Acquired apraxia of speech (AOS) in adults is a neurologic speech disorder. It affects a person’s ability to control the muscles responsible for forming words. The nerve pathways between your brain and your mouth get disrupted, which makes it challenging for your tongue and lips to move in the correct way to form words. AOS develops later in life and often occurs alongside other speech disorders, such as aphasia and dysarthria.

What Is Acquired Apraxia of Speech in Adults?

Acquired apraxia of speech (AOS) in adults is a rare disorder that develops later in life, making it different than childhood apraxia of speech. AOS is a neurologic speech disorder that significantly impairs a person’s capacity to plan or program sensorimotor commands needed for directing movement necessary for normal speech.

In AOS, nerve pathways between the brain and the mouth get disrupted, which negatively affects planning the sequence of movements related to speech. Essentially, the brain knows what to say but cannot appropriately plan or follow the sequence of movements necessary for forming words and speaking. AOS is not weakness or paralysis of the speech muscles.

The severity of AOS varies between individuals. Mild cases may only affect a few speech sounds or pronunciations with longer words containing several syllables. In more severe cases, communicating through speaking may prove too difficult and requires the help of alternative communication methods.

How Rare Is Apraxia of Speech in Adults?

AOS is generally considered a rare disorder in adults, however, there has been some debate regarding how many people go undiagnosed. It may be more accurate to say the number of adults living with apraxia is currently unknown.

What Causes Apraxia of Speech in Adults?

AOS occurs when there is a disruption in the nerve pathways between the brain and the mouth, which is usually caused by an injury to the brain or a condition that affects the brain. Possible causes of AOS include:

• Tumor
• Stroke
• Alzheimer’s disease
• Parkinson’s disease
• Dementia
• Frontotemporal dementia
• Cognitive impairment
• Traumatic brain injury

Acquired Apraxia of Speech Symptoms

Symptoms of AOS vary between individuals and can range from mild to severe. Symptoms may include:

• Changes in prosody or speech rhythms and inflection.
• Difficulty saying the correct word, even if you know the correct word.
• Difficulty making certain sounds.
• Inability or difficulty in saying longer words that have more syllables.
• Variations in your ability to say certain words from one day to the next.

Acquired Apraxia of Speech Assessment and Diagnosis

AOS is usually diagnosed by a speech-language pathologist (SLP). Your SLP will take you through a series of assessments to help rule out other conditions and determine an AOS diagnosis. A comprehensive evaluation process typically includes:

• Medical history. Your SLP will take a thorough medical history, which helps to rule out other conditions, check for genetic links, and assess for any brain injuries or health conditions that can cause AOS.
• Hearing test. Administering a hearing test can also rule out other conditions that may be causing difficulties with speech.
• Speech production. Your SLP will listen for your ability to produce individual sounds, words, and sentences, assessing for any difficulty with articulation, clarity, and fluency.
• Oral motor skills. To assess oral motor skills, your SLP will give you an oral motor examination that evaluates strength, coordination, and flexibility of the lips, tongue, jaw, and mouth. Your SLP will be looking for any limitations that impact speech production.
• Phonological awareness. This assessment evaluates your ability to break down words into syllables and identify individual sounds.
• Language abilities. A language evaluation will assess your language skills in language comprehension, vocabulary, spoken language skills, and grammar. The assessment will identify any potential communication impairments.

Treatment for Acquired Apraxia of Speech

Treatment for AOS varies between individuals, usually depending on the severity of the condition. Most treatment requires the help of a speech-language pathologist. Your SLP will create a treatment plan based on your individual needs. Your treatment plan will address specific motor planning and coordination challenges that affect speech production. Three different strategies or treatment approaches include:

• Sensory cueing. Using visual, auditory, and tactile cues can give people with AOS helpful feedback and prompts that can aid in producing certain sounds and sequences during speech.
• Rate and rhythm control. This strategy aims to modify speech rate and introduce rhythmic patterns to help facilitate speech production.
• Augmentative and alternative communication (AAC). If speech proves too challenging, your SLP may incorporate AAC devices into therapy. AAC devices can range from picture boards to speech-generating devices.

Resources and Support for Acquired Apraxia of Speech

People with AOS benefit from having support from family and friends. Support from friends and family can look like:

• Have patience and allow the person enough time to communicate.
• Communicate face to face.
• Have an established topic so both parties know what is being talked about.
• Clarify what you have heard by using yes or no questions, or ask questions that offer two to three choices.
• Do not pretend that you understand when you do not.
• Repeat what you have heard and ask the person to confirm if your understanding is correct.
• Focus on the parts that are still unclear and try a different approach.
• Agree to come back to the topic later if you cannot figure it out.
• Provide pen and paper or electronic device to aid with communication.

It is also important to be able to connect those with AOS to helpful resources. Ask your SLP what resources might be available to you!

FAQs About Acquired Apraxia of Speech

How Does Apraxia of Speech Differ from Aphasia or Dysarthria?

Apraxia of speech differs from aphasia and dysarthria in several ways. The biggest difference between AOS and aphasia is that AOS is a disruption of nerve pathways between the brain and mouth that impact the planning of movements needed for speech. Aphasia is a language disorder that is caused by damage in a specific area of the brain that impacts language comprehension and language expression. Dysarthria is a motor speech disorder that involves difficulty with coordinating or controlling the movements needed for speech. It can be caused by weak or poorly coordinated muscles.

Can Apraxia of Speech Be Cured in Adults?

There is no single cure for adult AOS. However, working with an SLP who creates a treatment plan for your unique needs may lead to significant improvement in speech and may even get your speech ability back to relatively normal.