Anna L. Barnett

Cognitive Outcome at Early School Age in Term-Born Children With Perinatally Acquired Middle Cerebral Artery Territory Infarction

Background and Purpose— To assess cognitive outcome at early school age in term-born children with middle cerebral arterial (MCA) territory infarction of perinatal onset and examine the correlation between cognitive abilities and the extent of lesions as seen on neonatal MRI, epilepsy, and hemiplegia. Methods— Thirty-one children were seen as newborns with an acutely evolving MCA territory infarction documented on neonatal MRI scan. IQ was assessed (WIPPSI/WISC where appropriate) and they had a standardized neurological examination at early school age. Lesion(s) site was recorded from the neonatal images. Results— Twenty-eight of 31 children were assessed (median age 5.75 range 5.33 to 10.33 years); 1 child died and 2 were abroad. IQ was within the normal range (mean 104, range 82 to 144) in 21 (78%); 1 child did not complete all tests but had a normal PIQ; 3 had a low and 3 an exceptionally low IQ. Verbal IQs were more varied and lower than performance IQs especially in children from multilingual backgrounds. There was no consistent association between cognitive impairment, side, or extent of the MCA lesion. Cognitive impairments were more frequent in children with seizures or hemiplegia. All 6 children with low IQ also had behavioral problems or unusual associated clinical or scan features. Conclusions— In our cohort a low IQ at early school age did not occur in children with the common presentation of neonatal unilateral MCA territory infarction. Cognitive impairment appeared more frequently when an MCA arterial territory infarction, even if relatively small, was associated with other risk factors.

Structural validity of the Movement ABC-2 test: Factor structure comparisons across three age groups

BACKGROUND The Movement ABC test is one of the most widely used assessments in the field of Developmental Coordination Disorder (DCD). Improvements to the 2nd edition of the test (M-ABC-2) include an extension of the age range and reduction in the number of age bands as well as revision of tasks. The total test score provides a measure of motor performance, which can be used to help make a diagnosis of DCD. M-ABC-2 also provides 3 sub-scales for Manual Dexterity, Aiming and Catching and Balance but the validity of these conceptually derived sub-scales has not previously been reported. AIM To examine the factor structure of the M-ABC-2 test across the three age bands (AB): AB1 (3-6-year olds), AB2 (7-10-year olds) and AB3 (11-16-year olds). METHOD Data from the 2007 standardisation sample (N=1172) were used in this study. Confirmatory factor analyses (CFA) and structural equation modelling (LISREL 8.8) were employed to explore the relationship between the tasks within each of the 3 age bands. A model trimming approach was used to arrive at a well fitting model. RESULTS In AB1 a complex factor structure emerged providing evidence for an independent general factor, as well as specific factors representing the 3 test components. In AB2 a final model emerged with four correlated factors, an additional distinction being drawn between static and dynamic balance. In addition, a 2nd order general factor explained a considerable amount of variance in each primary factor. In AB3 CFA supported the 3-factor structure of the M-ABC-2, with only modest correlations between each factor. CONCLUSIONS The confirmatory factor analyses undertaken in this study further validate the structural validity of the M-ABC-2 as it has developed over time. Although its tasks are largely associated with the three sub-components within each age band, there was also clear evidence for a change in the factor structure towards differentiation in motor abilities with age.

Motor Assessment in Developmental Coordination Disorder: From Identification to Intervention

A description of Developmental Coordination Disorder (DCD) is included in the Diagnostic Manual of the American Psychiatric Association fourth edition (DSM‐IV‐TR). The major feature of this condition is impairment in motor skill, which has a negative impact on the performance of everyday life tasks. The present review outlines major issues concerning the assessment of motor performance in DCD. First, the psychometric principles of reliability and validity are considered, together with a discussion of test norms. This is followed by a review of 5 major purposes of assessment: screening and identification, measurement of motor performance, making a diagnosis, understanding the nature and mechanisms of the condition, and planning for intervention. In each case, the relevant assessment tools are identified and their application discussed. The article concludes with recommendations for future work, which include the need to refine the DCD diagnostic criteria in order to offer a more principled approach to the selection of assessment techniques.

