- 1 Brief guide to reviewing literature on apraxia Vol. 2
- 1.1 1. Definition of apraxia as a disorder of learned, skilled movements
- 1.2 2. The double meaning of ideational apraxia
- 1.3 3. Criteria for a general classification of apraxia
- 1.4 4. A comprehensive classification of apraxia
- 1.5 5. More notes on possible confusions derived from the use of language and translation
- 2 Bibliography
Do you sometimes get lost while reading different articles and books on apraxia?
This is the second installment of a brief guide to reviewing literature on apraxia, designed to make it easier for professionals and amateurs to consult a variety of publications on the subject.
For a better understanding of this blog post and to get a complete picture of the subject, it is recommended to read both volumes of the guide. Here you can read the first volume of this brief guide to reviewing literature on apraxia.
I hope the following will be of help.
Brief guide to reviewing literature on apraxia Vol. 2
1. Definition of apraxia as a disorder of learned, skilled movements
Apraxia has been defined in different ways. Many authors consider it to be a disorder in the execution of previously learned movements that results from acquired brain disease in the absence of sensory (afferent) and motor (efferent) deficits, and not attributable to comprehension problems, deficits in object recognition, or a lack of motivation [1,2,3].
Norman Geschwind replaced the conscious mental images of Liepmann’s seminal model of apraxia  by a stock of learned motor skills, thus conceiving motor control as dependent upon previous experiences (motor memories) and relegating the posterior to anterior stream to a path for the transport of learned movements from their storehouse to the place of execution .
Therefore, the definition of apraxia as a disorder of learned, skilled movements impliesthat we have a storehouse of motor skills and that apraxia as a disorder affects these motor memories.
It has been suggested  that by eliminating both mental images and their conversion into motor commands, Geschwind’s model of apraxia also eliminated the cognitive component of action control.
The cognitive component of apraxia is no longer disputed and, in the current literature, the definition of apraxia as a disorder of learned movement coexist with the classification of limb apraxia as ideational and ideomotor, and therefore with the sequential mechanism ‘concept-execution’ and with the cognitive component of motor control.
Some authors describe apraxia as deficits in the execution of purposive movements , thus assuming the cognitive component more explicitly, while others view it as a symptom on the border between cognition and motor control .
2. The double meaning of ideational apraxia
As noted , the term ideational apraxia has been used in two different ways:
- As the inability to perceive the properuse of objects (the loss of tool-action knowledge), which could be consideredan agnosia related to the use of objects.
- As the inability to plan and execute a sequence of actions (e.g., preparing a cup of coffee or brushing your teeth) in an orderly fashion, even though each individual motor action is properly executed.
This dual conception overlaps with the different definitions of ideational apraxia according to various clinical or behavioral criteria (see volume 1 of this guide), which may add further confusion to the reader of the literature on limb apraxia.
3. Criteria for a general classification of apraxia
In the literature, there is some discrepancy in relation to the general classifications of apraxias .
Criteria used to developthese classificationsinclude:
- Whether apraxia is unilateral or bilateral.
- The part of body affected: limbs, trunk or facial parts.
- Whether language/speech are affected.
- Whether apraxia is due to a disorder of movement execution (motor apraxias) or to spatial disturbances (apraxias such asconstructional apraxia and dressing apraxia).
Some authors prefer not to consider constructional apraxia and dressing apraxia as apraxias per se but as visuospatial and/or visuoconstructive disorders.
4. A comprehensive classification of apraxia
Ardila and Rosselli [1, 7] propose a general classification of apraxia that integrates all the criteria mentioned above (Fig. 1):
5. More notes on possible confusions derived from the use of language and translation
- Purposive movements can be also called intentional, voluntary,deliberate, andpurposeful.Other possible names are useful or functional movements.
A movement may have no other purpose or function than to be performedso as to be assessed by a neuropsychologist. In fact, a well-known part of apraxia is the voluntary-automatic dissociation, when patients may spontaneously perform gestures that they cannot perform on command.As a consequence, there are researchers who believe that limb apraxia is a disorder limited to the assessment context and that it goes unnoticed in everyday life .
It may be useful to consider all possible connotations of purposive movements when interpreting the definitions of apraxia and the models advocated in different publications.
By Lidia García Pérez
If you liked this brief guide to reviewing literature on apraxia, you might find the following posts by NeuronUP interesting as well:
- Briefguide to reviewing literature on apraxia Vol. 1
- Ángel Sánchez continues answering questions from his presentation “Functional consequences of apraxia”
- Aphasia: Differential Diagnosis
- Activities for the neuropsychological rehabilitation in patients with Broca´s aphasia
- Ardila, A. y Rosselli, M. (2007). Apraxia. En E. Márquez y L. Rodríguez (Ed.), Neuropsicología clínica(p. 127-139). México D. F., México: El Manual Moderno.
- Portellano, J. A. (2010). Introducción a la neuropsicología. Madrid: McGraw Hill.
- Bartolo, A. &Ham, H. S. (2016). A CognitiveOverview of Limb Apraxia. CurrentNeurology and NeuroscienceReports16:75
- Liepmann H. Apraxie. In: Brugsch H, editor. Ergebnisse der gesamtenMedizin. WienBerlin: Urban&Schwarzenberg; 1920. p. 516–43.
- Goldenberg (2014b). Thecognitiveside of motor control.Cortex, 57, 270-274
- Goldenberg (2014a). Challengingtraditions in apraxia. Brain, 137, 1854-1862.
- Ardila, A. y Rosselli, M. (1992). Neuropsicología clínica. Medellín: Prensa Creativa.