Search

IntroductionHandwriting disorder is commonly observed in Developmental Coordination Disorder (DCD) (87-88%) and is often noted in children with high Intellectual Quotient (HIQ).Two mainly pure DCD subtypes: ideomotor-DCD (IM), visuospatial/or visuoconstructional-DCD (VSC) and a mixed subtype (MX) were identified in the literature but nothing is known regarding IQ and dysgraphia.ObjectivesTo refine the specific clinical features of dysgraphia related to DCD subtypes regarding IQ levels.Methods Neurovisual, neuropsychological, neuropsychomotor functions, and handwriting performances of 38 children (6-to-12 years-old: mean 9y, SD 2.7) diagnosed with DCD (DSM-5 criteria) were collected. Two matched groups were analyzed according to their IQ: 19 (TC) typical children (IQ=90-110) and 19 HIQ children (IQ> 120).Results IQ scores were not significantly associated with dysgraphia. There isa significant difference between TC vs HIQ with a lower rate of IM-DCD respectively 11% vs 5% (p=.035) and 68% vs 37% for VSC-DCD (p=.03) but 21% vs 58% in MX-DCD (p=.41). Dysgraphia was significantly more present in TC group with MX-DCD and in HIQ with VSC-DCD. A negative correlation between Kho’s’ cubes test failure (p=.006), visual-spatial memory (p=.05) and VSC-DCD was noted in HIQ group. The deficit of visual spatial memory was significantly related to dysgraphia in HIQ children (p=.01) associated to visual gnosis impairment (p=.03).ConclusionsDysgraphia was significantly found with VSC-DCD subgroup in FIQ>120 with specific features of visual perception disorders suggesting more involvement of the right cortex. These results suggest that VSC-DCD in HIQ could be a neurovisual impairment rather than a pure VSC-DCD.

IntroductionHandwriting disorder is considered to be one of the major public health problems among school-aged children worldwide. All the scales in the literature use handwriting tasks but it could be interesting to investigate a more accurate assessment of handwriting difficulties before the development and acquisition of handwriting as such.ObjectivesThe objective of our study is to examine the validity of a prescriptural task consisting of copying a line of cycloid loops in the diagnosis of handwriting disorders.Methods 35 children with handwriting disabilities and 331 typically developing right-handed children in primary school, aged 6-11 years old, were included in the study. They performed a copy of a line of cycloid loops, in an ecological setting, with a paper sheet put on the table. The kinematic measures were recorded with a digital pen. A Receiver Operating Characteristic method (ROC curve) was used to determine whether the loops line copy may be a sensitive test to diagnose handwriting disorders.Results Six kinematic variables recorded during the prescriptural task were found to be relevant markers of handwriting disorders with a sensibility between 0.743 and 0.880: strokes number, total and effective drawing time, in-air pauses times, loops number, number of peaks velocity.ConclusionsThe graphomotor task of copying a line of cycloid loops showed a good sensitivity to diagnose handwriting disorders and appeared to be a good predictor test, more particularly with the variables reflecting the strokes temporal organization.Drawing loops is a rapid graphomotor task, useful for exploring prerequisites of handwriting in screening for handwriting disorders.

IntroductionAlthough more than 85% of children with DCD are affected by handwriting disorders, their characteristics and underlying mechanisms remain poorly known.ObjectivesWe aim to better identify the nature of handwriting disorders in subtyping DCD children.MethodsSchool children aged between 5 to 15 years and exhibited a DCD (according to DSM-5) are eligible for inclusion. They were classified in three subtypes of DCD: ideomotor (IM), visual-spatial and/or constructional (VSC), and mixed (MX). They were assessed with a standardized handwriting evaluation including quality and speed and a clinical observation of motor gestual developmental and temporal-spatial organization of handwriting highlighting six qualitative criteria: irregular handwriting (criterion 1), immaturity of handwriting gesture (criterion 2), excessive pressure of the pen on the paper (criterion 3), neuro-vegetative responses (criterion 4), trembling (criterion 5), slow handwriting velocity (criterion 6). Two groups are established: children with poor handwriting (PH) and children with dysgraphia (DysG).ResultsWhile 89% of children have handwriting disorders, only 20% exhibit dysgraphia. IM DCD is characterized by an immaturity of handwriting gesture and is associated with PH. Dysgraphia appears only in VSC and MX DCD which are characterized by the association of criteria 1, 2, 3, and 4. This association appears to more than 80% in DysG. Slow handwriting velocity is constant between PH and DysG.ConclusionImmaturity of handwriting gesture is a possible underlying mechanism of poor handwriting. Dysgraphia is associated with specific impairments in spatial organization of letters and in motor control of handwriting gesture.Disclosure of interestThe authors have not supplied their declaration of competing interest.

