Apraxia

Wednesday, October 12, 2011

Apraxia is a disturbance of goal-directed motor behavior characterized by an inability to perform previously learned movements in the absence of weakness or sensory defects. There is a striking preservation of perception, attention, coordination, motivation, and comprehension. Thus it represents a high-level disorder of movement representation. There is significant variation in the clinical manifestations. Patients may have selective deficits in their ability to generate actions performed by the limb or the mouth and face. Apraxia is a disturbance of goal-directed motor behavior characterized by an inability to perform previously learned movements in the absence of weakness or sensory defects. There is a striking preservation of perception, attention, coordination, motivation, and comprehension. Thus it represents a high-level disorder of movement representation. There is significant variation in the clinical manifestations. Patients may have selective deficits in their ability to generate actions performed by the limb or the mouth and face.

Apraxic patients may be unable to move with respect to imitation, verbal command, or both. Apraxia is often associated with deficits of more complex movements such as gestures, pantomime, and sequential movement. There may be failure to perform a movement in response to an object or failure to handle an object correctly. Motor errors vary in severity, ranging from an inability to generate any appropriate movement to mild clumsiness in generating a complex movement. Inaccuracy of arm movements, particularly reaching, pointing, and grasping, can be observed and form an important link to optic ataxia and related disorders of visually guided movement. Apraxia is caused by damage to a specific area of the cerebral cortex.