Aphasia is a language disorder that occurs when the part of the brain that is responsible for language becomes damaged. The damage usually happens to the left hemisphere of the brain and can happen quite quickly in cases such as head injury or stroke. Brain tumors can also cause aphasia, but the symptoms of these may only be seen gradually over a longer period of time.
Sufferers can also develop impairments in facial expressions and the understanding of language. They also have difficulty with reading and writing. A stroke is a very common cause of aphasia. A stroke occurs when brain cells die due to a lack of blood reaching the brain, resulting in a lack of vital nutrients and oxygen. Other causes of brain injury are brain infections and serious blows to the head.
There are three main types of aphasia. Sufferers of Broca's aphasia have had damage to the frontal lobe of the brain. They must make a great effort to talk and speech is usually in short, meaningful sentences. The person will often leave out short words such as "is" and "the". Broca's is characterized as non-fluent aphasia, due to the short length of sentences.
People with Broca's can usually understand the speech of others. They are also aware of their own speech and how others hear them. This can cause sufferers great frustration as they try to produce longer sentences. People with Broca's usually suffer from paralysis or weakness of the right arm or leg. This is because the frontal lobe of the brain is also responsible for movement of the body.
People who have had damage to the temporal lobe of the brain can suffer from Wernicke's aphasia. This is a fluent aphasia that results in the sufferer talking in long sentences which have no meaning. They add unnecessary words or often create new words. They are usually unaware of these mistakes, as they have great difficulty understanding speech. They also usually have no body weakness, as the temporal lobe is not needed for body movement.
A third type of aphasia is known as global aphasia. This results from damage to large parts of the brain. Sufferers have extreme difficulty communicating verbally and understanding language.
Aphasia usually occurs in the middle to later years of life. It can occur in both men and women. It is estimated that about 80,000 people are afflicted every year, and there are over 1 million sufferers in the United States. Some individuals recover completely without treatment, but a large amount of sufferers require treatment such as speech therapy. At the moment, there are also a large number of research studies being undertaken, as well new drugs available to help sufferers now and in the future.