Aphasia is an acquired disorder caused by brain damage which affects a person's ability to communicate.
The principal signs of aphasia are impairments in the ability to express oneself when speaking, trouble understanding speech, and difficulty with reading and writing. Aphasia is most often the result of stroke or head injury, but can also occur in other neurological disorders, such as brain tumor or Alzheimer's disease.
The effects of aphasia differ from person to person, and can sometimes benefit from speech therapy. Strategies to communicate non-verbally (without words) may also be helpful to the person with aphasia.

Types of Aphasia.

• People with Broca's aphasia (non-fluent aphasia) have suffered damage to the frontal lobe of the brain. These individuals speak in short, meaningful phrases that are produced with great effort. However, they are able to understand the speech of other people rather well.
• People with Wernicke's aphasia (fluent aphasia) have suffered damage to the temporal lobe (towards the rear of the brain). These individuals may speak in long sentences that have no meaning, add unnecessary words, or even create new words. These individuals also have great difficulty in understanding the speech of other people. They usually have no body weakness because their brain injury is not near the parts of the brain that control movement.
• People with Global aphasia have suffered damage to extensive portions of the brain. These people have severe communication difficulties and may be limited in their ability to speak or comprehend language.
• People with Transient aphasia refers to a communication problem that lasts only a few hours or days.
  

The Numbers

According to a National Institutes of Health study in 1997 (N.I.H. Publication 97-4257), approximately one million people in the U.S. have acquired aphasia. The majority of these victims have aphasia as a result of a stroke. In fact, of the 400,000 people who suffer a stroke each year in the U.S., 80,000 are left with aphasia. About one-third of severely head injured persons are aphasic.

Cure

Currently there are no steps to prevent aphasia in the event of a stroke or head trauma. Some studies have cited several possible contributing factors to the onset of aphasia such as a high cholesterol level, but no conclusive results have been released. The condition is determined by the location and size of the area of damage to the brain.
Thus far, no medicine, drugs, or surgery has been known to cure aphasia. Speech therapy is often provided to aphasic patients, but it does not guarantee a cure. Speech therapy is intended to help the patient utilize the remaining skills and learn complementary means of communication. Research and surgeries in the areas of brain repair and regeneration may provide for a "partial cure" in the near future.