The Global aphasia Is characterized primarily by an inability to convert thoughts into language, as well as difficulties in understanding the verbalizations of others.
This type of aphasia is serious deficiencies for the individual, as it presents both expressive and receptive alterations of the language. This supposes a generalized affectation of the communication, occupying anterior and posterior perisilvian areas.
Prevalence of global aphasia
This disorder appears to be relatively frequent, ranging from 25% to 32% of those affected by aphasia in the acute phases of a Stroke .
However, after a year the percentage drops significantly. For example, in the Copenhagen Stroke Study the percentage decreased to 11%.
Causes
Its main cause is stroke (stroke), as are other types of aphasia. In fact, in the acute phase of stroke it is estimated that between 20 and 30% of people present some type of aphasia. The percentage is higher the less time has passed after brain damage.
Usually, the left hemisphere Or dominant is the one that is most related to language. Therefore, lesions in the left brain areas that produce and receive language are those associated with this pathology (Nieto, Barroso, Galtier and Correia, 2012).
The damages cover the Areas of Broca and of Wernicke , Necessary both for understanding and expressing language, accessing words, using grammar and constructing phrases (National Aphasia Association, 2016).
Global aphasia appears to be due to strokes that extensively affect the middle cerebral artery of the left hemisphere. The entire perisilvian area of this hemisphere is altered, covering the inferoposterior region of the Frontal lobe , the Basal ganglia , the Auditory cortex , the Insula And posterior areas of the Temporal lobe .
Less commonly, it may also occur due to subcortical lesions of the left hemisphere, hemorrhagic or Ischemic :, Affecting the thalamus, basal ganglia, Internal capsule , Periventricular white matter and temporal isthmus (connections that arrive from other areas towards the temporal cortex).
How does it manifest?
- Speak little and when you do, you do it with effort and lack of fluency. The way of speaking is known as"telegraphic speech".
- Lack of comprehension both oral and written, understanding only a few words, verbs or expressions.
- Repeated words and phrases altered.
- Poor reading and writing.
- Almost immediately after the injury, the patient may present complete mutism. This means that it does not emit any verbal content. As time goes on, she is able to speak.
- Failure to name people, objects or animals.
- Propositional or voluntary speech is limited to a few simple words or phrases, which are sometimes repetitive or stereotyped. Kertesz in 1985 describes the case of a patient with global aphasia who only repeated the word"cigarette"even though he was asking for water. This author believes that he could influence that the patient was a tobacco addict.
- However, stereotypes (repeated vocal utterances with no specific purpose) that are not real words or contain no content may be present; Calling attention to how well they pronounce them. However, contrary to what can be believed, the type of stereotypy (whether real or not) does not indicate that the case is more serious or that there is a poor prognosis.
An example is seen in the case presented by Nieto, Barroso, Galtier and Correia (2012), in which the patient with global aphasia presents a stereotypy consisting of always repeating"that you, that you, that you."
- Normally, the lesion produced by aphasia also causes alterations in somatosensory and movement areas, which can lead to Hemiplegia (When half of the body is paralyzed by lesions located in the opposite hemisphere) or Hemiparesis (Equal but slight) and Hemihypesthesia (Lack of sensitivity in the middle of the body), in addition to Hemianopsia (The person only sees half of his field of vision).
- They may also appear Apraxia , Which are problems for movements that are not related to physical damage, but brain damage. They are mainly bucofacial or ideomotor.
- Global aphasia may be accompanied by other problems such as apraxia of speech, alexia , Pure deafness for words, Print , Or facial apraxia.
- Apathy or depression is common.
- The little communication that they establish is thanks to simple automated expressions that are emitted with the correct intonation, like"damn!".
- Automated verbal series such as days of the week, months, numbers or letters of the alphabet are usually kept (and spoken fluently). It is believed to be due to the intact activity of the right hemisphere (the one normally preserved, since damage to the left hemisphere appears to be the cause of language problems).
- The ability to make gestures to communicate or use the correct intonation is also related to the conservation of the right hemisphere.
- They have completely preserved the intellectual capacity that is not associated with linguistic aspects (National Aphasia Association, 2016).
