Primary progressive aphasia (PAD): causes and symptoms

One of the definitions of language is that of the human being’s own ability to use to express thoughts and feelings through the word. Unfortunately, there are cases where this ability is truncated. One of these cases is aphasia, which is known to turn off speech.

A rare type of aphasia is primary progressive aphasia (PPA). which is characterized by progressive degeneration of speech ability in patients who retain the remainder of their cognitive, instrumental or behavioral abilities relatively intact.

    Causes of primary progressive aphasia

    Primary progressive aphasia (PPA), also called Meixul·las’s aphasia, it is a neurodegenerative disease which materializes in a pathology of the linguistic domain.

    This develops gradually and occurs in people who do not suffer from any other alterations in other cognitive areas, or experience behavioral alterations or are limited to carrying out their daily activities.

    During the early stages of the development of the disease, the patient is completely autonomous in terms of performing any task, but the degenerative course of this pathology ultimately leads to generalized dementia.

    Unlike what happens with secondary aphasias, primary aphasias do not seem to have a specific origin or cause. However, some 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:

    • Left inferior frontal and insular atrophy in grammatical APP
    • Bilateral anterior temporal atrophy with predominance to the left in the semantic variant
    • Left temporoparietal atrophy in the speech therapy variant

    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, each of them is associated with a functional anatomical pattern.

    These variants are the agrammatic / non-fluid variant, the semantic variant and the speech-language pathogen variant.

    1. Agrammatic variant

    This variant is characterized to appear in the form of a very difficult speech and a completely agrammatic production.

    To clarify this concept, it should be noted that agrammatism consists of the emission of short sentences with a very simple structure; by omitting functional expressions, which are those that serve as a link between words.

    The first symptom of the disease tends to be difficulty planning to speak. Which is starting to get slow and very laborious.

    Some minor grammatical errors can be detected early by applying oral production tests. Wherein patients with APP usually make mistakes in sentences with complex grammatical construction.

    2. Semantic variant

    Also called semantic dementia, in which the patient has enormous difficulty naming an object or thing; exhibiting normal exercise in the rest of the linguistic functions, at least at the onset of the disease.

    During illness, semantic memory gradually deteriorates, while further difficulties arise in understanding the meaning of objects. These difficulties in identifying and accessing knowledge arise regardless of the sensory modality in which the stimuli are presented.

    There is usually a gradual decrease in the body of knowledge that the patient has about the world around him.

    3. Variant of speech therapy

    It is considered the least common variant of the three, which has two characteristics:

    • Difficulty accessing vocabulary
    • Errors in repeating sentences

    The clearest way of examples of this type of aphasia is to represent it as the constant feeling of “having something on the tip of the tongue”. The patient does not suffer from agrammatism, but has recurring difficulties finding the words he is looking for; presenting, in addition, errors of a phonological type.

    This last point raises the suspicion that patients with primary progressive aphasia also present with impaired phonological memory; because understanding single words and short sentences is correct, but difficulties arise when interpreting long sentences.

    Diagnosis: criteria of mesulam

    There are two distinct steps to making a diagnosis of primary progressive aphasia:

    1. Patients should meet the characteristics of Meixul·lam for APP without considering any specific variant.
    2. Once APP is diagnosed, it will be determined which variant it is by evaluating linguistic cognitive processes.

    Mix of criteria by APP

    These criteria described by Meixul·lam in 2003 take into account both diagnostic inclusion and exclusion criteria. These criteria are as follows:

    • The language becomes a slow and progressive speech. As much when naming objects, as in syntax or in oral comprehension.
    • Other activities and functions that do not involve intact communication skills.
    • Aphasia is the most important deficit at the onset of the disease. Although other psychological functions can be affected during this operation, the tongue is damaged the most from the start.
    • APP is excluded if there is a stroke, tumor or trauma-related trauma in the patient’s history.
    • If there are any weird behavior changes that are more obvious than aphasic disorder, APP is dropped.
    • If there are significant alterations in episodic memory, non-verbal memory, or visuospatial processes, APP will not be considered.
    • In the presence of symptoms of Parkinson’s disease such as stiffness or tremor is excluded in the APP.


    There is no cure or medicine for APP. However, there are speech therapies that help improve and maintain the patient’s communication skills.

    These therapies focus on the person’s efforts to compensate for the deficiency in language skills.. This way, although the course of the disease cannot be stopped, the condition can be controlled.

    Evolution and prognosis

    Although APP can occur at a wide range of ages, it is more likely to occur in people between the ages of 50 and 70.. As mentioned above, there is currently no cure for APP, so the prognosis for this disease is demoralizing.

    Once the disease sets in, this aphasic disorder tends to progress to severe cases of mutism. But unlike other dementias, the patient becomes dependent much later.

    As for 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 cognitive, behavioral, extrapyramidal alterations, etc. However, it is not known how often dementias become common during the course of the disease.

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