aphasia
American Heritage Dictionary:
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a·pha·sia
(ə-fā'zhə) 
n.
Partial or total loss of the ability to articulate ideas or comprehend spoken or written language, resulting from damage to the brain caused by injury or disease.
aphasic a·pha'sic (-zĭk, -sĭk) adj. & n.
n.
Partial or total loss of the ability to articulate ideas or comprehend spoken or written language, resulting from damage to the brain caused by injury or disease.
[Greek, from aphatos, speechless : a-, not; see a-1 + phatos, spoken, speakable (from phanai, to speak; see -phasia).]
aphasiac a·pha'si·ac' (-zē-ăk') n.aphasic a·pha'sic (-zĭk, -sĭk) adj. & n.
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aphasia
Britannica Concise Encyclopedia:
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aphasia
Defect in the expression and comprehension of words, caused by damage to the frontal and temporal lobes of the brain. It can result from head trauma, tumour, stroke, or infection. Symptoms vary with the brain area involved, and the ability to put words in a meaningful order may be lost. Speech therapy may be useful. In some cases, improvement may be due to assumption of some language functions by other areas of the brain.
For more information on aphasia, visit Britannica.com.
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Impairment in the use of spoken or written language caused by injury to the brain which cannot be accounted for by paralysis or incoordination of the articulatory organs, impairment of hearing or vision, impaired level of consciousness, or impaired motivation to communicate. The language zone in the brain includes the portion of the frontal, temporal, and parietal lobes surrounding the sylvian fissure and structures deep to these areas. In right-handed persons, with few exceptions, only injury in the left cerebral hemisphere produces aphasia. Lateralization of language function is variable in left-handers, and they are at greater risk for becoming aphasic from a lesion in either hemisphere. See also Hemispheric laterality.
Distinctive recurring patterns of deficit are associated with particular lesion sites within the language zone. These patterns may entail selective impairment of articulation, ability to retrieve concept names, or syntactic organization. Other dissociations affect principally the auditory comprehension of speech, the repetition of speech, or the recognition of written words. The erroneous production of unintended words in speech (paraphasia), oral reading (paralexia), or writing (paragraphia) is a feature of some forms of aphasia.
Mixed forms of aphasia, caused by multiple lesions or lesions spanning anterior and posterior portions of the speech zone, are quite common, and massive destruction of the entire language area results in a global aphasia. Further, individual variations in behavioral manifestations of similar lesions have set limits on the strict assignment of function to structures within the language area.
Preadolescent children suffering aphasia after unilateral injury usually recover rapidly, presumably by virtue of the capacity of the right cerebral hemisphere early in life to acquire the language functions originally mediated by the left hemisphere. Capacity for recovery of function decreases during later adolescence and young adulthood.
Complete recovery in adults after a severe injury is much less common, and severe aphasia may persist unchanged for the duration of the person's life. Many patients are aided by remedial language training, while others continue severely impaired. See also Memory.
Oxford Dictionary of Philosophy:
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aphasia
The disruption or total loss of the faculty of speech, often resulting from local damage to the left hemisphere of the brain. In ancient scepticism aphasia is the silence enjoined on us after we have suspended judgement on things.
Columbia Encyclopedia:
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aphasia
aphasia (əfā'zhə), language disturbance caused by a lesion of the brain, making an individual partially or totally impaired in his ability to speak, write, or comprehend the meaning of spoken or written words. It is distinguished from functional disorders such as stammering or stuttering, and from impaired speech due to physical defects in the organs used for speaking. Treatment consists of reeducation; the oral and lip-reading methods employed in the education of deaf and mute children have been found to be of assistance in therapy.
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Aphasia, a word proposed by Armand Trousseau to replace the term "aphemia," created by Paul Broca, refers to language disturbances that arise from specific cerebral lesions, most often in the cortex. Between 1861 and 1865, when the dispute ended concerning the question of determining whether the cerebral cortex operated as a unit or as a collection of separate elements, Paul Broca showed, through a series of anatomical and clinical observations, that the destruction of the left side of the base of the third circumvolution of the frontal lobe in a right-handed subject who until then was able to speak normally led to the loss of articulate language. The subject was unable to express himself using a sequence of words or phrases.
In 1874 Carl Wernicke extended the field of research by describing two other types of aphasia, all caused by a lesion in the left hemisphere: sensory aphasia from damage to the posterior areas of the second and third circumvolution of the cortex, and conduction aphasia, arising from the disconnection of the bundles connecting this region to the base of the third circumvolution of the frontal lobe. Afterwards, the disturbance identified by Broca would be known as "motor aphasia." Later Wernicke identified two other types of aphasia: "motor transcortical aphasia" and "sensory transcortical aphasia."
By the end of the nineteenth century, three separate approaches to the problem had been developed. Some researchers, such as Jean Martin Charcot and Joseph Grasset, increased the number of types of aphasia; others, like Alfred Vulpian, and later Pierre Marie, renewed the "unitarian" position; the third group, following the important work by Jules Déjerine, demonstrated through the use of clinical and anatomical arguments that the nature of the aphasia would change with the nature and location of the lesion. For example, frontal lesions seemed to primarily affect speech production, posterior lesions seemed to affect speech recognition, and the destruction of the cortex resulted in disturbances of internal language, which affected the subject's autonomy.