Reaching to throw compared to reaching to place: A comparison across individuals with and without Developmental Coordination Disorder

When picking up an object, adults show a longer deceleration phase when the onward action has a greater precision requirement. Tailoring action in this way is thought to need forward modelling in order to predict the consequences of movement. Some evidence suggests that young children also tailor reaching in this way; however, how this skill develops in children with Developmental Coordination Disorder (DCD) is unknown. The current study compared the kinematics of reaching to an object when the onward intention was: to place the object on a target (either with high or low precision requirements), to throw the object or to lift the object vertically. Movements of both adults (N = 18) and children (N = 24) with DCD and their age-matched controls were recorded. The typically developing adults discriminated across all action types, the adults with DCD and the typically developing children only across the actions to place and throw and the children with DCD only between the actions to lift and throw. The results demonstrate developmental progression towards fine tuning the planning of reaching in relation to onward intentions. Both adults and children with DCD are able to plan movement using inverse models but this skill is not yet fully developed in early adulthood.

The Influence of Spelling Ability on Handwriting Production: Children with and without Dyslexia.

Current models of writing do not sufficiently address the complex relationship between the 2 transcription skills: spelling and handwriting. For children with dyslexia and beginning writers, it is conceivable that spelling ability will influence rate of handwriting production. Our aim in this study was to examine execution speed and temporal characteristics of handwriting when completing sentence-copying tasks that are free from composing demands and to determine the predictive value of spelling, pausing, and motor skill on handwriting production. Thirty-one children with dyslexia (Mage = 9 years 4 months) were compared with age-matched and spelling-ability matched children (Mage = 6 years 6 months). A digital writing tablet and Eye and Pen software were used to analyze handwriting. Children with dyslexia were able to execute handwriting at the same speed as the age-matched peers. However, they wrote less overall and paused more frequently while writing, especially within words. Combined spelling ability and within-word pausing accounted for over 76% of the variance in handwriting production of children with dyslexia, demonstrating that productivity relies on spelling capabilities. Motor skill did not significantly predict any additional variance in handwriting production. Reading ability predicted performance of the age-matched group, and pausing predicted performance for the spelling-ability group. The findings from the digital writing tablet highlight the interactive relationship between the transcription skills and how, if spelling is not fully automatized, it can constrain the rate of handwriting production. Practical implications are also addressed, emphasizing the need for more consideration to be given to what common handwriting tasks are assessing as a whole.

An examination of writing pauses in the handwriting of children with developmental coordination disorder.

Difficulties with handwriting are reported as one of the main reasons for the referral of children with Developmental Coordination Disorder (DCD) to healthcare professionals. In a recent study we found that children with DCD produced less text than their typically developing (TD) peers and paused for 60% of a free-writing task. However, little is known about the nature of the pausing; whether they are long pauses possibly due to higher level processes of text generation or fatigue, or shorter pauses related to the movements between letters. This gap in the knowledge-base creates barriers to understanding the handwriting difficulties in children with DCD. The aim of this study was to characterise the pauses observed in the handwriting of English children with and without DCD. Twenty-eight 8-14 year-old children with a diagnosis of DCD participated in the study, with 28 TD age and gender matched controls. Participants completed the 10 min free-writing task from the Detailed Assessment of Speed of Handwriting (DASH) on a digitising writing tablet. The total overall percentage of pausing during the task was categorised into four pause time-frames, each derived from the literature on writing (250 ms to 2 s; 2-4 s; 4-10 s and >10 s). In addition, the location of the pauses was coded (within word/between word) to examine where the breakdown in the writing process occurred. The results indicated that the main group difference was driven by more pauses above 10 s in the DCD group. In addition, the DCD group paused more within words compared to TD peers, indicating a lack of automaticity in their handwriting. These findings may support the provision of additional time for children with DCD in written examinations. More importantly, they emphasise the need for intervention in children with DCD to promote the acquisition of efficient handwriting skill.

Locomotor adjustments when navigating through apertures.

