Aphasia is a disorder that results from damage to portions of the brain that are responsible for language. For most people, these are areas on the left side (hemisphere) of the brain. The disorder impairs the expression and understanding of language as well as reading and writing.
Aphasia usually occurs suddenly, often as the result of a stroke or head injury, such as severe blows to the head, brain tumors, brain infections, and other conditions that affect the brain. However, it may also develop slowly, as in the case of a brain tumor, an infection, or dementia. Aphasia may co-occur with speech disorders such as dysarthria or apraxia of speech, which also result from brain damage.
Anyone can acquire aphasia, including children, but most people who have aphasia are middle-aged or older. Men and women are equally affected. Approximately 80,000 individuals acquire aphasia each year from strokes. About one million people in North America currently have aphasia.
There are two broad categories of aphasia: fluent and non-fluent.
Damage to the temporal lobe (the side portion) of the brain may result in a fluent aphasia called Wernicke’s aphasia. In most people, the damage occurs in the left temporal lobe, although it can result from damage to the right lobe as well. People with Wernicke’s aphasia may:
As a result, it is often difficult to follow what the person is trying to say. People with Wernicke’s aphasia usually have great difficulty understanding speech, and they are often unaware of their mistakes. These individuals usually have no body weakness because their brain injury is not near the parts of the brain that control movement.
A type of non-fluent aphasia is Broca’s aphasia. People with Broca’s aphasia have damage to the frontal lobe of the brain. They frequently:
People with Broca’s aphasia typically understand the speech of others fairly well. Because of this, they are often aware of their difficulties and can become easily frustrated. People with Broca’s aphasia often have right-sided weakness or paralysis of the arm and leg because the frontal lobe is also important for motor movements.
Another type of non-fluent aphasia, global aphasia, results from damage to extensive portions of the language areas of the brain. Individuals with global aphasia have severe communication difficulties and may be extremely limited in their ability to speak or comprehend language.
There are other types of aphasia, each of which results from damage to different language areas in the brain.
In some cases, a person will completely recover from aphasia without treatment. This type of spontaneous recovery usually occurs following a type of stroke in which blood flow to the brain is temporarily interrupted but quickly restored, called a transient ischemic attack. In these circumstances, language abilities may return in a few hours or a few days.
For most cases, however, language recovery is not as quick or as complete. While many people with aphasia experience partial spontaneous recovery, in which some language abilities return a few days to a month after the brain injury, some amount of aphasia typically remains. In these instances, speech-language therapy is often helpful. Recovery usually continues over a two-year period.
Some of the factors that influence the amount of improvement include:
Aphasia therapy aims to improve a person’s ability to communicate by helping him or her to use remaining language abilities, restore language abilities as much as possible, compensate for language problems, and learn other methods of communicating. Individual therapy focuses on the specific needs of the person, while group therapy offers the opportunity to use new communication skills in a small-group setting.
Family involvement is often a crucial component of aphasia treatment so that family members can learn the best way to communicate with their loved one. Family members are encouraged to:
Other treatment approaches involve the use of computers to improve the language abilities of people with aphasia.