White matter organization in developmental coordination disorder: A pilot study exploring the added value of constrained spherical deconvolution

Interlimb Coordination and Auditory-Motor Synchronization in Children with Developmental Coordination Disorder: Examining Antiphase Knee Movements with Auditory Metronomes While Seated

Background: Children with developmental coordination disorder (DCD) exhibit reduced interlimb coordination compared to typically developing children (TDC) during complex tasks like running, which requires dynamic postural control. However, the extent of interlimb coordination difficulties in DCD during tasks that demand minimal dynamic balance, such as self-paced and externally auditory-paced tasks, remains unclear. This study aimed to compare interlimb coordination and auditory-motor synchronization between children with DCD and TDC during a seated antiphase coordination task of the lower limbs, which has minimal postural control requirements. Methods: Twenty-one children with DCD and 22 TDC performed an antiphase knee flexion and extension task while seated, in three conditions (baseline silence, metronome discrete, and metronome continuous), for three minutes. The interlimb coordination, synchronization, and spatiotemporal movement parameters were analyzed using a mixed model analysis; Results: Children with DCD displayed less coordinated interlimb movements compared to TDC (p = 0.0140), which was the result of the greater variability in coordinating antiphase knee flexion-extension movements (p < 0.0001). No group differences in spatiotemporal movement parameters were observed. Children with DCD, compared to TDC, had a lower synchronization consistency to metronomes (p = 0.0155). Discrete metronomes enhanced interlimb coordination compared to the baseline silence condition (p = 0.0046); Conclusions: The study highlights an inferior interlimb coordination and auditory-motor synchronization in children with DCD compared to TDC. Implementing metronomes with a discrete temporal structure improved the interlimb coordination of both groups during the used fundamental seated interlimb coordination task, supporting theorical frameworks of event-based timing.

Motor proficiency of persons with attention deficit hyperactivity disorder or autism spectrum disorder diagnosed in adulthood

PURPOSE

To compare (1) motor proficiency of persons diagnosed in adulthood with attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) with normative values of motor proficiency, and (2) motor proficiency between persons with ADHD and those with ASD diagnosed in adulthood.

METHODS

A total of 153 adults (median age 32 years, 36% women) participated in this cross-sectional study. Fifty-three persons with predominately inattentive presentation (ADHD-I), 67 persons with combined presentation (ADHD-C), and 33 persons with ASD performed the Bruininks-Oseretsky Test of Motor Proficiency (BOT-2). One-sample binominal tests were used to compare motor proficiency against standardized norms of BOT-2 for young adults. One-way ANOVAs and Kruskal-Wallis tests were used to compare test outcomes between the groups.

RESULTS

The total sample showed significantly impaired motor proficiency in comparison to norms in all test domains (p < 0.001-0.006), except for fine motor skills. The ASD group showed significantly poorer body coordination compared with the ADHD-I and ADHD-C groups, with a moderate effect size (p = 0.003-0.02, η2 = 0.061).

CONCLUSIONS

Motor proficiency is impaired in most persons with ADHD or ASD diagnosed in adulthood, suggesting that motor assessment should be included in clinical examinations of adults with suspected neurodevelopment disorders.

Attention and motor profiles in children with developmental coordination disorder: A neuropsychological and neuroimaging investigation

AIM

This study aimed to (1) quantify attention and executive functioning in children with developmental coordination disorder (DCD), (2) assess whether some children with DCD are more likely to show attention difficulties, and (3) characterize brain correlates of motor and attention deficits.

METHOD

Fifty-three children (36 with DCD and 17 without) aged 8 to 10 years underwent T1-weighted and diffusion-weighted magnetic resonance imaging, and standardized attention and motor assessments. Parents completed questionnaires of executive functioning and symptoms of inattention and hyperactivity. We assessed regional cortical thickness and surface area, and cerebellar, callosal, and primary motor tract structure.

