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

Handwriting difficulties in children with autism spectrum disorders: a scoping review

Functional handwriting involves complex interactions among physical, cognitive and sensory systems. Impairments in many aspects of these systems are associated with Autism spectrum disorders (ASD), suggesting a heightened risk of handwriting difficulties in children with ASD. This scoping review aimed to: (1) survey the existing evidence about potential contributions to compromised handwriting function in children with ASD, and (2) map out the existing studies documenting handwriting difficulties in children with ASD. The current evidence implicates impairments in fine motor control and visual-motor integration as likely contributors to handwriting difficulties in children with ASD, though the role of the latter is not well-understood. Moreover, diminished overall legibility and compromised letter formation are emerging points of convergence among existing studies of handwriting quality in children with ASD.

Handwriting performance and underlying factors in children with Attention Deficit Hyperactivity Disorder

Preliminary evidence suggests that handwriting difficulties are common to children with Attention Deficit Hyperactivity Disorder (ADHD). However, the nature of the task-specific impairments is needed to be clarified. The aim of this study was to describe handwriting capacity in ADHD children without DCD and identify underlying factors of performance by use of outcome-oriented assessments and a digitizing tablet. Twenty-one children with ADHD (8.59±1.25 years) and 21 match controls (8.5±1.08 years) were recruited. Children with ADHD scored lower than controls on Tseng Handwriting Problem Checklist and writing composite of Basic Reading and Writing Test, indicating the ADHD group wrote less legibly. The ADHD group spent more on-paper time to copy 50 Chinese characters and exhibited more writing time during the writing process. The ADHD group scored significantly lower on tasks demanding upper limb and eye-hand coordination and visual-motor integration compared with controls. Furthermore, motor skill and visual-motor integration were positively correlated with the legibility. Motor skill was negatively correlated with writing time, in-air time, and in-air trajectory.

Handwriting capacity in children newly diagnosed with Attention Deficit Hyperactivity Disorder

Preliminary evidence suggests that children with Attention Deficit Hyperactivity Disorder (ADHD) may exhibit handwriting difficulties. However, the exact nature of these difficulties and the extent to which they may relate to motor or behavioural difficulties remains unclear. The aim of this study was to describe handwriting capacity in children newly diagnosed with ADHD and identify predictors of performance. Forty medication-naïve children with ADHD (mean age 8.1 years) were evaluated with the Evaluation Tool of Children's Handwriting-Manuscript, the Movement Assessment Battery for Children (M-ABC), the Developmental Test of Visual Motor Integration (VMI) and the Conner Global Index. An important subset (85.0%) exhibited manual dexterity difficulties. Handwriting performance was extremely variable in terms of speed and legibility. VMI was the most important predictor of legibility. Upper extremity coordination, as measured by the M-ABC ball skills subtest, was also a good predictor of word legibility.

CONCLUSION

Poor handwriting legibility and slow writing speed were common in children newly diagnosed with ADHD and were associated with motor abilities. Future studies are needed to determine whether interventions, including stimulant medications, can improve handwriting performance and related motor functioning.

Written-language disorder among children with and without ADHD in a population-based birth cohort

OBJECTIVE

We determined the incidence of written-language disorder (WLD) among children with and without attention-deficit/hyperactivity disorder (ADHD) in a population-based birth cohort.

METHODS

Subjects included a birth cohort of all children born in 1976-1982 who remained in Rochester, Minnesota, after 5 years of age (N = 5718). Information from medical, school, and private tutorial records was abstracted. Cumulative incidences of WLD with or without reading disability (RD), identified with any of 3 formulas, among children with and without ADHD and hazard ratios (HRs) were calculated.

RESULTS

For both genders, the cumulative incidence of WLD by 19 years of age was significantly higher for children with ADHD than for children without ADHD (boys: 64.5% vs 16.5%; girls: 57.0% vs 9.4%). The magnitude of association between ADHD and WLD with RD was significantly higher for girls than for boys (adjusted HR: girls: 9.8; boys: 4.2; P < .001). However, this was not true for WLD without RD (adjusted HR: girls: 7.4; boys: 6.6; P = .64).

CONCLUSIONS

ADHD is strongly associated with an increased risk of WLD (with or without RD) for both boys and girls. Girls with ADHD are at higher risk of having WLD with RD compared with boys with ADHD, whereas boys and girls are at the same risk of having WLD without RD.

