Treatment-induced plasticity in cerebral palsy: a diffusion tensor imaging study.

Diffusion tensor imaging is used as a measure of white-matter organization to probe mechanisms underlying clinical responses. Diffusion tensor imaging and clinical assessment in 8 patients with spastic quadriparesis (mean age, 6.13 years) was performed before and 6 months after therapy (botulinum injection, followed by physiotherapy). All patients were graded on the basis of gross motor function. Serial diffusion tensor imaging was also performed on 10 age/sex-matched controls at baseline and after 6 months. Regions of interests were placed on corticospinal tracts at different levels (i.e., corona radiata, posterior limb of internal capsule, midbrain, pons, and upper medulla) and on other major white-matter tracts, in both patients and controls. A significant increase in fractional anisotropy was evident in corticospinal tracts at the level of the posterior limb of the internal capsule and periventricular white matter of the temporal lobe, relative to baseline values in the patient group. Gross motor function classification system grades improved in all patients during follow-up relative to baseline values. The increase in fractional anisotropy in corticospinal tracts, along with improved clinical motor scores, suggests plasticity of the central motor pathway after combined therapy.