In the world of speech therapy, apraxia of speech can be a hot topic to discuss. Many in the field feel that AOS is overdiagnosed, while some believe it is not recognized enough. In reality, AOS is both under diagnosed (some children who have it are not diagnosed) and over diagnosed (some children who do not have it are given the diagnosis). So what exactly is it, and how do we determine if someone really has it or not?
Defining apraxia and motor planning disorders
Apraxia of speech (AOS) is known by several names, including acquired apraxia of speech, verbal apraxia, or childhood apraxia of speech (CAS) when diagnosed in children. It’s important to note that AOS is not caused by a weakness or physical abnormality - AOS is a neurological disorder that affects the planning of movements involved in producing speech.
When apraxia presents later in life due to a neurological injury or damage to the speech area of the brain, it is called acquired apraxia. This type of apraxia refers to a loss of previous speech skills. Childhood apraxia of speech (CAS) is also known as developmental apraxia. The symptoms become noticeable as speech develops. Often the exact cause of CAS is not known, though it may be related to neurological or genetic disorders. Children with CAS often have other speech, language and/or motor problems such as reduced vocabulary, trouble learning to read, or clumsiness.
Neurological or genetic disorders that may be related to AOS include:
Certain mitochondrial disorders
Other intellectual disability
AOS may run in families. Many children with the disorder have a family member with a communication disorder or a learning disability.
Recognizing apraxia and motor planning disorders
AOS symptoms may range in severity - from mild/occasional problems saying longer words or phrases, to severe problems in which the person is unable to voluntarily produce any sounds. AOS may affect the order in which one produces sounds (for example, saying “lippo” instead of “pillow”). It may also cause one to produce the wrong sound entirely (for example, saying “douse” instead of “mouse”). These symptoms can be very frustrating for a person with AOS. They are usually aware of their speech errors and may try to repeat themselves to correct them, often unsuccessfully.
Common symptoms include:
Inconsistent error patterns
Difficulty imitating sounds or words
More errors on longer words and words with more complex sound patterns
Understanding language much better than expressing it
May be able to produce automatic speech such as counting, naming days of the week, or singing very familiar songs
Groping movements of the mouth may occur as the person tries to get their mouth into the correct position to say a word or sound
Problems with “prosody,” the varying rhythms and tones that help express meaning (the emotional content) of speech
Some children have additional signs, such as:
Fine motor delays
Sensory processing difficulties
Overall delayed language development
Problems with reading, writing, spelling, or math
Chewing and swallowing difficulties
For more information on apraxia symptoms and how they may present in a child, check out this YouTube video that has several examples (starting around the 2-minute mark).
Because apraxia is often misdiagnosed as a similar speech/language disorder causing limited or unclear speech, it’s important to find an experienced speech-language pathologist (SLP) to make a definitive diagnosis. The SLP can distinguish AOS from other types of speech difficulties.
When evaluating a person for suspected AOS, a comprehensive medical history should be discussed. Observations of spontaneous speech may need to occur over several visits and in various settings (e.g., home videos, school observation, in-clinic visits). The SLP can rule out other possible causes for the speech problems, including muscle weakness, comprehension problems, or hearing difficulties.
Treating apraxia and motor planning disorders
Treatment of AOS is primarily focused on teaching specific movements and patterns of movements needed to make speech sounds. Coordination of the articulators (tongue, lips, airflow, vocal cords, etc.) is taught and practiced at length to improve muscle memory of speech movements. Once progress is made with simpler targets (e.g., single sounds, short words), therapy expands to more complex targets such as sequenced sounds/words, longer phrases, and spontaneous sentences. Rhythm - clapping, tapping along with speech or singing – or a reduced speaking rate may be incorporated to help movements flow more smoothly. In more severe cases of AOS where progress with verbal speech is limited, alternative communication methods may be considered.