These are disorders of motor speech production. They can be congenital (present from birth) or acquired (resulting from stroke, head injury, or illness). The act of producing understandable speech is very complex. The brain, having decided what message it wishes to send, must then send a series of signals to the speech muscles, telling them what to do. The muscles must then act in a coordinated fashion to produce the series of sounds intended. Many things can go wrong along the way. Please click below to see just what can go wrong.