Sigmund Freud's work on aphasia, published in 1891, accepts the work of Paul Broca but questions Wernicke's research, which Freud criticizes for being excessively schematic and lacking in clinical observations. Freud did not question the relationship of language function with the brain but was cautious about hastily assigning specific locations to specific functions. Although he accepts that certain clinically based forms of aphasia—"verbal aphasia," "asymbolic aphasia," "agnosic aphasia"—can be used to localize the cortical lesion with certainty (which was later confirmed by neurosurgery during the First World War), he refused to extrapolate from pathology to physiology and deduced a cerebral concept of the normal operation of language, with a critical position that was far removed from the scientism that is often attributed to him in this field. In the descriptive sections of his work, Freud distinguished between the representation of words and the representation of things, and their links with auditory images, visual images, and the motor images at work in these phenomena.
Bibliography
Freud, Sigmund. (1891b [1953]), On aphasia (A critical study) (E. Stengel, Trans.). New York: International Universities Press.
Hécaen, H. and Lantéri-Laura, Georges. (1977).Évolution des connaissances et des doctrines sur les localisations cérébrales. Paris: Desclée de Brouwer.
——. (1989). Les fonctions du cerveau. Paris: Masson.
Lantéri-Laura, Geoerges. (1993). Histoire de la phrénologie. Paris: Presses Universitaires de France.
Further Reading
Miller, Laurence (1991). On aphasia at 100: the neuropsychodynamic legacy of Freud. Psychoanalytic Review, 78, 365-378.
Rizzuto, Anna-Marie. (1990). Origin of Freud's concept of object representation: "On Aphasia." International Journal of Psychoanalysis, 71, 241-248.
—GEORGES LANTÉRI-LAURA
Oxford Companion to the Mind:
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aphasia
The ability to talk may not, as was once thought, be the crucial factor that distinguishes humans from the animals, but loss of the power of speech is one of the most distressing things that can happen to a human being. Aphasia (the disruption of speech) commonly follows a stroke — especially if the stroke also impairs movement of the right arm or leg. The loss of articulated language is not always or necessarily accompanied by loss of other linguistic functions, like reading and writing. Least of all is it necessarily accompanied by loss of comprehension: a sufferer often knows that the words he is uttering are wrong, but he cannot correct or alter them ('Pass me the bread — no, not the bread the bread — no!'). However, where one of the linguistic skills is seriously disturbed, one or more of the others tends to be somewhat reduced as well. Neither does the disruption of speech mean that all aspects of it are obliterated, nor, even if it is seriously reduced in the early stages after the disrupting incident, that it can never be regained. But the recovery of abilities by an aphasic person does not follow the same principles of learning as the acquisition of learning a language by a normal, healthy child or adult. Asking the patient to repeat a word or phrase over and over again is not necessarily going to help him to say it later on; it is more likely merely to make him angry and depressed. Impairment of language does not necessarily imply loss of other faculties, such as intelligence or memory.
The three aspects of aphasia that have been studied most intensively are the manner in which speech breaks down, the causes of the breakdown, and treatment of and recovery from it.
1. The manner of breakdown
2. The causes of breakdown
3. Recovery
In non-fluent aphasia, the sufferer has difficulty finding words, particularly uncommon ones. He has difficulty naming objects, and his syntax is often faulty. He tends to talk hesitantly and gropingly, although he is often acutely aware of how stupid he sounds. The fluent aphasic, on the other hand, emits a stream of words the intonation of which is perfectly normal. Heard from a distance, they sound obscure or clever, but closer listening reveals meaningless jargon. Unlike the non-fluent aphasic, the fluent one seems undisturbed by, and even unaware of, his poor communication. In each of these conditions, concomitant disorders of reading, writing, and comprehension may be present in some degree, but are usually more severe in fluent than in non-fluent disorders.
An important factor relating to breakdown is the degree to which a person made use of language before his injury. Although after breakdown the words and phrases previously used most commonly can usually be found more easily than others, this does not necessarily mean that the first language of a bilingual or polyglot is the one best preserved: it is frequency of usage rather than recency that is important. Even so, there is a tendency for sufferers of non-fluent aphasia to emit swear words and taboo words when searching for those they cannot find. Here it is the words which have not been uttered in the past that appear before those which have. The reason for this is probably that inhibition or repression of an act gives it particularly strong emotional force, and the emotional aspects of mental behaviour are not controlled by the same areas of the brain as language. Indeed, they tend to be released when intellectual control is removed.
(a) Arousal of previous or common contexts. In most languages there are words that have different meanings in different contexts. In English, the word hand can be applied to a part of the human body, parts of a clock-face, a unit for the measurement of horses, a style of penmanship, a pledge of fidelity, a member of a ship's crew. The first usage here is undoubtedly the commonest, and aphasics can often name the body part when asked to do so, even when they cannot find the word 'hand' in its other contexts. However, once a word has been found in its most common context, it can often be found in others too ('Of course, those are called "hands", aren't they?').
(b) Narrowing of syntactical constraints. In most languages, words are uttered and understood in sequences rather than individually, and are controlled by those preceding them. For instance, in the sentence starting 'The man was bitten by — ', there is a limit to the choice of words that can follow. Narrowing the field of possibilities by such means seems to be very helpful to the aphasic patient, who can often find words if they form parts of familiar sentences (or song phrases) when not able to do so otherwise.
(c) The hesitancy seen in non-fluent aphasia is usually due to the patient's knowledge that the first words which occur to him are wrong and must be corrected. Yet if these words are uttered, they are usually far from random. Indeed, they tend to be closely related to the word being sought. They arise from the same semantic field or consist of functional descriptions of the object to be named ('They're the things that point to the time — the fingers — no, the pointers — no!').
