What is Apraxia?
Apraxia is a motor speech disorder which affects voluntary or learned motor acts. Apraxia can be oral, verbal, or developmental. Caused by any damage or accident to the area of the brain responsible for performing these acts, apraxia may or may not exist with a language disorder and can effect any part of the body. Because our focus is communication, we will address the types of apraxia that impair it.
Apraxia can be oral, verbal, or developmental. In oral apraxia the patient has difficulty performing nonspeech tasks with muscles in the larynx, pharynx, tongue, or cheeks.
Reflexive or automatic tasks are intact, but the patient is usually unable to carry out specific directions when asked. For example the patient may open his mouth when asked to close his eyes or say the word “blow” when asked to blow out a match. It is not uncommon for a patient to insist he has elicited the correct movement when no movement has been made at all. Many of the responses can be considered bizarre, while the patient may be completely unaware of any abnormality.
Verbal apraxia is defined as difficulty executing the appropriate movements for speech when paralysis, weakness, or incoordination exist. As a result, apraxic patients may have extreme difficulty making speech movements. Such impairments may lead to the omission, distortion, or replacement of certain sounds. Errors seem to increase as the length of the word or utterance increases, and initiating speech can be almost impossible. Repetition of phrases may be inconsistent and overall quality of sound may be poor. Debate regarding the cause of apraxia continues. It is generally accepted however, that the lesion causing apraxia is most likely deep within the left frontal lobe.
Apraxia can also occur developmentally in children, as noted by awkward speech movements that cannot be connected to dysarthria. Symptoms may include difficulty initiating speech, difficulty sequencing speech sounds, and oral struggle behaviors. Children with developmental apraxia may not show evidence of a brain lesion, while adults always do.