- They are usually oriented, attentive and have socially appropriate behaviors (Brookshire, 2007).
- They can respond with monosyllables as"yes"or"no". They respond best if asked about personal experiences or family issues.
- They are able to recognize real object names or locations, just as they know when they are saying non-real words or even detect an incorrect word for that situation (Wapner & Gardner, 1979).
Types
You can distinguish:
- Classical global aphasia Which is the one discussed here, which is accompanied by motor problems such as hemiparesis or hemiplegia, since the lesions usually occupy motor and somatosensory regions. This is why it also frequently presents with hemi-anesthesia and hemianopsia (described above).
- Global aphasia without hemiparesis (GAWH), which has been underdeveloped lately and appears to be caused by, among other things, Cerebral embolisms Which produce noncontiguous damage in anterior and posterior perisilvian areas.
How does it evolve?
Compared with other types of aphasia, global aphasia has the worst prognosis (Nieto, Barroso, Galtier and Correia, 2012).
In the first months, the symptoms are improving drastically. This is called spontaneous recovery, and much more is noted if the damage is not very extensive (National Aphasia Association, 2016).
Generally, the evolution of this type of aphasia is not very favorable, especially if the diagnosis is late. As indicated by Nieto, Barroso, Galtier and Correia (2012) if diagnosed during the first week after injury, 15% of the subjects at the end of one year recover from aphasia.
These same authors indicated that 22% can be maintained with slight improvements, 35% evolve to a Aphasia of Broca , Anomic aphasia (22%) or very rarely, to a Wernicke's aphasia (7%).
A study by Oliveira and Damasceno (2011) found that global aphasia could be a predictor of mortality after an acute stroke, indicating that this condition negatively affected the prognosis.
When it is of the classic type it occurs along with hemiplegia or hemiparesis, hemihipoestesia and hemianopsia. The severity and duration of these associated problems will affect the prognosis of aphasia, making it more severe and difficult to recover.
On the other hand, Smania et al. (2010) wanted to observe how the evolution of global aphasia is in a long-term patient (25 years). They found three important stages in recovery: one year after stroke, where verbal understanding and word repetition were restored; Over 1 to 3 years later, improved naming and reading; And from 3 to 25 years spontaneous speech emerged in addition to increasing performance in the tasks mentioned.
Nevertheless, patients with aphasia treated adequately present significant improvements in their communicative skills and linguistic tasks.
How is it evaluated?
Global aphasia is evaluated in a similar way to other forms of aphasia, that is, with various tests that cover as much as possible aspects of language and cognitive abilities (to rule out other problems).
The most widely used to assess language skills in aphasia is the Boston Test for the diagnosis of aphasia. It consists of subtests that measure fluency in expressive language, listening comprehension, naming, reading ability, repetition, automatic speech (such as emitting automated sequences and reciting), and reading comprehension.
It is also used for the Western Aphasia (WAB) Battery, which values both linguistic and non-linguistic abilities. Among the former are speech, fluency, listening, repetition, reading and writing; While non-linguistic ones examine drawing, calculus, praxis, and visuospatial tasks.
It also values praxias, memory And visoperceptive functions.
The frontal functions, which are related to impulsivity, planning capacity, categorization and flexibility of cognitive strategies, can often be affected. They can be evaluated with tests such as the Porteus Labyrinth, Wisconsin Card Classification Test, or the Tower of Hanoi.
These tests can also be used to see if rehabilitation has or has not changed the patient.
Treatment
There is no single treatment for global aphasia. The main objective will be to improve the adaptation to the environment and the quality of life to the maximum. For this, agreements must be reached through the multidisciplinary collaboration of speech therapists, neuropsychologists, physiotherapists and occupational therapists, in addition to the support of the family.
Rehabilitation should be designed for the individual's unique and personal capacities and situation, that is, it has to be personalized.
- Speech and language therapy To improve communication with other people and the quality of life.
- Group Therapies: May be useful in patients with global aphasia, since their social skills are often intact. Thus, they perform simple activities or games that promote social communication.
