Giving a voice to individuals with apraxia of speech
Understanding Nonverbal Oral Apraxia
Understanding difficulties with voluntary movements of the mouth and face
Nonverbal oral apraxia (NVOA), also known as oral apraxia or buccofacial apraxia, is a neurological condition affecting a person's ability to plan and perform voluntary movements involving the mouth, lips, tongue and face.
An individual may have difficulty carrying out movements such as sticking out their tongue, blowing a kiss or moving their lips into a particular position when asked, even though the muscles themselves are capable of moving.
Non verbal oral apraxia as a distinct condition
Nonverbal oral apraxia can occur in children and adults. It may be associated with neurological conditions, including stroke and other acquired brain injuries, and can also occur alongside childhood apraxia of speech.
Although nonverbal oral apraxia and apraxia of speech can occur together, they are distinct conditions and should not be confused.
What Is Nonverbal Oral Apraxia?
Nonverbal oral apraxia is a disorder affecting the planning and execution of voluntary, non-speech movements involving the oral and facial structures.
The brain has difficulty organising the movements required to perform a particular action, despite the individual understanding what they have been asked to do and having sufficient muscle strength and range of movement.
For example, an individual may be able to move their tongue naturally while eating but struggle to stick it out when specifically instructed to do so.
Similarly, they may smile spontaneously when amused but have difficulty producing a smile on command.
This difference between automatic and voluntary movements is an important characteristic of apraxia.
Movements that may be affected
Movements that may be affected
Nonverbal oral apraxia is a disorder affecting the planning and execution of voluntary, non-speech movements involving the oral and facial structures.
The brain has difficulty organising the movements required to perform a particular action, despite the individual understanding what they have been asked to do and having sufficient muscle strength and range of movement.
For example, an individual may be able to move their tongue naturally while eating but struggle to stick it out when specifically instructed to do so.
Similarly, they may smile spontaneously when amused but have difficulty producing a smile on command.
This difference between automatic and voluntary movements is an important characteristic of apraxia.
Signs and Symptoms of Nonverbal Oral Apraxia
Common characteristics
The most recognisable feature of nonverbal oral apraxia is difficulty performing voluntary oral or facial movements that the individual may be capable of producing automatically.
Difficulty following movement instructions
An individual may understand an instruction such as “stick out your tongue” but be unable to perform the movement accurately.
Difficulty imitating movements
Watching someone else perform an action does not necessarily enable the individual to reproduce it.
Inconsistent performance
A movement may be achieved successfully on one occasion but prove difficult to repeat.
Searching movements
Some individuals may make several attempts to position their lips, tongue or jaw correctly before achieving the intended movement.
Differences between automatic and voluntary movements
An individual may smile naturally during conversation but struggle to smile when asked.
Difficulty sequencing movements
Performing a series of oral movements may be more challenging than producing an individual movement.
Differential diagnosis of Oral Apraxia From Other Disorders
Symptoms of other disorders that are not oral apraxia
Nonverbal oral apraxia does not automatically indicate:
- Reduced intelligence.
- Poor language comprehension.
- Muscle weakness.
- An inability to communicate.
- An inability to speak.
- A swallowing disorder
Difficulties alongside a diagnosis of oral apraxia
Some individuals have isolated difficulties with voluntary oral movements, while others have additional neurological, motor or communication conditions.
The presence of these symptoms does not establish a diagnosis on its own. A comprehensive clinical assessment is required.
Are oral apraxia and apraxia of speech the same thing?
Sometimes, both terms are used interchangeably by clinicians.
Nonverbal oral apraxia and apraxia of speech are both neurological disorders involving difficulties with motor planning, but they affect different types of movement.
Can someone have both conditions?
Yes.
Nonverbal oral apraxia and apraxia of speech can occur together, particularly following neurological injury.
However, they can also occur independently.
A person may experience significant difficulty with voluntary oral movements but have relatively preserved speech abilities.
Conversely, someone with apraxia of speech may be able to perform non-speech oral movements without difficulty.
Why is this distinction important?
Why is this distinction important?
The movements involved in speaking are not identical to those used for non-speech oral activities.
Being able to stick out the tongue, blow or move the lips on command does not necessarily indicate that a person can plan and coordinate speech movements effectively.
Likewise, difficulty performing non-speech oral movements does not automatically explain a speech disorder.
Assessment and treatment should therefore consider the two conditions separately.
Causes of Nonverbal Oral Apraxia
What Causes Nonverbal Oral Apraxia?
Nonverbal oral apraxia is associated with disruption to the neurological systems responsible for planning and organising voluntary movements.
It can occur following acquired neurological damage or alongside developmental conditions.
Stroke-cerebrovascular accident (CVA)
Nonverbal oral apraxia may develop following a stroke affecting brain networks involved in voluntary movement planning.
An individual may retain the physical ability to move their mouth and face but experience difficulty performing particular movements on command.
Traumatic brain injury
Injuries affecting the brain's motor planning networks may result in difficulties performing purposeful oral and facial movements.
Neurological conditions
Nonverbal oral apraxia may occur alongside neurological disorders, including some neurodegenerative conditions.
It has been described in association with conditions affecting movement planning and cortical motor networks.
Developmental presentations
You can be born with non-verbal oral apraxia or develop it in early childhood. Difficulties with voluntary oral movements can also be identified in children.
Some children with childhood apraxia of speech demonstrate co-occurring difficulties with non-speech oral movements.
However, the relationship between developmental oral apraxia and childhood apraxia of speech is complex, and difficulties performing oral movements should not be assumed to indicate either condition.
Treatment and therapy for non-verbal oral apraxia
Can nonverbal oral apraxia be treated?
Treatment depends on the underlying cause, severity, functional impact and individual needs.
Intervention may involve:
- Practising selected voluntary movements that have a meaningful functional purpose.
- Using visual demonstrations and imitation.
- Providing verbal, visual or other cues.
- Breaking complex movement sequences into smaller components.
- Gradually reducing assistance as movements become more consistent.
- Developing compensatory strategies when particular movements remain difficult.
Treatment approaches should be selected according to the individual's presentation.
What happens during an assessment?
Usually a speech and language professional may examine the individual's ability to perform a range of voluntary oral and facial movements.
This may include:
Following verbal instructions
The individual may be asked to perform movements such as sticking out their tongue, smiling or puckering their lips.
Imitating movements
The clinician demonstrates an action and observes whether the individual can reproduce it.
Comparing automatic and voluntary movements
The clinician considers whether movements that occur naturally can also be produced deliberately.
Assessing movement accuracy
The therapist observes whether movements are accurate, consistent and appropriately sequenced.
Examining oral structure and function
Assessment may include checking muscle strength, range of movement, symmetry and other aspects of oral function to help distinguish apraxia from other difficulties.
Assessing speech and swallowing where appropriate
If the individual also experiences speech or swallowing difficulties, these should be assessed separately.