Jill Zwicker

Developmental Coordination Disorder (DCD) is neurodevelopmental disorder that affects a child's ability to learn and perform motor skills which significantly interferes with their activities of daily living. Currently only one study has identified volume-based brain differences in children with DCD compared to typically developing (TD) children. Furthermore, no study has yet determined if occupational therapy intervention induces a change in grey matter volume in this population. The objectives for this study were to: (1) compare grey matter volume in children with DCD and TD children; (2) examine the relationship of grey matter volume to motor function and attentional performance; and (3) examine neuroplastic changes in grey matter volume in children with DCD following Cognitive Orientation to Occupational Performance intervention. Objectives 1 and 2 were addressed using 30 DCD and 12 TD MRI scans for cross-sectional voxel-based morphometry with a one-way Analysis of Variance (ANOVA) design. Objective 3 was addressed using 20 MRI scans for pre-post longitudinal voxel-based morphometry with a Repeated Measures ANOVA design. Regression analyses were used to examine the relationship between grey matter volume, motor function, and attentional performance. The baseline results revealed that children with DCD had greater grey matter volume in the left superior frontal gyrus (working memory). Poorer motor function was associated with greater grey matter volume in the right middle frontal gyrus, left frontal pole, and superior frontal gyrus. Greater grey matter volume in parietal regions (left precuneus, left superior parietal lobe) was associated with poorer attentional performance. After intervention, grey matter volume decreased in right-sided regions associated with self-regulation (posterior cingulate gyrus), voluntary thinking, cognitive and motor connections (middle cingulate) and executive functioning (superior frontal gyrus). This study suggests that children with DCD may have altered brain development and that CO-OP intervention may facilitate brain maturation in targeted regions.

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The full abstract for this thesis is available in the body of the thesis, and will be available when the embargo expires.

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Developmental Coordination Disorder (DCD) is a neurodevelopmental disorder that affects a child’s ability to learn motor skills and participate in self-care, educational, and leisure activities. The cause of DCD is unknown, but evidence suggests that children with DCD have atypical brain structure and function. Resting-state MRI assesses functional connectivity by identifying brain regions that have correlated activation during rest. As only a few studies have examined functional connectivity in this population, our objective was to compare whole-brain resting-state functional connectivity of children with DCD and typically-developing children, and examine the correlation of functional connectivity with behavioural measures of motor function and ADHD symptoms. Children 8-12 years old were classified as DCD if they scored ≤16th percentile on the Movement Assessment Battery for Children - 2nd edition (MABC-2) and scored in the suspected or indicative range on the DCD Questionnaire (N=35). The control group included children with a score ≥25th percentile on the MABC-2 (N=23). Children were excluded if they were born preterm (
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Developmental coordination disorder (DCD) is a neurodevelopmental disorder of unknown etiology characterized by poor motor coordination and difficulty learning motor skills. Recent research has shown brain differences in children with DCD compared to typically-developing children. Diffusion Tensor Imaging (DTI) is a neuroimaging technique used to identify diffusion properties of white matter of the brain. Only a handful of studies have started to elucidate the white matter pathways that are implicated in children with DCD. These studies used tractography to look at a priori white matter pathways. The objective of this thesis is to be the first to apply a DTI method called tract-based spatial statistics (TBSS), a user independent analysis of the whole brain white matter to investigate the neural correlates of children with and without DCD. We hypothesized that the white matter differences would be widespread and implicate white matter pathways such as the: corticospinal motor tract (CST); sensorimotor pathways of the posterior thalamic radiation (PTR); corpus callosum; and cerebellar pathways (CP). To achieve our research goals, DTI data were collected from 61 children between 8-12 years of age (31 DCD; 30 TD) who had an MRI scan at a mean age of 10.02 years. Voxel-wise statistical analysis of diffusion metrics such as fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) was conducted using TBSS. A two-group comparison design matrix with age and attention as covariates was used. Data were corrected for multiple comparisons across space and statistical significance was set at p
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