RESULTS

Analyses of covariance and one-sample t-tests identified impaired attention, non-motor processing speed, and executive functioning in children with DCD, yet partial Spearman's rank correlation coefficients revealed these were unrelated to one another or the type or severity of the motor deficit. Robust regression analyses revealed that cortical morphology in the posterior cingulate was associated with both gross motor skills and inattentive symptoms in children with DCD, while gross motor skills were also associated with left corticospinal tract (CST) morphology.

INTERPRETATION

Children with DCD may benefit from routine attention and hyperactivity assessments. Alterations in the posterior cingulate and CST may be linked to impaired forward modelling during movements in children with DCD. Overall, alterations in these regions may explain the high rate of non-motor impairments in children with DCD.

WHAT THIS PAPER ADDS

Children with developmental coordination disorder have difficulties in attention, processing speed, and executive functioning. Non-motor impairments were not interrelated or correlated with the type or severity of motor deficit. Posterior cingulate morphology was associated with gross motor skills and inattention. Gross motor skills were also associated with left corticospinal tract morphology.

Awareness about developmental coordination disorder

The present paper is designed to promote awareness of DCD outside the academic world. With a prevalence of 5-6% it is one of the most common disorders of child development. It is therefore surprising that so little is known about it among professionals in child healthcare and education. Parents have expressed frustration about this lack of awareness, including the general public. The general aim of this paper was to describe those critical aspects of DCD that will promote awareness.

Association between Motor Planning and the Frontoparietal Network in Children: An Exploratory Multimodal Study

OBJECTIVE

Evidence from adult literature shows the involvement of cortical grey matter areas of the frontoparietal lobe and the white matter bundle, the superior longitudinal fasciculus (SLF) in motor planning. This is yet to be confirmed in children.

METHOD

A multimodal study was designed to probe the neurostructural basis of childhood motor planning. Behavioural (motor planning), magnetic resonance imaging (MRI) and diffusion weighted imaging (DWI) data were acquired from 19 boys aged 8-11 years. Motor planning was assessed using the one and two colour sequences of the octagon task. The MRI data were preprocessed and analysed using FreeSurfer 6.0. Cortical thickness and cortical surface area were extracted from the caudal middle frontal gyrus (MFG), superior frontal gyrus (SFG), precentral gyrus (PcG), supramarginal gyrus (SMG), superior parietal lobe (SPL) and the inferior parietal lobe (IPL) using the Desikan-Killiany atlas. The DWI data were preprocessed and analysed using ExploreDTI 4.8.6 and the white matter tract, the SLF was reconstructed.

RESULTS

Motor planning of the two colour sequence was associated with cortical thickness of the bilateral MFG and left SFG, PcG, IPL and SPL. The right SLF was related to motor planning for the two colour sequence as well as with the left cortical thickness of the SFG.

CONCLUSION

Altogether, morphology within frontodorsal circuity, and the white matter bundles that support communication between them, may be associated with individual differences in childhood motor planning.

Behavioral and Neuroimaging Research on Developmental Coordination Disorder (DCD): A Combined Systematic Review and Meta-Analysis of Recent Findings

AIM

The neurocognitive basis of Developmental Coordination Disorder (DCD; or motor clumsiness) remains an issue of continued debate. This combined systematic review and meta-analysis provides a synthesis of recent experimental studies on the motor control, cognitive, and neural underpinnings of DCD.

METHODS

The review included all published work conducted since September 2016 and up to April 2021. One-hundred papers with a DCD-Control comparison were included, with 1,374 effect sizes entered into a multi-level meta-analysis.

RESULTS

The most profound deficits were shown in: voluntary gaze control during movement; cognitive-motor integration; practice-/context-dependent motor learning; internal modeling; more variable movement kinematics/kinetics; larger safety margins when locomoting, and atypical neural structure and function across sensori-motor and prefrontal regions.

INTERPRETATION

Taken together, these results on DCD suggest fundamental deficits in visual-motor mapping and cognitive-motor integration, and abnormal maturation of motor networks, but also areas of pragmatic compensation for motor control deficits. Implications for current theory, future research, and evidence-based practice are discussed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier: CRD42020185444.

