Standardization of quantitative tests for preclinical detection of neuromotor dysfunctions in pediatric neurotoxicology.

In the neurotoxicology pediatric domain, few neuromotor tests are specifically designed to be sensitive enough for the early detection of subtle deficits in voluntary and involuntary movements. In research and clinical domains, an effort is done to objectify or quantify the qualitative aspects of a movement (pattern of movement) in predicting neurological problems. This study aimed to standardize quantitative motor measures initially developed for adults and adapted to the evaluation of preschoolers. The sample consisted of 110 healthy children aged 4-6. The following quantitative neuromotor tests were selected: alternating movements and pointing movements (DOCO Microsystèmes Inc., Montréal, Canada), postural tremor, postural sway and simple reaction time (Danish Product Development Ltd., Snekkersten, Denmark). Validation measures included global motor tasks and a neurological examination. Results indicate adequate test-retest reliability and complementarities amongst the selected voluntary and involuntary measures. Both the feasibility and relevance of quantitative neuromotor tests in preschool aged children were established. Results also provide a representation of intra-individual and inter-individual variability within this population. Lastly, the results highlight the importance of developmental factors, behavioral factors and testing conditions in the neuromotor evaluation of young children. The proposed tests could help in the early detection of children at risk for motor dysfunctions following neurotoxic exposure. The tests can also be used for the follow up of various conditions relating to motor functions (cerebral palsy, muscular dystrophy, preterm infants) and in the evaluation of the effects of medication.