Chorea and Choreoathetosis (Pediatric) Mechanism

Chorea is thought to be caused by damage to the basal ganglia. As described in the section on anatomy and physiology, the basal ganglia can be divided into two fundamental pathways: the direct and the indirect pathways. In some cases, chorea seems to result from damage to the indirect pathway. For example, chorea or ballism may be caused by injury to the subthalamic nucleus. Huntington's chorea is caused by selective loss of the indirect pathway cells in the striatum. Current theories suggest that the indirect pathway helps to inhibit unwanted movements, so it is possible that damage to this pathway allows the "escape" of movements that would ordinarily be suppressed. The random initiation of movements suggests that the indirect pathway serves not only to suppress unwanted movements but also to prevent the initiation of movement. It is not known why some children with diffuse injury to the basal ganglia (such as occurs in cerebral palsy) develop choreoathetosis, while others develop dystonia.

	Etiology