Apraxia.

Humans need to perform skilled movements to successfully interact with their environment as well as take care of themselves and others. These important skilled purposeful actions are primarily performed by the forelimb, and the loss of these skills is called apraxia. This review describes the means of testing, the pathophysiology, and the clinical characteristics that define five different general forms of forelimb apraxia including: (1) ideational apraxia, an inability to correctly sequence a series of acts leading to a goal; (2) conceptual apraxia, a loss of mechanical tool knowledge; (3) ideomotor apraxia, a loss of the knowledge of how when making transitive and intransitive movements to correctly posture and move the forelimb in space; (4) dissociation apraxia, a modality-specific deficit in eliciting learned skilled acts; and (5) limb-kinetic apraxia, a loss of hand-finger deftness.