Summing up, it seems that in non-fluent aphasia the difficulty is one of having lost not the ability to speak, but only the ability to find the right words at the right moment. Any stimulus that gives a 'lead in' to the general semantic field helps. After this, it is a matter of sifting through the various items until the target is found. (How one recognizes the target is a different problem, and although this ability seems to be intact in the non-fluent aphasic, it seems to be at fault in the fluent one, who does not try to inhibit or correct his 'near misses'.)
Experiments with normal, healthy humans indicate that the processes whereby they find and utter words are very similar to those seen in aphasia, but that the processes take place more quickly and efficiently. But rare words take longer to find than common ones, and if the sorting/sifting/correcting process is impeded by external factors (such as distraction) or internal ones (such as intoxication), 'near misses' of much the same sort as those given by the aphasic may be emitted.
(Published 2004)
The three aspects of aphasia that have been studied most intensively are the manner in which speech breaks down, the causes of the breakdown, and treatment of and recovery from it.
1. The manner of breakdown
2. The causes of breakdown
3. Recovery
1. The manner of breakdown
The different forms of breakdown can be classified in different ways, but most people nowadays consider just two major groups: non-fluent (or Broca's) and fluent (or Wernicke's), the names in parentheses being those of the neurologists who first described them. (See language: neuropsychology, for a fuller discussion.)In non-fluent aphasia, the sufferer has difficulty finding words, particularly uncommon ones. He has difficulty naming objects, and his syntax is often faulty. He tends to talk hesitantly and gropingly, although he is often acutely aware of how stupid he sounds. The fluent aphasic, on the other hand, emits a stream of words the intonation of which is perfectly normal. Heard from a distance, they sound obscure or clever, but closer listening reveals meaningless jargon. Unlike the non-fluent aphasic, the fluent one seems undisturbed by, and even unaware of, his poor communication. In each of these conditions, concomitant disorders of reading, writing, and comprehension may be present in some degree, but are usually more severe in fluent than in non-fluent disorders.
2. The causes of breakdown
Aphasia is caused by damage to tissue within the brain. But whether injuries to different areas of the brain cause different types of disorder, and whether the same patterns of disorder occur in all individuals, is less certain. Each hemisphere of the brain not only controls movement and sensation of the opposite side of the body, but seems to specialize in particular mental functions. (See neuropsychology.) It is the left hemisphere that seems to be most closely concerned with language, although in left-handed people and those with a family history of left-handedness the association is not so strong. Moreover it is not inevitable. People whose left hemispheres are damaged in early infancy or childhood can 'learn to speak' perfectly adequately with their right. By and large, however, it is damage to the left hemisphere that most commonly causes aphasia, that to the anterior part causing non-fluent disorders, and that to the posterior part causing those of the fluent type. It is sometimes held, though, that in fluent aphasia there is also usually some damage to the right or non-dominant hemisphere as well as to the left.An important factor relating to breakdown is the degree to which a person made use of language before his injury. Although after breakdown the words and phrases previously used most commonly can usually be found more easily than others, this does not necessarily mean that the first language of a bilingual or polyglot is the one best preserved: it is frequency of usage rather than recency that is important. Even so, there is a tendency for sufferers of non-fluent aphasia to emit swear words and taboo words when searching for those they cannot find. Here it is the words which have not been uttered in the past that appear before those which have. The reason for this is probably that inhibition or repression of an act gives it particularly strong emotional force, and the emotional aspects of mental behaviour are not controlled by the same areas of the brain as language. Indeed, they tend to be released when intellectual control is removed.
3. Recovery
The vast majority of aphasic people, especially in the younger age groups, recover a good deal of speech as time goes on; and a few of the more literary ones have written accounts of their experiences. Unfortunately these seldom contain information about how the faculties were regained, probably because such processes — like many other forms of learning and remembering — occur at a level that is not available to normal consciousness. Psychologists who have been able to watch and study these people have, however, identified several factors that seem to be involved, especially in non-fluent aphasia.(a) Arousal of previous or common contexts. In most languages there are words that have different meanings in different contexts. In English, the word hand can be applied to a part of the human body, parts of a clock-face, a unit for the measurement of horses, a style of penmanship, a pledge of fidelity, a member of a ship's crew. The first usage here is undoubtedly the commonest, and aphasics can often name the body part when asked to do so, even when they cannot find the word 'hand' in its other contexts. However, once a word has been found in its most common context, it can often be found in others too ('Of course, those are called "hands", aren't they?').
(b) Narrowing of syntactical constraints. In most languages, words are uttered and understood in sequences rather than individually, and are controlled by those preceding them. For instance, in the sentence starting 'The man was bitten by — ', there is a limit to the choice of words that can follow. Narrowing the field of possibilities by such means seems to be very helpful to the aphasic patient, who can often find words if they form parts of familiar sentences (or song phrases) when not able to do so otherwise.
(c) The hesitancy seen in non-fluent aphasia is usually due to the patient's knowledge that the first words which occur to him are wrong and must be corrected. Yet if these words are uttered, they are usually far from random. Indeed, they tend to be closely related to the word being sought. They arise from the same semantic field or consist of functional descriptions of the object to be named ('They're the things that point to the time — the fingers — no, the pointers — no!').
