One of the definitions of language is the ability of the human being to express thoughts and feelings through words. Unfortunately, there are cases in which this ability is truncated. One of these cases is aphasia, which is known to disable people from speaking.
A rare type of aphasia is primary progressive aphasia (PPA) which is characterized by a progressive degeneration of speech capacity in patients who maintain the rest of their cognitive, instrumental or behavioral abilities relatively intact.
Causes of primary progressive aphasia
Primary progressive aphasia (PPA), also called Mesulam aphasia, It is a neurodegenerative disease that materializes in a pathology of the linguistic domain
This develops gradually and occurs in people who do not suffer any other alterations in other cognitive areas, nor do they experience behavioral alterations or are limited in carrying out their daily activities.
During the early stages of the disease’s development, the patient is completely autonomous in achieving any task, however the degenerative course of this pathology eventually leads to generalized dementia.
Unlike what happens with secondary aphasias, primary aphasias do not seem to have a specific origin or cause. Even so, certain studies have attempted to detect the presence of atrophy patterns associated with this aphasia. Through the use of magnetic resonance imaging, atrophies characteristic of each of the types of aphasia have been observed:
Types of primary progressive aphasia
Researchers in this field detail three variants of this type of aphasia in which, as mentioned in the previous section, a functional anatomical pattern is associated with each of them.
These variants are the agrammatical/non-fluent variant, the semantic variant and the logopenic variant.
1. Ungrammatical variant
This variant is characterized by presenting itself in the form of very difficult speech and completely agrammatic production.
To clarify this concept, it should be noted that agrammatism consists of the emission of short phrases with a very simple structure; omitting functional expressions, which are those that serve as a link between words.
The first symptom of the disease tends to be difficulty in planning speech Which begins to become slow and very laborious.
Certain minor grammatical errors can be detected early by applying oral production tests. In which patients with PPA generally make some errors in sentences with a complex grammatical construction.
2. Semantic variant
Also called semantic dementia, in which the patient has enormous difficulties when naming any object or thing ; presenting normal performance in the rest of the linguistic functions, at least at the beginning of the disease.
During the course of the disease, semantic memory gradually deteriorates, while other difficulties appear in understanding the meaning of objects. These difficulties when identifying and accessing knowledge occur regardless of the sensory modality in which the stimuli are presented.
Generally, there is a gradual decrease in the set of knowledge that the patient has about the world around him.
3. Logopenic variant
It is considered the least common variant of the three, which presents two characteristic features:
The clearest way to exemplify this type of aphasia is to represent it as the constant sensation of “having something on the tip of your tongue.” The patient does not suffer from agrammatism, but You encounter recurring difficulties when finding the words you are looking for; also presenting phonological errors
This last point raises the suspicion that patients who suffer from primary progressive aphasia also present a deterioration in the phonological store; since the understanding of isolated words and short phrases is correct, but difficulties appear when interpreting long phrases.
Diagnosis: Mesulam criteria
There are two different stages when making a diagnosis of primary progressive aphasia:
- Patients should meet the characteristics of Mesulam for PPA without considering any specific variant.
- Once APP has been diagnosed, it will be determined which variant it is by evaluating the cognitive-linguistic processes.
Mesulam Criteria for the PPP
These criteria described by Mesulam in 2003 take into account both diagnostic inclusion and exclusion criteria. These criteria are the following:
Treatment
There is no cure or medication for PPA. However, there are speech therapy therapies that help improve and maintain the patient’s communication ability.
These therapies focus the person’s effort on compensating for the deterioration of language skills In this way, although the evolution of the disease cannot be stopped, the condition can be controlled.
Evolution and prognosis
Although PPA can occur in a wide age range, it is most likely to occur in people between 50 and 70 years old As mentioned above, there is currently no cure for PPA, so the prognosis for this disease is somewhat demoralizing.
Once the disease has established itself, this aphasic disorder tends to progress in such a way that it ends up leading to severe cases of mutism. But unlike other dementias, the patient becomes dependent much later.
Regarding the presence of other additional deficits, language is the only clinical manifestation or, at least, the most predominant. But if there are cases of other alterations at a cognitive, behavioral, extrapyramidal level, etc. However, it is unknown how often generalized dementia appears during the course of the disease.