Developmental coordination disorder: a pilot diffusion tensor imaging study.

Motor deficits associated with developmental coordination disorder are not attributable to macrostructural brain abnormalities, but differences in brain microstructure may exist. Using diffusion tensor imaging, we explored the integrity of motor, sensory, and cerebellar pathways in children with and without developmental coordination disorder. In seven children with the disorder and nine typically developing children (aged 8-12 years), we measured diffusivity and fractional anisotropy of the corticospinal tract, posterior thalamic radiation, and superior and middle cerebellar peduncles. Fractional anisotropy of motor and sensory tracts and diffusion parameters in cerebellar peduncles did not differ between groups. Mean diffusivity of the corticospinal tract and posterior thalamic radiation was lower in children with developmental coordination disorder compared with control children (P < 0.04 and P < 0.06, respectively). Results were driven by lower axial diffusivity, which was significantly correlated with motor impairment scores on the Movement Assessment Battery for Children-2 for both the corticospinal tract (r = 0.56, P = 0.03) and posterior thalamic radiation (r = 0.70, P = 0.003). Reduced axial diffusivity in motor and sensory tracts may be implicated in developmental coordination disorder, but replication in a larger study is needed to confirm these findings.