Chinese handwriting performance of primary school children with dyslexia

The aim of this study was to investigate the Chinese handwriting performance of typical children and children with dyslexia, and to examine whether speed and accuracy of handwriting could reliably discriminate these two groups of children. One hundred and thirty-seven children with dyslexia and 756 typical children were recruited from main stream primary schools for the study. They were requested to copy 90 Chinese characters using the Chinese Handwriting Assessment Tool (CHAT) jointly developed by a project team from two universities in Hong Kong. The process of handwriting was recorded and the stroke errors in writing were analyzed using the CHAT system. Results indicated that children with dyslexia wrote significantly slower, with greater average character size and variation in size (p<.05) than the typical children of same age group. They also wrote with significantly lower accuracy (p<.05). Commonly observed writing errors among the Dyslexic group were missing strokes and concatenated strokes. From the discriminant analysis, it was found that writing speed and accuracy were satisfactory discriminators that could discriminate students into the two groups, with reasonably good classification accuracy of over 70% for every grade. The results were discussed with theoretical implications in relation to fine motor skills, kinesthetic abilities, visual perceptual skills, and the demand of written tasks in school.

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.

Changes in kinetics and kinematics of handwriting during a prolonged writing task in children with and without dysgraphia

Handwriting difficulties or dysgraphia have a profound impact on children's psychosocial development, and yet, 10-30% of school-aged children are reported to experience difficulties mastering this skill. Several studies have examined the nature and biomechanical underpinnings of handwriting difficulties in children with and without dysgraphia. While the majority of these studies have considered short handwriting activities involving a sentence or a paragraph, handwriting quality and speed are reported to vary with the length of the writing task. Further, it is suggested that the biomechanics of handwriting also evolve over extended writing periods, and that these changes may be distinct between children with and without dysgraphia. The nature and specificity of these biomechanical alterations remain unknown. To address this knowledge gap, we examined changes in writing speed, grip forces on the pen barrel, and normal forces on the writing surface, over the course of a 10-min writing task, in a large cohort of 4th grade children with and without dysgraphia. Horizontal stroke speed, grip force and normal force increased over time while vertical stroke speed decreased in all children. These biomechanical changes may be attributable to physical and psychological fatigue and the corresponding compensatory processes invoked by the motor system.

Academic, behavioral, and cognitive effects of OROS® methylphenidate on older children with attention-deficit/hyperactivity disorder

OBJECTIVE

To assess the effect of Osmotic-Release Oral System (OROS) methylphenidate (MPH) on a variety of measures evaluating academic performance, cognition, and social behavior in children with attention-deficit/hyperactivity disorder (ADHD).

METHODS

This double-blind, randomized, placebo-controlled, crossover laboratory school study enrolled 78 children aged 9-12 years with ADHD who responded to OROS MPH. After determining individualized OROS MPH dosing (18-54 mg/day), 71 subjects received blinded treatment (OROS MPH or placebo then vice versa) on each of 2 laboratory school days, separated by 1 week. Primary efficacy was measured by Permanent Product Measure of Performance at 4 hours after study drug administration.

RESULTS

Treatment with OROS MPH resulted in statistically significant improvement in Permanent Product Measure of Performance and Swanson, Kotkin, Agler, M-Flynn, and Pelham scores, measures of response time, and of working memory compared to placebo. Other measures did not meet all pre-established criteria for significance (maintenance of the overall type I error rate at 5%). Adverse events were consistent with previous reports of stimulant medications used in the management of ADHD. There were no discontinuations due to adverse events, and no serious adverse events or deaths.

CONCLUSIONS

OROS MPH dosed to reduce core symptoms of ADHD to within the normal range also improved performance on a variety of academic tasks in school-aged children compared to placebo. Adverse effects reported were consistent with prior studies. CLINICAL TRIAL REGISTRY INFORMATION: Double-Blind, Randomized, Placebo-Controlled, Crossover Study Evaluating the Academic, Behavioral and Cognitive Effects of Concerta on Older Children with ADHD, URL: http://clinicaltrials.gov/ct2/show/NCT00799409, unique identifier: NCT00799409.

