There are several causes that can lead to brain damage. Likewise, the impact of an injury on the nervous system can produce a wide variety of symptoms depending on the area affected and the type of damage that has occurred.
Examples of this may be problems with speech comprehension, sensory perception of stimuli, or problems with the motor system. In this last type of problematic one can find the difficulty or the loss of capacity when performing sequential movements, which were used on a daily basis when performing very diverse actions. We are talking about apraxia.
A little preamble: what kind of movements do we do?
To understand what an apraxia is, we must take into account the great diversity of movements we make. Whether they are voluntary or not, the ability to move has allowed humans to develop as a species and be able to perform actions of great complexity.
Some of the main movements performed by human beings are as follows.
These types of movements tend to be intense reactions of little complexity and duration.Usually due to activation of a specific nerve fiber bundle. These are small movements made involuntarily.
2. Voluntary movements
Voluntary movements are those that we perform with a certain objective, At a conscious level and which, at least initially, need the individual’s attention to be able to perform it properly. With enough practice, they can automate themselves.
3. Automatic movements
On this occasion a behavior is performed on purpose, but it is automatedIn other words, you don’t need conscious attention to the sequence of actions to do it beyond choosing your start and / or end time. They are sequences of actions internalized thanks to the practice and the habit of the person to perform them, like the set of actions that we perform to have a soup, to ride a bike, to drive, to sit down or even to speak. .or walk. It is in this type of movement that apraxias appear.
Describe the concept of apraxia
Given the brief explanation above, it is easier to explain the concept of apraxia. It is understood as such in the arrest or increased difficulty in the ability to perform propositional movements that require sequencing and coordination of movements, Being impossible to realize certain automatic movements.
This alteration is usually due to brain injury, maintaining the subject who suffers from the ability to understand the action being asked to do, being the task easy to perform or already known to the individual and maintaining muscle function. correct. The individual usually does not have anosognosia, so they are fully aware of their deficit.
The most famous types of apraxia
As we have mentioned, apraxia involves an inability to perform coordinated sequences of movements in a sequential and orderly fashion.
However, nor there is only one typology of this problem, there is a large number of classes of apraxia. Some of the main ones are shown below.
1. Ideational apraxia
In this type of apraxia, subjects find it difficult not only to perform coordinated tasks, but also to imagine them.Without being in many cases able to imagine the correct sequencing necessary to achieve a particular behavior. However, the individual actions that make up the sequence can be performed correctly.
We also consider as ideational apraxia (although in this case it is also called conceptual) the difficulty of using objects for the same causes, i.e. ignorance of the sequence of actions necessary to use , for example, a painting. It is common in neurodegenerative diseases such as dementia due to Alzheimer’s disease or Parkinson’s disease, as well as lesions of the dominant hemisphere and the corpus callosum.
2. Ideomotor apraxia
This type of apraxia is the most common in clinical practice. On this occasion, subjects can correctly imagine the sequence of actions required to perform a certain behavior, although they are not able to do it physically.
In ideomotor apraxia, the deficit is in difficulty in the planning of movements. In this typology, we can find different subtypes, such as oral, speech, limb and axial apraxia (of the axis of the body, which affect actions such as sitting and posture) . They are common in bilateral lesions and corticobasal degenerations, usually affecting both sides of the body.
3. Constructive apraxia
As for constructive apraxia, is based on construction or drawing difficulties due to difficulties in spatial perception and manual eye coordination. Thus, there is no correct association between the image perceived visually and the movements necessary to carry out the elaboration. Some subjects with this type of problem are unable to recognize the differences between the stimulus they are asked to copy and its elaboration, even arguing whether the problem is movement or integration between information.
Also called visuoconstructive deficit, this type of apraxia is used as an indicator of cognitive impairment due to its rapid onset in patients with Alzheimer’s disease. It usually appears in patients with lesions of the right hemisphere, but a large number of cases have been observed in which the damaged hemisphere is the left. The lesion is usually localized in the parietooccipital region, which is consistent given the mismatch between vision (located primarily in the occipital lobe) and movement (present in the parietal).
Apraxia, as a product of brain injury, can have a wide variety of causes. Although the list of possible causes is much broader, some of them may be as follows.
Whether it’s a hemorrhage or a stroke, heart attacks usually cause part of the brain to die, Being the most common cause of apraxia and other disorders related to brain damage.
traumatic brain injury
A contusion that affects the brain can cause serious damage to that organ, which may or may not be reversible.. Depending on the area damaged by the blow, or the possible counterattack (i.e. the blow produced on the side opposite to the injury due to the rebound against the skull), apraxia can appear easily.
The presence of a strange and growing mass in the brain damages various areas of the brain, Both due to the tumor itself and the pressure exerted on the brain against the skull. If this lesion occurs in the responsible areas of the motor system or in the areas of association that make up the coordination of movements, the appearance of apraxia is greatly facilitated.
The disorders that occur with a progressive deterioration of the nervous system are closely related to the presence of apraxia. In fact, one of the hallmarks of cortical dementias is the presence of an aphasic-apraxo-agnostic syndromeThis includes the gradual onset of speech problems, sequencing of movements, and perceptual and intellectual skills.
Usually the product of brain damage, apraxias are problematic, the form of treatment will vary widely depending on its cause. Although difficult to recover and although in some cases there may be sequelae, the type of treatment generally tends to use therapy at the physical level and rehabilitation or compensation of lost functions.
- Ardila, A. (2015). Kinetic, ideomotor, ideational and conceptual apraxia. Journal of Neuropsychology, Neuropsychiatry and Neurosciences, Vol. 15, Nº1, pp. 119-139
- Bradley, WG; Daroff, RB et al. (2004) Clinical Neurology: Diagnosis and Treatment. Vol I. Fourth edition. Pages 127-133.
- García, R. and Perea, MV (2015). Constructive and dressed apraxia. Journal of Neuropsychology, Neuropsychiatry, and Neurosciences, 15, 1, 159-174.
- Greene, JDW (2005). Apraxia, agnosia and abnormalities of visual function. Neurosurgery Psychiatry J Neurol; 76: v25-v34.