APRAXIA QUICK REFERENCE
For a movement to be executed, its picture must be retrieved and activated and then be associated via cortical projections with the relevant motor engrams in the prefrontal regions. From here the information passes to the primary motor cortex before being fed down the corticospinal tracts. For the right upper limb to move the information remains contained within the left hemisphere, but for the left upper limb to move the information from the left parietal lobe must first be sent to the right prefrontal and frontal regions through the corpus callosum.
|Types of Apraxia||Description||Examples|
|An inability to carry out a motor act on verbal command or imitation but can perform the task when using the actual object, in context.
The patient can conceptualize but not actually execute the action, demonstrating spared recognition of tools but deficient ability to use them appropriately or to imitate actions.
|Traditionally characterized by deficits in properly performing tool-use pantomimes (e.g. pretending to use a hammer) and communicative gestures (e.g. waving goodbye).
Performing tool-use pantomimes- transitive act pantomime
The patient might be able to describe how to use an object but is not able to demonstrate the actual use of the object. This typically results in the patient failing to pantomime a transitive act (actions with object interaction).
The patient will not be able to carry out gestures of “act as if you are waving hello” or “salute”.
|A disorder involving the motor planning and sequencing of complex motor acts – the patient appears to have lost the overall concept of how to proceed in order to complete a complex motor task. The patient is able to carry out individual motor acts but cannot complete a hierarchical sequence of a complete act.
|Characterized by an inability to conceptualize a task, despite intact identification of tools. This is illustrated when a patient is presented with a stamp and an envelope, the patient is able to name the objects correctly, but is unable to demonstrate how to mail an envelope using these objects.
• Asking a patient to strike a match against a matchbox-
• Functionally, a patient with ideational apraxia will be unable to cook a meal, make-up a bed, go shopping for groceries.
|Conceptual Apraxia||Conceptual apraxia- the function of tools is no longer understood. The patient may misuse objects, have difficulty matching objects and actions (cannot select the proper tools to perform a task), be unaware of the mechanical advantage afforded by tools.||• Fails to describe the function of a tool
• Unable to point out a tool when its function is described by the examiner
• Misusing object – using a comb as a toothbrush
• Given the option of using either the camera or mirror to take a photo. By not knowing which tool to select, indicates that patient does not know the function of either the camera nor the mirror
• When a partially driven nail is shown, the patient may select a pair of scissors rather than a hammer from an array of tools to complete the action
|The term constructional disorder is now favored over the previously used term of two- and three-dimensional constructional apraxia since the deficit does not clearly fall within the definition of apraxia. Constructional disorder refers to the inability to organize or assemble parts into a whole, as in putting together block designs (three-dimensional) or drawings (two-dimensional).
The primary deficit in constructional disorder appears to involve the ability to perceive and imagine geometrical relations- the ability to organize and manually manipulate spatial information to make a design.
|• Inability to draw a picture of a simple object from memory
• Inability to copy and draw simple figures
• Inability to build and copy simple constructionsDifferent types of constructional disorders as determined by the location of brain insult. In general, patients with right hemisphere impairment make more coordinate type errors (e.g., distance and angular distortions), whereas those with left hemispheric impairment tend to make errors with pattern reversals
|Dressing Apraxia||Dressing apraxia is the inability to plan effective motor actions required during the complex perceptual task of dressing oneself It signifies a feature of the impaired tactile and visuospatial coordination plus hemineglect rather than the loss of the ability to use tools. i.e. visuospatial deficits which result in difficulty dressing
|Tested by asking the patient to wear a jacket with the sleeves deliberately turned inside out.
Observing patient getting dressed:
• Clothing on backwards
• Inability to spatially orient a body part to an article of clothing
• Can’t find the right armhole
• Trying to pass the head through the sleeve
• Putting cloths on upside down or inside out
Ideational vs Conceptual Apraxia
Ideational apraxia has been defined as an impairment in performing tasks that required a sequence of several acts with tools and objects (e.g., prepare a letter for mailing). However, some authors also use the term to denote a failure to use single tools appropriately. To overcome this confusion, restricting the term ideational apraxia has been suggested to be used for a failure to conceive a series of acts leading to an action goal. Conceptual Apraxia was therefore introduced to refer to a loss of knowledge of how objects are used. However, a strict difference between ideational and conceptual apraxia is not always feasible.