Attention deficits and clumsiness in Swedish 7-year-old children

Exploring the neural mechanisms that underlie motor difficulties in children with Attention Deficit Hyperactivity Disorder

BACKGROUND

Attention Deficit Hyperactivity Disorder (ADHD) is the most common neurobehavioural disorder of childhood. Motor performance appears to be impaired for an important sub-set of this population.

OBJECTIVES

This structured review draws attention to the neurological mechanisms that could potentially explain these difficulties.

METHODS

In August 2010, Medline, PsychINFO and Embase databases were searched with keywords related to ADHD, neuroimaging modalities and motor performance.

RESULTS

Four studies were retrieved that examined both motor performance and possible neural substrates. Each study explored different hypotheses and no common conclusion is emerging. The cortical activation dysregulation hypothesis, the cerebellar dysfunction hypothesis and the delayed white matter maturation hypothesis were proposed, applying combinations of motor observations and neuroimaging findings.

CONCLUSION

Published literature to date is insufficient to confirm specific hypotheses. Additional studies coupling discrete motor evaluations to neuroimaging techniques are needed in children with ADHD to better understand the neurobiological mechanisms of their motor difficulties.

Comorbid ADHD and DCD: examining cognitive functions using the WISC-IV

This study explored the cognitive performance of children with Attention Deficit/Hyperactivity Disorder (ADHD) and/or Developmental Coordination Disorder (DCD) using the Wechsler Intelligence Scale for Children-IV. Participants were 62 children with ages between 9 years 8 months and 12 years 7 months. These children were placed into one of the four groups: Comparison (n=26), ADHD (n=14), DCD (n=11), and ADHD+DCD (n=11) groups. The ADHD symptoms were assessed using the Australian Disruptive Behaviours Scale, and motor ability was assessed using the McCarron Assessment of Neuromuscular Development (MAND). Significantly poorer perceptual reasoning ability was seen in DCD and ADHD+DCD groups but not in the ADHD group. The findings provide evidence that a deficit in visuo-spatial ability may underlie DCD but not ADHD. These findings revealed different cognitive profiles for ADHD and/or DCD, thus the current study does not lend support to the common aetiology hypothesis in understanding the basis of ADHD and DCD comorbidity.

Life History of Aggression scores are predicted by childhood hyperactivity, conduct disorder, adult substance abuse, and low cooperativeness in adult psychiatric patients

The prevention of aggressive behaviours is a core priority for psychiatric clinical work, but the association between the diagnostic concepts used in psychiatry and aggression remains largely unknown. Outpatients referred for psychiatric evaluations of childhood-onset neuropsychiatric disorders (n=178) and perpetrators of violent crimes referred to pre-trial forensic psychiatric investigations (n=92) had comprehensive, instrument-based, psychiatric assessments, including the Life History of Aggression (LHA) scales. Total and subscale LHA scores were compared to the categorical and dimensional diagnoses of childhood and adult DSM-IV axis I and II mental disorders, general intelligence (IQ), Global Assessment of Functioning (GAF), and personality traits according to the Temperament and Character Inventory (TCI). Overall, the two groups had similar LHA scores, but the offender group scored higher on the Antisocial subscale. Higher total LHA scores were independently associated with the hyperactivity facet of attention-deficit/hyperactivity disorder (AD/HD), childhood conduct disorder, substance-related disorders, and low scores on the Cooperativeness character dimension according to the TCI. IQ and GAF-scores were negatively correlated with the LHA subscale Self-directed aggression. Autistic traits were inversely correlated with aggression among outpatients, while the opposite pattern was noted in the forensic group. The findings call for assessments of aggression-related behaviours in all psychiatric settings.

Understanding teachers' perceptions of the motor difficulties of children with developmental coordination disorder (DCD)

BACKGROUND

Children with developmental coordination disorder (DCD) are often identified by classroom teachers and the identification process relies heavily on teachers' perceptions. The literature would suggest that teachers' perceptions may be influenced by a child's gender, behaviour and the type of motor problem they demonstrate. To date, the influence of these factors on teachers' perceptions of children with DCD has not been empirically tested.

AIM

This study investigated whether child gender, behaviour and type of motor problem influenced teachers' ratings of concern and importance of intervening for children with motor difficulties.

SAMPLE

One hundred and forty-seven teachers of children from 6 to 9 years of age participated in this study.

METHOD

Hypothetical case scenarios were developed that experimentally manipulated the factors of child gender (male/female), behaviour (disruptive/non-disruptive) and type of motor problem (fine motor/gross motor). Teachers were given two case scenarios of the same gender (that varied by behaviour) and rated: (a) their degree of concern about children's motor problems and (b) how important they thought it was for the child to receive intervention for that problem.

RESULTS

The effect of child gender on teachers' perceptions depends upon the type of motor problem. While child behaviour had a marginal influence on teachers' perceptions, interestingly, teachers appeared to recognize motor problems only in the absence of disruptive behaviour. The type of motor problem demonstrated also influenced teachers' perceptions.

CONCLUSION

This study provides preliminary insight into factors that influence teachers' perceptions of children with DCD with clear implications for the classroom identification of children with DCD.

ADHD: volumetry, motor, and oculomotor functions

The use of quantitative neuroimaging (volumetry), motor, and oculomotor assessments for studying children with attention-deficit/hyperactivity disorder (ADHD) has grown dramatically in the past 20 years. Most evidence to date suggests that anomalous basal ganglia development plays an important role in early manifestation of ADHD; however, widespread cerebellar and cortical delays are also observed and are associated with the behavioral (cognitive, motor, oculomotor) phenotype in children with ADHD. These motor and "executive" control systems appear to develop in parallel, such that both systems display a similar protracted developmental trajectory, with periods of rapid growth in elementary years and continued maturation into young adulthood. Development of each system is dependent on the functional integrity and maturation of related brain regions, suggesting a shared neural circuitry that includes frontostriatal systems and the cerebellum (i.e., those identified as anomalous in studies of volumetry in ADHD). Motor and oculomotor paradigms provide unique opportunities to examine executive control processes that exist at the interface between movement and cognition in children with ADHD, also linking cognition and neurological development. The observed pattern of volumetric differences, together with the known parallel development of motor and executive control systems, appears to predict motor and oculomotor anomalies in ADHD, which are highly relevant, yet commonly overlooked in clinical settings.

