Childhood apraxia of speech (CAS) is a disorder that affects a person’s ability to organise the movements of the muscles used in speech. The person has difficulty making speech sounds voluntarily and stringing these sounds together in the correct order to make words. CAS is a speech disorder that can continue into adult life. Other names for the disorder are developmental apraxia of speech (DAS) or developmental verbal dyspraxia (DVD).
In a person with CAS, there is usually nothing wrong with the muscles used in speech. The difficulty seems to occur because of a breakdown in the program of movement (messages) sent from the brain to the muscles. This does not mean that the person has an intellectual impairment.
Features of CAS
A person diagnosed with CAS may:
· Pronounce the same word differently each time they say it
· Have general difficulties moving the muscles of their mouth and throat – for example, they may have trouble chewing, sucking, blowing or making certain speech sounds
· Look like they are searching or groping for the right sound
· Have difficulty imitating sounds and words
· Use a limited number of consonant sounds when speaking
· Mix up the order of sounds in words
· Have more difficulty saying longer rather than shorter words and sentences.
Signs shown by small children
Some very young children show signs that they may be having difficulty planning movements of their tongue, lips and jaw. Signs that may indicate a child is at risk of future speech difficulties include:
· Babies who don’t play with sounds – for example, coo or babble
· Babies and young children who have difficulties sucking, swallowing and chewing
· Young children who are not starting to speak like other children their age (although remember that there is enormous variation between children)
· Young children who only use noises, gestures and vowel sounds to communicate.
The cause is unknown
There is no known cause of CAS. Some people think that a particular area of the brain has been affected or has not developed normally. There is no evidence to suggest this is correct. Others think there may be a genetic factor that causes a person to have CAS. Again, there is no evidence to support this view. Further research is ongoing to see if a cause can be found.