Aphasia
What is aphasia?
Aphasia is a language disorder that results from damage
to portions of the brain that are responsible for language. For most people,
these are parts of the left side (hemisphere) of the brain. Aphasia usually
occurs suddenly, often as the result of a stroke or head injury, but it may also develop slowly, as in the
case of a brain tumor. The disorder impairs both the expression and
understanding of language as well as reading and writing. Aphasia may co-occur
with speech disorders such as dysarthria or apraxia of speech, which also result
from brain damage.
Who has aphasia?
Anyone can acquire aphasia, but most people who have aphasia are in their
middle to late years. Men and women are equally affected. It is estimated that
approximately 80,000 individuals acquire aphasia each year. About one million
persons in the United States currently have aphasia.
What causes aphasia?
Aphasia is caused by damage to one or more of the
language areas of the brain. Many times, the cause of the brain injury is a
stroke. A stroke occurs when, for some reason, blood is unable to reach a part
of the brain. Brain cells die when they do not receive their normal supply of
blood, which carries oxygen
and important nutrients. Other causes of brain injury are severe blows to the
head, brain tumors, brain infections, and other conditions of the brain.
Individuals with Broca's aphasia have damage to the frontal lobe of the
brain. These individuals frequently speak in short, meaningful phrases that are
produced with great effort. Broca's 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 Broca's aphasia may say, "Walk dog" meaning, "I will
take the dog for a walk." The same sentence could also mean "You take the dog
for a walk," or "The dog walked out of the yard," depending on the
circumstances. Individuals with Broca's 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.
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.
In contrast to Broca's aphasia, damage to the temporal lobe may
result in a fluent aphasia that is called Wernicke's aphasia. Individuals with
Wernicke's aphasia may speak in long sentences that have no meaning, add
unnecessary words, and even create new "words." For example, someone with
Wernicke's 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." Individuals with Wernicke's aphasia
usually have great difficulty understanding speech and are therefore 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 third type of 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.
Next: How is aphasia diagnosed? »
- Brain Tumor - Read about brain tumor symptoms such as headaches, nausea or vomiting, balance and walking problems, mood and personality changes, memory problems, and numbness or tingling in the legs.
- Stroke - Learn about strokes symtoms like sudden numbness or weakness in the face, arms, or legs, confusion, vision problems, problems with walking or coordination, or severe headache.
- Learning Disabilities - Read about learning disabilities, like the skills affected such as reading, writing, listening, speaking, reasoning, and mathematics. Causes, symptoms, diagnosis, and treatment information is included.
Latest Medical News
Specialty RSS
Slideshows