Apraxia is a motor disorder caused by damage to the brain (specifically the posterior parietal cortex or corpus callosum) which causes difficulty with motor planning to perform tasks or movements.
Apraxia is most often due to a lesion located in the dominant (usually left) hemisphere of the brain, typically in the frontal and parietal lobes.
Lesions may be due to stroke, acquired brain injuries, or neurodegenerative diseases such as Alzheimer’s disease or other dementias, Parkinson’s disease, or Huntington’s disease.
It is also possible for apraxia to be caused by lesions in other areas of the brain.
The nature of the damage determines the disorder’s severity, and the absence of sensory loss or paralysis helps to explain the level of difficulty.
There are several types of apraxia including:
Apraxia of speech: Difficulty planning and coordinating the movements necessary for speech (e.g. Potato=Totapo, Topato). AOS can independently occur without issues in areas such as verbal comprehension, reading comprehension, writing, articulation or prosody.
Buccofacial or orofacial apraxia: This is the most common type of apraxia and is the inability to carry out facial movements on demand. For example, an inability to lick one’s lips, wink, or whistle when requested to do so.
Constructional apraxia: The inability to draw, construct, or copy simple configurations, such as intersecting shapes.
Gait apraxia: The loss of ability to have normal function of the lower limbs such as walking. This is not due to loss of motor or sensory functions.
Ideational/conceptual apraxia: Patients have an inability to conceptualize a task and impaired ability to complete multistep actions. This form of apraxia consists of an inability to select and carry out an appropriate motor program.
Ideomotor apraxia: These patients have deficits in their ability to plan or complete motor actions that rely on semantic memory. They are able to explain how to perform an action, but unable to “imagine” or act out a movement such as “pretend to brush your teeth” or “pucker as though you bit into a sour lemon.”
Limb-kinetic apraxia: The inability to perform precise, voluntary movements of extremities. For example, a person affected by limb apraxia may have difficulty waving hello, tying their shoes, or typing on a computer.
Oculomotor apraxia: Difficulty moving the eye on command, especially with saccade movements that direct the gaze to targets. This is one of the 3 major components of Balint’s syndrome.
Children may be born with apraxia; its cause is unknown, and symptoms are usually noticed in the early stages of development.
Treatment for individuals with apraxia includes speech therapy, occupational therapy, and physical therapy. Currently there are no medications indicated for the treatment of apraxia, only therapy treatments.