Motor Speech Disorders: Apraxia and Dysarthria

People with apraxia and dysarthria struggle when their brain fails to effectively communicate with the muscles of the mouth, lungs, and throat for speech production. This can be a developmental impairment or happen as a result of a traumatic injury. People with these disorders generally know what they want to say, but can’t make it come out right. Observable symptoms include, but are not limited to: unintelligible speech, inability to say words or phrases correctly, and insufficient breath support for speech production.

Acquired Apraxia of Speech

Acquired apraxia of speech refers to the loss or impairment of speech skills that a person once had. It is caused by damage to the speech centers of the brain from stroke, traumatic brain injury, tumors, or other neurological diseases. It often occurs along with aphasia and may occur with dysarthria.

Childhood Apraxia of Speech

Childhood Apraxia of Speech (CAS) is also known as developmental apraxia. The symptoms become noticeable as the child learns to speak. CAS may be caused by neurological or genetic disorders, but most often the cause is not known. Children with CAS often have other speech, language, and/or motor problems such as reduced vocabulary, trouble learning to read, or clumsiness.

Symptoms of Apraxia of Speech

Apraxia symptoms may be very mild, with only occasional problems producing long words or sequences of words. They may also be so severe that the person cannot voluntarily produce any sound. People with apraxia of speech may have difficulty sequencing sounds in words (e.g., batle for table) or they may produce the wrong sounds altogether (e.g., dadle for table). They may become frustrated because they are usually aware of their mistakes and try repeatedly to correct their errors; often the harder they try, the more mistakes they make.

Symptoms include:
  • Inconsistent error patterns (e.g., the target word sounds different in each attempt to say the word)
  • More errors on longer words and words with more complex sound patterns
  • Difficulty imitating sounds or words
  • May be able to produce mouth movements without thinking about it (e.g., using the tongue to lick a piece of food off the lip) but cannot produce those same movements when they are told to
  • May be able to produce automatic speech such as counting, naming days of the week, or singing very familiar songs
  • Groping (trial and error movements of the mouth) may occur as the person tries to get his mouth into the correct position to say a word or sound
  • Abnormal rate, rhythm, or intonation pattern of speech

Assessing and Treating Apraxia of Speech

The speech-language pathologist (SLP) will perform a variety of tests to look at the client’s motor speech skills. She may look at his ability to imitate mouth movements, sounds, words, and sentences, or to say them without a model. The SLP will also perform other speech and language tests to rule out other types of disorders. She will ask about the medical history for clients with acquired apraxia, and the developmental and family history for children with suspected CAS.

Therapy will include different activities to work on motor planning of speech movements. Clients may practice sounds, words, and phrases in different ways, often moving from shorter/simpler to longer/more complex targets to practice sequencing and coordinating movements. The SLP may give different types of cues to help the client say the targets correctly, and provide feedback to the client about how well he is doing. Rhythm (clapping or tapping along with speech or singing) or a slow rate of speech may be used to make speech easier. The client will usually need to practice these speech exercises at home. If apraxia is very severe, the SLP may look at using an augmentative or alternative communication method.