Axonal Plasticity in the Developing Human Brain

Objectives: Focal lesions to the developing human brain can induce massive (re-) organization of cortical representations, but whether trajectories of growing axons can be altered by such insults has not been shown yet. Methods: We have studied four patients with congenital hemiparesis due to large unilateral periventricular brain lesions, acquired during the early 3rd trimester of pregnancy. During this period of brain development, cortico-spinal motor axons have already arrived at their spinal target areas, whereas outgrowing thalamo-cortical axons (including somatosensory afferent fibers) have not yet reached…