What is aphasia?
Aphasia is defined as impaired language ability. It ranges from forgetting names (nominal aphasia) to complete inability to speak, read or write (global aphasia).
A neurologist and/or speech pathologist should evaluate a patient with aphasia. The commonest cause of aphasia is brain damage from a stroke (cerebrovascular accident or CVA). Strokes occur from thrombosis (clotting) of vessels supplying blood to the brain, hemorrhage (bleeding) from vessels within the brain, or clots originating elsewhere in the circulatory system which then lodge in the vessels of the brain.
Aphasia patients are given a thorough neurologic examination. An MRI (Magnetic Resonance Imaging) scan is used to detect areas of brain injury.
Early neurologists Paul Broca and Carl Wernicke described aphasia and identified areas of brain injury responsible for the condition. Some of their work has been superseded by modern imaging studies, and it is currently felt that assigning specific brain injury sites to aphasia type is difficult.
One useful classification of aphasia is as follows:
1. Receptive Aphasia
a. Word deafness (patient hears but does not understand words)
b. Alexia (patient reads but does not understand words)
c. Visual asymbolia (words are disorganized and can not be recognized)
2. Intermediate Aphasia: Nominal amnestic aphasia (patient can not remember names)
3. Expressive Aphasia, also called Broca’s aphasia (patient has difficulty putting thoughts into words)