During everyday locomotion we encounter a range of obstacles which require specific motor responses, for example a narrow aperture forces us to rotate the shoulders to pass through. Research has demonstrated that the decision to rotate the shoulders is body scaled (Warren & Whang, 1987) and that the visuo-motor system generates a rotation proportional to aperture size (Higuchi, Cinelli, Greig, & Patla, 2006). The current study considered how shoulder angle and movement speed are tailored to aperture size in nine adults. Aperture sizes were classified into shoulder/aperture ratios (SA ratio), including two for which participants had to rotate (0.9/1.1) and two for which participants could pass freely (1.5/1.7). During the initial approach phase (first 3s), shoulder rotation and movement speed were invariant across SA ratio. Later in the movement, angle of shoulder rotation and the magnitude and timing of the reduction in speed were proportional to SA ratio. The timing of the reduction in speed was progressively later in the movement as SA ratio increased, suggesting early adjustments of movement, such as the timing of the reduction in speed are tightly tuned to the ratio between aperture size and shoulder width, even when no later body adjustments are needed.

Adaptation and Extension of the European Recommendations (EACD) on Developmental Coordination Disorder (DCD) for the UK context

ABSTRACT Background: Developmental Coordination Disorder (DCD) affects the learning and performance of everyday motor skills. It commonly co-occurs with other developmental disorders and a range of associated psycho-social impairments. Recent evidence-based guidelines on diagnosis, assessment, and intervention provide valuable information for practitioners. However these are directed primarily at German-speaking countries and focus on work with children. Aim: The aim of this project was to consider the application of these guidelines in the UK and to extend them for use with adults with DCD. Methods: Individuals with DCD, parents, and professionals from a wide range of disciplines were invited to two workshops to discuss and debate the guidelines, to adapt them for the UK and produce dissemination materials. Results: A working definition of DCD was agreed, minor revisions were made to the guidelines to reflect the UK context, an extension for adults was compiled and a series of leaflets was produced to disseminate this information to health and education professionals, parents, and employers. Conclusions: This work will raise awareness of the condition across different professional groups. It provides information to help those working with children and adults with DCD in the UK to assist in the process of diagnosis, assessment, and intervention.

Neonatal brain MRI and motor outcome at school age in children with neonatal encephalopathy: a review of personal experience.

The aim of this paper is to review (i) the spectrum of neuromotor function at school age in children who had been born full-term and presented with neonatal encephalopathy (NE) and low Apgar scores and (ii) the relation between the presence/absence of such difficulties and neonatal brain MRI. Motor outcome appears to be mainly related to the severity of basal ganglia and internal capsule involvement. Severe basal ganglia lesions were always associated with the most severe outcome, microcephaly, tetraplegia, and severe global delay, whereas more discrete basal ganglia lesions were associated with athetoid cerebral palsy, with normal cognitive development or minor neuro-motor abnormalities. White matter lesions were associated with abnormal motor outcome only if the internal capsule was involved. Children with moderate white matter changes but normal internal capsule, had normal motor outcome at school age.

Level walking in adults with and without Developmental Coordination Disorder: An analysis of movement variability

Several studies have shown that Developmental Coordination Disorder (DCD) is a condition that continues beyond childhood. Although adults with DCD report difficulties with dynamic balance, as well as frequent tripping and bumping into objects, there have been no specific studies on walking in this population. Some previous work has focused on walking in children with DCD but variation in the tasks and measures used has led to inconsistent findings. The aim of the current study therefore was to examine the characteristics of level walking in adults with and without DCD. Fifteen adults with DCD and 15 typically developing (TD) controls walked barefoot at a natural pace up and down an 11 m walkway for one minute. Foot placement measures and velocity and acceleration of the body were recorded, as well as measures of movement variability. The adults with DCD showed similar gait patterns to the TD group in terms of step length, step width, double support time and stride time. The DCD group also showed similar velocity and acceleration to the TD group in the medio-lateral, anterior-posterior and vertical direction. However, the DCD group exhibited greater variability in all foot placement and some body movement measures. The finding that adults with DCD have a reduced ability to produce consistent movement patterns is discussed in relation to postural control limitations and compared to variability of walking measures found in elderly populations.