brain, spinal cord, and nerve disorders
Aphasia
Introduction
Aphasia is partial or complete loss of the ability to express or understand spoken or written language. It results from damage to the areas of the brain that control language. People may have difficulty reading, writing, speaking, understanding, or repeating language. Doctors can usually identify the problem by asking the person questions. Imaging tests, such as computed tomography (CT) or magnetic resonance imaging (MRI), are done. Speech therapy can help many people with aphasia. In right-handed people and about two thirds of left-handed people, language function is controlled by the left half of brain (left cerebral hemisphere). In the other third of left-handed people, much of language function is controlled by the right half. Thus, in most people, language function is controlled by the following areas of the brain: Part of the left frontal lobe called Broca area Part of the left temporal lobe called Wernicke area The lower back part of the left parietal lobe (next to the Wernicke area) The connections between these areas Damage to any part of these areas interferes with at least some aspect of language function. Usually, writing and speech are affected similarly. 