What is aphasia?
Aphasia is a defect or loss of language function in which the comprehension or expression of words (or nonverbal equivalents of words) is impaired as a result of injury to or degeneration of the language centers in the cerebral cortex. Aphasia is condition characterized by either partial or total loss of the ability to communicate verbally or using written words. A person with aphasia may have difficulty speaking, reading, writing, recognizing the names of objects, or understanding what other people have said. Aphasia is caused by a brain injury, as may occur during a traumatic accident or when the brain is deprived of oxygen during a stroke. It may also be caused by a brain tumor, a disease such as Alzheimer's, or an infection, like encephalitis. Aphasia may be temporary or permanent. Aphasia does not include speech impediments
caused by loss of muscle control.
Aphasia is a total or partial loss of the ability to use words. It may be caused by brain injury or disease. It's most often caused by a stroke that injures the brain's language center. Some people with aphasia recover quickly and completely after a stroke. Others may have permanent speech and language problems. Speech problems can range from trouble finding words to being unable to talk at all. Some people have problems understanding what others are saying or have trouble with reading, writing or math. In other cases, a person with aphasia may have trouble talking but can understand what others say perfectly. Each person's speech and language problem is unique. A language professional (speech therapist) can help set up a treatment plan and help others understand the needs of a person with aphasia. Aphasia is the most common speech disorder among the elderly, followed by dysarthria. Aphasia occurs in about 40% of patients with stroke that affects the left hemisphere (where the cortical language centers reside in about 95% of right-handed persons and in about 60% of left-handed persons).
Aphasia may be classified as receptive, in which expression is better than comprehension; expressive, in which comprehension is better than expression; or global, in which comprehension and expression are both impaired. Some authorities use the terms mixed aphasia and global aphasia interchangeably. However, in general, mixed aphasia refers to less severe global aphasia. Other classifications exist, an indication that aphasia is never purely receptive or purely expressive. No classification is completely satisfactory.
Aphasia is sometimes confused with other conditions that affect speech, such as dysarthria and apraxia. These condition affect the muscles used in speaking rather than language function itself. Dysarthria is a speech disturbance caused by lack of control over the muscles used in speaking, perhaps due to nerve damage. Speech apraxia is a speech disturbance in which language comprehension and muscle control are retained, but the memory of how to use the muscles to form words is not.
More information on aphasia
What is aphasia? - Aphasia is a defect or loss of language function in which the comprehension or expression of words (or nonverbal equivalents of words) is impaired as a result of brain injury.
What is Broca's aphasia? - Broca's aphasia, also called motor aphasia, results from damage to the front portion or frontal lobe of the language-dominant area of the brain.
What is Wernicke's aphasia? - Wernicke's aphasia is caused by damage to the side portion or temporal lobe of the language-dominant area of the brain.
What is global aphasia? - Global aphasia is caused by widespread damage to the language areas of the left hemisphere. As a result, all basic language functions are affected.
What is nominal aphasia? - Nominal aphasia is a form of aphasia in which the subject has difficulty remembering or recognizing names which the subject should know well.
What is conduction aphasia? - Conduction aphasia is a relatively rare form of aphasia, caused by damage to the nerve fibres connecting Wernicke's and Broca's areas.
What causes aphasia? - Aphasia is caused by damage to one or more of the language areas of the brain. This damage affects one or more of the basic language functions.
How is aphasia diagnosed? - Commonly used tests to diagnose aphasia include the Boston Diagnostic Aphasia Examination, the Western Aphasia Battery, and possibly, the Porch Index of Speech Ability.
What's the treatment for aphasia? - Aphasia treatment therapy strives to improve an individual's ability to communicate by helping the person to use remaining abilities, to restore language abilities.
What's the prognosis of aphasia? - The outcome of aphasia is difficult to predict given the wide range of variability of the condition. The location of the injury is important and is clue to prognosis.