Reint H. Geuze

Clinical and research diagnostic criteria for developmental coordination disorder: a review and discussion

The aim of this review was to investigate the selection criteria used in the past in studies of children with developmental motor problems (excluding those suffering from neurological dysfunctions such as cerebral palsy, muscular dystrophy, etc.). We therefore conducted an extensive analysis of 176 publications. First, an overview of the main characteristics of these studies (terminology, population, type and purpose) and the selection criteria that are reported in these publications are presented. Following this, the DSM-IV selection criteria for developmental coordination disorder (DCD) are contrasted with the selection criteria reported in 41 publications that have used this terminology to classify the children. The results of this comparison show that the inclusion criteria are largely followed, albeit with little consistency concerning selection instruments and quantitative cut-offs, while adherence to the exclusion criteria is not common practice. Strengths and weaknesses of the DSM-IV criteria, complementary to the previous discussion by Henderson and Barnett in the HMS special issue on DCD in 1998 on this same topic, are discussed. The results of the review also show that many studies have used additional selection criteria related to the specific research questions of the study concerned. In the broader context of clinical practice as well as basic research, the latter result suggests the usefulness of a distinction between Clinical Diagnostic Criteria and Research Diagnostic Criteria. This distinction helps to develop a unifying view on the use of diagnostic criteria for research and clinical practice. We conclude with a number of recommendations concerning the selection criteria for children with DCD.

Event-related desynchronization: the effects of energetic and computational demands

The effects of a subjects activation state on cognitive processing were studied, while subjects performed verbal and non-verbal tasks under a speed and accuracy instruction. It was found that stressing speed influenced the level of prestimulus alpha power and consequently the amount of relative event-related desynchronization (ERD). Increasing task complexity led to an increase in the amount and duration of relative ERD. Both prestimulus level of alpha power and relative ERD were asymmetrically distributed over the left and right hemispheres. No verbal/non-verbal task-dependent asymmetries in phasic ERD were found. The data suggest that the level of prestimulus alpha power is mainly influenced by the subjects activation state, whereas relative ERD mainly reflects phasic changes in cognitive processing.

Postural control in children with developmental coordination disorder.

The development of static balance is a basic characteristic of normal motor development. Most developmental motor tests include a measure of static balance. Children with Developmental Coordination Disorder (DCD) often fail this item. This study reviews the balance problems of children with DCD. The general conclusion is drawn that under normal conditions static balance control is not a problem for children with DCD. Only in difficult, unattended, or novel situations such children seem to suffer from increased postural sway. These findings raise the question of what happens when balance is lost. The present study addresses the strength of correlation between the electromyography (EMG) and force plate signals in one-leg stance over epochs of stable and unstable balance. Four groups of children were involved in the study: two age groups and a group of children with DCD and balance problems and their controls. The results show a clear involvement of tibialis anterior and peroneus muscles in the control of lateral balance in all conditions and groups. The group of children with DCD and balance problems,however, showed a weaker coupling between EMG and corrective force compared with control children, indicating non-optimal balance control. An evaluation of the existing data in terms of evidence of specific structural deficits associated with DCD provided converging evidence that suggests cerebellar involvement.

Heart rate variability and sustained attention in ADHD children

The major goal of the current study was to investigate the association between continuous performance tests (CPTs) and the heart rate variability (HRV) of attention deficit hyperactivity disorder (ADHD) children. The HRV, specifically the 0.10-Hz component, may be considered to be a psychophysiological index of effort allocation (motivation): The less effort the subject allocates, the greater the 0.10-Hz component. Results indicated that, compared to controls, ADHD subjects had a greater 0.10-Hz component, which was associated with poor test performance over time. Thus, using a psychophysiological measure, we were able to confirm the clinical concept of ADHD from a motivational perspective.

Relative phase stability of bimanual and visuomanual rhythmic coordination patterns in children with a Developmental Coordination Disorder

Abstract A dynamic pattern approach is used to examine the relative phase stability of rhythmic coordination in 24 children with a Developmental Coordination Disorder (DCD) and 24 matched controls in two functionally different tasks – a within-subject task (bimanual coordination) and a subject-environment task (visuomanual coordination). The stability of basic rhythmic coordination patterns (in-phase and antiphase patterns) was tested by applying perturbations, and by increasing the movement frequency towards the frequency where a loss of stability occurred. Coordination patterns of children with DCD were less stable than those of controls, both in the bimanual and the visuomanual task. According to the dynamic model (Haken, H., Kelso, J.A.S., Bunz, H., 1985. Biological Cybernetics 51, 347–356; Kelso, J.A.S., Delcolle, J.D., Schoner, G., 1990. In: Jeannerod, M. (Ed.), Attention and Performance XIII: Motor Representation and Control. Lawrence Erlbaum, Hillsdale, NJ, pp. 139–169), this reduced stability is due to a weaker coupling strength between the oscillators that represent the rhythmic units involved in the tasks. Further, within the DCD group three subtypes were found on the basis of particularly poor stability in bimanual rhythmic coordination ( N =2), visuomanual rhythmic coordination ( N =4), or both ( N =7). These data were related to the presence of neurological soft signs in the DCD group, which did not reveal specific patterns of minor neurological dysfunction in these children. Theoretical and practical implications of these findings were discussed. PsycINFO classification : 2323; 2330; 3250; 3297