Summing up, it seems that in non-fluent aphasia the difficulty is one of having lost not the ability to speak, but only the ability to find the right words at the right moment. Any stimulus that gives a 'lead in' to the general semantic field helps. After this, it is a matter of sifting through the various items until the target is found. (How one recognizes the target is a different problem, and although this ability seems to be intact in the non-fluent aphasic, it seems to be at fault in the fluent one, who does not try to inhibit or correct his 'near misses'.)
Experiments with normal, healthy humans indicate that the processes whereby they find and utter words are very similar to those seen in aphasia, but that the processes take place more quickly and efficiently. But rare words take longer to find than common ones, and if the sorting/sifting/correcting process is impeded by external factors (such as distraction) or internal ones (such as intoxication), 'near misses' of much the same sort as those given by the aphasic may be emitted.
(Published 2004)
— Moyra Williams
- Bibliography
- Basso, A. (2003). Aphasia and its Therapy.
- Gardner, H. (1977). The Shattered Mind.
- Luria, A. R. (1970). Traumatic Aphasia.
- Russell, W. R., and Espir, M. L. E. (1961). Traumatic Aphasia.
- Spreen, O., and Risser, A. H. (2003). Assessment of Aphasia.
- Wernicke, C. (1874). Der Aphasische Symptomenkomplex.
Word Tutor:
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aphasia
IN BRIEF: n. - Inability to use or understand language (spoken or written) because of a brain lesion.
Tutor's tip: "Aphagia" (inability to swallow) is worse than "aphasia" (inability to comprehend words), because you need to eat to survive.
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Mosby's Dental Dictionary:
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aphasia
(ə-fa′zhə)
n
n
A loss of power of expression through speech, writing, or signs of comprehension of spoken or written language resulting from disease or injury of the brain centers.
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categories related to 'aphasia'
- Defects and Disabilities - aphasia: speech and language comprehension disorder due to disease in left half of brain
Wikipedia on Answers.com:
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Aphasia
For other uses, see Aphasia (disambiguation).
| Aphasia | |
|---|---|
| Classification and external resources | |
| ICD-10 | F80.0-F80.2, R47.0 |
| ICD-9 | 315.31, 784.3, 438.11 |
| DiseasesDB | 4024 |
| MedlinePlus | 003204 |
| eMedicine | neuro/437 |
| MeSH | D001037 |
| Dysphasia | |
|---|---|
| Classification and external resources | |
| ICD-10 | F80.1, F80.2, R47.0 |
| ICD-9 | 438.12, 784.5 |
Aphasia (
/əˈfeɪʒə/ or /əˈfeɪziə/, from ancient Greek ἀφασία (ἄφατος, ἀ- + φημί), "speechlessness"[1]) is an impairment of language ability. This class of language disorder ranges from having difficulty remembering words to being completely unable to speak, read, or write.
Acute aphasia disorders usually develop quickly as a result of head injury or stroke, and progressive forms of aphasia develop slowly from a brain tumor, infection, or dementia.[2][3] The area and extent of brain damage or atrophy will determine the type of aphasia and its symptoms. Aphasia types include expressive aphasia, receptive aphasia, conduction aphasia, anomic aphasia, global aphasia, primary progressive aphasias and many others (see Category:Aphasias). Medical evaluations for the disorder range from clinical screenings by a neurologist to extensive tests by a Speech-Language Pathologist.[2][4]
Most acute aphasia patients can recover some or most skills by working with a Speech-Language Pathologist. This rehabilitation can take two or more years and is most effective when begun quickly. Only a small minority will recover without therapy, such as those suffering a mini-stroke. Improvement varies widely, depending on the aphasia's cause, type, and severity. Recovery also depends on the patient's age, health, motivation, handedness, and educational level.[2]
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Contents
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Classification
Classifying the different subtypes of aphasia is difficult and has led to disagreements among experts. The localizationist model is the original model, but modern anatomical techniques and analyses have shown that precise connections between brain regions and symptom classification don't exist. The neural organization of language is complicated; language is a comprehensive and complex behavior and it makes sense that it isn't the product of some small, circumscribed region of the brain.
No classification of patients in subtypes and groups of subtypes is adequate. Only about 60% of patients will fit in a classification scheme such as fluent/nonfluent/pure aphasias. There is a huge variation among patients with the same diagnosis, and aphasias can be highly selective. For instance, patients with naming deficits (anomic aphasia) might show an inability only for naming buildings, or people, or colors.[5]
Localizationist model
The localizationist model attempts to classify the aphasia by major characteristics and then link these to areas of the brain in which the damage has been caused. The initial two categories here were devised by early neurologists working in the field, namely Paul Broca and Carl Wernicke. Other researchers have added to the model, resulting in it often being referred to as the "Boston-Neoclassical Model".
- Individuals with Expressive aphasia (also called Broca's aphasia) were once thought to have frontal lobe damage, though more recent work by Dr. Nina Dronkers using imaging and 'lesion analysis' has revealed that patients with Expressive aphasia have lesions to the medial insular cortex. Broca missed these lesions because his studies did not dissect the brains of diseased patients, so only the more temporal damage was visible. Dronkers and Dr. Odile Plaisant scanned Broca's original patients' brains using a non-invasive MRI scanner to take a closer look. [6] Damage to a region of the motor association cortex in the left frontal lobe (Broca's area) disrupts the ability to speak.[7] Individuals with Expressive aphasia often have right-sided weakness or paralysis of the arm and leg, because the frontal lobe is also important for body movement. Video clips showing patients with Expressive-type aphasia can be found here.