The relation between ADHD symptoms and fine motor control: a genetic study

Previous research has shown that fine motor control (MC) performance, measured with a computerized task, was less accurate in children with ADHD and in their unaffected siblings, compared to healthy children. This might indicate a shared genetic etiology between MC and ADHD; it was therefore suggested that MC could serve as endophenotype for ADHD. We examined the association between ADHD symptoms (AS) and MC in a genetically informative design that can distinguish between a genetic and a nongenetic familial etiology for the association. Participants were 12-year-old twins and their siblings (N = 409). AS were rated on a continuous scale with the Strengths and Weaknesses of ADHD and Normal behavior scale (SWAN). MC accuracy and stability was measured with the computerized pursuit task of the Amsterdam Neuropsychological Tasks (ANT). Analyses were performed with Structural Equation Modelling. AS were weakly associated with MC accuracy of the left and right hand (r = -.10/-.10). No association with MC stability was found (r = -.01/-.03). AS were highly heritable (75%), while MC accuracy of the right hand and MC stability showed no genetic influences. For MC accuracy of the left hand, variance was explained by genetic (10%), common environmental (23%), and unique environmental variances. The association between MC accuracy of the left hand and AS was explained by a shared genetic influence but the genetic correlation was low (r = -.14). The phenotypic and genetic associations between AS and computerized MC were weak, suggesting that fine MC is not a proper endophenotype for ADHD.

A preliminary study on the effect of methylphenidate on motor performance in children with comorbid DCD and ADHD

Attention Deficit Hyperactive Disorder (ADHD) and Developmental Coordination Disorder (DCD) are two developmental disorders with considerable comorbidity. The impact of Methylphenidate (MPH) on ADHD symptoms is well documented. However, the effects of MPH on motor coordination are less studied. We assessed the influence of MPH on motor performance of children with comorbid DCD and ADHD. Participants were 18 children (13 boys, mean age 8.3 years) diagnosed with comorbid DCD and ADHD. A structured clinical interview (K-SADS-PL) was used to determine psychopathology and the Movement Assessment Battery for Children-Checklist were used to determine criterion for motor deficits. The Movement Assessment Battery for Children (M-ABC) was administrated to all participants once under the influence of MPH and once under a placebo pill condition. The motor tests were administered on two separate days in a double-blinded design. Participants' motor performance with MPH was significantly superior to their performance in the placebo condition. Significant improvement was observed in all the M-ABC sub-tasks except for static balance performance. The findings suggest that MPH improves motor coordination in children with comorbid DCD and ADHD but clinically significant improvement was found in only 33% of the children.

Can the Child Behavior Checklist be used to screen for motor impairment?

AIM

It has been suggested that one approach to identifying motor impairment in children is to use the Child Behavior Checklist (CBCL) as a screening tool. The current study examined the validity of the CBCL in identifying motor impairment.

METHOD

A total of 398 children, 206 females and 192 males, aged from 3 years 9 months to 14 years 10 months were assessed on the McCarron Assessment of Neuromuscular Development to determine their motor ability. Parents completed the CBCL.

RESULTS

The 'Clumsy' item on the CBCL was found to predict motor ability independent of the child's age, sex, and scores on other items of the CBCL. However, the sensitivity of the 'Clumsy' item in terms of identifying motor impairment was found to be a low 16.7% compared with specificity of 93.2%. The item 'Not liked' was also found to be a significant predictor of motor impairment.

INTERPRETATION

Although the 'Clumsy' and 'Not liked' items were found to have a relationship with motor ability, they should not be relied upon to categorize children as motor impaired versus not impaired. It is possible that these items may be better indicators of motor impairment in children with developmental disorders such as attention-deficit-hyperactivity disorder, but clinical samples are needed to address this.

Developmental delay syndromes: psychometric testing before and after chiropractic treatment of 157 children

OBJECTIVE

This study presents a case series of 157 children with developmental delay syndromes, including the conditions such as dyspraxia, dyslexia, attention-deficit hyperactivity disorder, and learning disabilities who received chiropractic care.

CLINICAL FEATURES

A consecutive sample of 157 children aged 6 to 13 years (86 boys and 71 girls) with difficulties in reading, learning, social interaction, and school performance who met these inclusion criteria were included.

INTERVENTION AND OUTCOMES

Each patient received a multimodal chiropractic treatment protocol, applied kinesiology chiropractic technique. The outcome measures were a series of 8 standardized psychometric tests given to the children by a certified speech therapist pre- and posttreatment, which evaluate 20 separate areas of cognitive function, including patient- or parent-reported improvements in school performance, social interaction, and sporting activities. Individual and group data showed that at the end of treatment, the 157 children showed improvements in the 8 psychometric tests and 20 areas of cognitive function compared with their values before treatment. Their ability to concentrate, maintain focus and attention, and control impulsivity and their performance at home and school improved.

CONCLUSIONS

This report suggests that a multimodal chiropractic method that assesses and treats motor dysfunction reduced symptoms and enhanced the cognitive performance in this group of children.

Routine developmental screening at 5.5 and 7 years of age is not an efficient predictor of attention-deficit / hyperactivity disorder at age 10

AIM

The aim of this study was to assess the efficiency of developmental screening for deficits in attention, motor control and perception or attention-deficit/hyperactivity disorder (DAMP/ADHD) at 5.5 and 7 years of age for diagnosing ADHD in grade 4.

METHOD

The study population consisted of 442 children from a cohort study of ADHD in 10-year olds in one municipality in Stockholm County. Sensitivity, specificity and positive predictive value of a developmental screening at 5.5 and at 7 years of age for being diagnosed with ADHD at 10 years of age was calculated.

RESULTS

The sensitivity was 44%, the specificity 85% and the positive predictive value for having a diagnosis of pervasive ADHD in 4th grade was 15%, when at least two deviations in nine items was used as the cut-off point in 5.5-year screening at Child Health Centres (CHCs). With a cut-off score of at least two deviations in four items rated by parents or and teachers in 1st grade, these estimates were 58%, 81% and 15% respectively.

