Understanding Apraxia of speech

What is Apraxia of speech?

AoS is chronic neurological disorder characterised by impaired, or difficulty with planning, speech movements. There is no negative impact or involvement of things like intelligence, sensory processing or other functions the brain carries out. AoS has also been historically known under different names such as: speech apraxia, verbal dyspraxia, articulatory dyspraxia, etc.

It can result from a number of different things, such as a head injury or stroke, or some other condition where the brain’s healthy tissue has been injured.

Relaying messages from the brain

Within the brain, there are a number of different areas that are responsible to work together in order for us to both comprehend and express speech and language, which is our way to connect with others and the world around us.

When we want to say something (in other words, produce speech), the brain must first encode that message using a number of different linguistic representations that is part of the language system that speaker uses. The brain carries that out below the conscious level. 

After the message has been encoded (or prepared and finalised), it sends it to another part of the brain called the motor cortex, and that is where the brain prepares the planning and coordination of movement for the mouth to produce that message. Neural signals are sent from the motor cortex to the mouth in order for that message to be produced physically by moving, what we call, the articulators (e.g. jaws, tongue, lips, etc).

Speech is a complex action

Speaking is one of the most complex functions we do as humans that is not based on biological need, but is one of the most socially important things we do.

There are numerous sounds that needs to be connected in order to form words and sentences, so the mouth must be able to coordinate those movements with efficient precision in order to be understood by the listener.

In AoS, the motor cortex has experienced some kind of injury, resulting in its efficiency and effectiveness to plan and coordinate those movements. There is a natural knock-on effect which further results in a difficulty producing the intended speech message – this is why we refer to this condition as a speech motor disorder.

What are the symptoms?

People with AoS can present with a number of symptoms, such as (but not limited to): slow rate of speaking, prolonged sounds, distorted articulation of consonants and vowels, difficulty with initiating speech, and difficulty with producing speech that might be long or what we refer to as complex.

Because the impairment resides solely in the planning and coordination, it can be overloaded easily and result in a breakdown of communication. AoS is seen across the entire lifespan, from childhood to the elderly.

The best ways to support people with AoS is to allow them time to speak as initiating speech is difficult, ask for clarification if the listener has not understood and to be aware of that the individual has this condition as that will help the speaker and listener to repair communication breakdowns.