Aphasia is a communication disorder that leaves patients unable to effectively express or understand spoken or written language. The possibility of recovery from aphasia depends on its cause, which part of the brain is affected, and how extensive the damage is. There are many types of aphasia, and a patient may suffer from more than one type. Aphasia can result from physical or psychological trauma, or from a degenerative process. Aphasia has a variety of causes. Most commonly, the condition results from a stroke or progressive dementia. Other causes of aphasia may include:
- Extreme mental retardation
- Severe autism
- Certain rare diseases
- Traumatic brain injury
- Very serious infections
At times, seizures or transient ischemic attacks (TIAs) may precipitate episodes of aphasia. Temporary aphasia may also result from severe psychological trauma or extreme depression.
Types of Aphasia
There are five basic types of aphasia, differentiated by their symptoms.
Expressive aphasia, sometimes called nonfluent aphasia, is a condition in which affected individuals know what they want to say but are unable to communicate it, either verbally or in writing.
Receptive (fluent) aphasia is a condition in which the affected individual can hear a voice or read print, but cannot understand what is being said or read. Often, those with receptive aphasia take language literally.
With anomic aphasia, the affected individual has difficulty finding appropriate words, a condition known as anomia. Because of difficulty recalling appropriate vocabulary, the individual struggles to communicate both verbally and in writing.
Global aphasia is the most severe type of aphasia, and is frequently observed in stroke victims. In global aphasia, all communication skills are affected. Although global aphasia is severe, patients can be helped with speech therapy. They may recover part or, occasionally, much of their language ability, although rehabilitation may be a lengthy process.
Primary Progressive Aphasia
Primary progressive aphasia is a rare type of the disorder. Patients with primary progressive aphasia gradually lose the ability to talk, read, write and comprehend language. This is a progressive disease for which there is no known cure, and for which therapy is not effective.
Symptoms of Aphasia
The symptoms of aphasia may vary according to the portion of the brain affected, but the following symptoms are common:
- Speaking unusually slowly or hesitantly
- Taking time to understand conversation
- Having trouble deciphering conversation
- Saying unrecognizable words
- Speaking/writing phrases that do not make sense
- Interpreting figurative language literally
- Using peculiar spelling or grammatical sequences
- Calling objects by the wrong names
Diagnosis of Aphasia
Aphasia is usually diagnosed through a series of tests, during which the patient is asked to respond to questions or simple commands, or to identify common objects. If aphasia is diagnosed, these tests also allow its type and severity to be assessed. They are usually performed after a patient has had a stroke or brain injury, or when a tumor or degeneration is suspected. The patient is evaluated for the following:
- Fluency, voice quality and articulation
- Coordination of speech muscles of the tongue and lips
- Comprehension of questions and ability to respond to them
- Ability to follow directions
- Ability to relate a simple story in sequence (verbally and in writing)
- Ability to explain the purpose of a simple object
These tests may be performed by neurologists, psychologists, speech-language pathologists or other healthcare professionals.
Treatment of Aphasia
In some cases, patients recover spontaneously from aphasia. Most of the time, however, language therapy will need to be implemented as soon as possible. Additional treatment methods include learning to communicate with gestures or by using a computer. Recovery of language skills is usually a long and arduous process, though many patients are able to become significantly more communicative through therapy. For young children whose brains are more plastic, language skills may be recovered more quickly.