Apraxia is a motor speech disorder that is present from birth. What that means, is that it is a condition that is neurological in nature. It adversely affects the ability to speak, by creating a disruption in the message sent from the brain to the muscles of the mouth. The message is the program or steps for how to make speech sounds.
Each speech sound can be thought of as a musical note. Certain conditions need to occur for the sound to be produced. Think of playing a guitar. To create a c-note certain conditions need to be meet. The guitar must have all its strings stretched to the correct level of tightness. The player needs to know the number of fingers and placement of one's fingers onto the neck of the guitar. Then the player needs to strum the strings at the same time as holding the finger placement of the neck. A song, similar to a conversation, has many notes strung together in a particular order. Play the notes in the wrong order or too quickly or slowly and the song doesn't sound right. It may be so disorganized and different than the intended song that the song will be unrecognizable.
Now think of that analogy with speech. The conditions for production of speech sounds include: exhalation of breath, presence or absence of vocal fold movement (voice), and placement of tongue, lips, and teeth. Again it all needs to happen in a particular sequence for one intended speech sound to sound correct. Now multiple that by the multiple sounds in just one word and then by the number of words needed to express a thought or desire! That's a lot of planning, organization, and synchronization. Individuals with apraxia can create the message in their brain and the muscles can execute the necessary movements, but somehow there is a breakdown in the transmission from the brain to the muscles of the mouth.
Diagnosis of apraxia is made by a speech-language pathologist (SLP) using informal and/or formal tests. Apraxia is diagnosed based upon the absence and/or presence of certain speech and developmental characteristics. At this time, there is not a MRI, cat-scan, blood test, or other medical test that can identify if an individual has apraxia. To the left, is a graphic that gives some of those characteristics that SLPs look for. These are speech characteristics that are more indicative of apraxia versus an articulation disorder or developmental error in a speech sound. In addition, children with apraxia tend to have higher receptive language (what they understand) than their expressive language skills (what they can say). In language disordered children, it is the other way around. Apraxia can occur in children with other disorders as well. On common dual diagnosis is autism and apraxia. Again a cause or link is not yet understood.
Often times, children with apraxia are very frustrated and often cry or tantrum. Or they simply shut down and refuse to communicate. Think if you had been trying to sequence a movement, like tying your shoes for 2 years; you would be extremely frustrated, feel stupid, and/or give up learning the task. This is how children with apraxia feel. Check out this great article-----
http://community.advanceweb.com/blogs/sp_1/archive/2010/01/29/effective-apraxia-therapy.aspx
http://www.apraxia-kids.org/
http://www.nidcd.nih.gov/health/voice/pages/apraxia.aspx