White matter structural connectivity as a biomarker for detecting juvenile myoclonic epilepsy by transferred deep convolutional neural networks with varying transfer rates

Objective. By detecting abnormal white matter changes, diffusion magnetic resonance imaging (MRI) contributes to the detection of juvenile myoclonic epilepsy (JME). In addition, deep learning has greatly improved the detection performance of various brain disorders. However, there is almost no previous study effectively detecting JME by a deep learning approach with diffusion MRI.Approach. In this study, the white matter structural connectivity was generated by tracking the white matter fibers in detail based on Q-ball imaging and neurite orientation dispersion and density imaging. Four advanced deep convolutional neural networks (CNNs) were deployed by using the transfer learning approach, in which the transfer rate searching strategy was proposed to achieve the best detection performance.Main results. Our results showed: (a) Compared to normal control, the white matter' neurite density of JME was significantly decreased. The most significantly abnormal fiber tracts between the two groups were found to be cortico-cortical connection tracts. (b) The proposed transfer rate searching approach contributed to find each CNN's best performance, in which the best JME detection accuracy of 92.2% was achieved by using the Inception_resnet_v2 network with a 16% transfer rate.Significance. The results revealed: (a) Through detection of the abnormal white matter changes, the white matter structural connectivity can be used as a useful biomarker for detecting JME, which helps to characterize the pathophysiology of epilepsy. (b) The proposed transfer rate, as a new hyperparameter, promotes the CNNs transfer learning performance in detecting JME.

Indices of callosal axonal density and radius from diffusion MRI relate to upper and lower limb motor performance

Understanding the relationship between human brain structure and functional outcome is of critical importance in systems neuroscience. Diffusion MRI (dMRI) studies show that fractional anisotropy (FA) is predictive of motor control, underscoring the importance of white matter (WM). However, as FA is a surrogate marker of WM, we aim to shed new light on the structural underpinnings of this relationship by applying a multi-compartment microstructure model providing axonal density/radius indices. Sixteen young adults (7 males / 9 females), performed a hand/foot tapping task and a Multi Limb Reaction Time task. Furthermore, diffusion (STEAM &HARDI) and fMRI (localizer hand/foot activations) data were obtained. Sphere ROIs were placed on activation clusters with highest t value to guide interhemispheric WM tractography. Axonal radius/density indices of callosal parts intersecting with tractography were calculated from STEAM, using the diffusion-time dependent AxCaliber model, and correlated with behavior. Results indicated a possible association between larger apparent axonal radii of callosal motor fibers of the hand and higher tapping scores of both hands, and faster selection-related processing (normalized reaction) times (RTs) on diagonal limb combinations. Additionally, a trend was present for faster selection-related processing (normalized reaction) times for lower limbs being related with higher axonal density of callosal foot motor fibers, and for higher FA values of callosal motor fibers in general being related with better tapping and faster selection-related processing (normalized reaction) times. Whereas FA is sensitive in demonstrating associations with motor behavior, axon radius/density (i.e., fiber geometry) measures are promising to explain the physiological source behind the observed FA changes, contributing to deeper insights into brain-behavior interactions.

White Matter Changes With Rehabilitation in Children With Developmental Coordination Disorder: A Randomized Controlled Trial

Background and Objectives: Children with developmental coordination disorder (DCD) have difficulty learning motor skills, which can affect their participation in activities of daily living and psychosocial well-being. Over 50% of children with DCD also have attention deficit hyperactivity disorder (ADHD), which further exacerbates their motor problems and impact on quality of life. A rehabilitation approach known as Cognitive Orientation to Occupational Performance uses problem-solving strategies to help children learn motor skills they wish to achieve. While this cognitive approach has been effective for children with DCD, few studies have examined the effectiveness of this approach for children with co-occurring ADHD. Further, the underlying mechanism and neural basis of this intervention are largely unknown.

