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Adult Aphasia: Recent Research

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What is aphasia?

Aphasia (uh-fay'-zhuh) is a communication disorder that can affect a person's ability to use and understand spoken or written words. It results from damage to the side of the brain dominant for language. For most people, this is the left side. Aphasia usually occurs suddenly and often results from a stroke or head injury, but it can also develop slowly because of a brain tumor, an infection, or dementia.


Types of aphasia

There are many different classification systems for aphasia and many different types of aphasia within each system. Some systems are based primarily on the location of the lesion, while others are based solely on the person's behavior. One system adopted by the National Aphasia Association divides aphasia into two broad categories: fluent and non-fluent aphasia.

People with fluent aphasia have problems understanding spoken and written language. This type is also known as sensory, posterior, or Wernicke's aphasia.

People with non-fluent aphasia have difficulty communicating orally and in writing. This type of aphasia is also called motor, anterior, or Broca's aphasia. Within the non-fluent category is the most severe type, called global aphasia. People with this type have difficulty both expressing and understanding written and oral communication.


Aphasia treatment

In general, treatment strives to improve a person's ability to communicate. The most effective treatment begins early in the recovery process and is maintained consistently over time. Major factors that influence the amount of improvement include the cause of the brain damage, the area of the brain that was damaged, the extent of the injury, and the person's general health.

Usually a speech-language pathologist works with other rehabilitation and medical professionals, such as physicians, nurses, neuropsychologists, occupational therapists, physical therapists, and social workers, as well as families, to provide a comprehensive evaluation and treatment plan for the person with aphasia.


Aphasia research at NIDCD

The National Institute on Deafness and Other Communication Disorders (NIDCD) is one of the Institutes of the National Institutes of Health. The NIDCD supports and conducts biomedical and behavioral research and research training on normal and disordered processes of hearing, balance, smell, taste, voice, speech, and language. Currently supported aphasia research focuses on evaluating, characterizing, and treating the disorder, as well as on improving the understanding of the relationship between the language disorder and the brain.


New approaches to evaluation

Scientists are attempting to reveal the underlying problems that cause specific aphasia symptoms. The goal is to understand how injury to a particular brain structure impairs specific portions of a person's language process. The results could be useful in treating many types of aphasia, since the underlying cause can vary.

Other research is attempting to develop a model of sentence comprehension and production that can help provide a functional explanation for aphasia symptoms. These studies look at how difficulties in word representations and processes contribute to problems with sentence production and comprehension so that specific symptoms can be traced back to identifiable processing deficits. This would help focus treatment on the responsible word processes or representations.


New approaches to characterization

Since the same types of aphasia look different from one language to another, some scientists are attempting to distinguish between universal symptoms of the disorder and those that are language specific. Others are examining how people with aphasia maintain their knowledge of a language, but seem to have difficulty accessing that knowledge. Scientists are also comparing aspects of language that are at risk or are protected within and across language types and assessing the effect of stress on language expression in people without aphasia. These studies may help with the development of tests tailored to specific characteristics of individual languages and in clinical services to bilingual communities.


New therapeutic approaches

Pharmacotherapy is a new, experimental approach to treating aphasia. Some studies are testing how drugs can be used in combination with speech therapy to improve recovery of various language functions by increasing the task-related flow of activation in the left hemisphere of the brain. These studies indicate that drugs may help improve aphasia in acute stroke and as an adjuvant to language therapy in postacute and chronic aphasia.

Other treatment approaches use computers to improve the language abilities of people with aphasia. Studies have shown that computer-assisted therapy can help people with aphasia retrieve and produce verbs. People who have auditory problems perceiving the difference between phonemes can benefit from computers, which can be used for speech-therapeutic auditory discrimination exercises.

Researchers are also looking at how treatment of other cognitive deficits involving attention and memory can improve communication deficits.


A closer look at the brain

To understand recovery processes in the brain, some researchers are attempting to use functional MRI (magnetic resonance imaging) to uncover the anatomical organization of the human brain regions involved in comprehending words and sentences. This type of research may improve understanding of how these areas reorganize after focal brain injury. The results could have implications for both the basic understanding of brain function and the diagnosis and treatment of neurological diseases.


About the Recent Research Series

This series is intended to inform health professionals, patients, and the public about progress in understanding the normal and disordered processes of human communication through recent advances made by NIDCD-supported scientists in each of the Institute's seven program areas: hearing, balance, smell, taste, voice, speech, and language.

If you have any other questions, please call the NIDCD Information Clearinghouse. Here are several ways to contact us:

Toll-free: (800) 241-1044
Toll-free TTY: (800) 241-1055
Address: 1 Communication Avenue, Bethesda, MD 20892-3456


Where can I get more information?

NIDCD maintains a directory of organizations that can answer questions and provide printed or electronic information on adult aphasia. Please see the list of organizations at

Use the following keywords to help you search for organizations that are relevant to adult aphasia:

For more information, additional addresses and phone numbers, or a printed list of organizations, contact:

NIDCD Information Clearinghouse
1 Communication Avenue
Bethesda, MD 20892-3456
Toll-free Voice:  (800) 241-1044
Toll-free TTY:  (800) 241-1055
Fax:  (301) 770-8977

NIH Pub. No. 01-4257
June 2001
Updated February 2002


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National Institute on Deafness and Other Communication Disorders. Celebrating 20 years of research: 1988 to 2008