Aphasia - A short Overview

Aphasia is a disorder that results from damage to the portions of the brain that are responsible for language. It occurs suddenly and usually as a result of a stroke or head injury. However, it may also be the cause of brain tumor, an infection or dementia.

Aphasias can be divided into:

-receptive and expressive aphasias

-fluent and non-fluent

-anterior and posterior aphasias

Broca Aphasia

The name of this aphasia comes from the area that is affected, the Broca area. This area is located in the  posterior inferior frontal gyrus of the brain. It is the most common type of aphasia and it’s non-fluent.

The speech is affected and talking is only reduced to a few nouns and verbs. This is usually the first sign that occurs when a person has Broca aphasia. In some extreme cases, patients only produce a single word. Sometimes writing can be affected too.

Here is a girl suffering from Broca aphasia after an ischemic stroke:

Here is a man suffering from Broca Aphasia:

Wernike Aphasia

The name of this aphasia also comes from the affected area. It is a fluent aphasia and it is characterized by a severe impairment of understanding. Patients can hear that the person is speaking but they cannot understand the message. Although it is a fluent aphasia, talking can be affected too. People can produce “word salad” in the most extreme cases. This happens because the person cannot verify what they say since they cannot understand language. So even if they hear themselves talking and they are able to talk (their expressive ability is not impaired), their speech seems affected because they simply cannot correct themselves. A word salad happens when a person says intelligible words but they are randomly put together. If a person has used certain expressions for a long time, they are automated and they can be preserved and understood.

Here is the patient with Wernike Aphasia:

Conduction aphasia
This is also called associative aphasia – is a rare form of aphasia. It is caused by damage in the language centers and it’s usually acquired from stroke, traumatic brain injuries or localized lesions – like the rest of the aphasias. The main characteristic is the fact that patients cannot repeat words, not even when they read aloud. However, their speech and writing is almost normal. They understand words and their grammar is good. They might also have frequent errors during spontaneous speech but they are aware of them.

Anomic aphasia/ amnesic aphasia/nominal aphasia
Patients suffering from this type of aphasia have a problem with recalling words or names. In severe cases the person speaks without nouns. It is probably one of the most frequent forms of aphasia and it can also appear as a residual aphasia.

Transcortical motor aphasia 
This aphasia affects speech and writing but it can also induce a strange phenomena: echolalia  - the patient automatically repeats what another person says perfectly but they cannot talk themselves.

Transcortical sensory aphasia 
The patient has a poor comprehension but has a good speech with correct grammar. Patients will be able to communicate and repeat. However, they suffer from semantic paraphasia, so they cannot understand what they are being told.

Global aphasia 
 A massive aphasia that effects both expression and understanding.

Recovery: speech language therapy and support groups

Further reading:

The National Aphasia Association http://www.aphasia.org/

http://www.nidcd.nih.gov/health/voice/aphasia.htm#what