Movement disorders in children: definitions, classifications, and grading systems.

Disorders that affect movement in children are relatively common. However, they have received little attention, especially when compared with epilepsy and neuromuscular disorders. In this review article, we address the major types of movement disorders that affect children, their clinical characteristics and etiologies, and, when available, the scales used to grade them. A discussion on spasticity, which traditionally is not addressed in reviews of "movement disorders," is also included.