Aphasia: A Language Disorder

Aphasia: A Language Disorder

"My most valuable tool is words, the words I can now use only with difficulty. My voice is debilitated - mute, a prisoner of a communication system damaged by a stroke that has robbed me of language," stated A. H. Raskins, one of approximately one million people in the United States who suffer from aphasia (1), a disorder which limits the comprehension and expression of language. It is an acquired impairment due to brain injury in the left cerebral hemisphere. The most common cause of aphasia is a stroke, but other causes are brain tumors, head injury, or other neuralgic illnesses. Of the estimated 400,000 strokes which occur a year, approximately 80,000 of those patients develop some form of aphasia (2). Another important observation is that within the United States, there are twice as many people with aphasia as there are individuals with Parkinson's disease (2). Yet, what is so astounding is the lack of public awareness about aphasia. Aphasia attacks an intricate part of a person's daily life - the simple act of communication and sharing. The disbursement of such a tool deprives an individual of education learned through their life, often leaving the ill fated feeling hopeless and alone. In considering the effects of aphasia, a deeper analysis of the two most common forms of aphasia will be examined: Broca's aphasia and Wernicke's aphasia. While both forms occur usually as a result of a stroke in the left hemisphere of the brain, their particular site of impairment produces different side effects in an individual's comprehension and speech. These regions have been further studied through experimental researches such as positron emission tomography (PET). Moreover, although there is currently no cure for the disorder, there are treatments and certain guidelines to follow when encountering an aphasic.

In physiological terms, Broca's aphasia and Wernicke's aphasia occur in the left hemisphere of the brain, which is responsible for controlling the right side of the body along with speech and language abilities. Broca's aphasia affects the frontal lobe adjacent to the primary motor cortex, and Wernicke's aphasia affects the posterior portion of the first frontal lobe (3). A general distinction made between the two disorders are that Broca's aphasia limits speech, while Wernicke's aphasia limits comprehension.

Broca's aphasia characterizes patients as people who has loss the production of complete sentence structures in speech and writing. Although the individual may retain the usage of nouns and verbs, the aphasic may have lost all forms of pronouns, articles, and conjunctions (3).