked with DCD to date. This cross-sectional study assessed structural brain differences in children with and without DCD. METHODS: High-resolution structural images were acquired from 44 children aged 7.8-12 years, including 22 children with DCD (≤16th percentile on MABC-2; no ADHD/ASD), and 22 typically developing controls (≥20th percentile on MABC-2). Structural voxel-based morphology analysis was performed to determine group differences in focal GM volumes. RESULTS: Children with DCD were found to have significant, large, right lateralised reductions in grey matter volume in the medial and middle frontal, and superior frontal gyri compared to controls. The addition of motor proficiency as a covariate explained the between-group GM volume differences, suggesting that GM volumes in motor regions are reflective of the level of motor proficiency. A positive correlation between motor proficiency and relative GM volume was also identified in the left posterior cingulate and precuneus. CONCLUSIONS: GM volume reductions in premotor frontal regions may underlie the motor difficulties characteristic of DCD. It is possible that intervention approaches targeting motor planning, attention, and executive functioning processes associated with the regions of reduced GM volume may result in functional improvements in children with DCD.

Poor Imitative Performance of Unlearned Gestures in Children with Probable Developmental Coordination Disorder.

It has been hypothesized that deficits in imitation, linked to abnormal functioning of the mirror neuron system (MNS), may contribute to the motor impairments associated with developmental coordination disorder (DCD). The authors aimed to examine imitation of complex novel postures and sequences of gestures in children with and without probable DCD (pDCD), using the postural praxis and sequencing praxis subtests of the Sensory Integration and Praxis Tests (Ayres, 1989 ). Participants were 29 boys with pDCD between 6.08 and 13.33 years old, and 29 group age-matched typically developing boys between 6.08 and 13.83 years old. Responses of children with pDCD on both imitation tasks were less accurate than controls, with group differences more apparent with increasing task complexity. Furthermore, as a group, children with pDCD were slower and had a higher number of non-mirror-imitated responses. There was considerable variability within the pDCD group, with some children displaying imitation scores within the normative range. Given the importance of imitation and visual learning for motor development, the difficulties in imitation displayed by some children with pDCD have the potential to impact on movement acquisition. Interventions to target imitation may be beneficial for these children. The results show that children with pDCD had difficulty imitating complex novel postures, children with pDCD had difficulty imitating gesture sequences, children with pDCD had slower responses than controls, group differences in imitation performance increased with task complexity, and not all children with pDCD displayed imitation deficits.

Mirror neuron activation in children with developmental coordination disorder: A functional MRI study.

The aim of this study was to reveal cortical areas that may contribute to the movement difficulties seen in children with Developmental Coordination Disorder (DCD). Specifically, we hypothesized that there may be a deficit in the mirror neuron system (MNS), a neural system that responds to both performed and observed actions. Using functional MRI, 14 boys with DCD (x=10.08 years ± 1.31, range=7.83-11.58 years) and 12 typically developing controls (x=10.10 years ± 1.15, range=8.33-12.00 years) were scanned observing, executing and imitating a finger sequencing task using their right hand. Cortical activations of mirror neuron regions, including posterior inferior frontal gyrus (IFG), ventral premotor cortex, anterior inferior parietal lobule and superior temporal sulcus were examined. Children with DCD had decreased cortical activation mirror neuron related regions, including the precentral gyrus and IFG, as well as in the posterior cingulate and precuneus complex when observing the sequencing task. Region of interest analysis revealed lower activation in the pars opercularis, a primary MNS region, during imitation in the DCD group compared to controls. These findings provide some preliminary evidence to support a possible MNS dysfunction in children with DCD.

Motor imagery ability and internal representation of movement in children with probable developmental coordination disorder.

It has been hypothesised that deficits in the functioning of the mirror neuron system (MNS) and internal modelling may contribute to the motor impairments associated with DCD. These processes can be explored behaviourally through motor imagery paradigms. Motor imagery proficiency of children with and without probable DCD (pDCD) was examined using a complex hand rotation task to explore whether motor imagery strategies could be used during more complex tasks. Forty-four boys aged 7-13 years participated, 22 with pDCD (mean = 9.90 years ± 1.57) and 22 controls (mean = 9.68 years ± 1.53). Participants completed the task twice: with and without motor imagery instructions. Stimuli were presented in two rotational axes--palm/back, and eight 45° rotational steps. Both groups showed evidence of following the biomechanical and postural constraints of actual movements. Responses of children with pDCD were slower and less accurate than controls, with group differences increasing alongside task complexity. A greater impact of biomechanical constraints for accuracy was observed in the DCD group. The response characteristics of children with pDCD likely reflects a reduced capacity to mentally manipulate a body schema and reduced visuo-motor processing capabilities. Behaviourally, these processes are linked to MNS and internal modelling function, suggesting deficits in these systems may contribute to the movement difficulties characteristic of DCD.