The neurobiological basis of ADHD

Attention-Deficit/Hyperactivity Disorder is not a single pathophysiological entity and appears to have a complex etiology. There are multiple genetic and environmental risk factors with small individual effect that act in concert to create a spectrum of neurobiological liability. Structural imaging studies show that brains of children with Attention-Deficit/Hyperactivity Disorder are significantly smaller than unaffected controls. The prefrontal cortex, basal ganglia and cerebellum are differentially affected and evidence indicating reduced connectivity in white matter tracts in key brain areas is emerging. Genetic, pharmacological, imaging, and animal models highlight the important role of dopamine dysregulation in the neurobiology of Attention-Deficit/Hyperactivity Disorder. To date, stimulants are the most effective psychopharmacological treatments available for Attention-Deficit/Hyperactivity Disorder. Currently only immediate release methylphenidate and atomoxetine are approved for the treatment of ADHD in Italy. Drug treatment should always be part of a comprehensive plan that includes psychosocial, behavioural and educational advice and interventions.

Beyond age and gender: relationships between cortical and subcortical brain volume and cognitive-motor abilities in school-age children

There is growing evidence that cognitive and motor functions are interrelated and may rely on the development of the same cortical and subcortical neural structures. However, no study to date has examined the relationships between brain volume, cognitive ability, and motor ability in typically developing children. The NIH MRI Study of Normal Brain Development consists of a large, longitudinal database of structural MRI and performance measures from a battery of neuropsychological assessments from typically developing children. This dataset provides a unique opportunity to examine relationships between the brain and cognitive-motor abilities. A secondary analysis was conducted on data from 172 children between the ages of 6 to 13 years with up to 2 measurement occasions (initial testing and 2-year follow-up). Linear mixed effects modeling was employed to account for age and gender effects on the development of specific cortical and subcortical volumes as well as behavioral performance measures of interest. Above and beyond the effects of age and gender, significant relationships were found between general cognitive ability (IQ) and the volume of subcortical brain structures (cerebellum and caudate) as well as spatial working memory and the putamen. In addition, IQ was found to be related to global and frontal gray matter volume as well as parietal gray and white matter. At the behavioral level, general cognitive ability was also found to be related to visuomotor ability (pegboard) and executive function (spatial working memory). These results support the notion that cognition and motor skills may be fundamentally interrelated at both the levels of behavior and brain structure.

Recognition of handwriting from electromyography

Handwriting – one of the most important developments in human culture – is also a methodological tool in several scientific disciplines, most importantly handwriting recognition methods, graphology and medical diagnostics. Previous studies have relied largely on the analyses of handwritten traces or kinematic analysis of handwriting; whereas electromyographic (EMG) signals associated with handwriting have received little attention. Here we show for the first time, a method in which EMG signals generated by hand and forearm muscles during handwriting activity are reliably translated into both algorithm-generated handwriting traces and font characters using decoding algorithms. Our results demonstrate the feasibility of recreating handwriting solely from EMG signals – the finding that can be utilized in computer peripherals and myoelectric prosthetic devices. Moreover, this approach may provide a rapid and sensitive method for diagnosing a variety of neurogenerative diseases before other symptoms become clear.

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.

Relação entre indícios de disgrafia funcional e desempenho acadêmico

OBJETIVO: avaliar a relação entre sinais indicativos de disgrafia e desempenho acadêmico. MÉTODOS: foram incluídas no estudo 25 crianças, matriculadas na 3ª. série do ensino fundamental de uma escola pública da Região Metropolitana de Campinas/SP, sem histórico de lesão cerebral e/ou déficit intelectual. Quanto à idade, 21 tinham nove anos e quatro tinham dez anos; 12 eram do sexo masculino. A avaliação foi realizada por meio da Escala de Disgrafia (Lorenzini, 1993) e do Teste de Desempenho Escolar (TDE) (Stein, 2003). RESULTADOS: seis crianças apresentaram sinais indicativos de disgrafia. A maioria dos alunos teve desempenho acadêmico classificado como inferior em escrita (15/25) e em aritmética (10/25). As crianças com indícios de disgrafia (6/25) tiveram pior desempenho em escrita e aritmética no TDE, quando comparado às demais crianças, porém essa diferença não foi estatisticamente significativa. CONCLUSÃO: conclui-se que, neste grupo, não foi possível estabelecer a relação entre baixo desempenho acadêmico com escrita disgráfica, uma vez que tal dificuldade também foi identificada também entre as crianças consideradas não disgráficas.