Fast responses to target changes are not impaired in children with spastic hemiplegia.

Humans are able to correct an ongoing movement very quickly in response to a suddenly moving target. Such fast responses possibly bypass the motor cortex and if so, one would expect that damage to the motor cortex would not greatly affect them. A group of children with congenital spastic hemiplegia were asked to move to a target, which, in some trials, jumped to a new position. It was found that the congenital spastic hemiplegia group was not affected more by the target jumps than the typically developing children. The moving targets made adaptive movements faster instead of slower for the affected hand. It is concluded that fast-adjusting movements do not necessarily rely on the motor cortex in these children.