IntroductionThere is currently a resurgence of handwriting difficulties in school-age children. Researches in literature focus on kinematics temporal and spatial measures of letters in the writing process and on clinical performances such as the handwriting scale (BHK). This assessment doesn’t consider the organization and the maturation of the handwriting gesture.ObjectivesWe aim to study the developmental organization of the handwriting gesture to provide developmental standards of reference in order to complete performances measures allowing a better understanding of handwriting disabilities.MethodsHealthy children of elementary school aged between 6 and 11 years old are eligible for inclusion. All children are assessed with neuropsychological and neuropsychomotor evaluations and with handwriting assessment (BHK). Two groups are established, the one with handwriting difficulties and the other one (control group) without writing disorder or learning disabilities. The children were matched for age, gender and school level. All children are filmed with a camera suspended over to observe with specific handwriting tasks, the upper limb gesture about segmental organization of fingers, hand, forearm, arm, shoulder and postural organization.ResultsPreliminary findings show significant differences of the segmental organization of the writing gesture between the two groups. We will discuss the identified causes of the handwriting disorders with the analysis of neuropsychomotor and neurological assessments data in correlation with gesture segmental organization.ConclusionDevelopmental organization of the writing gesture is a possible underlying mechanism of handwriting disabilities. Practically, it appears important to improve news tools of evaluations with gestural writing consideration and to implement it in intervention process.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Objectives The DSM IV-R criteria for Developemental Coordination Disorder (DCD) involve a marked impairment in the development of motor coordination although visual-spatial, digital and visuo-motor perception, neuromuscular tone, qualitative and quantitative measures impairments related to of gross and fine motor coordination might be used to isolate three main subtypes of DCD/dyspraxia: Ideomotor, Visual-Spatial/Constructional, and a Mix group sharing common impairments with additional comorbidities. This study focus on isolating specific markers with high predictive discriminatory power from a wide range testing battery in a sample of DCD children. Methods Data were collected on 63 children with DCD aged 5-15 years (median 8.1), enrolled on DSM IV-R criteria. Children were free of previous assessment, medication, and therapy followup-up. Each subject underwent a neuropsychological, neuropsychomotor and neurovisual testing batteries comprised of 49 milestones assessment. Results The most salient markers with respect to the three subtypes of dyspraxia studied in this sample are digital praxia, imitation of gestures, digital perception, visual-motor integration, manual dexterity, visual spatial structuration, coordination between upper and lower limbs, and lego blocks. Clustering results suggest Ideomotor patients define a homogeneous group of patients and Mix group with specific difficulties in coordinating lower and upper limbs or poor manual dexterity. Conclusion This study confirms the importance of some aspects of neurovisual processing of spatial information, and motor control in DCD. Less than 15 neurovisual, neuro-psychomotor and neuropsychological milestone tests might be required to provide a sensitive and specific diagnostic of DCD subtypes, and isolated markers allow a better understanding of DCD.

Objectives The DSM-IV-TR criteria for Developmental Coordination Disorder (DCD) involve a marked impairment in the development of motor coordination although visuo-spatial, digital and visuo-motor perception, neuromuscular tone, qualitative and quantitative measures of gross and fine motor coordination related impairments might be used to isolate three main subtypes of DCD/dyspraxia: ideo-motor, visuo-spatial and constructional, and a mix group sharing common impairments with additional comorbidities. This study focus on isolating specific markers of coordination disorder and their interactions in mix vs. pure form of dyspraxia. Methods Tree-based bagged classifiers were used to highlight relevant markers among 49 pass/fail tests that best discriminate two clinical subgroups based on a sample (N = 63) of 5–15 years old children having IQ in the expected range (40% mix dyspraxia). Model calibration was done on a training sample through nested repeated 5-fold cross-validation while predictive performance were assessed on a held-out validation sample, using a split ratio of 0.7/0.3. Results We found that digital praxia, imitation of gestures, manual dexterity, digital perception, lego blocks, and visual motor integration were among the top most important impairments when predicting subtypes. Specific interactions among those predictors and other impairments (motor pathway, visual evoked potential, language) were shown to provide additional insights into DCD subtyping. Conclusions Taylored follow-up of patients presenting with DCD should consider the specificity of visuo-spatial, neuromotor and neuropsychological impairments whose co-occurrence allow to define different subtypes of DCD.