Methods: In this randomized waitlist-controlled trial, we used MRI to examine white matter microstructure after intervention in 8–12-year-old children with DCD (n = 28) and with DCD and co-occurring ADHD (n = 25). Children in both groups were randomized to either a treatment group or waitlist group at their first MRI. The treatment group began the intervention after their MRI scan and returned for a post-treatment scan at 3 months, and follow-up scan at 6 months; the waitlist group waited 3 months before their second MRI, received the intervention, and then had a post-treatment scan. Each child received intervention once weekly for 10 weeks. Diffusion tensor imaging was used to acquire white matter diffusion parameters and was analyzed using tract-based spatial statistics (TBSS).

Results and Conclusion: Children with DCD showed significant improvement in white matter microstructure in the bilateral anterior thalamic radiation, bilateral sensorimotor tract, bilateral cingulum, fornix, splenium and body of corpus callosum, right inferior fronto-occipital fasciculus, and white matter pathways to bilateral inferior gyri, right middle frontal gyrus, frontal medial cortex, and left cuneus. We suggest that these rehabilitation-induced neural changes in children with DCD occurred in regions associated with attention, self-regulation, motor planning, and inter-hemispheric communication, which positively affected brain connectivity and motor function. In contrast, children with DCD and co-occurring ADHD did not show any brain changes following the intervention. Modifications to the treatment protocol might help address the attentional and self-regulatory needs of children with a dual diagnosis.

Clinical Trial Registration: ClinicalTrials.gov ID: NCT02597751.

Procedural learning and retention of audio-verbal temporal sequence is altered in children with developmental coordination disorder but cortical thickness matters

Rhythmic abilities are impaired in developmental coordination disorder (DCD) but learning deficit of procedural skills implying temporal sequence is still unclear. Current contradictory results suggest that procedural learning deficits in DCD highly depend on learning conditions. The present study proposes to test the role of sensory modality of stimulations (visual or auditory) on synchronization, learning, and retention of temporal verbal sequences in children with and without DCD. We postulated a deficit in learning particularly with auditory stimulations, in association with atypical cortical thickness of three regions of interesting: sensorimotor, frontal and parietal regions. Thirty children with and without DCD (a) performed a synchronization task to a regular temporal sequence and (b) practiced and recalled a novel non-regular temporal sequences with auditory and visual modalities. They also had a magnetic resonance imaging to measure their cortical thickness. Results suggested that children with DCD presented a general deficit in synchronization of a regular temporal verbal sequence irrespective of the sensory modality, but a specific deficit in learning and retention of auditory non-regular verbal temporal sequence. Stability of audio-verbal synchronization during practice correlated with cortical thickness of the sensorimotor cortex. For the first time, our results suggest that synchronization deficits in DCD are not limited to manual tasks. This deficit persists despite repeated exposition and practice of an auditory temporal sequence, which suggests a possible alteration in audio-verbal coupling in DCD. On the contrary, control of temporal parameters with visual stimuli seems to be less affected, which opens perspectives for clinical practice.

Differences in White Matter Microstructure Among Children With Developmental Coordination Disorder

IMPORTANCE

Developmental coordination disorder (DCD) is a motor impairment that significantly interferes with activities of daily living. Little is known about the cause of DCD and how it develops, making it difficult to understand why children with DCD struggle in learning motor skills and to determine the best intervention to optimize function.

OBJECTIVE

To characterize white matter differences using diffusion tensor imaging in children with and without DCD.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study collected diffusion tensor imaging data at BC Children's Hospital Research Institute in Vancouver, British Columbia, Canada, from September 2014 to January 2017. Using a sample of convenience, children with DCD and children without DCD aged 8 to 12 years underwent magnetic resonance imaging. Data analysis was conducted from January 2017 to January 2020.

MAIN OUTCOMES AND MEASURES

The main outcome measures were diffusion parameters, including fractional anisotropy and mean, axial, and radial diffusivity, which are thought to provide an indirect measure of white matter microstructure. Tract-based spatial statistics, a voxelwise statistical analysis of diffusion parameters, were conducted using a 2-group comparison design matrix with age and attention as covariates.