- In contrast to Expressive aphasia, damage to the temporal lobe may result in a fluent aphasia that is called Receptive aphasia (also known as Sensory aphasia and Wernicke's aphasia). These individuals usually have no body weakness, because their brain injury is not near the parts of the brain that control movement. A video clip with a patient exhibiting Receptive aphasia can be found here
- Working from Wernicke's model of aphasia, Ludwig Lichtheim proposed five other types of aphasia, but these were not tested against real patients until modern imaging made more in-depth studies available. The other five types of aphasia in the localizationist model are:
- Auditory verbal agnosia (also known as Pure Word Deafness)
- Conduction aphasia
- Apraxia of speech (now considered a separate disorder in itself)
- Transcortical motor aphasia (also known as Adynamic aphasia and Extrasylvian motor aphasia)
- Transcortical sensory aphasia
- Anomic aphasia, also known as Anomia, is another type of aphasia proposed under what is commonly known as the Boston-Neoclassical model, which is essentially a difficulty with naming.
- Global aphasia, results from damage to extensive portions of the perisylvian region of the brain. An individual with global aphasia will have difficulty understanding both spoken and written language and will also have difficulty speaking. This is a severe type of aphasia which makes it quite difficult when communicating with the individual.[8]
- Isolation Aphasia, also known as Mixed Transcortical Aphasia, is a type of disturbance in language skill that causes the inability to comprehend what is being said to you or the difficulty in creating speech with meaning without affecting the ability to recite what has been said and to acquire newly presented words. This type of aphasia is caused by brain damage that isolates the parts of the brain from other parts of the brain that are in charge of speech.[9] The brain damages are caused to left temporal/parietal cortex that spares the Wernicke's area. Isolation aphasia patients can repeat what other people say, thus they do recognize words but they can't comprehend the meaning of what they hear and repeat themselves. However, they can not produce meaningful speech of their own. [10]
Progressive aphasias
Primary progressive aphasia (PPA) is associated with progressive illnesses or dementia, such as frontotemporal dementia / Pick Complex Motor neuron disease, Progressive supranuclear palsy, and Alzheimer's disease; which is the gradual process of losing the ability to think. It is characterized by the gradual loss of the ability to name objects. People suffering from PPA may have difficulties comprehending what others are saying. They can also have difficulty trying to find the right words to make a sentence.[11][12][13] There are three classifications of Primary Progressive Aphasia : Progressive nonfluent aphasia (PNFA), Semantic Dementia (SD), and Logopenic progressive aphasia (LPA)[14]
Progressive Jargon Aphasia is a fluent or receptive aphasia in which the patient's speech is incomprehensible, but appears to make sense to them. Speech is fluent and effortless with intact syntax and grammar, but the patient has problems with the selection of nouns. They will either replace the desired word with another that sounds or looks like the original one, or has some other connection, or they will replace it with sounds. Accordingly, patients with jargon aphasia often use neologisms, and may perseverate if they try to replace the words they can't find with sounds. Commonly, substitutions involve picking another (actual) word starting with the same sound (e.g. clocktower - colander), picking another semantically related to the first (e.g. letter - scroll), or picking one phonetically similar to the intended one (e.g. lane - late).
Fluent, non-fluent and "pure" aphasias
The different types of aphasia can be divided into three categories: fluent, non-fluent and "pure" aphasias.[15]
- Receptive aphasias, also called Fluent aphasias, are impairments related mostly to the input or reception of language, with difficulties either in auditory verbal comprehension or in the repetition of words, phrases, or sentences spoken by others. Speech is easy and fluent, but there are difficulties related to the output of language as well, such as paraphasia. Examples of fluent aphasias are: Receptive aphasia, Transcortical sensory aphasia, Conduction aphasia, Anomic aphasia[15]
- Expressive aphasias, also called Nonfluent aphasias, are difficulties in articulating, but in most cases there is relatively good auditory verbal comprehension. Examples of nonfluent aphasias are: Expressive aphasia, Transcortical motor aphasia, Global aphasia[15]
- "Pure" aphasias are selective impairments in reading, writing, or the recognition of words. These disorders may be quite selective. For example, a person is able to read but not write, or is able to write but not read. Examples of pure aphasias are: Pure alexia, Agraphia, Auditory verbal agnosia[15]
Primary and secondary cognitive processes
Aphasias can be divided into primary and secondary cognitive processes.
- Primary aphasia is due to problems with cognitive language-processing mechanisms, which can include: Transcortical sensory aphasia, Semantic Dementia, Apraxia of speech, Progressive nonfluent aphasia, and Expressive aphasia
- Secondary aphasia is the result of other problems, like memory impairments, attention disorders, or perceptual problems, which can include: Transcortical motor aphasia, Dynamic aphasia, Anomic aphasia, Receptive aphasia, Progressive jargon aphasia, Conduction aphasia, and Dysarthria.[16]
Cognitive neuropsychological model
The cognitive neuropsychological model builds on cognitive neuropsychology. It assumes that language processing can be broken down into a number of modules, each of which has a specific function.[17] Hence there is a module which recognises phonemes as they are spoken and a module which stores formulated phonemes before they are spoken. Use of this model clinically involves conducting a battery of assessments (usually from the PALPA, the "psycholinguistic assessment of language processing in adult acquired aphasia ... that can be tailored to the investigation of an individual patient's impaired and intact abilities" [18]), each of which tests one or a number of these modules. Once a diagnosis is reached as to where the impairment lies, therapy can proceed to treat the individual module.
