ظرفیت دست خط در کودکان تازه تشخیص داده مبتلا با اختلال نقص توجه و بیش فعالی

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.

Attention Deficit Hyperactivity Disorder (ADHD) is the most common neurobehavioural disorder encountered in childhood with an estimated prevalence ranging from 3% to 12% of the school-age population (Faraone, Sergeant, Gillberg, & Biederman, 2003). Symptoms of ADHD include lack of sustained attention, forgetfulness, disorganization, distractibility, restlessness and impulsivity. This disorder appears as a single diagnosis, and as a comorbidity with a variety of other diagnoses, including Oppositional Defiant Disorder, Anxiety Disorder (August, Realmuto, MacDonald, Nugent, & Crosby, 1996) and Developmental Coordination Disorder (DCD) (Pitcher et al., 2003 and Watemberg et al., 2007). Discrete motor difficulties and differences in motor processes have also been described in this population (Buderath et al., 2009, Piek et al., 1999, Pitcher et al., 2003 and Schoemaker et al., 2005). It is increasingly appreciated that academic productivity, leisure and recreational activities, and social-emotional well-being are negatively impacted by this condition (Barkley, 1998). Nevertheless, the extent to which these motor differences and/or difficulties contribute to the presence of activity limitations in everyday meaningful activities has not been explored. Handwriting is an example of an important life skill that if impaired, can lead to academic challenges or failure and diminished self esteem (Maeland, 1992). Although most children are now exposed to computers at an early age, handwriting is still used on a daily basis in the classroom and everyday life. Research has shown that children spend 31–60% of their school days performing fine motor tasks, and 85% of this time is devoted to paper–pencil tasks such as handwriting (McHale & Cermak, 1992). This has not changed much in the last decade, despite the increasing integration of computers into the school environment. Traditional handwriting is still the primary medium of written expression required by teachers (Latio, 2009). Handwriting is a complex task that requires the integrity of different sensorimotor components to be performed successfully. Kinaesthesia (Levine et al., 1981 and Tseng and Cermak, 1993), motor planning (Tseng & Murray, 1994), in-hand manipulation (Cornhill & Case-Smith, 1996), and visual-motor skills (Cornhill and Case-Smith, 1996, Tseng and Murray, 1994 and Weil and Amundson, 1994) were all identified as being associated with good handwriting legibility in typically developing children. Cognitive and psychosocial components are also known to influence handwriting performance (Amundson & Weil, 2001). Handwriting difficulties are not specific to children with ADHD. Estimates of the incidence of poor performance in typically developing children have ranged from 10% to 30% (Karlsdottir & Stefansson, 2002). Preliminary evidence suggests that handwriting deficits in terms of speed and legibility are not uncommon in children with ADHD. Nevertheless, the majority of studies that have examined this important life skill in this population have only utilized observational evaluations of handwriting in small samples of children. Furthermore, children studied were often being treated with psychostimulant medications, which could have influenced handwriting performance parameters (Tucha & Lange, 2001). The precise nature of handwriting difficulties and the predictors of performance remain unclear at this point (Brossard-Racine, Majnemer, Shevell, & Snider, 2008). The relationship between the role of underlying motor impairments and handwriting capacity remains to be determined in this population. Since children with ADHD are already at higher risk for learning difficulties, poor handwriting legibility and speed may further challenge their learning progress. Therefore, the objectives of our study were: (1) to describe the handwriting legibility and speed of children newly diagnosed with ADHD using a standardized measure; and (2) to determine the extent to which these difficulties are associated with motor skills and behavioural difficulties in this population.

The present study suggests that medication-naïve children newly diagnosed with ADHD are at greater risk for handwriting difficulties. Motor impairments, specifically deficits of manual dexterity and visual motor integration, are present in the majority of these children. Visual motor integration was the best predictor of legibility in this high risk population. Upper-limb and eye hand coordination were also a good predictors of word legibility. These results need further validation as we did not compare our sample to a matched control group. The children in our sample were from different grade levels and schools and thus exposed to different instructional methods, limiting the sample's homogeneity. Nonetheless, we used a clinically representative sample of children who were just diagnosed with ADHD, we evaluated motor and behaviour using age-appropriate standardized tools, and compared the results to published normative obtained in age-matched peers. Moreover, we demonstrated that the handwriting difficulties and the variability of the performance appear independent of a co-morbidity of substantial motor difficulties and possibly DCD. This study provides new evidence on the specific challenges encountered by this population, using an objective standardized measure of handwriting and emphasizing the need for a comprehensive clinical evaluation of children with ADHD at diagnosis. Such an evaluation should include an assessment of possible activity limitations such as handwriting and overall motor functioning, thus extending beyond an evaluation of behavioural symptoms. Future studies should determine the possible benefit of interventions including stimulant medications on motor functioning and handwriting performance, to enhance performance in these areas