The relationship between physical growth, the level of activity and the development of motor skills in adolescence: Differences between children with DCD and controls

Abstract This study uses a longitudinal design to explore the relationships between physical growth, motor competence and level of participation in physical activity, during the adolescent growth spurt. Thirty boys were selected, representing the range of motor competence. Out of this sample two groups were formed, eight boys with clumsy child syndrome (DCD) and 16 boys with adequate motor skills. The size of the DCD group was increased to 15 by an additional selection. During a period of 2 1 2 years, starting from the age of 11 years and six months, general motor skills were assessed half-yearly with the Movement Assessment Battery for Children (ABC). Growth was measured monthly and a crude measure of level of activity was obtained with a questionnaire. Multi-level regression modelling was used to examine the relationships between these variables. Among the sample representing the whole range of motor competence, the results support the view that high velocities in physical growth are negatively related to motor competence, with high levels of activity showing a positive relationship with competence. Surprisingly, children with DCD do not seem to be affected by the growth spurt. A majority of the children with DCD catches up with controls to some extent and five even reach full competence. The results are discussed in terms of theories of both normal and atypical development. PsycINFO classification 2330; 2800; 3250

What is the evidence of impaired motor skills and motor control among children with attention deficit hyperactivity disorder (ADHD)? Systematic review of the literature

This article presents a review of the studies that have analysed the motor skills of ADHD children without medication and the influence of medication on their motor skills. The following two questions guided the study: What is the evidence of impairment of motor skills and aspects of motor control among children with ADHD aged between 6 and 16 years? What are the effects of ADHD medication on motor skills and motor control? The following keywords were introduced in the main databases: attention disorder and/or ADHD, motor skills and/or handwriting, children, medication. Of the 45 articles retrieved, 30 described motor skills of children with ADHD and 15 articles analysed the influence of ADHD medication on motor skills and motor control. More than half of the children with ADHD have difficulties with gross and fine motor skills. The children with ADHD inattentive subtype seem to present more impairment of fine motor skills, slow reaction time, and online motor control during complex tasks. The proportion of children with ADHD who improved their motor skills to the normal range by using medication varied from 28% to 67% between studies. The children who still show motor deficit while on medication might meet the diagnostic criteria of developmental coordination disorder (DCD). It is important to assess motor skills among children with ADHD because of the risk of reduced participation in activities of daily living that require motor coordination and attention.

The impact of Wii Fit intervention on dynamic balance control in children with probable Developmental Coordination Disorder and balance problems.

The aim of this study was to examine differences in the performance of children with probable Developmental Coordination Disorder (p-DCD) and balance problems (BP) and typical developing children (TD) on a Wii Fit task and to measure the effect on balance skills after a Wii Fit intervention. Twenty-eight children with BP and 20 TD-children participated in the study. Motor performance was assessed with the Movement Assessment Battery for Children (MABC2), three subtests of the Bruininks Oseretsky Test (BOT2): Bilateral Coordination, Balance and Running Speed & Agility, and a Wii Fit ski slalom test. The TD children and half of the children in the BP group were tested before and after a 6weeks non-intervention period. All children with BP received 6weeks of Wii Fit intervention (with games other than the ski game) and were tested before and afterwards. Children with BP were less proficient than TD children in playing the Wii Fit ski slalom game. Training with the Wii Fit improved their motor performance. The improvement was significantly larger after intervention than after a period of non-intervention. Therefore the change cannot solely be attributed to spontaneous development or test-retest effect. Nearly all children enjoyed participation during the 6weeks of intervention. Our study shows that Wii Fit intervention is effective and is potentially a method to support treatment of (dynamic) balance control problems in children.

Infants' shifts of gaze from a central to a peripheral stimulus : a longitudinal study of development between 6 and 26 weeks

Abstract This article reports the results of an intensive, longitudinal investigation of the development of infants’ ability to shift gaze from a central to a peripheral stimulus. Sixteen infants were followed at 2-week intervals from 6 to 26 weeks of age. A high degree of discontinuity was found in the development of both frequency and latency of shifts of gaze, with rapid improvement between 9 and 16 weeks, followed by more gradual improvement between 16 and 26 weeks. Individual developmental trajectories for frequency were highly similar to the group trajectory. Trajectories for latency cost differed more across infants. Inter-infant differences had not become stable for either measure at 26 weeks. The findings are consistent with explanations of the development of gaze shifting in terms of changes in the relative strength of processes which maintain the focus of attention and gaze, and processes which interrupt and shift it.

Temporal stability of rhythmic tapping "on" and "off the beat": a developmental study.

Abstract This study, following a dynamic pattern approach, examines age-related differences in the stability of unimanual rhythmic perception-action patterns. Thirty-six children, aged 7, 9, and 11 years, attempted to synchronize their finger tapping to the beats of an auditory metronome, either “on the beat” (i.e., in-phase coordination), or “off the beat” (i.e., antiphase coordination). The temporal stability of these perception- action patterns was measured by the variability of the relative phase between taps and auditory events and by the critical frequency, that is, the frequency at which a loss of stability was observed when the metronome frequency was increased. Age-related differences in stability were found for both relative phase variability and critical frequency. These findings suggest that the relative phase dynamics underlying perception-action coordination patterns change with age in the direction of an increased temporal stability.