Signs and symptoms
People with aphasia may experience any of the following behaviors due to an acquired brain injury, although some of these symptoms may be due to related or concomitant problems such as dysarthria or apraxia and not primarily due to aphasia.
- inability to comprehend language
- inability to pronounce, not due to muscle paralysis or weakness
- inability to speak spontaneously
- inability to form words
- inability to name objects
- poor enunciation
- excessive creation and use of personal neologisms
- inability to repeat a phrase
- persistent repetition of phrases
- paraphasia (substituting letters, syllables or words)
- agrammatism (inability to speak in a grammatically correct fashion)
- dysprosody (alterations in inflexion, stress, and rhythm)
- incomplete sentences
- inability to read
- inability to write
- limited verbal output
- difficulty in naming
- Speech disorder
Presentation
Acute Aphasias
The following table summarizes some major characteristics of different acute of aphasia:
| Type of aphasia | Repetition | Naming | Auditory comprehension | Fluency |
|---|---|---|---|---|
| Receptive aphasia | mild–mod | mild–severe | defective | fluent paraphasic |
| Transcortical sensory aphasia | good | mod–severe | poor | fluent |
| Conduction aphasia | poor | poor | relatively good | fluent |
| Anomic aphasia | mild | mod–severe | mild | fluent |
| Expressive aphasia | mod–severe | mod–severe | mild difficulty | non-fluent, effortful, slow |
| Transcortical motor aphasia | good | mild–severe | mild | non-fluent |
| Global aphasia | poor | poor | poor | non-fluent |
| Mixed transcortical aphasia | moderate | poor | poor | non-fluent |
- Individuals with Receptive aphasia may speak in long sentences that have no meaning, add unnecessary words, and even create new "words" (neologisms). For example, someone with Receptive aphasia may say, "You know that smoodle pinkered and that I want to get him round and take care of him like you want before", meaning "The dog needs to go out so I will take him for a walk". They have poor auditory and reading comprehension, and fluent, but nonsensical, oral and written expression. Individuals with Receptive aphasia usually have great difficulty understanding the speech of both themselves and others and are therefore often unaware of their mistakes.
- Individuals with Transcortical sensory aphasia Similar deficits as in Receptive aphasia, but repetition ability remains intact.
- Individuals with Conduction aphasia is caused by deficits in the connections between the speech-comprehension and speech-production areas. This might be caused by damage to the arcuate fasciculus, the structure that transmits information between Wernicke's area and Broca's area. Similar symptoms, however, can be present after damage to the insula or to the auditory cortex. Auditory comprehension is near normal, and oral expression is fluent with occasional paraphasic errors. Repetition ability is poor.
- Individuals with Anomic aphasia is essentially a difficulty with naming. The patient may have difficulties naming certain words, linked by their grammatical type (e.g. difficulty naming verbs and not nouns) or by their semantic category (e.g. difficulty naming words relating to photography but nothing else) or a more general naming difficulty. Patients tend to produce grammatic, yet empty, speech. Auditory comprehension tends to be preserved.
- Individuals with Expressive aphasia frequently speak short, meaningful phrases that are produced with great effort. Expressive aphasia is thus characterized as a nonfluent aphasia. Affected people often omit small words such as "is", "and", and "the". For example, a person with Expressive aphasia may say, "Walk dog" which could mean "I will take the dog for a walk", "You take the dog for a walk" or even "The dog walked out of the yard". Individuals with Expressive aphasia are able to understand the speech of others to varying degrees. Because of this, they are often aware of their difficulties and can become easily frustrated by their speaking problems. It is associated with right
- Individuals with Transcortical motor aphasia Similar deficits as Expressive aphasia, except repetition ability remains intact. Auditory comprehension is generally fine for simple conversations, but declines rapidly for more complex conversations. It is associated with right hemiparesis, meaning that there can be paralysis of the patient's right face and arm.
- Individuals with Global aphasia have severe communication difficulties and will be extremely limited in their ability to speak or comprehend language. They may be totally nonverbal, and/or only use facial expressions and gestures to communicate. It is associated with right hemiparesis, meaning that there can be paralysis of the patient's right face and arm.
- Individuals with Mixed transcortical aphasia have similar deficits as in global aphasia, but repetition ability remains intact.
Subcortical aphasias
- Subcortical aphasias Characteristics and symptoms depend upon the site and size of subcortical lesion. Possible sites of lesions include the thalamus, internal capsule, and basal ganglia.
Causes
Aphasia usually results from lesions to the language-relevant areas of the frontal, temporal and parietal lobes of the brain, such as Broca's area, Wernicke's area, and the neural pathways between them. These areas are almost always located in the left hemisphere, and in most people this is where the ability to produce and comprehend language is found. However, in a very small number of people, language ability is found in the right hemisphere. In either case, damage to these language areas can be caused by a stroke, traumatic brain injury, or other brain injury.
