Abstract
Background: Developmental Coordination Disorder (DCD) is a neurodevelopmental condition characterized by impaired motor coordination, yet its neural underpinnings remain poorly understood. Motor cortex plasticity, as assessed by transcranial magnetic stimulation (TMS), may offer insights into the pathophysiology of DCD.Methods: We recruited 24 children with DCD and 24 age- and sex-matched typically developing (TD) controls (aged 8–12 years). Paired-pulse TMS was applied to the left primary motor cortex to measure short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF). Motor cortex plasticity was assessed using a paired associative stimulation (PAS) protocol. Motor performance was evaluated with the Movement Assessment Battery for Children-2 (MABC-2).Results: Baseline SICI was significantly reduced in the DCD group compared to controls (p = 0.003), while ICF did not differ (p = 0.21). Following PAS, the DCD group showed diminished long-term potentiation (LTP)-like plasticity (p = 0.008). MABC-2 total scores correlated positively with PAS-induced plasticity in the DCD group (r = 0.52, p = 0.009).Conclusions: Children with DCD exhibit reduced GABAergic inhibition and impaired LTP-like plasticity in the motor cortex, which may contribute to their motor learning difficulties. TMS measures of plasticity could serve as biomarkers for DCD and guide targeted interventions.