Brain motor excitability and visuomotor coordination in 8-year-old children born very preterm.

OBJECTIVE: Our study aimed to test in 8 years old children born very prematurely whether a faulty primary motor cortex (M1) functioning could parallel visuomotor coordination difficulties. METHODS: Ten very preterm children (PT; gestational age ≤32 weeks; 6 boys; 8 years 6 months, SD 4 months) were compared to seven healthy term peers (4 boys; 8 years 4 months, SD 4 months). Clinical assessment comprised two standardized tests for motor skills and visuomotor coordination. Transcranial magnetic stimulation (TMS) was applied over M1 area of the preactivated first dorsal interosseous muscle to measure the corticomotor excitability and the short intracortical inhibition (SICI). RESULTS: PT scores were significantly lower on the Developmental Test of Visual-Motor Integration (p=0.0018) and on the Movement Assessment Battery for Children (p=0.038). In parallel, the dominant hemisphere worked differently with no SICI in PT (p=0.009) and more variability of corticomotor excitability (p=0.001). CONCLUSIONS: These intertwined neurophysiological findings suggest that a faulty motor programming in the dominant M1 of PT could explain visuomotor coordination deficits. SIGNIFICANCE: Our study contributes to the understanding of possible mechanisms that underlie motor difficulties commonly observed in children who were born premature. In addition, the effectiveness of rehabilitation interventions may be better understood by applying TMS as an outcome measure in the future.