Aphasia

*Aphasia facts medical author: Charles Patrick Davis, MD, PhD

• Aphasia, a disturbance in the formulation and comprehension of language, is due to damage to brain tissue areas responsible for language; aphasia may occur suddenly or develop over time, depending on the type and location of brain tissue damage.
• Strokes are a common cause of aphasia.
• Causes of aphasia are mainly due to strokes, severe head trauma, brain tumors, and brain infections; however, any brain tissue damage for whatever reason that occurs in the language centers of the brain may cause aphasia.
• Two broad categories of aphasia are fluent and non-fluent (also termed Broca's aphasia), but there are subtypes of these categories.
• Aphasia, especially a subtype, is diagnosed by tests given to people to determine the individual's ability to communicate and understand, using language skills; neurologists most frequently diagnose the type of aphasia.
• Aphasia is mainly treated by speech and language therapy and therapy methods are based on the extent and locale of the brain damage.
• Aphasia research is ongoing; studies include revealing underlying problems of brain tissue damage, the links between comprehension and expression, rehabilitation methods, drug therapy, speech therapy, and other ways to understand and treat aspects of aphasia.

Aphasia is a neurological disorder caused by damage to the portions of the brain that are responsible for language. Primary signs of the disorder include difficulty in expressing oneself when speaking, trouble understanding speech, and difficulty with reading and writing. Aphasia is not a disease, but a symptom of brain damage.

Most commonly seen in adults who have suffered a stroke, aphasia can also result from a brain tumor, infection, head injury, or dementia that damages the brain. It is estimated that about 1 million people in the United States today suffer from aphasia. The type and severity of language dysfunction depends on the precise location and extent of the damaged brain tissue.

Generally, aphasia can be divided into four broad categories: (1) Expressive aphasia involves difficulty in conveying thoughts through speech or writing. The patient knows what he wants to say, but cannot find the words he needs. (2) Receptive aphasia involves difficulty understanding spoken or written language. The patient hears the voice or sees the print but cannot make sense of the words. (3) Patients with anomic or amnesia aphasia, the least severe form of aphasia, have difficulty in using the correct names for particular objects, people, places, or events. (4) Global aphasia results from severe and extensive damage to the language areas of the brain. Patients lose almost all language function, both comprehension and expression. They cannot speak or understand speech, nor can they read or write.

Picture of aphasia

In some instances, an individual will completely recover from aphasia without treatment. In most cases, however, language therapy should begin as soon as possible and be tailored to the individual needs of the patient. Rehabilitation with a speech pathologist involves extensive exercises in which patients read, write, follow directions, and repeat what they hear. Computer-aided therapy may supplement standard language therapy.

The outcome of aphasia is difficult to predict given the wide range of variability of the condition. Generally, people who are younger or have less extensive brain damage fare better. The location of the injury is also important and is another clue to prognosis. In general, patients tend to recover skills in language comprehension more completely than those skills involving expression.

The NINDS and the National Institute on Deafness and Other Communication Disorders conduct and support a broad range of scientific investigations to increase our understanding of aphasia, find better treatments, and discover improved methods to restore lost function to people who have aphasia.