Jill G. Zwicker

Developmental coordination disorder: A review and update

Present in approximately 5-6% of school-aged children, developmental coordination disorder (DCD) is a neuromotor disability in which a childs motor coordination difficulties significantly interfere with activities of daily living or academic achievement. These children typically have difficulty with fine and/or gross motor skills, with motor performance that is usually slower, less accurate, and more variable than that of their peers. In this paper, we review the history of various definitions leading up to the current definition of DCD, prevalence estimates for the disorder, etiology, common co-morbidities, the impact of DCD on the childs life, and prognosis. As well, we briefly describe current interventions for children with the disorder and results of recent neuroimaging studies of the brains of children with DCD, including research by the authors of this paper.

Quality of life of formerly preterm and very low birth weight infants from preschool age to adulthood: a systematic review.

OBJECTIVE. The goal of this systematic review was to synthesize studies that examined the health-related quality of life of preschool- and school-aged children, adolescents, and young adults who were born preterm and/or at very low birth weight. METHODS. We searched 7 databases up to September 2006 (Medline, PubMed, Embase, EBM Reviews, Cumulative Index of Nursing and Allied Health Literature, PsycINFO, and the Educational Resource Information Center) as well as gray literature sources. We independently screened studies and included them only if a quality-of-life outcome measure was used and findings compared preterm, very low birth weight, or extremely low birth weight infants with term or normal birth weight peers. We independently assessed the methodologic quality of each study by using criteria adapted from the Centre for Reviews and Dissemination. RESULTS. Fifteen cohort or cross-sectional studies met the review criteria. In 6 studies of preschool-aged children, differences were found between study and control groups, suggesting that many preschool children born preterm or at very low birth weight perform more poorly than their peers in physical, emotional, and/or social functioning. Extremely low birth weight school-aged children had lower health utility scores compared with their peers, and similar results were found for adolescents. Parents of preterm and very low birth weight teens noted significantly poorer performance in their childs global health, behavior, and physical functioning, whereas the teenagers themselves did not. In young adulthood, differences in physical functioning remained, but subjective quality of life was similar to normal birth weight peers. CONCLUSIONS. The effects of preterm birth/very low birth weight on health-related quality of life seem to diminish over time, which possibly reflects issues related to a childs report versus a parent-proxy report, differing definitions of health-related quality of life, and adaptation of individuals over time, versus true change in health-related quality of life.

Neural correlates of developmental coordination disorder: a review of hypotheses.

Affecting 5% to 6% of school-age children, developmental coordination disorder is characterized by a marked impairment of motor coordination that significantly interferes with activities of daily living and academic achievement. Little is known about the etiology of developmental coordination disorder, but the disorder often coexists with attention-deficit hyperactivity disorder (ADHD), speech/language impairment, and/or reading disability. This comprehensive review examines the literature supporting or refuting hypothesized neural correlates of developmental coordination disorder and suggests directions for future research. Potential sources of neuropathology include the cerebellum, parietal lobe, corpus callosum, and basal ganglia. Comorbidities and deficits associated with developmental coordination disorder are highly suggestive of cerebellar dysfunction; yet, given the heterogeneity of this disorder, it is likely that the cerebellum is not the only neural correlate. Neuroimaging studies and behavioral investigations of learning-related change in motor behavior are the next critical step in enhancing our understanding of developmental coordination disorder.

Brain activation associated with motor skill practice in children with developmental coordination disorder: an fMRI study.

Children with developmental coordination disorder (DCD) have difficulty in learning new motor skills. At present, it is not known whether these children employ a different set of brain regions than typically developing (TD) children during skilled motor practice. Using functional magnetic resonance imaging, we mapped brain activity associated with skilled motor practice of a trail‐tracing task in 7 children with DCD and 7 age‐matched controls (aged 8–12 years). We indexed change in motor performance as a reduction in tracing error from early practice to retention. Children with DCD showed less blood‐oxygen‐level‐dependent signal as compared to TD children in a network of brain regions associated with skilled motor practice: bilateral inferior parietal lobules (Brodmann Area (BA) 40), right lingual gyrus (BA 18), right middle frontal gyrus (BA 9), left fusiform gyrus (BA 37), right cerebellar crus I, left cerebellar lobule VI, and left cerebellar lobule IX. While no statistically significant differences were detected, effect size testing revealed that children with DCD demonstrated poorer tracing accuracy than TD children at retention (d = 0.48). Our results suggest that, compared to TD peers, children with DCD demonstrate under‐activation in cerebellar–parietal and cerebellar–prefrontal networks and in brain regions associated with visual‐spatial learning. These data suggest a neurobiological correlation with impaired learning of motor skills in children with DCD, which will need to be confirmed with a larger sample.

