Apraxia is loss of the ability to do tasks that require remembering patterns or sequences of movements.
Apraxia is relatively uncommon. It is usually caused by damage to the parietal lobes or to nerve pathways that connect these lobes to other parts of the brain. These areas store memories of learned sequences of movements. Less often, apraxia results from damage to other areas of the brain. Damage may result from a stroke, a tumor, an injury, or dementia.
People with apraxia cannot remember or do the sequence of movements needed to complete simple skilled or complex tasks, even though they have the physical ability to do the task and they can do the individual movements of the task. For example, buttoning a button, which consists of a series of steps, may be impossible, even though the hands are physically capable of doing the task. People with verbal (speech) apraxia cannot produce the basic sound units of speech because they cannot initiate, coordinate, or sequence the muscle movements needed to talk. Typically, people with apraxia do not recognize that they have a problem.
Some forms of apraxia affect only particular tasks. For example, people may lose the ability to do any one of the following: draw a picture, write a note, button a jacket, tie a shoelace, pick up a telephone receiver, or play a musical instrument.
To diagnose apraxia, doctors ask the person to do or imitate common learned tasks, such as using a toothbrush, scissors, or a screwdriver. Doctors also do a physical examination to determine whether symptoms are caused by muscle weakness or a muscle or joint problem. Family members or caregivers are asked how well the person does daily activities, such as eating with utensils, preparing meals, and writing.
Certain standardized tests of brain function (neuropsychologic testing) may be done. These tests may involve questions and/or requests to do specific movements (such as waving or showing how a hammer is used).
Imaging tests, such as computed tomography (CT) or magnetic resonance imaging (MRI), and other tests are done.
The disorder causing apraxia is treated if possible.
Physical and occupational therapy (see Verbal apraxia) may help some people with apraxia learn to compensate for their losses. But the main use of these therapies is to make the environment safer and to provide devices that help people function better.
Last full review/revision October 2013 by Juebin Huang, MD, PhD