CONCLUSION

This study demonstrates that developmental screening for DAMP/ADHD at 5.5 and 7 years of age does not identify children who are diagnosed with ADHD in grade 4 with a high degree of selectivity.

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.

Gross motor performance and self-perceived motor competence in children with emotional, behavioural, and pervasive developmental disorders: a review

AIMS

Motor performance and self-perceived motor competence have a great impact on the psychosocial development of children in general. In this review, empirical studies of gross motor performance and self-perception of motor competence in children with emotional (depression and anxiety), behavioural, and pervasive developmental disorders are scrutinized, with the objective of identifying specific motor characteristics that may be relevant to clinical practice.

METHOD

A systematic search of studies published between 1997 and 2007 was performed using nine search engines.

RESULTS

Children in all three categories (emotional, behavioural, and pervasive developmental disorders) exhibit poor gross motor performance and problematic self-perception of motor competence, with certain indications of disorder-specific characteristics. In particular, children with emotional disorders have balance problems and self-perceived motor incompetence; children with behavioural disorders show poor ball skills and tend to overestimate their motor performance; children with pervasive developmental disorders demonstrate poor gross motor performance and self-perceived motor incompetence. As a result, children with developmental and emotional disorders are restricted in participating in games and play, which may lead to inactive lifestyles and further disruption of their psychosocial and physical development.

INTERPRETATION

Motor problems need more, to some extent disorder-specific, attention in clinical practice than has been provided to date.

The evolution of hyperactivity, impulsivity and cognitive diversity

The evolutionary status of attention deficit/hyperactivity disorder (ADHD) is central to assessments of whether modern society has created it, either physically or socially; and is potentially useful in understanding its neurobiological basis and treatment. The high prevalence of ADHD (5-10%) and its association with the seven-repeat allele of DRD4, which is positively selected in evolution, raise the possibility that ADHD increases the reproductive fitness of the individual, and/or the group. However, previous suggestions of evolutionary roles for ADHD have not accounted for its confinement to a substantial minority. Because one of the key features of ADHD is its diversity, and many benefits of population diversity are well recognized (as in immunity), we study the impact of groups' behavioural diversity on their fitness. Diversity occurs along many dimensions, and for simplicity we choose unpredictability (or variability), excess of which is a well-established characteristic of ADHD.Simulations of the Changing Food group task show that unpredictable behaviour by a minority optimizes results for the group. Characteristics of such group exploration tasks are risk-taking, in which costs are borne mainly by the individual; and information-sharing, in which benefits accrue to the entire group. Hence, this work is closely linked to previous studies of evolved altruism.We conclude that even individually impairing combinations of genes, such as ADHD, can carry specific benefits for society, which can be selected for at that level, rather than being merely genetic coincidences with effects confined to the individual. The social benefits conferred by diversity occur both inside and outside the 'normal' range, and these may be distinct. This view has the additional merit of offering explanations for the prevalence, sex and age distribution, severity distribution and heterogeneity of ADHD.

Sensorimotor Therapy: Using Stereotypic Movements and Vestibular Stimulation to Increase Sensorimotor Proficiency of Children with Attentional and Motor Difficulties

The current naturalistic study examined whether sensorimotor therapy utilizing the training program, Retraining for Balance, might be an appropriate technique for sensorimotor proficiency. The 232 children (181 boys, 51 girls), whose mean age was 9.3 yr. ( SD = 2.7), presented attentional and motor difficulties (according to the School Health Care) as indicated by their parents before starting therapy. The children were divided into three groups, i.e., a younger group (7 yr. old or younger, n = 65), a middle group (8 to 10 yr. old, n = 91), and an older group (11 yr. old or older, n = 76). The program has seven parts, including fetal and neonatal movements, vestibular and auditory perceptual stimulation, and gross motor movements, among others. The treatment period was close to 3 yr. on the average. Analyses in a repeated-measures design indicated significant improvement of sensorimotor skills among the three age groups, but the older children performed better than the others on several tests. There were only a few sex differences. Retraining for Balance may be a functional technique for training children and youth with sensorimotor difficulties and might constitute a complement to regular treatment of Developmental Coordination Disorder, Learning Disability, and ADHD, but controlled studies are necessary before more decisive conclusions can be drawn.

The Motor Function Neurological Assessment (MFNU) as an indicator of motor function problems in boys with ADHD

BACKGROUND

The paper presents the Motor Function Neurological Assessment (MFNU), as a tool for identifying typical motor function problems in children with Attention Deficit Hyperactivity Disorder (ADHD). The study investigated motor functions in boys diagnosed with Hyperkinetic Disorder (HKD, F.90.0). HKD corresponds to the ADHD-combined (ADHD-C) diagnosis in the DSM-IV. The paper addresses the ability of the instrument to discriminate between non-medicated boys with HKD and a control group consisting of normal non-referred boys without any clinical significant ADHD symptoms.

METHODS

25 drug-naïve boys, aged 8-12 years and recently diagnosed as HKD F90.0, were compared with 27 controls, all boys in the same age range, on 17 MFNU subtests, and with a 'Total score' parameter.

RESULTS

On the individual subtests 80-96% (median 88%) of the ADHD group showed 'moderate' to 'severe' problems, compared to 0-44% (median 14.8%) within the control group. The percentage of 'severe problems' ranged from 44-84%, (median 64%) in the ADHD group, and 0-44% (median 0%) in the control group. The highly significant differences found between the groups on all subtests, and on the Total score scores, indicated that the MFNU had a high discriminative power when children with ADHD and normal controls were compared. The Total score parameter seemed to be a meaningful discriminator of a common underlying factor of the 17 subtests used in the study.

CONCLUSION

The study confirms our clinical findings that the MFNU measures a consistent pattern of motor function problems in children with HKD, and that these problems are rarely represented in individuals without ADHD. Further research is needed to investigate to what extent the MFNU taps motor problems that are truly specific to ADHD, in contrast to motor problems common to children with DCD or other clinical problems.

