Cortical reorganization in the human brain

Does the human brain reorganize differently depending on the stimulus? Does the type of injury affect how the brain reacts, or does cortical reorganization follow a set pattern regardless of the etiology of injury? Past studies have focused on where cortical functions relocate to and what factors enhance or inhibit that relocation process. In this issue of Neurology, Burneo et al.1 and Pataraia et al.2 used magnetoencephalography (MEG) to compare how cortical reorganization differs in patients with different types of brain lesions.

Until recently, the prevailing thought was that the brain’s ability to change is limited to the developing nervous system. It has now been firmly established that even the adult CNS is capable of developing adaptive changes and substantial cortical reorganization3 that may underlie recovery of function. Studies in both animals and humans have shown that damage to the CNS results in cortical reorganization that varies depending on age, extent and location of injury, and the presence of rehabilitative training. Plasticity, the ability of the CNS to adapt to new environmental requirements or lesions by functional changes in synapses, can occur at cortical and subcortical levels of the neuroaxis. The mechanisms implicated may include dendritic growth and synaptogenesis,4 changes in synaptic efficiency like long-term potentiation or depression, 5 and reorganizational changes in body part representations that are partially maintained by GABA.6 Cortical plasticity can …