The ability to read it is a fundamental skill in today’s society. Academic and professional life generally requires mastery of this skill. This is why from childhood we learn to make sense of the words we form through written language, which to an adult may seem relatively simple if it has been done since childhood requires a high level. processing and a large number of mental operations and transformations to be able to be carried out.
However, sometimes people who have possessed and properly developed the ability to read lose this ability for some reason, losing the ability to read altogether. This circumstance corresponds to Alexia, Which we will talk about throughout this article.
Alexia: basic definition
Her name is Alexia 1 written language disorder characterized by partial or total loss of reading ability, being the latter produced by the appearance of some type of brain injury. It is therefore a type of secondary affectation, that is to say resulting from another alteration, which can even be interpreted as a symptom of it.
It is considered to be a type of visual agnosia, that is, the failure to recognize any type of stimulation that is perceptible through sight. In this case, the subject loses the ability to understand written words, He being impossible or at least assuming a great difficulty the fact of codifying – being able to transform the spelling into a phoneme, although he possessed this capacity previously.
Types of alexia
Although the allergy implies the loss of reading ability does not always appear in the same way, there may also be other problems or the start of different deficits. Among the main types that we can find
Alexia pure or without staple
This type of alexia is one in which only serious difficulties or the complete impossibility appear in the visual recognition of letters or words, nevertheless being able to the subject to write correctly (although not being able to understand what has written). It’s also called word blindness. It is possible to recognize some vague words frequently used for the topic.
This is not the most common, as it usually involves bilateral involvement such that visual information cannot pass into areas that interpret and generate language, in the left hemisphere. This usually corresponds to problems in the occipital area of the brain, In the fusiform, lingual and / or angular whorls, or the uncus.
Alexia central Or with clip
As in the previous case, we find an alteration and an impossibility or a great difficulty in the recognition of the written words, but also in their production. In other words, in this case we find that the subject can neither read nor write. Anomie may also appear, Having difficulty identifying objects and visual stimuli beyond literacy.
This type of alexia usually corresponds to lesions of angular rotation, which is responsible for processing information so that spelling or letters are transmitted to phonemes or sounds and vice versa, which is necessary for the both for reading and writing. It is also linked to lesions in the parietals or fibers of the temporal and occipital lobes.
Alexia earlier or with aphasia
Also called frontal alexia, we are faced with a circumstance in which not only alterations occur in reading but also in speech production. In this case, the lesion is usually produced at a more frontal level, being its functionality similar to that of a subject with Broca’s aphasia. It is common for there to be less problems with words familiar to the subject than with other allergies.
Differentiation from other situations
It is important to keep in mind that in Alexia we are faced with a situation in which the subject already knew how to read and there was a loss of this ability, not being considerable like Alexia the cases of those people who do not ‘have never learned to do so, that is to say from illiteracy.
It is also relevant to differentiate it from progressive dyslexia, Who would be this neurodevelopmental disorder (which implies that at the neuronal level what exists is an atypical organization of cerebral development and not a lesion itself) in which there is a difficulty in reading and writing that appears from the childhood and in which never been a greater degree of capacity than what the subject expresses at the moment (not being a loss but rather a difficulty).
Finally, it should be noted that the allergy it is not derived from the absence of visual perception proper: the subject can see the words and his eyes are working precisely enough to perceive them, the problem being coding and transforming them into something meaningful.
Alexia is considered to be a type of agnosia and a literacy impairment caused by a certain type of brain injury. But the causes of this injury can vary widely. It should also be borne in mind that the lesion can appear in different places of the nervous system, from the angular and / or supramarginal coils to the fibers of the occipital or temporal lobes, passing through the lingual and fusiform coils among others. Among the main causes of allergy we can find the following events.
One of the main causes of alexia is suffering from a certain type of stroke or stroke, this is called ischemia (blockage of the blood vessel that prevents blood from reaching certain areas) or hemorrhage. (break in taste). Depending on the affected areas, death of brain tissue can lead to loss of reading ability.
2. Cranioencephalic trauma
Another classic reason for the onset of allergy is the fact that you have suffered some type of traumatic brain injury. Traffic accidents, accidents at work or assaults are some of the causes that can cause the appearance of a certain type of alexia.
3. Dementia and other neurodegenerative disorders
The allergy can appear throughout the deterioration caused by a certain type of dementia, such as Alzheimer’s disease, or other similar disorders. Depending on the disorder itself, the difficulty, worsening, and inability to read it can appear at different stages of the disease.
4. Brain tumor
Another possible cause of allergy is the appearance of brain tumors that affect, pinch or compress. areas of the brain and nerve fibers involved in the reading process.
5. Brain infections
Allergy can also appear with certain infectious processes which end up affecting the brain. Some are typical meningitis or encephalitis.
Treating allergy is not straightforward, since we are faced with a phenomenon resulting from some type of brain injury, and in fact, we may be faced with permanent damage. However, this does not mean that it is not possible to achieve different levels of recovery, depending on the injured areas or the degree of involvement of the injury, or compensation of functions.
The type of treatment will depend on these and other factors, and for its realization will be necessary a multidisciplinary team in which disciplines such as neurology or psychology work, In addition to other health or even social specialties.
The first will be to determine and treat the cause of the onset of the allergy. Most of the time, an early diagnosis will do a better job of treatment and can prevent it from getting worse (for example, if we are faced with an infection or a tumor, these can occur. develop and cause more damage).
will be necessary use a personalized rehabilitation program, The use of language therapy and different types of cognitive stimulation is common. Psychoeducation will also become important both for people and for their environment, so that they can understand what has happened and know how to apply different means so that the difficulties do not imply limitation. It can also be important to work on the affective sphere, self-concept and self-esteem, which can be altered by the presence of deficits.
- Junqué, C. and Barroso, J. (Coords.) (2009). Textbook of Neuropsychology. Madrid: Synthesis.
- Portellano, JA (2005). Introduction to neuropsychology. Madrid: McGraw Hill.