Methylphenidate improves motor functions in children diagnosed with Hyperkinetic Disorder

Background

A previous study showed that a high percentage of children diagnosed with Hyperkinetic Disorder (HKD) displayed a consistent pattern of motor function problems. The purpose of this study was to investigate the effect of methylphenidate (MPH) on such motor performance in children with HKD

Methods

25 drug-naïve boys, aged 8–12 yr with a HKD-F90.0 diagnosis, were randomly assigned into two groups within a double blind cross-over design, and tested with a motor assessment instrument, during MPH and placebo conditions.

Results

The percentage of MFNU scores in the sample indicating 'severe motor problems' ranged from 44–84%, typically over 60%. Highly significant improvements in motor performance were observed with MPH compared to baseline ratings on all the 17 subtests of the MFNU 1–2 hr after administration of MPH. There were no significant placebo effects. The motor improvement was consistent with improvement of clinical symptoms.

Conclusion

The study confirmed our prior clinical observations showing that children with ADHD typically demonstrate marked improvements of motor functions after a single dose of 10 mg MPH. The most pronounced positive MPH response was seen in subtests measuring either neuromotor inhibition, or heightened muscular tone in the gross movement muscles involved in maintaining the alignment and balance of the body. Introduction of MPH generally led to improved balance and a generally more coordinated and controlled body movement.

Psychopathology, psychosocial functioning, and IQ before and after epilepsy surgery in children with drug-resistant epilepsy

This is a prospective study of a consecutive series of children undergoing epilepsy surgery. The main aims were to evaluate the heterogeneity with respect to psychopathology and IQ, and to use a global assessment scale (Children's Global Assessment Scale [CGAS]) to evaluate psychosocial functioning. Clinical neuropsychiatric and neuropsychological assessments were made at baseline and at the 2-year follow-up in 24 patients, and changes were analyzed at an individual level. Psychiatric disorders (mainly attention deficit hyperactivity disorder and/or autism spectrum disorders) were found in 17 of 24 at some point. All except one child with psychiatric diagnoses before surgery still had at least one diagnosis at follow-up. Intellectual ability remained stable in the majority of cases, both in individuals with and in individuals without mental retardation. The CGAS illustrated the consequences of the extensive comorbidity in this cohort. The behavioral problems had been undiagnosed despite parental concern in many cases, indicating an unrecognized need for services for children with drug-resistant epilepsy.

ADHD and poor motor performance from a family genetic perspective

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is frequently accompanied by motor problems (MPs). We investigated a possible shared etiology between the two traits in the Dutch sample of the International Multicenter ADHD Genetics study comprising 275 children with ADHD and their affected or unaffected sibling and 146 unrelated control children.

METHOD

Exploratory data analysis and bivariate structural equation modeling were used to estimate the familiality of MP rated by parents (Developmental Coordination Disorder Questionnaire [DCD-Q]) or teachers (Groningen Motor Observation Scale [GMO]) and to determine the familial and environmental correlation between MP and ADHD. Furthermore, the nature of the familiality was explored by studying the siblings of ADHD-affected children.

RESULTS

The ADHD-affected children had significantly more MP than their unaffected siblings, who in turn had significantly more MP than the control subjects. The familial component of MP measured by DCD-Q and GMO was 47% and 22%, respectively. The familial correlation between motor performance measures and ADHD was -0.38 for DCD-Q and -0.40 for GMO. Our data suggested that co-occurrence of ADHD and MP possibly marks a distinct subtype of ADHD, rather than signaling increased severity of disease.

CONCLUSIONS

Attention-deficit/hyperactivity disorder and MP have a common basis that may be due to genetic factors and/or shared environmental factors. Attention-deficit/hyperactivity disorder accompanied by MP may behave like a distinct subtype of ADHD, but more research will be needed to support that hypothesis.

Old people reporting childhood AD/HD symptoms: retrospectively self-rated AD/HD symptoms in a population-based Swedish sample aged 65-80

Our knowledge of attention deficit/hyperactivity disorder (AD/HD) has increased in recent years. Little is still known about the course and manifestations in later parts of life and whether elderly persons who once presented childhood AD/HD symptoms can be identified. The aim of the study was to explore the occurrence to which elderly individuals retrospectively report symptoms that may indicate childhood AD/HD. The 25-item Wender Utah Rating Scale (WURS) was administered in a population-based sample of 2500 persons aged 65-80. Demographics, self-ratings of problems in childhood, current health and memory were also investigated. A total of 1599 individuals participated, which corresponds to a response rate of 64%. The prevalence of self-rated childhood AD/HD symptoms was 3.3% using a cut-off score of 36 or more in the WURS. Men rated significantly more AD/HD symptoms. Those who reported more childhood AD/HD symptoms also claimed general problems in childhood as well as worse current health. The proportion of individuals among 65-80-year-olds, who report childhood AD/HD symptoms is slightly lower but comparable with recent prevalence rates of childhood AD/HD. The study encourages further studies of AD/HD using a lifespan perspective.

Dyslexia and developmental co-ordination disorder in further and higher education-similarities and differences. Does the 'label' influence the support given?

Developmental co-ordination disorder (DCD) is a developmental disorder affecting motor co-ordination. The Diagnostics Statistics Manual-IV classification for DCD describes difficulties across a range of activities of daily living, impacting on everyday skills and academic performance in school. Recent evidence has shown that difficulties persist into adulthood. As a consequence, increasing numbers of students are arriving at university and colleges in the UK with a diagnosis of DCD and requesting Disabled Students' Allowance (DSA) to gain support. This preliminary study examined a cohort of 115 students currently in further or higher education in order to compare and contrast similarities and differences in three subgroups: those with a diagnosis of DCD, a second group with DCD and dyslexia and a third group with dyslexia only. It examines how students were supported in the past and now as students. Additionally it identifies differences in reported strengths and difficulties. A higher percentage of those with dyslexia receive DSA. All students have similar types of support not dependent on their diagnosis. The DCD only group lives at home with parents more and has a significantly greater reported motor and executive functioning difficulty than the other two groups.

