The term language refers to the selection and order of words according to the rules. When this language is produced orally or verbally, a series of acquired skills are necessary, at the vocal, auditory, visual and motor levels at the same time; to be able to achieve correct communication.
However, when a person suffers from a certain type of head trauma, aphasias may appear which, in the strict sense, are disturbances in the use of language, accompanied by a speech impediment.
However, there are different types of aphasia depending on the areas of the brain damaged; as well as according to the symptoms that the person presents.
What is aphasia Definition and causes
Primarily, aphasia is the total or partial inability to use the tongue. The deficits associated with different types of aphasia range from problems with word search to complete inability to speak.
Likewise, the various aphasias also include problems with written language, listening comprehension, reading or having to operate on numbers. In other cases, people have deficits in speaking but keep their ability to understand intact. For this reason, it is necessary to detect in each patient to whom specific alterations in speech and language are subjected in order to be able to develop an appropriate treatment.
The causes of aphasia are varied, but all occur under circumstances of brain injury:
- traumatic brain injury
- Central nervous system tumors
- Stroke (most common cause of aphasia)
- Degenerative diseases (Alzheimer’s disease, Parkinson’s disease, etc.)
- Localized or diffuse infections of the brain
Types of aphasia
The symptoms of aphasia depend both on the location of the brain damage and on the compensatory reactions of the brain tissue which remains intact.
However, there are a number of common brain injuries that seem to group together certain dysfunctions.
1. Pierce aphasia or major motor aphasia
In Broca’s aphasia, deficits predominate in the motor aspects of language and writing, they are also accompanied by agrammatism and in many cases impaired understanding of language. Sometimes sensory problems can appear on the right side and hemiparesis, which refers to a decrease in driving force or partial paralysis that affects a single arm or a single leg on the same side of the body.
This aphasia is the consequence of a large lesion that includes cortical and subcortical elements along the frontal and upper part of Silvio’s cleft, including the insula; but its name comes from the involvement of the inferior frontal gyrus or the region of Broca in this disorder.
The most common causes of Broca’s aphasia can be:
- Embolic occlusion of the superior division of the left middle cerebral artery
- Frontal lobe abscess
- Hypertensive bleeding from putamen
- metastatic lesions
- Subdural hematoma
During the course of Broca’s aphasia, the patient may be in the acute or subacute phase. During the acute phase, the patient is practically dumb, unable to understand and unable to communicate; suffer more from a strong emotional impact. As the patient progresses, comprehension begins to improve, while language and writing deficits persist. As this improved, he was able to speak aloud, not without a great deal of slowness and effort.
Articulation and intonation are also affected, so that language becomes primarily a discourse of nouns and adjectives in which functional words such as articles, prepositions or conjunctions are omitted; to become an agrammatic and telegraphic language.
After the acute and subacute phases, speech difficulties may persist. however, a therapy in which the language is worked can significantly improve the patient’s condition.
Finally, due to paralysis of the right hand, many patients cannot continue to write with it; it is therefore necessary to re-educate writing with the left hand or to take advantage of new technologies to enable communication.
2. Transcortical motor aphasia
This aphasia manifests similar problems to those of Broca’s aphasia. The main difference is that Transcortical motor aphasia has a deficit in speech production, especially during speech initiation, In spontaneity or in its organization.
The articulatory aspect of speech does not generally present any difficulties and the comprehension of language remains intact, as does the production of names of places and people.
The cause of problems similar to those of Broca’s aphasia may be that the genesis of the disorder is due to a small subcortical lesion above the Broca region. Currently, the involvement of an additional motor zone circuit is suspected, through the sub-calling fascicle to the basal ganglia and the drill zone.
3. Wernicke’s aphasia
Wernicke’s aphasia is characterized by fluent speech but with a large number of substitutions and paraphrases., With difficulty in understanding.
During the subacute phase, language comprehension is often severely impaired in severe cases, leading to absolute misunderstanding. However, speech is easy, clear and well articulated, and the outline of the rhythm is similar to that of normal speech. After these phases, hearing comprehension generally improves and paraphasia is reduced.
Compared to Broca’s aphasia, functional words are present in Wernicke’s aphasia, but there are semantic and grammatical confusions. In addition, in this type of aphasia, the motor area is intact so there is no paralysis on the right side, so patients can write, even if the content is disorganized and confusing, just like speaking.
4. Motor aphasia
In this syndrome, what is severely impaired is the repetition. Motor aphasia is fluid aphasia with almost normal comprehension; but in which, in severe cases, fluency is severely compromised due to problems in producing single words; thus becoming a sequential speech and short sentences.
It is traditionally believed that this aphasia appears as a result of injury to the fibers connecting the Broca and Wernike regions. But it was found that there is also a relationship with injuries in the superior temporal gyrus and in the insula.
In addition to repetition difficulties, these patients have problems with word selection and phonemic sequencing within individual words.
5. Global aphasia
People with global aphasia suffer from severe speech problems, including problems with fluency and comprehension.; so the communication is affected very strictly.
The most common cases are those that only patients can say, a few words, and their understanding of the language is also very limited, as they cannot read or write.
The most common cause of global aphasia is an injury that destroys much of the speech-related areas of the dominant hemisphere and is caused by obstruction of the left internal carotid artery or cerebral artery.
6. Amnesic or anemic aphasia
Since anomie is a common feature in fluids, Wernicke’s aphasia and conduction aphasia, only anomic aphasia will be discussed. when the difficulty of finding commonly used words appears relatively in isolation.
- Kuljic-Obradovic, DC (2003). Subcortical aphasia: three different syndromes of speech disorder ?. European Journal of Neurology. 10 (4): 445-8.