Aphasia may also develop slowly, as in the case of a brain tumor or progressive neurological disease, e.g., Alzheimer's or Parkinson's disease. It may also be caused by a sudden hemorrhagic event within the brain. Certain chronic neurological disorders, such as epilepsy or migraine, can also include transient aphasia as a prodromal or episodic symptom.[19]
Aphasia can result from Herpes Simplex virus (HSV) encephalitis. The (HSV) affects the frontal and temporal lobes, subcortical structures and the hippocampal tissue which can trigger aphasia. [20]
Aphasia is also listed as a rare side effect of the fentanyl patch, an opioid used to control chronic pain.[21]
Management
There is no one treatment proven to be effective for all types of aphasias. The reason that there is no universal treatment for aphasia is because of the nature of the disorder and the various ways it is presented, as explained in the above sections. Aphasia is rarely exhibited identically, implying that treatment needs to be catered specifically to the individual. Studies have shown that although there isn't consistency on treatment methodology in literature, there is a strong indication that treatment in general has positive outcomes.[22]
A multi-disciplinary team, including doctors (often a physician is involved, but more likely a clinical neuropsychologist will head the treatment team), physiotherapist, occupational therapist, speech-language pathologist, and social worker, works together in treating aphasia. For the most part, treatment relies heavily on repetition and aims to address language performance by working on task-specific skills. The primary goal is to help the individual and those closest to them adjust to changes and limitations in communication.[22]
Treatment techniques mostly fall under two approaches:
- Substitute Skill Model - an approach that uses an aid to help with spoken language, i.e. a writing board
- Direct Treatment Model - an approach which targets deficits with specific exercises[22]
Several treatment techniques include the following:
- Visual Communication Therapy (VIC) - the use of index cards with symbols to represent various components of speech
- Visual Action Therapy (VAT) - involves training individuals to assign specific gestures for certain objects
- Functional Communication Treatment (FCT) - focuses on improving activities specific to functional tasks, social interaction, and self-expression
- Promoting Aphasic's Communicative Effectiveness (PACE) - a means of encouraging normal interaction between patients and clinicians. In this kind of therapy the focus is on pragmatic communication rather than treatment itself. Patients are asked to communicate a given message to their therapists by means of drawing, making hand gestures or even pointing to an object.[23]
- Other - i.e. drawing as a way of communicating, trained conversation partners[22]
More recently, computer technology has been incorporated into treatment options. A key indication for good prognosis is treatment intensity. A minimum of 2–3 hours per week has been specified to produce positive results.[24] The main advantage of using computers is that it can greatly increase intensity of therapy. These programs consist of a large variety of exercises and can be done at home in addition to face-to-face treatment with a therapist. However, since aphasia presents differently among individuals, these programs must be dynamic and flexible in order to adapt to the variability in impairments. Another barrier is the capability of computer programs to imitate normal speech and keep up with the speed of regular conversation. Therefore, computer technology seems to be limited in a communicative setting, however is effective in producing improvements in communication training.[24]
Several examples of programs used are StepByStep, Linguagraphica, Computer-Based Visual Communication (C-VIC), TouchSpeak (TS), and Sentence Shaper.[24]
Melodic intonation therapy is often used to treat non-fluent aphasia and has proved to be very effective in some cases.[25]
Zolpidem, a drug with the trade name of Ambien, may provide short-lasting but effective improvement in symptoms of aphasia present in some survivors of stroke. The mechanism for improvement in these cases remains unexplained and is the focus of current research by several groups, to explain how a drug which acts as a hypnotic-sedative in people with normal brain function, can paradoxically increase speech ability in people recovering from severe brain injury. Use of zolpidem for this application remains experimental at this time, and is not officially approved by any pharmaceutical manufacturers of zolpidem or medical regulatory agencies worldwide.
History
The first recorded case of aphasia is from an Egyptian papyrus, the Edwin Smith Papyrus, which details speech problems in a person with a traumatic brain injury to the temporal lobe.[26]
Notable cases
See also
References
- ^ ἀφασία, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
- ^ a b c "Aphasia". MedicineNet.com. http://www.medicinenet.com/aphasia/article.htm. Retrieved 2011-05-23.
- ^ "American Speech-Language-Hearing Association (ASHA):- Aphasia Causes and Number". http://www.asha.org/public/speech/disorders/AphasiaCauses.htm.
- ^ "American Speech-Language-Hearing Association (ASHA):- Aphasia". http://www.asha.org/public/speech/disorders/Aphasia/.
- ^ Kolb, Bryan; Whishaw, Ian Q. (2003). Fundamentals of human neuropsychology. [New York]: Worth. pp. 502, 505, 511. ISBN 0-7167-5300-6. OCLC 464808209.
- ^ Dronkers NF, Plaisant O, Iba-Zizen MT, Cabanis EA (May 2007). "Paul Broca's historic cases: high resolution MR imaging of the brains of Leborgne and Lelong". Brain 130 (Pt 5): 1432–41. doi:10.1093/brain/awm042. PMID 17405763. http://brain.oxfordjournals.org/content/130/5/1432.long.
- ^ Masdeu, Joseph (June 2000). "Aphasia". Archives of Neurology 57 (6).
- ^ Taylor Sarno, M. (2007). Neurogenic disorders of speech and language. In: O’Sullivan, S.B. & Schmitz, T.J. (2007). Physical Rehabilitation (5th ed.). Philadelphia (PA): F.A. Davis Company.
- ^ Carlson, Neil (2007). Psychology the Science of Behaviour. Toronto: Pearson. pp. 278. ISBN 978-0-205-64524-4.
- ^ Carlson, Neil (2007). Psychology the Science of Behaviour. Toronto: Pearson. pp. 305. ISBN 978-0-205-64524-4.
- ^ Mesulam MM (April 2001). "Primary progressive aphasia". Ann. Neurol. 49 (4): 425–32. doi:10.1002/ana.91.abs. PMID 11310619.