RESULTS

Thirty children without DCD (mean [SD] age, 9.9 [1.4] years; 21 [70%] boys) and 31 children with DCD (mean [SD] age, 10.1 [1.2] years; 26 [84%] boys) were included in the study. Compared with children without DCD, children with DCD were characterized by significantly lower fractional anisotropy and axial diffusivity in regions of white matter pathways associated with motor and sensorimotor processing, including the corticospinal tract (fractional anisotropy: mean [SD], 0.54 [0.03] vs 0.51 [0.03]; P < .001; axial diffusivity: mean [SD], 0.13 [0.98] vs 0.12 [0.46]; P = .01), posterior thalamic radiation at the retrolenticular part of the internal capsule (axial diffusivity: mean [SD], 0.14 [0.57] vs 0.14 [0.44]; P = .01), and cerebellar pathways (eg, superior cerebellar peduncle, fractional anisotropy: mean [SD], 0.49 [0.05] vs 0.46 [0.03]; P = .03; axial diffusivity: mean [SD], 0.14 [0.66] vs 0.14 [0.63]; P = .009). There were no significant differences in mean diffusivity and radial diffusivity between children with and without DCD.

CONCLUSIONS AND RELEVANCE

These findings suggest that children with DCD show significant brain differences in motor and sensorimotor white matter pathways compared with children without DCD. The pattern of diffusion parameters in children with DCD suggests that axonal development may be disrupted in this neurodevelopmental disorder.

Quantitative tractography reveals changes in the corticospinal tract in drug-naïve children with attention-deficit/hyperactivity disorder

BACKGROUND

The specific role of the corticospinal tract with respect to inattention and impulsive symptoms in children with attention-deficit/hyperactivity disorder (ADHD) has been explored in the past. However, to our knowledge, no study has identified the exact regions of the corticospinal tract that are affected in ADHD. We aimed to determine comprehensive alterations in the white matter microstructure of the corticospinal tract and underlying neuropsychological substrates in ADHD.

METHODS

We recruited 38 drug-naïve children with ADHD and 34 typically developing controls. We employed a tract-based quantitative approach to measure diffusion parameters along the trajectory of the corticospinal tract, and we further correlated alterations with attention and response inhibition measures.

RESULTS

Compared with controls, children with ADHD demonstrated significantly lower fractional anisotropy and higher radial diffusivity at the level of cerebral peduncle, and higher fractional anisotropy at the level of the posterior limb of the internal capsule in the right corticospinal tract only. As well, increased fractional anisotropy in the posterior limb of the internal capsule was negatively correlated with continuous performance test attention quotients and positively correlated with reaction time on the Stroop Colour–Word Test; increased radial diffusivity in the right peduncle region was positively correlated with omissions in the Stroop test.

LIMITATIONS

The sample size was relatively small. Moreover, we did not consider the different subtypes of ADHD and lacked sufficient power to analyze subgroup differences. Higher-order diffusion modelling is needed in future white matter studies.

CONCLUSION

We demonstrated specific changes in the right corticospinal tract in children with ADHD. Correlations with measures of attention and response inhibition underscored the functional importance of corticospinal tract disturbance in ADHD.

A Review of Functional and Structural Neurobiology of the Action Observation Network in Autism Spectrum Disorder and Developmental Coordination Disorder

Recent research has reported motor impairment similarities between children with developmental coordination disorder (DCD) and a subgroup of individuals with autism spectrum disorder (ASD). However, there is a debate as to whether DCD is a co-occurring diagnosis in individuals with ASD and motor impairments (ASDd), or if motor impairments in ASD are distinct from DCD. However, the etiology of motor impairments is not well understood in either disorder. Clarifying comorbidities in ASD is important to determine different etiopathological phenotyping clusters in ASD and to understand the variety of genetic and environmental factors that contribute to the disorder. Furthermore, this distinction has important therapeutic relevance. Here we explore the current neuroimaging findings in ASD and DCD and discusses possible neural mechanisms that underlie similarities and differences between the disorders.