What is Aphasia?
Aphasia is the impairment of spoken or written language caused by injury to the brain. It is also commonly referred to as Dysphasia. There are several different categories and many different types of Aphasia.
What causes Aphasia?
Aphasia is usually the result of a brain tumor, lesion, stroke, or severe blow to the head. Right-handed people can only acquire Aphasia if they have an injury in the left cerebral hemisphere, whereas left-handed people can quire Aphasia from an injury in either the right or left cerebral hemisphere. Therefor, left-handed people are more prone to getting Aphasia.
Categories of Aphasia
There are several different systems for categorizing Aphasia. The more common one consists of two broad classifications: Broca’s and Wernickes. In Broca’s, the patient normally understands speech fairly well, but has difficulty in retrieving words and has hence naming objects or expressing themselves.
In Wernickes, the patient normally produces fluent but incomprehensible speech, or jargon, and comprehends poorly the speech of others.
The other systems places all types of Aphasia in categories labeled fluent and nonfluent. In fluent, the patient usually has a normal rate of speech without the hesitations or pauses common in nonfluent. Generally, people whose type of Aphasia falls under the fluent category have difficulty comprehending speech. In nonfluent, the patient usually produces effortful, telegraphic style speech marked by pauses. The ability of these patients to understand speech is usually good.
Types of Aphasia
There are many different types of Aphasia. Some of them are:
Global Aphasia: This is the most severe form of Aphasia. Patients with Global Aphasia produce hardly any recognizable words and understand barely any spoken language. People with Global Aphasia do not have the ability to read or write.
Broca’s Aphasia: This is a form of Aphasia where the patient has reduced speech outturn, and produces mainly short utterances of less than four words. Vocabulary access is limited, and forming of sound is often difficult and clumsy. The patient may understand speech reasonably well and may be able to read, but is limited in their writing abilities.
Mixed non-fluent Aphasia: This term is applied to patients with an illness similar to sever Broca’s Aphasia. Unlike Broca’s Aphasia, tough, patients with mixed non-fluent Aphasia are limited in their understanding of speech and cannot read or write much beyond an elementary level. It can also be known as damage to the frontal lobe of the brain.
Wernicke’s Aphasia: The patient has lost the ability to understand the meaning of spoken words, while the ability to produce understandable, connected speech has not been much affected. Their speech, though, is not really normal, as sentences do not hang together and unrelated words infringe. Writing and reading are often severely impaired. It can also be known as damage to the temporal lobe of the brain.
Sensory Aphasia: The loss of the meaning of symbols, leaving the patient to hear but not understand words.
Anomic Aphasia: Patients with this have an inability to supply words for the very things they are trying to talk about. As a result their speech is full of vague expressions and frustration.
Transient Aphasia: This is the name for temporary aphasia, which lasts for only a few hours or days.
Characteristics of patients with Aphasia
When a person with Aphasia speaks the smaller words are often left out, reducing the sentence to “Key” words, like a message from a telegraph. Some times sounds are mixed up, like calling a “bank teller” a “tank beller,” and some times words are mixed up, like calling a table a chair. People with Aphasia often need more time than a normal person would to understand what is being said to them. They often do not immediately know the meaning of the words they are hearing, kind of like listening to somebody speaking in a foreign language. Many people with Aphasia, however, are able to remember certain automatic responses, like naming the days of the week, counting, and social responses, like please and thank you.
The most common characteristic in Aphasia is difficulty in naming.
Statistics
About one million people in the United States have Aphasia. The majority of these people have the disease as the result of a stroke. About one third of people with severe head injuries have it. It is estimated that about 80,000 people worldwide acquire aphasia each year. Most people who get it are in their middle to late years, although anyone can.
History of Aphasia
The earliest written references to speechlessness due to trauma can be found in the writings of the ancient Greek philosopher Hypocrites. It has only been in the past 20 years that scientists have been able to do productive research on Aphasia and its origins.