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.

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.

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.

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.