Evaluation of the psychometric properties of the developmental coordination disorder questionnaire for parents (DCD-Q): results from a community based study of school-aged children

In this study, we examine several key psychometric properties (reliability, construct validity, concurrent validity) of the Developmental Coordination Disorder Questionnaire (DCD-Q) using a large, school-based sample of children (n=523) and their parents. Children completed the Children's Self-perceptions of Adequacy in and Predilection toward Physical Activity (CSAPPA) and parents completed the DCD-Q. The internal reliability of the DCD-Q was high for both the full scale and the subscales. Confirmatory factor analysis established that the scale was multifactorial, but the fit of the hypothesized factor structure was poor. Finally, moderate correlations were observed between the CSAPPA and the DCD-Q, with the strongest correlation found between the "perceived adequacy" subscale of the CSAPPA and "control during movement" subscale of the DCD-Q. Implications for screening and further research are discussed in relation to both instruments.

Differences in Schoolwork Performance between Typically Developing Students and Students with Mild Disabilities

The purpose of this study was to examine whether students with mild disabilities differed from typically developing students in their ability to perform schoolwork tasks. The participants, selected from the School Assessment of Motor and Process Skills (School AMPS) database, comprised 175 students in each group. Their data were subjected to many-faceted Rasch analyses and then analyzed for statistically significant differences in mean school motor and school process abilities between groups. The relative and actual item difficulty calibration values were then compared to identify meaningful differences between groups. The results revealed a statistically significant mean difference in school motor and school process ability between groups (large effect sizes), essentially stable relative skill item hierarchies between groups, and actual hierarchies that differed such that some school motor and almost all school process skill items (occupational performance skills) were more difficult to perform for the mild disabilities group. The results of this study also provided evidence of validity for the use of the School AMPS measures to assist in identifying lower than expected schoolwork performance of students with mild disabilities.

Prenatal organochlorine exposure and measures of behavior in infancy using the Neonatal Behavioral Assessment Scale (NBAS)

BACKGROUND

Previous literature suggests an association between organochlorines and behavioral measures in childhood, including inattention.

OBJECTIVE

This study was designed to assess whether prenatal organochlorine exposure is associated with measures of attention in early infancy.

METHODS

We investigated an association between cord serum polychlorinated biphenyls (PCBs) and p,p'-dichlorodiphenyl dichloroethene (DDE) levels and measures of attention from the Neonatal Behavioral Assessment Scale (NBAS) in a cohort of 788 infants born 1993-1998 to mothers residing near a PCB-contaminated harbor and Superfund site in New Bedford, Massachusetts.

RESULTS

Medians (ranges) for the sum of four prevalent PCB congeners and DDE levels were 0.19 (0.01-4.41) and 0.30 (0-10.29) ng/g serum, respectively. For the 542 subjects with an NBAS exam at 2 weeks, we observed consistent inverse associations between cord serum PCB and DDE levels and NBAS measures of alertness, quality of alert responsiveness, cost of attention, and other potential attention-associated measures including self-quieting and motor maturity. For example, the decrement in quality of alert responsiveness score was -0.51 (95% confidence interval, -0.99 to -0.03) for the highest quartile of exposure to the sum of four prevalent PCB congeners compared with the lowest quartile. We found little evidence for an association with infant orientation, habituation, and regulation of state, assessed as summary cluster measures.

CONCLUSIONS

Our findings provide evidence for an association between low-level prenatal PCB and DDE exposures and poor attention in early infancy. Further analyses will focus on whether organochlorine-associated decrements in attention and attention-related skills in infancy persist in later childhood.

Attention deficit hyperactivity disorder in preschool children

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder with a childhood onset of symptoms and impairment. Although it is most frequently identified during elementary school years, epidemiologic data suggest that the onset of ADHD frequently occurs earlier, with presentation as young as 3 years of age. Early identification, however, allows consideration of appropriate interventions. Many data are available on safe and efficacious treatment options for school-aged children who have ADHD; however, little is known about the use of these modalities in preschoolers and, ultimately, the long-term effects of early treatment. Recognition of the preschool presentation of ADHD, appropriate differential diagnosis, and identification of comorbid conditions, and a developmental perspective on the course and potential outcomes of the disorder may guide treatment planning. Newly available data on the safety and efficacy of pharmacotherapy and psychosocial intervention for preschoolers who have ADHD may help clinicians make treatment decisions for these young children and their families.

Beyond the 'typical' patient: treating attention-deficit/hyperactivity disorder in preschoolers and adults

Attention-deficit/hyperactivity disorder (ADHD), typically affects school-aged children, but can present during the preschool years and persist into adulthood. Accurate diagnosis for preschoolers and adults requires adaptation of the current diagnostic criteria to account for differences in symptomatology across the age span. The differential diagnosis of ADHD and the pattern of psychiatric comorbidity vary with each age group and complicate diagnosis and management. To maximize outcomes clinicians must be able to accurately identify ADHD across the lifespan, and develop comprehensive, collaborative treatment plans. The Preschool ADHD Treatment Study (PATS) demonstrated the potential utility of methylphenidate for treating ADHD in preschoolers, and trials of psychostimulants and atomoxetine have shown some benefits for adults. Behavioural interventions likely have an adjunctive role in ADHD treatment for both groups. More research, however, is needed to determine the safest and most effective pharmacotherapies and psychosocial interventions for these non-typical patients.

Handwriting performance in children with attention deficit hyperactivity disorder (ADHD)

Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioral condition of childhood. Consequences are multifaceted and include activity limitations in daily-living skills, academic challenges, diminished socialization skills, and motor difficulties. Poor handwriting performance is an example of an affected life skill that has been anecdotally observed by educators and clinicians for this population and can negatively impact academic performance and self-esteem. To guide health and educational service delivery needs, the authors reviewed the evidence in the literature on handwriting difficulties in children with ADHD. Existing evidence would suggest that children with ADHD have impaired handwriting performance, characterized by illegible written material and/or inappropriate speed of execution compared to children without ADHD. Studies with larger sample sizes using standardized measures of handwriting performance are needed to evaluate the prevalence of the problem and to better understand the nature of handwriting difficulties and their impact in this population.

