Apraxia: causes, symptoms and treatment.

A neurological symptom that prevents coordination of movements.

There are multiple causes that can lead to brain injury. Similarly, the repercussions of an injury to 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 in speech comprehension, perception of stimuli through the senses or problems related to the motor system. Within this last type of problems we can find the difficulty or loss of ability to perform sequential movements, which are used on a daily basis when performing a wide range of actions. We are talking about apraxias.

A small preamble: what kind of movements do we do?

To understand what an apraxia is, it is necessary to take into account the great diversity of movements we make. Whether they are voluntary or not, the ability to move has allowed human beings to develop as a species and to be able to perform and to be able to execute actions of great complexity.

Some of the main movements that humans perform are the following.

1. Reflexes

This type of movement tends to be intense reactions of low complexity and durationgenerally due to the activation of a bundle of specific nerve fibers. They are small movements made involuntarily.

2. Voluntary movements

Voluntary movements are those that we perform with a determined goal in mind, at a conscious level and that at leastThey are conscious movements that at least originally need the individual's attention in order to be performed correctly. With sufficient practice, they can become automatic.

3. Automatic movements

On this occasion a behavior is performed voluntarily, but it is automated.In other words, no conscious attention to the sequence of actions is required to carry it out beyond choosing the moment of beginning and/or end. These are sequences of actions internalized through practice and habituation of the person to perform them, such as the set of actions we perform to eat soup, ride a bike, drive, sit or even talk or walk. It is in these types of movements that apraxias appear.

Describing the apraxia concept

Having taken into account the brief explanation above, it is easier to explain the concept of apraxia. Apraxia is understood as the cessation or high difficulty of the ability to perform purposeful movements that require sequencing and coordination of movements, making it impossible to perform certain movements.It is impossible to perform certain automatic movements.

This alteration is generally due to a brain lesion, with the subject having the capacity to understand the action he/she is asked to perform, the task being easy to perform or already known to the individual, and maintaining correct muscular functioning. Generally, the individual does not present anosognosia, and is therefore fully aware of his or her deficit.

Most known types of apraxia

As we have mentioned, apraxia implies an inability to perform sequences of coordinated movements in a sequential and orderly manner.

However, there is not only one type of apraxia, there is not just one typology of this problem, and there are many different types of apraxia.. Some of the main ones are reflected below.

1. Ideational apraxia

In this type of apraxia, the subjects have difficulty not only in performing coordinated tasks, but also in imagining them.In many cases, they are not able to imagine the correct sequencing necessary to carry out a specific behavior. However, the individual actions that compose the sequence can be performed correctly.

It is also considered as ideational apraxia (although in this case it is also called conceptual) the difficulty to use objects due to the same causes, i.e. the lack of knowledge of the sequence of actions necessary to use, for example, a comb. It is common in neurodegenerative diseases such as Alzheimer's dementia or Parkinson's disease, as well as in lesions of the dominant hemisphere and corpus callosum.

2. Ideomotor apraxia

This type of apraxia is the most common in clinical practice. In this case, the subjects can correctly imagine the sequence of actions necessary to perform a given behavior, although they can also imagine the sequence of actions necessary to perform a given behavior. are not able to carry it out physically..

In ideomotor apraxia the deficit lies in a difficulty in movement planning. Within this typology different subtypes could be found, such as buccofacial, speech, limb and axial apraxia (of the body axis, affecting actions such as sitting and posture). They are frequent in bilateral lesions and cortico-basal degenerations, both sides of the body being generally affected.

3. Constructive apraxia

As for constructive apraxia, it is based on the difficulty in construction or drawing due to difficulties in spatial perception and oculomotor coordination.. Thus, there is no correct association between the image perceived visually and the movements necessary to perform 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, and it is even discussed whether the problem is one of movement or of integration between information.

Also called visuoconstructive deficit, this type of apraxia is used as an indicator of cognitive impairment due to its early onset in Alzheimer's patients. It usually appears in patients with lesions in the right hemisphere, but a large number of cases have been observed in which the damaged hemisphere is the left one. The lesion is usually located in the parieto-occipital region, which is consistent with the lack of coordination between vision (located mainly in the occipital lobe) and movement (present in the parietal lobe).

Possible causes

Apraxias, as a product of a brain injury, can have a wide variety of causes. Although the list of possible causes is much longer, some of them may include the following.

Cardiovascular accidents

Whether it is a hemorrhage or a stroke, Cardiovascular accidents usually cause the death of a part of the brain, cardiovascular accidents usually cause the death of a part of the brain, being the most common cause of stroke.The most common cause of apraxias and other disorders linked to brain injury.

Cranioencephalic traumas

A contusion affecting the brain can cause severe damage to this organ, which may or may not be reversible.. Depending on the area damaged by the blow, or the possible backlash (i.e., the blow produced on the opposite side of the injury due to the rebound against the skull), apraxia can easily appear.

Brain tumors

The presence of a foreign and growing mass in the brain causes damage to various areas of the brain.The damage is caused both by the tumor itself and by the pressure exerted on the brain against the skull. If this damage occurs in the areas responsible for the motor system or in areas of association that integrate the coordination of movements, the onset of apraxia is greatly facilitated.

Neurodegenerative disease

Disorders involving progressive deterioration of the nervous system are closely linked to the presence of apraxias. In fact, one of the characteristics of cortical dementias is the presence of the aphaso-apraxia-agnostic syndrome, which includes progressive apraxia.which includes the progressive onset of problems with speech, sequencing of movements and perceptual and intellectual abilities.

Treatment

Being generally the product of brain lesions, apraxias are problematic whose form of treatment will vary greatly according to their cause. Although difficult to recover from and although in some cases sequelae may remain, the type of treatment generally tends to use physical therapy and rehabilitation or compensation of lost functions.