Definition: Difficulty understanding the speech of other people and/or expressing oneself verbally. This is a result of damage to the part of the brain that is responsible for language, specifically the cerebral cortex.
Although usually used in reference to spoken language, aphasia is sometimes used to mean inability to use or understand written language.
People with multiple sclerosis (MS) often have cognitive impairments which affect speech, resulting in word-finding delays or problems remembering how to spell words. This is most often classified as dysphasia, which is less severe than aphasia. True aphasia is an uncommon symptom of MS.
Aphasia should also be differentiated from problems which affect the voice in people with MS, such as dysarthria or dysphonia.