Cooccurrence of problems in activity level, attention, psychosocial adjustment, reading and writing in children with developmental coordination disorder

The purpose of this paper was to investigate the cooccurrence of problems in activity level, attention, reading, writing and psychosocial adjustment of children with developmental coordination disorder (DCD). A parent-report questionnaire, the Developmental Coordination Disorder Questionnaire - Chinese version (DCDQ-C), was used to screen first to third graders from 13 mainstream schools in Taipei. Two standardized motor tests were then administered to those who scored below 10% on the DCDQ-C. Tests of activity level, attention, reading, writing and psychosocial adjustment were then administered to this sample. Thirty-eight children identified as DCD, 32 as suspect for DCD and 82 as normal comparison were included in the final sample. Multivariate analysis of variance comparing the three groups (DCD, suspect DCD, and comparison) revealed that both children with DCD and suspect for DCD obtained significantly poorer scores on measures of attention and reading, and were more hyperactive than comparison children. Children with DCD and suspect for DCD were also reported to have more internalizing and social problems than children without motor problems. No significant differences, however, were noted between children with different degree of motor coordination problems (categorized as DCD and suspect for DCD) on any measure. Furthermore, a high percentage of children in both the DCD and suspect groups fell in the clinical range of attention, activity level and psychosocial adjustment problems. The results revealed a high risk for these problems in nonreferred children with motor coordination problems. The high percentage of clinical range behavioral problems warrants attention of clinicians who work with children with motor coordination difficulties to the need to promote early identification and referral.

Handedness in patients with developmental coordination disorder

Developmental coordination disorder affects 5% to 8% of the general population, and about 50% to 60% of these children have a comorbid attention-deficit disorder with hyperactivity and learning disorders. Left-handedness is relatively common among children with dyslexia, learning disabilities, and autism; however, its frequency in children with developmental coordination disorder is less clear. The present study investigated the distribution of hand dominance in 98 children (age range, 5.5-17 years) with developmental coordination disorder compared with their parents or siblings. Thirty children (30.6%) were left-handed and 13 (13.3%) were ambidextrous. The prevalence of left-handedness among their parents and siblings was similar to that of the general population. The results suggest that children with developmental coordination disorder, like children with learning disorders and deficit disorder with hyperactivity, present with higher frequency of left-hand dominance compared with the general population.

Bullying and attention-deficit- hyperactivity disorder in 10-year-olds in a Swedish community

The association of attention-deficit-hyperactivity disorder (ADHD) with bullying in the peer group in school was studied in an entire population of 577 fourth graders (10-year-olds) in one municipality in Stockholm, Sweden. The schoolchildren were screened for ADHD in a two-step procedure that included Conners'ratings of behavioural problems: teacher and parent interviews in a first step; and a clinical assessment in the second. Information about bullying was collected from the children themselves in a classroom questionnaire. Five-hundred and sixteen children (89.4%; 252 females, 264 males), for whom there was information from all data sources, were included in the study population. Conners'ratings that were collected from parents early in first grade were available for 382 of these children. Hypotheses were tested by multivariate analyses with adjustment for sex and parental education. Pervasive ADHD was diagnosed in 9.5% (95% confidence interval [CI] 5.6-12.8) of the males and 1.6% (CI 0.1-3.1) of the females. ADHD was associated with bullying other students (adjusted odds ratios (OR) 3.8 [CI 2.0-7.2]) as well as being bullied (often, OR 10.8 [CI 4.0-29.0]; sometimes, OR 2.9 [CI 1.5-5.7]). Bullying other students in fourth grade was associated with high scores in parental reports of behavioural problems at entry into first grade, suggesting a causal link to the ADHD syndrome. Being bullied, on the other hand, was not linked to behavioural problems at school entry. This study demonstrates a connection between ADHD and bullying in the peer group at school. Evaluation and treatment strategies for ADHD need to include assessment and effective interventions for bullying. Evaluation of ADHD should be considered in children involved in bullying.

Learning, attention, writing, and processing speed in typical children and children with ADHD, autism, anxiety, depression, and oppositional-defiant disorder

Learning, attention, graphomotor, and processing speed scores were analyzed in 149 typical control children and 886 clinical children with normal intelligence. Nonsignificant differences were found between control children and children with anxiety, depression, and oppositional-defiant disorder. Control children performed better than children with ADHD and autism in all areas. Children with ADHD and autism did not differ, except that children with ADHD had greater learning problems. Attention, graphomotor, and speed weaknesses were likely to coexist, the majority of children with autism and ADHD had weaknesses in all three areas, and these scores contributed significantly to the prediction of academic achievement.

Multidisciplinary assessment of children with developmental coordination disorder: using the ICF framework to inform assessment

The aim of this study was to describe relationships in young children with motor coordination problems between measures of motor, functional, self-efficacy, and communication administered by a multidisciplinary team and the fit of these measures within the framework of the International Classification of Functioning, Disability and Health (ICF) (World Health Organisation, 2001). Sixty children, 40 males and 20 females, with mean age 72.5 months (SD= 11.4 months) referred to a university physiotherapy clinic met the inclusion criteria for developmental coordination disorder (DCD). Each measure provided a different perspective of performance when considered within the framework of the ICF. The findings suggest caution when using the Movement Assessment Battery for Children (M-ABC) for the purpose of diagnosis with young referred children, since 25 of the 60 children scored > 15th percentile, despite demonstrating motor deficits at home and school. Further research is needed to address assessment at the participation level. Viewing children from the multiple perspective of each discipline highlights the range of challenges faced by children with DCD.

