What is Apraxia?
- Traditionally defined through exclusion: "Geschwind (1975), for example, defined apraxia as a disorder of learned movement which could not be accounted for by muscle weakness, lack of coordination, poor sensation, poor comprehension, or inattention" (Landry & Spaulding, 1999).
- "Apraxias may be defined as disorders of the execution of learned movement in the absence of weakness, incoordination, sensory loss, incomprehension or inattention to commands" (Geschwind, 1975).
- Apraxia is “the inability to carry out skilled movement in the presence of intact sensation, movement, and coordination" (Heilman & Rothi, 1993).
- "Apraxia is the absence of the ability to perform volitional movement", with volitional movement involving "the sensory/perceptual system (information coming in); the conceptual system (the idea and the analysis of the information); and the production system (the motor output)" (Tempest & Roden, 2008, p. 33).
- Apraxia is the loss of a skill known as praxis. Praxis refers to the innate capacity people have to rapidly take in information and plan motor action in response to their environment (Quintana, 2008). Praxis involves the following characteristics (Gillen, 2009):
- It is usually lateralized to the left hemisphere of the brain.
- It allows for storage of skilled motor information to be used in the future.
- It facilitates interaction with the environment.
- It provides a processing advantage because new planning is not required each time we start an activity.
- It is a process that results in execution of a purposeful activity:
2) Production (how to do it)
Important to Note:
- "A breakdown of the praxis skills (conceptual or production errors) results in apraxia, whereas a breakdown in execution is attributed to a primary motor or sensory deficit" (Gillen, 2009, p. 110).
- Tempest & Roden suggest that there is no consensus on the difference between Apraxia and Dyspraxia, but describe the difference in the following way: Dyspraxia is "a disorder of new learning of motor patterns and sequences and is more suited to describing neurodevelopment disorders" whereas Apraxia "is a disorder of learned movement...tending to affect the stages of conceptualizing (the idea stage) or producing (motor stage) volitional movement" (2008, p. 33-34).