- Apraxia of speech, also known as verbal apraxia or dyspraxia, is a speech disorder in which a person has trouble saying what he or she wants to say correctly and consistently. It is not due to weakness or paralysis of the speech muscles (the muscles of the face, tongue, and lips). The severity of apraxia of speech can range from mild to severe. Childhood Apraxia of Speech (CAS) presents in children who have no evidence of difficulty with strength or range of motion of the articulators, but are unable to execute speech movements because of motor planning and coordination problems. This is not to be confused with phonological impairments in children with normal coordination of the articulators during speech
- There are two main types of speech apraxia: acquired apraxia of speech and developmental apraxia of speech. Acquired apraxia of speech can affect a person at any age, although it most typically occurs in adults. It is caused by damage to the parts of the brain that are involved in speaking, and involves the loss or impairment of existing speech abilities. The disorder may result from a stroke, head injury, tumor, or other illness affecting the brain. Acquired apraxia of speech may occur together with muscle weakness affecting speech production (dysarthria) or language difficulties caused by damage to the nervous system (aphasia).
Developmental apraxia of speech (DAS) occurs in children and is present from birth. It appears to affect more boys than girls. This speech disorder goes by several other names, including developmental verbal apraxia, developmental verbal dyspraxia, articulatory apraxia, and childhood apraxia of speech. DAS is different from what is known as a developmental delay of speech, in which a child follows the “typical” path of speech development but does so more slowly than normal.
The cause or causes of DAS are not yet known. Some scientists believe that DAS is a disorder related to a child’s overall language development. Others believe it is a neurological disorder that affects the brain’s ability to send the proper signals to move the muscles involved in speech. However, brain imaging and other studies have not found evidence of specific brain lesions or differences in brain structure in children with DAS. Children with DAS often have family members who have a history of communication disorders or learning disabilities. This observation
- People with either form of apraxia of speech may have a number of different speech characteristics, or symptoms. One of the most notable symptoms is difficulty putting sounds and syllables together in the correct order to form words. Longer or more complex words are usually harder to say than shorter or simpler words. People with apraxia of speech also tend to make inconsistent mistakes when speaking. For example, they may say a difficult word correctly but then have trouble repeating it, or they may be able to say a particular sound one day and have trouble with the same sound the next day. People with apraxia of speech often appear to be groping for the right sound or word, and may try saying a word several times before they say it correctly. Another common characteristic of apraxia of speech is the incorrect use of “prosody” — that is, the varying rhythms, stresses, and inflections of speech that are used to help express meaning.
- Children with developmental apraxia of speech generally can understand language much better than they are able to use language to express themselves. Some children with the disorder may also have other problems. These can include other speech problems, such as dysarthria; language problems such as poor vocabulary, incorrect grammar, and difficulty in clearly organizing spoken information; problems with reading, writing, spelling, or math; coordination or “motor-skill” problems; and chewing and swallowing difficulties.
- General things to look for include the following:
A Very Young Child: Does not coo or babble as an infant, first words are late, and they may be missing sounds, only a few different consonant and vowel sounds, problems combining sounds; may show long pauses between sounds, simplifies words by replacing difficult sounds with easier ones or by deleting difficult sounds (although all children do this, the child with apraxia of speech does so more often), may have problems eating
An Older Child: makes inconsistent sound errors that are not the result of immaturity, can understand language much better than he or she can talk, has difficulty imitating speech, but imitated speech is more clear than spontaneous speech, may appear to be groping when attempting to produce sounds or to coordinate the lips, tongue, and jaw for purposeful movement, has more difficulty saying longer words or phrases clearly than shorter ones, appears to have more difficulty when he or she is anxious, is hard to understand, especially for an unfamiliar listener, sounds choppy, monotonous, or stresses the wrong syllable or word
Potential Other Problems: Delayed language development, other expressive language problems like word order confusions and word recall, difficulties with fine motor movement/coordination, over sensitive (hypersensitive) or under sensitive (hyposensitive) in their mouths (e.g., may not like toothbrushing or crunchy foods, may not be able to identify an object in their mouth through touch), children with CAS or other speech problems may have problems when learning to read, spell, and write