Developmental coordination disorder in children with attention-deficit-hyperactivity disorder and physical therapy intervention

Although physical therapy (PT) is effective in improving motor function in children with developmental coordination disorder (DCD), insufficient data are available on the impact of this intervention in children with combined attention-deficit-hyperactivity disorder (ADHD) and DCD. This prospective study aimed to establish the prevalence of DCD among a cohort of patients with ADHD, characterize the motor impairment, identify additional comorbidities, and determine the role of PT intervention on these patients. DCD was detected in 55.2% of 96 consecutive children with ADHD (81 males, 15 females), mostly among patients with the inattentive type (64.3% compared with 11% of those with the hyperactive/impulsive type, p<0.05). Mean age was 8 years 4 months (SD 2 y). Individuals with both ADHD and DCD more often had specific learning disabilities (p=0.05) and expressive language deficits (p=0.03) than children with ADHD only. Twenty-eight patients with ADHD and DCD randomly received either intensive group PT (group A, mean age 9 y 3 mo, SD 2 y 3 mo) or no intervention (group B, mean age 9 y 3 mo, SD 2 y 2 mo). PT significantly improved motor performance (assessed by the Movement Assessment Battery for Children; p=0.001). In conclusion, DCD is common in children with ADHD, particularly of the inattentive type. Patients with both ADHD and DCD are more likely to exhibit specific learning disabilities and phonological (pronunciation) deficits. Intensive PT intervention has a marked impact on the motor performance of these children.

Motor coordination problems in children and adolescents with ADHD rated by parents and teachers: effects of age and gender

OBJECTIVE

ADHD is frequently accompanied by motor coordination problems. However, the co-occurrence of poor motor performance has received less attention in research than other coexisting problems in ADHD. The underlying mechanisms of this association remain unclear. Therefore, we investigated the prevalence of motor coordination problems in a large sample of children with ADHD, and the relationship between motor coordination problems and inattentive and hyperactive/impulsive symptoms. Furthermore, we assessed whether the association between ADHD and motor coordination problems was comparable across ages and was similar for both genders.

METHOD

We investigated 486 children with ADHD and 269 normal controls. Motor coordination problems were rated by parents (Developmental Coordination Disorder Questionnaire) and teachers (Groningen Motor Observation Scale).

RESULTS

Parents and teachers reported motor coordination problems in about one third of children with ADHD. Problems of fine and gross motor skills, coordination skills and motor control were all related to inattentive rather than hyperactive/impulsive symptoms. Relative to controls, motor coordination problems in ADHD were still present in teenagers according to parents; the prevalence diminished somewhat according to teachers. Boys and girls with ADHD were comparably affected, but motor performance in controls was better in girls than in boys.

CONCLUSIONS

Motor coordination problems were reported in one third of children with ADHD and affected both boys and girls. These problems were also apparent in adolescents with ADHD. Clinicians treating children with ADHD should pay attention to co-occurring motor coordination problems because of the high prevalence and the negative impact of motor coordination problems on daily life.

Motor control in children with ADHD and non-affected siblings: deficits most pronounced using the left hand

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is strongly influenced by heritability. Identifying heritable vulnerability traits (endophenotypes) that mark a relatively high risk of developing the disorder can contribute to the identification of risk genes. A fruitful area for the search for such endophenotypes may be motor control in children with ADHD, since the disorder is frequently accompanied by motor problems.

METHOD

The current study used a large sample of 350 children with ADHD, 195 non-affected siblings and 271 normal controls aged 5-19 years. Children were administered two computerised motor control tasks in which they had to trace a path between two circles (Tracking task) and follow a randomly moving target (Pursuit task). Both tasks were performed with both the right and the left hand.

RESULTS

Children with ADHD were less precise and stable than controls. Non-affected siblings also deviated from controls, but only on the Tracking task. Group differences were modulated by the use of the right versus the left hand: no group differences emerged when the right hand was used, yet group differences did emerge when the left hand was used. Performance on both tasks was significantly familial.

CONCLUSIONS

Imprecision and instability of movements in children with ADHD and in their non-affected siblings as measured by the Tracking task might be suitable endophenotypic candidates: these deficits are familially present in children having ADHD as well as in their non-affected siblings. Motor performance might be best assessed in children using their left hand, because motor control deficits are most pronounced using the left hand. This might relate to right hemispheric brain pathology in children with ADHD (and possibly in their non-affected siblings) that is related to the control of the left hand and/or relate to differential effects of daily life practice on both hands, which may be smaller on the left hand.

Motor impairment in dyslexia: the influence of attention disorders

Developmental dyslexia is a heterogeneous syndrome with a phonological core deficit and frequent association with other developmental disorders. Controversies exist about the influence of motor difficulties frequently encountered in dyslexia. According to different theoretical approaches, these motor impairments would reflect either a frequent co-morbid entity or a cerebellar dysfunction that could constitute the causal factor of reading disabilities. The principal aim of this study was to determine the frequency of motor impairments in a population of children with phonological dyslexia and specify possible links with attention deficit. We analysed retrospectively motor and attention abilities of 58 children with phonological dyslexia. An important sub-group of children with dyslexia (40-57% depending on the severity of motor difficulties) presented a motor impairment affecting co-ordination, balance and manual dexterity suggesting a cerebellar dysfunction. There was a significant association between attention deficit and motor impairments, with a specific impact on balance and co-ordination deficits. The comparison of performance in four groups defined according to the presence versus absence of attention deficit and motor impairment, respectively, were not in favour of a unequivocal causal link between reading disabilities and motor or attention disorders.

Evaluating the CSAPPA subscales as potential screening instruments for developmental coordination disorder

OBJECTIVE

In this study, we assess the potential of three subscales of the Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity (CSAPPA), a measure of generalised self-efficacy, as possible screens for developmental coordination disorder (DCD).

DESIGN

We used the Bruininks-Oseretsky Test of Motor Proficiency short form (BOTMP-SF) to identify probable cases of DCD. We administered the BOTMP-SF and the CSAPPA to 590 children in grades 4-8 from four schools in the Niagara region of Ontario, Canada. We used receiver operator characteristic (ROC) analysis to assess and compare the performance of the subscales and the full instrument.

RESULTS

The area under the receiving operating characteristic curve (AUC), a measure of the overall performance of the test against a diagnostic standard, was good for the full CSAPPA (AUC = 0.81, 95% CI 0.75 to 0.87). The adequacy (AUC = 0.79, 95% CI 0.73 to 0.85) and predilection (AUC = 0.80, 95% CI 0.74 to 0.87) subscales had performance statistically equivalent to the full scale. Since the adequacy subscale is shorter and has good content validity with respect to DCD, we ran additional analyses on this measure. A cut-point of 24 on this subscale gives a sensitivity of 0.86 (95% CI 0.76 to 0.97) and a specificity of 0.47 (95% CI 0.43 to 0.51).