- ^ Wilson SM, Henry ML, Besbris M, et al. (July 2010). "Connected speech production in three variants of primary progressive aphasia". Brain 133 (Pt 7): 2069–88. doi:10.1093/brain/awq129. PMC 2892940. PMID 20542982. http://brain.oxfordjournals.org/content/133/7/2069.long#xref-ref-18-1.
- ^ Harciarek M, Kertesz A (September 2011). "Primary progressive aphasias and their contribution to the contemporary knowledge about the brain-language relationship". Neuropsychol Rev 21 (3): 271–87. doi:10.1007/s11065-011-9175-9. PMC 3158975. PMID 21809067. http://www.springerlink.com/content/3334m228j54ntq10/?MUD=MP.
- ^ Harciarek M, Kertesz A (September 2011). "Primary progressive aphasias and their contribution to the contemporary knowledge about the brain-language relationship". Neuropsychol Rev 21 (3): 271–87. doi:10.1007/s11065-011-9175-9. PMC 3158975. PMID 21809067. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3158975.
- ^ a b c d Kolb, Bryan; Whishaw, Ian Q. (2003). Fundamentals of human neuropsychology. [New York]: Worth. pp. 502–504. ISBN 0-7167-5300-6. OCLC 464808209.
- ^ Rohrer JD, Knight WD, Warren JE, Fox NC, Rossor MN, Warren JD (January 2008). "Word-finding difficulty: a clinical analysis of the progressive aphasias". Brain 131 (Pt 1): 8–38. doi:10.1093/brain/awm251. PMC 2373641. PMID 17947337. http://brain.oxfordjournals.org/content/131/1/8.long.
- ^ Luria's Areas of the Human Cortex Involved in Language Illustrated summary of Luria's book Traumatic Aphasia
- ^ Coltheart, Max; Kay, Janice; Lesser, Ruth (1992). PALPA psycholinguistic assessments of language processing in aphasia. Hillsdale, N.J: Lawrence Erlbaum Associates. ISBN 0-86377-166-1.
- ^ Quigg M, Fountain NB (March 1999). "Conduction aphasia elicited by stimulation of the left posterior superior temporal gyrus". J. Neurol. Neurosurg. Psychiatr. 66 (3): 393–6. PMC 1736266. PMID 10084542. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1736266.
- ^ "Can Herpes Simplex Virus Encephalitis Cause Aphasia".
- ^ "Fentanyl Transdermal Official FDA information, side effects and uses". Drug Information Online. http://www.drugs.com/pro/fentanyl-transdermal.html#A02A9CB6-35CF-4F01-A980-C3733E0F861A.
- ^ a b c d O’Sullivan, S. B., & Schmitz, T. J. (2007). Physical rehabilitation. (5th ed.). Philadelphia (PA): F. A. Davis Company.
- ^ Alexander, Michael P; Hillis, Argye E (2008). "Aphasia". In Georg Goldenberg; Bruce L Miller; Michael J Aminoff; Francois Boller; D F Swaab. Neuropsychology and Behavioral Neurology: Handbook of Clinical Neurology. 88. Elsevier Health Sciences. pp. 287-310. ISBN 978-0-444-51897-2. OCLC 733092630.
- ^ a b c van de Sandt-Koenderman WM (February 2011). "Aphasia rehabilitation and the role of computer technology: can we keep up with modern times?". Int J Speech Lang Pathol 13 (1): 21–7. doi:10.3109/17549507.2010.502973. PMID 21329407.
- ^ Norton A, Zipse L, Marchina S, Schlaug G (July 2009). "Melodic intonation therapy: shared insights on how it is done and why it might help". Ann. N. Y. Acad. Sci. 1169: 431–6. doi:10.1111/j.1749-6632.2009.04859.x. PMC 2780359. PMID 19673819. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2780359.
- ^ McCrory PR, Berkovic SF (December 2001). "Concussion: the history of clinical and pathophysiological concepts and misconceptions". Neurology 57 (12): 2283–9. PMID 11756611. http://www.neurology.org/cgi/content/abstract/57/12/2283.
- ^ Richardson, Robert G. (1995). Emerson: the mind on fire: a biography. Berkeley: University of California Press. ISBN 0-520-08808-5. OCLC 31206668.
External links
 |
Look up aphasia or aphemia in Wiktionary, the free dictionary. |
- Academy of Aphasia
- Aphasia at the Open Directory Project
- Luria's Areas of the Human Cortex Involved in Language Illustrated summary of Luria's book Traumatic Aphasia
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Translations:
Top
Aphasia
Nederlands (Dutch)
afasie (verlies van vermogen tot taalgebruik)
Français (French)
n. - aphasie
Deutsch (German)
n. - Aphasie, (Verlust der Sprechfähigkeit)
Ελληνική (Greek)
n. - (παθολ.) αφασία
Português (Portuguese)
n. - afasia (f) (Med.)
Русский (Russian)
афазия, потеря речи
中文（简体）(Chinese (Simplified))
失语症
中文（繁體）(Chinese (Traditional))
n. - 失語症
العربيه (Arabic)
(الاسم) الحبسه : فقدان القدره على الكلام نتيجه تعرض الدماغ لأذى نتيجه اصابه
עברית (Hebrew)
n. - אובדן היכולת לדבר או להבין דיבור, שכחת הלשון, אפזיה
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Mentioned in
acalculia
(medicine)
dysphasia
(medicine)
heterolalia
(psychology)
mixed aphasia
(psychology)
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