- Visual Action Therapy (TAV): Is a program that enhances the use of symbolic gestures for communication and reduces apraxia. However, it does not improve verbal expression. For this reason, Ramsberger and Helm-Estabrooks in 1989 designed the orthodontic AVT program, in which they introduced stimuli involving facial and oral movements to perform the gestures. It consists of 3 levels: the first includes the manipulation of real objects, drawings of objects and action images, the second only uses action images and the third only objects.
- Educate caregivers and family So that they learn to communicate with the affected. The most used strategies are: to simplify phrases, to use words that are very used, to capture the attention of the person before speaking to him, to use signs, to leave a time for the person to respond and to try that the communication takes place in a calm and Without distractions (Collins, 1991).
- Use of computers and new technologies Focused on improving language, especially reading and the ability to remember words. In a study by Steele, Aftonomos, & Koul (2010) it was found that the use of a speech-generating device decreased the deterioration associated with chronic global aphasia, improving communication and quality of life.
- Influence on recovery the Level of motivation And aspects of personality (Brookshire, 2007).
Important Tips for Treating Aphasia
It is important to distinguish between language and intelligence, since many people may believe that speech difficulties are due to deficits in intellectual abilities.
This is not so, it should be noted that there are Cognitive abilities Completely preserved, only that these people do not know how to express what they think. For example, they can have independent living, travel alone, retain opinions and have a memory for faces just like before the problem.
Try to provide a means for people with aphasia to express what they want, avoiding frustration and isolation.
Some techniques the family can use to facilitate communication can be: using closed-ended questions (which can be answered with"yes"or"no"), paraphrasing the conversation, using simpler phrases, trying to make conversation less , Use gestures to emphasize important content, say which subject is going to be spoken before the conversation starts, and so on.
It seems that it is simpler to start rehabilitation at the beginning with a single person who understands this disorder and with whom the patient is comfortable. Little by little, as you improve, add more partners until you end up talking to small groups of people.
A quiet environment is best without distractions, noises or other conversations in the background.
Better to discuss common and useful topics that are used in everyday life; Or current events.
The supervised practice of conversations is useful, without tiring the affected.
Other possible channels of communication can be created if it is of very serious type. The important thing is that this person can understand the language and express it, even if he can not speak or write.
References
- Brookshire, R.H. (2007). Introduction to neurogenic communication disorders (Seventh edition.). St. Louis, Mo.: Mosby Elsevier.
- Collins, M., (1991). Diagnosis and Treatment of Global Aphasia. San Diego, CA: Singular Publishing Group, Inc.
- Global Aphasia . (S.f.). Retrieved on June 22, 2016, from the National Aphasia Association
- Kertesz, A. (1985). Aphasia. In: Frederiks J.A.M., ed. Handbook of clinical neurology, vol 1. Clinical Neuropsychology. (Pp. 287-331). Amsterdam: Elsevier.
- Nieto Barco, A., Barroso Ribal, J., Galtier Hernández, I. and Correia Delgado, R. (2012). Chapter 12: Global Aphasia. In M. Arnedo Montoro, J. Bembibre Serrano and M. Triviño Mosquera (Ed.), Neuropsychology through clinical cases. (Pp. 151-161). Madrid: Medical Editorial Panamericana.
- Oliveira, F.F. & Damasceno, B. P. (2011). Global aphasia as a predictor of mortality in the acute phase of a first stroke. Neuro-Psychiatry Archives, (2b) , 277.
- Smania, N., Gandolfi, M., Girardi, P., Fiaschi, A., Aglioti, S., & Girardi, F. (2010). How long is the recovery of global aphasia? Twenty-five years of follow-up in a patient with left hemisphere stroke. Neurorehabilitation And Neural Repair, 24 (9), 871-875.
- Steele, R., Aftonomos, L., & Koul, R. (2010). Outcome improvements in persons with chronic global aphasia following the use of a speech-generating device. Acta Neuropsychologica, 8 (4), 342-359
- Types of Aphasia . (March 6, 2015).
- Wapner, W., & Gardner, H. (1979). A note on patterns of comprehension and recovery in global aphasia . Journal of Speech and Hearing Research, 22 , 765-772.
- Western Aphasia Battery. (S.f.)