Aphasia

Name	Aphasia
Diseasesdb	4024
Icd10	-,
Icd9	, ,
Medlineplus	003204
Emedicinesubj	neuro
Emedicinetopic	437
Meshid	D001037

Name	Dysphasia
Icd10	, ,
Icd9	,

Aphasia ( or ) 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.

Aphasia disorders usually develop quickly as a result of head injury or stroke, but can develop slowly from a brain tumor, infection, or dementia, or can be a learning disability such as dysnomia.

The area and extent of brain damage determine the type of aphasia and its symptoms. Aphasia types include Broca's aphasia, non-fluent aphasia, motor aphasia, expressive aphasia, receptive aphasia, global aphasia and many others (see :Category:Aphasias).

Medical evaluations for the disorder range from clinical screenings by a neurologist to extensive tests by a language pathologist.

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.

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". The most prominent writers on this topic have been Harold Goodglass and Edith Kaplan.

Individuals with Broca's aphasia (also termed expressive aphasia) were once thought to have ventral temporal damage, though more recent work by Dr. Nina Dronkers using imaging and 'lesion analysis' has revealed that patients with Broca's 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. Individuals with Broca's 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 Broca-type aphasia can be found here.

In contrast to Broca's aphasia, damage to the temporal lobe may result in a fluent aphasia that is called Wernicke's aphasia (also termed sensory 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 Wernicke's 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:

#Pure word deafness #Conduction aphasia #Apraxia of speech (now considered a separate disorder in itself) #Transcortical motor aphasia #Transcortical sensory aphasia

Anomia is another type of aphasia proposed under what is commonly known as the Boston-Neoclassical model, which is essentially a difficulty with naming. A final type of aphasia, 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.

Other ways to classify aphasia

Aphasia can also be classified as

# Receptive # Intermediate # Expressive

Receptive aphasias can be subdivided into

A - pure word deafness (patient can hear but not understand words) B - alexia (patient can read but not understand words) C - visual asymbolia (written words are disorganized and can not be recognized).

Intermediate - also called nominal amnestic aphasia.

Expressive aphasia also known as Broca's aphasia or cortical motor aphasia (patient has difficulty in putting his thoughts into words)

Fluent, non-fluent and "pure" aphasias

The different types of aphasia can be divided into three categories: fluent, non-fluent and "pure" aphasias.

Fluent aphasias, also called receptive 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: Wernicke's aphasia, Transcortical sensory aphasia, Conduction aphasia, Anomic aphasia Age of onset is usually defined as from infancy until but not including adolescence.

ACA should be distinguished from developmental aphasia or developmental dysphasia, which is a primary delay or failure in language acquisition. An important difference between ACA and developmental childhood aphasia is that in the latter there is no apparent neurological basis for the language deficit.

ACA is one of the more rare language problems in children and is notable because of its contribution to theories on language and the brain.

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)

uncompleted sentences

inability to read

inability to write

limited verbal output

difficulty in naming

The following table summarizes some major characteristics of different types of aphasia:

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).

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. Aphasia is also listed as a rare side effect of the fentanyl patch, an opioid used to control chronic pain.

Treatment

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.

A multi-disciplinary team, including the doctor, psychologist, 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. 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.

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.

Notable cases

Ralph Waldo Emerson

Maurice Ravel

Jan Berry of Jan and Dean

Sven Nykvist

Robert E. Lee

Edwyn Collins

Paul David Wilson

Joseph Chaikin

Deangelo Vickers (Will Ferrell's character on the NBC television show, "The Office")

See also

Aphasiology

Speech disorder

Dysnomia disorder

Aprosodia

Dysprosody

Glossolalia

Paragrammatism

References

External links

Category:Communication disorders Category:Neurological disorders Category:Alexia acquired dyslexia Category:Language disorders Category:Symptoms and signs: Speech and voice