Quality of life domains affected in children with developmental coordination disorder: a systematic review

The quality of life (QOL) of children with developmental coordination disorder (DCD) is largely unknown, but evidence suggests that multiple QOL domains are affected by the disorder. While DCD is primarily considered a motor disorder, multiple studies have reported psychological and social concerns in children with this condition. Our primary aim was to present the current state of the evidence regarding the physical, psychological, and social QOL domains that can be affected in children with DCD. Systematic review of articles from seven databases through November 2010 (MEDLINE, EMBASE, CINAHL, PsycINFO, ERIC, CDSR, DARE) was conducted. Search terms included developmental coordination disorder, dyspraxia, quality of life, life satisfaction, well-being, activities of daily living, and participation. Two independent reviewers screened titles, abstracts, and full-text articles. Studies meeting the following criteria were selected: (1) sample comprised solely of individuals with coordination difficulties consistent with DCD; (2) outcome measures related to physical, psychological, or socials domains of QOL; and (3) articles published in English. Data were extracted by one author and verified by a second. Outcomes were categorized according to physical, psychological and social domains of QOL and study quality was rated by case definitions of DCD based on diagnostic criteria as per the Diagnostic and Statistical Manual - 4th edition. Forty-one articles were included. Most studies reported significantly poorer results in physical, psychological and social functioning in children with DCD compared with peers. Despite the impact of DCD on multiple domains, only one study used a QOL measure as an outcome. Although DCD impacts several QOL domains, the QOL of children with this disorder remains largely unknown. The next critical step is for clinicians and researchers to use QOL measures to gather information on how DCD may affect the QOL of children with this disorder.

Brain Activation of Children With Developmental Coordination Disorder is Different Than Peers

OBJECTIVES: Children with developmental coordination disorder (DCD) struggle to learn new motor skills, demonstrating more variable performance than typically developing (TD) children. The purpose of this study was to determine whether patterns of brain activity differed between children with and without DCD while performing a motor task. METHODS: Using functional MRI, we measured brain activation patterns in 7 children with DCD and 7 age-matched peers (aged 8–12 years) during a fine-motor, trail-tracing task. RESULTS: Despite similar levels of behavioral motor performance, different patterns of brain activity were noted between the 2 groups. The group with DCD showed significantly more activation than control subjects in left inferior parietal lobule, right middle frontal gyrus, right supramarginal gyrus, right lingual gyrus, right parahippocampal gyrus, right posterior cingulate gyrus, right precentral gyrus, right superior temporal gyrus, and right cerebellar lobule VI. These results suggest that the group with DCD relied on visuospatial processing to complete the task. The TD group demonstrated significantly more activation than the group with DCD in left precuneus, left superior frontal gyrus, right superior temporal gyrus/insula, left inferior frontal gyrus, and left postcentral gyrus; these regions have been associated with spatial processing, motor control and learning, and error processing. CONCLUSIONS: Children with DCD activate different brain regions from typical children when performing the same trail-tracing task. Despite the small sample size, our results contribute to a growing body of literature suggesting that children with DCD exhibit differences in neural networks and patterns of brain activation relative to same-age peers.

Developmental Coordination Disorder in School-aged Children Born Very Preterm and/or at Very Low Birth Weight: A Systematic Review

