Alexia: What It Is, Types, Symptoms, Causes And Treatment
The ability to read It is a fundamental skill in today’s society. Academic and work life generally require mastery of this skill.
That is why, from childhood, we learn to give meaning to the words we form through written language, something that, although for an adult it may seem relatively simple if it has been done since childhood, requires a high level of processing and a large number of operations and mental transformations to be carried out successfully.
However, sometimes people who have possessed and have correctly developed the ability to read lose this possibility for some reason, completely losing the ability to read. This circumstance corresponds to alexia which we are going to talk about throughout this article.
Receives the name Alexia A written language disorder characterized by the partial or complete loss of reading ability, this being produced by the appearance of some type of brain injury. It is therefore a secondary type of affectation, that is, derived from another alteration, which can even be interpreted as a symptom of it.
Visual agnosia is considered a type, that is, the absence of recognition of some type of stimulation perceptible through sight. In the case at hand, the subject loses the ability to understand written words making it impossible or at least very difficult for him to encode them in order to transform the spelling into a phoneme, although he has previously possessed this ability.
Types of Alexia
Although alexia implies the loss of reading ability, it does not always appear in the same way, and there may also be other problems or based on different deficits. Among the main types we can find
1. Alexia pure or without agraphia
This type of alexia is one in which only severe difficulties or complete impossibility appear in the visual recognition of letters or words, while the subject is nevertheless able to write correctly (despite not being able to understand what they have written). Also called word blindness It is possible that some frequently used single words for the subject will be recognized.
It is not the most common, since it usually involves bilateral involvement such that visual information cannot pass to the areas that interpret and generate language, in the left hemisphere. It usually corresponds to problems in the occipital area of the brain in the fusiform, lingual and/or angular turns, or the uncus.
2. Central Alexia or with agraphia
As in the previous case, we find an alteration and impossibility or great difficulty in the recognition of written words, but also in their production. In other words, in this case we find that the subject cannot read or write. Anomia may also occur having problems when identifying objects and visual stimuli beyond reading and writing.
This type of alexia usually corresponds to lesions in the angular gyrus, which is responsible for processing information in such a way that spelling or letters are converted to phonemes or sounds and vice versa, something necessary for both reading and writing. It is also related to lesions in the parietal muscles or in the fibers coming from the temporal and occipital lobes.
3. Alexia anterior or with aphasia
Also called frontal alexia, we are faced with a circumstance in which not only alterations occur at the reading level but also in speech production. In this case the injury is generally produced at a more frontal level, its functionality being similar to that of a subject with Broca’s aphasia It is usually common for there to be fewer problems with words familiar to the subject than compared to the rest of the alexias.
Differentiation from other situations
It is important to keep in mind that in alexia we are facing a situation in which the subject already knew how to read previously and there has been a loss of said ability, with cases of those people who have never learned to do so not being considerable as alexia, that is, illiteracy.
It is also relevant to differentiate it from developmental dyslexia which would be that neurodevelopmental disorder (which implies that at the neuronal level what exists is an atypical organization of brain development and not a lesion per se) in which a difficulty in reading and writing appears since childhood and in which it never occurs. there has been a greater degree of capacity than the subject expresses at that moment (not being a loss but rather a difficulty).
Finally, it should be noted that alexia is not derived from the absence of visual perception Strictly speaking: the subject can see the words and their eyes function with sufficient precision to perceive them, the problem being the encoding and transformation of these into something meaningful.
Possible causes
Alexia is considered to be a type of agnosia and a reading and writing disorder generated by some type of brain injury. But the causes of said injury can vary greatly. It must also be taken into account that the lesion can appear in different locations of the nervous system, from the angular and/or supramarginal gyri to the fibers coming from the occipital or temporal lobes, passing through the lingual and fusiform gyri among others. Among the main causes of the appearance of alexia we can find the following events.
1. Stroke
One of the main causes of alexia is suffering from some type of cerebrovascular accident or stroke, we are talking about ischemia (blockage of the blood vessel that prevents blood from reaching certain areas) or hemorrhage (rupture of the vessel). Depending on the affected areas, Brain tissue death can lead to loss of reading ability
2. Head trauma
Another classic reason for the appearance of alexia is the fact of having suffered some type of traumatic brain injury. Traffic accidents, work accidents or attacks are some of the causes that cause some type of alexia to appear.
Alexia can appear during the deterioration generated by some type of dementia, such as Alzheimer’s, or other similar disorders. Depending on the disorder itself, the difficulty, worsening and impossibility of reading can appear in different phases of the disease
4. Brain tumor
Another possible cause of alexia is found in the appearance of brain tumors that affect, pinch or compress the brain areas and nerve fibers involved in the reading process
5. Brain infections
Alexia can also appear when faced with certain infectious processes that end up affecting the brain. Some typical ones are meningitis or encephalitis
Alexia treatment
The treatment of alexia is not simple, taking into account that we are facing a phenomenon derived from some type of brain injury, and in fact we may be facing 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 its implementation will require a multidisciplinary team in which disciplines such as neurology or psychology work in addition to other health or even social specialties.
The first thing will be to determine and treat the cause of the appearance of alexia. For the most part, an early diagnosis will allow better work at the treatment level and can prevent worsening (for example, if we are dealing with an infection or a tumor, these can grow and cause more damage).
It will be necessary employ an individualized rehabilitation program, the use of language therapies and different types of cognitive stimulation being common. Psychoeducation will also be important for both people and their environment, so that they can understand what has happened and know how to apply different means so that difficulties do not become a limitation. It may also be important to work on the emotional sphere, self-concept and self-esteem, which can be altered by the presence of deficits.
