The 6 types of aphasia (causes, symptoms and characteristics)
The term language refers to the selection and arrangement of words according to the rules . When this language is produced orally or verbally, a series of acquired skills is needed, both at the vocal, auditory, visual and motor levels; in order to achieve a correct communication.
However, when a person suffers some type of brain injury aphasias may appear, which in the strict sense are disorders in the use of language, accompanied by a speech disorder.
However, there are different types of aphasias according to the brain areas injured; as well as according to what symptoms the person presents.
- Recommended article: "Aphasias: the main language disorders"
What is aphasia? Definition and causes
Mainly, aphasia is the total or partial inability to use language . The deficits related to the different types of aphasia range from word problems to complete inability to speak.
Likewise, the different aphasias also include problems in written language, oral comprehension, reading or having to operate with numbers. In other cases, people have deficits in oral expression but retain their ability to understand intact. That is why it is necessary to detect in each patient what specific speech and language alterations are under way so that an adapted treatment can be elaborated.
The causes of aphasia are varied, but all occur in circumstances of brain injury:
- Cranioencephalic trauma
- Tumors of the central nervous system
- Stroke (most common cause of aphasia)
- Degenerative diseases (Alzheimer's disease, Parkinson's disease, etc.)
- Localized or diffuse brain infections
Types of aphasia
The symptomatology of aphasias depends both on the location of the brain lesions and on the compensatory reactions of the brain tissue that remains intact.
However, there is a series of common brain lesions that seem to group certain dysfunctions.
1. Broca's aphasia or major motor aphasia
In Broca's aphasia, deficits in the motor aspects of language and writing predominate, it is also accompanied by amatism and, in many cases, language comprehension disorders. Occasionally, sensory problems may appear on the right side and hemiparesis, which refers to a decrease in motor force or partial paralysis that affects only one arm or one leg on the same side of the body.
This aphasia is the consequence of a large lesion that includes the cortical and subcortical elements along the frontal and superior portion of the Sylvian fissure, also including the insula; but its name comes from the implication that the lower frontal gyrus or Broca's area has in this disorder.
The most common causes of Broca's aphasia can be:
- Embolic occlusion of the upper division of the left middle cerebral artery
- Abscess of the frontal lobe
- TumorHuman's Hypertensive Bleeding
- Metastatic lesions
- Subdural hematoma
During the evolution of Broca's aphasia the patient can be in acute or subacute phase . During the acute phase, the patient is practically mute, unable to understand and unable to communicate; As the patient progresses, comprehension begins to improve, while deficits in language and writing persist. As he gets better, he is able to speak loudly, not without a lot of slowness and effort.
The articulation and the intonation also are affected, reason why the language becomes mainly a discourse of names and adjectives in which the functional words like the articles, prepositions or conjunctions are omitted; becoming an agramatical and telegraphic language.
After the acute and subacute phases, speech difficulties may persist. But nevertheless, a therapy in which the language is worked can significantly improve the patient's condition .
Finally, due to the paralysis of the right hand, many patients can not continue writing with it; so it requires a reeducation of writing with the left hand or take advantage of new technologies to enable communication.
2. Motor transcortical aphasia
This aphasia manifests problems similar to those of Broca's aphasia. The main difference is that transcortical motor aphasia there is a deficit in the production of speech, especially when starting a speech , in the spontaneity or in the organization of this.
The articulatory aspect of speech does not usually present difficulties and the understanding 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 due to the fact that the genesis of the disorder is due to a small subcortical lesion above Broca's area. At present, the involvement of a circuit from the supplementary motor area is suspected, through the subcallosus fasciculus to the basal ganglia and the Broca area.
3. Wernicke's aphasia
Wernicke's aphasia is characterized by a fluid speech but with a large number of substitutions and paraphasias , along with difficulties in understanding.
During the subacute phase, the understanding of language is often very deteriorated in severe cases, reaching absolute misunderstanding. However, speech is easy, clear and correctly articulated, and the outline of the rhythm is similar to that of normal speech. After these phases, listening comprehension usually improves and paraphasia is reduced.
Compared with 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 that patients can write, even though the content is disorganized and confusing, as is speech.
4. Driving aphasia
In this syndrome what is seriously damaged is repetition . Driving aphasia is a fluid aphasia with an almost normal understanding; but in which, in serious cases, the fluidity is seriously compromised due to problems in the production of isolated words; thus becoming a sequential speech and short sentences.
Traditionally, it has been believed that this aphasia appeared as a consequence of a lesion in the fibers that connect the areas of Broca and Wernike. But it has been discovered that there is also a relationship with lesions in the superior temporal gyrus and in the insula.
In addition to the difficulties in repetition, these patients present problems when selecting words and in phonemic sequencing within individual words.
5. Global aphasia
People suffering from global aphasia suffer from severe speech disorders, including problems of fluency and comprehension ; so the communication is affected very strictly.
The most common cases are that patients only manage to say a few words and their understanding of language is also very limited, since they can not read or write either.
The most frequent cause of global aphasia is a lesion that destroys most of the speech-related areas of the dominant hemisphere and is caused by obstruction of the left internal carotid artery or the middle cerebral artery.
6. Amnesic or anomic aphasia
Since anomie is a common characteristic of fluid aphasia, Wernicke's and driving aphasia, only anomic aphasia will be discussed when the difficulty of finding commonly used words appears relatively isolated .