Apraxia is inability to execute purposeful, previously learned motor tasks, despite physical ability and willingness, as a result of brain damage. Diagnosis is clinical, often including neuropsychologic testing, with brain imaging (eg, CT, MRI) to identify cause. Prognosis depends on the cause and extent of damage and patient age. There is no specific treatment, but physical and occupational therapy may modestly improve functioning and patient safety.
Isolated apraxia is relatively uncommon.
Apraxia results from brain damage (eg, by infarct, tumor, or trauma) or degeneration, usually in the parietal lobes or their connections, which retain memories of learned movement patterns.
Less commonly, apraxia results from damage to other areas of the brain, such as the premotor cortex (the part of the frontal lobe anterior to the motor cortex), other parts of the frontal lobe, or the corpus callosum, or from diffuse damage related to degenerative dementias.
Patients with apraxia cannot conceptualize or do learned complex motor tasks despite having intact motor, sensory, and coordination systems and being able to do the individual component movements. For example, patients with constructional apraxia may be unable to copy a simple geometric shape despite being able to see and recognize the stimulus, hold and use a pen, and understand the task. Typically, patients do not recognize their deficits.
Bedside tests include asking patients to do or imitate common learned tasks (eg, saluting, stopping or starting to walk, combing hair, striking and blowing out a match, opening a lock with a key, using a screwdriver or scissors, taking a deep breath and holding it). Strength and range of motion must be assessed to exclude motor weakness and musculoskeletal abnormalities as the cause of symptoms.
Neuropsychologic testing or assessment by a physical or occupational therapist may help identify more subtle apraxias.
Caregivers should be asked about the patient’s ability to do activities of daily living, especially those that involve household tools (eg, correct and safe use of eating utensils, toothbrush, kitchen utensils to prepare a meal, hammer, and scissors) and writing.
Brain imaging (eg, CT, MRI; with or without angiographic protocols) is required to diagnose and characterize central lesions (eg, infarct, hemorrhage, mass, focal atrophy).
There is no specific medical treatment for apraxia. Drugs that slow the symptomatic progression of dementia do not appear beneficial.
Physical and occupational therapy may modestly improve functioning but is more often useful for making the environment safer and for providing devices that help patients circumvent the primary deficit.
Patients with apraxia cannot conceptualize or do learned complex motors tasks despite being able to do the individual component movements.
Ask patients to do common tasks at the bedside, recommend neuropsychologic testing, and do brain imaging.
Consider recommending supportive physical and occupational therapy.