CONCLUSION

The adequacy subscale of the CSAPPA appears to be equivalent to the full measure for the purposes of screening for DCD. Further research should explore the possibility of adding further criteria to improve the CSAPPA's modest specificity in this role.

Dental caries and oral health behavior in children with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a common developmental disorder. This study tested the hypothesis that children with ADHD exhibit a higher caries prevalence and poorer oral health behavior than children in a control group. Twenty-one children with ADHD and a control group of 79 children, all aged 13 yr, underwent a clinical dental examination and completed two questionnaires on dietary habits and dental hygiene habits. Differences between the groups regarding decayed, missed, or filled surfaces, decayed surfaces, initial caries lesions, and gingival inflammation were non-significant. Forty-eight percent in the ADHD group brushed their teeth every evening compared with 82% in the control group. The corresponding frequencies for brushing the teeth every morning were 48% and 75%. Children with ADHD were 1.74 times more likely to eat or drink more than five times a day than children in the control group. In conclusion, at age 13, children with ADHD do not exhibit a statistically significantly higher caries prevalence but do have poorer oral health behavior than children in a control group. The intervals between dental examinations of children with ADHD should be shorter than for other children to prevent a higher caries incidence in adolescence because of their oral health behavior.

Salivary cortisol levels and dental anxiety in children with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a common developmental disorder. The present study tested the hypotheses that children with ADHD, particularly those exhibiting severe hyperactivity and impulsivity, have a different stress reaction (measured by salivary cortisol) during a dental recall visit and are more dentally anxious than children in a control group. Eighteen children with ADHD and a control group of 71 children, all 13 yr of age, underwent a clinical dental examination and completed the Corah Dental Anxiety Scale (CDAS). Four saliva samples were gathered for analysis of cortisol: one prior to dental examination, one after, and two the following morning. The subgroup ADHD with hyperactivity/impulsivity had statistically significantly lower cortisol levels than the control group 30 min after awakening. When cortisol values were plotted on a timeline, this subgroup always had lower cortisol concentrations than children in the control group. There was a significant correlation between CDAS scores and cortisol concentrations prior to the dental examination in both the ADHD and the control group. Behavioral expressions of anxiety in children with ADHD may be different from those in other children, not only due to the characteristics of their disorder, but also because of lower stress reactivity.

Early identification: are speech/language-impaired toddlers at increased risk for Developmental Coordination Disorder?

BACKGROUND

Developmental Coordination Disorder (DCD) is a movement skill disorder which impacts upon a child's ability to perform age-appropriate self-care and academic tasks. DCD is commonly comorbid with speech/language learning disabilities.

AIM

The present study was conducted to determine whether children who had been identified with speech/language delays as toddlers demonstrated characteristics of DCD and/or speech/language problems at kindergarten age.

RESULTS

Speech/language and motor assessments who were followed up at 63-80 months of age. Of the 40 children, 18 showed evidence of significant motor impairment and two-thirds of these met diagnostic criteria for DCD at follow-up. Twelve children were identified as having persistent speech/language problems and, of these, nine presented with significant motor co-ordination difficulties. Parental report of gross motor and fine motor problems at follow-up correlated highly with actual motor impairment scores.

CONCLUSIONS

Young children who are in early intervention programmes for speech/language delays may have significant co-ordination difficulties that will become more evident at kindergarten age when motor deficits begin to impact self-care and academic tasks. Clinical implications for early recognition of motor issues by speech/language pathologists and the potential use of parental reporting tools are addressed.

Birth weight and attention-deficit/hyperactivity symptoms in childhood and early adolescence: a prospective Swedish twin study

OBJECTIVE

To determine whether low birth weight increases the risk of attention-deficit/hyperactivity disorder (ADHD) in childhood and early adolescence.

METHOD

In a population-based sample of 1,480 twin pairs born in the period 1985-1986 ascertained from the Swedish Twin Registry, birth weight was collected prospectively through the Medical Birth Registry. ADHD symptoms were measured with a 14-item checklist covering DSM-III-R criteria (parental rating) at age 8 to 9 years and 13 to 14 years. We used both a dichotomous approach for birth weight (>400 g or 15% weight difference) and ADHD (eight or more symptoms) and continuous measures to investigate between- and within-twin pair effects.

RESULTS

Our results showed that low birth weight was a risk factor for symptoms of ADHD and the associations did not diminish when we controlled for genetic influence. The lighter twin in birth weight-discordant pairs had on average 13% higher ADHD symptom score at age 8 to 9 years (p = .006) and 12% higher ADHD score at age 13 to 14 years (p = .018) compared with the heavier twin. The genetic correlations suggest modest or no genetic overlap between birth weight and ADHD.

CONCLUSIONS

The hypothesis that low birth weight is associated with the development of ADHD symptoms was supported in this prospective twin study. Fetal growth restriction seems to represent a modest but fairly consistent environmental influence on the development of ADHD symptoms.

Motor and gestural performance in children with autism spectrum disorders, developmental coordination disorder, and/or attention deficit hyperactivity disorder

Motor and gestural skills of children with autism spectrum disorders (ASD), developmental coordination disorder (DCD), and/or attention deficit hyperactivity disorder (ADHD) were investigated. A total of 49 children with ASD, 46 children with DCD, 38 children with DCD+ADHD, 27 children with ADHD, and 78 typically developing control children participated. Motor skills were assessed with the Bruininks-Oseretsky Test of Motor Proficiency Short Form, and gestural skills were assessed using a test that required children to produce meaningful gestures to command and imitation. Children with ASD, DCD, and DCD+ADHD were significantly impaired on motor coordination skills; however, only children with ASD showed a generalized impairment in gestural performance. Examination of types of gestural errors revealed that children with ASD made significantly more incorrect action and orientation errors to command, and significantly more orientation and distortion errors to imitation than children with DCD, DCD+ADHD, ADHD, and typically developing control children. These findings suggest that gestural impairments displayed by the children with ASD were not solely attributable to deficits in motor coordination skills.