Objective: To systematically review and synthesize the literature to document the association between infants born very preterm and/or very low birth weight (VLBW) and the presence of developmental coordination disorder (DCD) at school age. Methods: Seven databases were systematically searched. Studies were included if they examined very preterm (<32 weeks) and/or VLBW (<1500 g) infants to school age (age, 5–18 years), had a full-term and/or normal birth weight comparison group, and used a formal measure of motor impairment. Studies that included only infants who were small for gestational age or diagnosed with cerebral palsy were excluded. Two independent reviewers completed abstract and full-text screening, data extraction, and quality assessment of included studies. Results: Sixteen articles were included, with 7 studies incorporated into 2 meta-analyses using cutoff scores of either <5th or 5–15th percentile on the Movement Assessment Battery for Children. Both analyses showed a significant increase in the likelihood of DCD for children born very preterm and/or 1500 g or less, with odds ratios of 6.29 (95% confidence interval, 4.37–9.05, p < .00001) and 8.66 (95% confidence interval, 3.40–22.07, p < .00001) for <5th or 5–15th percentile scores, respectively. Conclusions: Consistent across studies, DCD is more prevalent in the VLBW/very preterm population than full-term/normal birth weight control children and the general school-age population, with significantly greater odds of developing the disorder. Clinical practice should focus on early identification of and intervention for children with DCD, while research should focus on determining the mechanisms underlying DCD in the preterm population.

Developmental Coordination Disorder: A Pilot Diffusion Tensor Imaging Study

Motor deficits associated with developmental coordination disorder are not attributable to macrostructural brain abnormalities, but differences in brain microstructure may exist. Using diffusion tensor imaging, we explored the integrity of motor, sensory, and cerebellar pathways in children with and without developmental coordination disorder. In seven children with the disorder and nine typically developing children (aged 8-12 years), we measured diffusivity and fractional anisotropy of the corticospinal tract, posterior thalamic radiation, and superior and middle cerebellar peduncles. Fractional anisotropy of motor and sensory tracts and diffusion parameters in cerebellar peduncles did not differ between groups. Mean diffusivity of the corticospinal tract and posterior thalamic radiation was lower in children with developmental coordination disorder compared with control children (P < 0.04 and P < 0.06, respectively). Results were driven by lower axial diffusivity, which was significantly correlated with motor impairment scores on the Movement Assessment Battery for Children-2 for both the corticospinal tract (r = 0.56, P = 0.03) and posterior thalamic radiation (r = 0.70, P = 0.003). Reduced axial diffusivity in motor and sensory tracts may be implicated in developmental coordination disorder, but replication in a larger study is needed to confirm these findings.

Perinatal and neonatal predictors of developmental coordination disorder in very low birthweight children

Objective To identify perinatal and neonatal risk factors associated with developmental coordination disorder (DCD) in very low birthweight children (VLBW: <1250 g). Design Retrospective design with prospectively collected cohort. Setting Neonatal Follow-Up Program, Vancouver, Canada. Patients 157 VLBW children assessed at 4–5 years who were free of cerebral palsy or major neurological impairment and had full-scale IQ >70. Main outcome measure Movement Assessment Battery for Children (MABC). Results Using ≤15th percentile on the MABC as the cut-off, 42% of our cohort developed DCD. Perinatal variables significantly associated with DCD were male sex, lower gestational age and lower birth weight, but only male sex and low birth weight independently predicted DCD, accounting for 20% of the variance in MABC scores. Compared with children without motor impairment, children with DCD had greater postnatal steroid exposure, longer duration of ventilation, more days on oxygen and significant retinopathy of prematurity, but only postnatal steroid exposure was significant, accounting for an additional 3% of the variance in MABC scores. Boys performed more poorly than girls on all subtests of the MABC. Conclusions Male sex and low birth weight were significant predictors of DCD, suggesting that these infants should be followed for detection of this common, but under-recognised disorder. Future research aimed at identifying neural underpinnings of DCD and possible antecedents to the disorder is warranted.

A reflection on motor learning theory in pediatric occupational therapy practice.

Background. Theory provides a guide to clinical practice. To date, the most prevalent theories in pediatric occupational therapy practice are sensory integration and neurodevelopmental treatment. Purpose. The purpose of this paper is to present a brief overview and reflection on motor learning theories as well as a summary of motor learning principles that can be used in pediatric practice. Key Issues. Over the past two decades, motor learning theory has been applied in adult occupational therapy practice, but it has been slow to gain popularity in pediatrics. Implications. Although therapists may be tacitly applying motor learning principles in practice, conscious and deliberate application of these principles to a variety of pediatric populations is required to determine if motor learning theory provides a viable and effective contribution to evidence-based, occupational therapy pediatric practice. Further research comparing motor learning interventions to other dominant interventions in pediatric occupational therapy is warranted.