Verbal apraxia, like aphasia, is caused by damage to the brain, but to a different part of the brain. Apraxia, caused by damage to the cerebrum, affects the brain’s ability to plan motor activities. With apraxia, individuals may be unable to respond to the brain’s commands to make certain movements, including those that produce speech. Aphasia, caused by damage to the left hemisphere, is a language disorder in which individuals may have difficulty understanding or producing language.
With apraxia, an individual will be unable to perform tasks or movements when asked; even though he or she may understand the request, the muscles needed to complete the task are not working properly. Apraxia may occur together with aphasia or with dysarthria, which is a muscle weakness affecting speech production.
With apraxia of speech, also called verbal apraxia and dyspraxia, an individual will not be able to put together the muscle movements required to say what he or she wants to say. Sometimes a completely different word than intended may come out of his or her mouth. What he or she says may be distorted; he or she may repeat things or may leave out words or put them in the wrong order. The person may struggle to find the right word or find it difficult to use longer words. At the same time, the individual may be able to use short everyday phrases like “How are you?” with no problem and may be able to write better than he or she can speak.