Apraxia is a neurological symptom that involves the inability to perform purposeful movements on demand. People with apraxia are not physically paralyzed, but they lack the ability to control the muscles required to perform certain tasks. It is usually the result of damage to the parietal lobe of the brain, which is associated with planning and executing movements.

People with apraxia may also experience seizures, aphasia (an inability to speak and understand language), memory loss and confusion.

There are various kinds of apraxia that affect different types of movement, including:

• Ideomotor apraxia. Inability to mimic or perform a movement (e.g. hammer a nail, brush hair, blow out a match, cough) in response to a verbal command.
  
  
• Ideational apraxia. Inability to correctly perform a series of movements to accomplish certain tasks (e.g., writing, bathing, dressing, eating or brushing teeth). Patients also may not know how to appropriately use certain tools or objects. For instance, a pen may be used in the manner of a comb.
  
  
• Verbal apraxia. Inability to coordinate lip, mouth and tongue movements in order to speak. People with verbal apraxia may be unable to say a word correctly and consistently (they can say a word correctly one moment but not the next).
  
  
• Buccofacial apraxia. Inability to perform movements of the face and mouth (without typically affecting a patient’s ability to speak). Patients with verbal apraxia may not be able to lick their lips, blow, cough or wink upon verbal command.

Additional types of apraxia that some experts believe should not be considered true forms of apraxia include constructional apraxia, limb-kinetic apraxia and oculomotor apraxia.

Apraxia can be caused by anything that causes neurological damage. This may include certain developmental disorders present at birth, traumatic brain injury and dementia.