Apraxia of Speech: Two Sides of the Same Coin?
Apraxia of speech is a disorder where the messages from the brain to the articulatory muscles become disrupted, causing the individual to have difficulty producing sounds correctly, or at all. It is important to note that this is not caused by muscle weakness. Individuals with AOS often describe knowing what they want to say, but not being able to produce the correct words or sounds. In face, inconsistency of articulation is a main characteristic of AOS.
Researchers and professionals in the field often debate whether developmental apraxia of speech (DAS) and acquired apraxia of speech (AOS) are fundamentally the same disorder or separate disorders entirely (Maassen, 2002).
The main difference between the two types of apraxia are the time of onset. With DAS it is assumed that the disorder is present from birth, even before symptoms appear; whereas an acquired apraxia is caused by damage to a previously normal speech system. This damage can be caused by traumatic brain injury (TBI), dementia, brain tumors, or progressive neurological disorders. Though most patients with the acquired form are adults, it is possible to acquire this disorder at any age depending on when the brain is injured.
American Speech-Language-Hearing Association. (2015a). Apraxia of speech in adults. Retrieved fromhttp://www.asha.org/public/speech/disorders/ApraxiaAdults/
American Speech-Language-Hearing Association. (2015b). Childhood apraxia of speech. Retrieved fromhttp://www.asha.org/public/speech/disorders/ChildhoodApraxia/
Maassen, B. (2002). Issues contrasting adult acquired versus developmental apraxia of speech. Seminars in Speech and Language, 23(4), 257-266. doi:10.1055/s-2002-35804
National Institute on Deafness and Other Communication Disorders, (2002). Apraxia ofspeech. Retrieved fromhttp://www.nidcd.nih.gov/health/voice/pages/apraxia.aspx