4.4 Apraxia

4.4.1  Definition of Apraxias

Define and classify apraxias.

Apraxia is a disorder of voluntary movement where one cannot execute a purposeful activity despite the presence of adequate mobility, strength, sensation, coordination and comprehension. 

Apraxia is common in patients with left hemispheric strokes, especially in lesions involving the left frontal and parietal lobes.  Apraxia is a disorder of voluntary movement where one cannot execute willed, purposeful activity despite the presence of adequate mobility, strength, sensation, coordination and comprehension.  In other words, patients are unable to perform previously learned tasks and the inability is not explained by weakness, aphasia, or sensory loss (p. 97)49. Alternatively, Caplan 49refers to it as an inability to perform previously learned tasks when such an inability cannot be explained by weakness, aphasia, or sensory loss. The difficulty can be spontaneous and noted during everyday activities (e.g. difficulty with dressing, using utensils, starting the car, turning keys to open doors, and lighting a cigarette).  In others the difficulty in performing motor tasks becomes evident when the patient is asked to do something (p. 97)49.

Table 4: Types of Apraxias

Type

Site of Lesion

Manifestation

Motor or Ideomotor

Often left hemisphere.

Can automatically perform a movement but cannot repeat it on demand.

Ideational

Often bilateral parietal.

Can perform separate movements but cannot co-ordinate all steps into an integrated sequence.

Constructional

Either parietal lobe but right more often than left.

Unable to synthesize individual spatial elements into a whole (e.g., cannot draw a picture).

Dressing

Either hemisphere, right more often than left.

Inability to dress oneself despite adequate motor ability.