Primary progressive apraxia of speech (PPAOS)

This speech disorder happens when the brain does not communicate properly with the muscles used for speech.

Update Date: 22.05.2026

Overview
Symptoms
Causes
Risk factors
Diagnosis
Treatment
Coping and support
Preparing for an appointment

Overview

Primary progressive apraxia of speech (PPAOS) is a neurodegenerative disease that slowly affects a person's ability to speak clearly. It is not caused by weakness of the mouth muscles. In people with PPAOS, it is hard for the brain to plan and coordinate the movements needed for speech. Talking may become more difficult over time. Eventually, some people may slowly lose the ability to speak. PPAOS is a condition that develops in adulthood. It is not seen in children.

Symptoms

People with PPAOS often know exactly what they want to say, but their speech becomes slow. Words may be difficult to form and hard for others to understand. The signals between the brain and the mouth muscles are not sent correctly. The brain struggles to make the lips, jaw and tongue move as they typically do.

The symptoms of primary progressive apraxia of speech usually begin gradually and change slowly over time. The early symptoms of primary progressive apraxia of speech may include:

  • Speaking more slowly than usual.
  • Pausing between words, especially those that have more than one syllable.
  • Difficulty expressing emotion through the voice.
  • Difficulty forming words, especially those that are longer and more complex.

Later symptoms:

  • Dysarthria. Speech becomes weak or imprecise.
  • Aphasia. Language issues, such as putting words in the correct order or difficulty understanding what you hear and thinking of the words you want to say.
  • Dysphagia. Issues with swallowing.
  • Spasticity. PPAOS may overlap with other conditions, which may cause stiffness to spread to other areas of the body, such as the arms, legs and torso.
  • Apraxia in other parts of the body. This may include not being able to use a common object, such as a brush or comb. It also may include not being able to do a familiar task, such as tie a shoe or write a note. This is because the brain has trouble planning.

Causes

Primary progressive apraxia of speech (PPAOS) is caused by gradual damage to cells in the front parts of the brain. These areas control speech planning and help organize speech timing and movements.

PPAOS happens when communication between nerve cells does not work as it should. In most people with PPAOS, the condition is linked to diseases that involve the buildup of a protein called tau. Many people with this condition also may have one of two diseases that cause symptoms. These are the two most common conditions linked to PPAOS:

  • Corticobasal degeneration (CBD). This is a rare condition in which areas of the brain shrink, causing nerve cells to stop working and die. CBD also may cause clinical changes called corticobasal syndrome (CBS). These changes may include poor coordination and stiffness. And they may include difficulty with thinking, speech, language and other issues.
  • Progressive supranuclear palsy (PSP). PSP is a rare condition that damages brain cells. The damaged cells are in areas that control body movement, coordination, thinking and other important functions. PSP can cause serious issues with balance and walking. It also can cause issues with eye movement and trouble swallowing.

While these are the two most common conditions, not everyone with PPAOS has the same underlying disease. Sometimes other proteins are involved.

Risk factors

No environmental or lifestyle risk factors have been clearly linked to PPAOS. Most people with PPAOS do not have a family history of the condition. In rare cases, genetic changes have been found. In some families, there may be more than one family member with a neurodegenerative disease. PPAOS typically begins after the age of 40 and most commonly after the age of 65.

Diagnosis

There is no single test that can diagnose primary progressive apraxia of speech (PPAOS). The symptoms can be mistaken for those of other conditions, such as aphasia or dysarthria.

Diagnosis typically begins with a thorough medical history and a physical exam. Your primary care team may refer you to specialists to help make a more accurate diagnosis. These specialists may include:

  • Neurologists. A neurologist diagnoses and treats conditions of the brain, spinal cord and nervous system.
  • Behavioral neurologists. Behavioral neurologists work with people who have brain conditions that affect memory and thinking.
  • Speech-language pathologists. These specialists help diagnose and treat a wide range of conditions. They include speech, language, thinking and trouble swallowing.

You also may be referred for neuropsychological testing. These tests examine memory, reasoning and judgment. They also examine language skills.

Your healthcare team also may recommend the following imaging exams:

  • Magnetic resonance imaging (MRI). This noninvasive imaging exam uses a magnetic field and radio waves. It shows detailed views of the brain from different angles.
  • Positron emission tomography (PET). This imaging scan uses a small amount of radioactive medicine, usually given through an IV in the arm. A PET scan shows how different parts of the brain are working. The scan can show brain changes. But it cannot diagnose PPAOS on its own. Diagnosis is based on a clinical exam in combination with other test results.

Imaging tests can show changes in the parts of the brain involved in speech. They can help support the diagnosis. But they cannot confirm PPAOS or identify the exact underlying cause of the condition.

Treatment

At this time, no treatment, surgery or medicine has been proven to cure or slow the progression of PPAOS. But some treatments, strategies and therapies can help people with PPAOS maintain communication skills longer and ease symptoms.

Speech-language therapy

This therapy is the most important treatment. You may work with a speech-language therapist who has experience with motor speech disorders. While speech therapy does not stop the disease, it can improve clarity, build confidence and help people with PPAOS continue to communicate longer.

Communication strategies

As PPAOS progresses, some strategies and tools help communication without relying on speech. Planning helps lessen frustration and supports independence.

Strategies may include:

  • Writing or typing messages. When speech is hard to understand, a person may write or type to share thoughts clearly.
  • Using gestures or pointing. A person may point to objects, pictures or people. The person may use a thumbs-up or thumbs-down gesture, nod, or shake their head. Or the person may use actions, such as lifting a hand to the mouth to ask for something to drink.
  • Communication boards. These tools can help support communication when speech is not clear. They also can help organize thoughts.
  • Speech-generating apps or devices. These devices speak the message aloud for the person who types the message or selects it. Apps can be on personal smartphones or tablets or in dedicated devices.
  • Helping family members help you. Teach family members how they can help. This can lessen frustration and improve communication for everyone. Explain that it can help everyone if they:
    • Give you extra time to respond.
    • Do not rush or finish your sentences unless asked.
    • Use questions that require only a yes or no response when possible.
    • Lessen background noise.
    • Focus on the message and not on how it sounds.

Treatments focus on maintaining communication and quality of life rather than stopping the disease. Research is ongoing to better understand PPAOS and develop improved treatments.

Coping and support

If you have primary progressive apraxia of speech (PPAOS), these steps may help you communicate more easily:

  • Carry a card that explains you have PPAOS and that it affects speech, not understanding.
  • Carry identification and emergency contact information.
  • Carry paper and a pen or use a smartphone or tablet to write or type messages.
  • Use drawings, pictures or photos to help you share your message.
  • Use gestures or point to objects when it is hard to speak.

Family and friends

Family members and friends can help by following these tips:

  • Speak at a natural pace. Use simple sentences.
  • Allow extra time for responses.
  • Ask simple yes-or-no or choice questions if speech is hard to understand.
  • Keep conversations one-on-one when possible.

More tips to help with communication:

  • Do not interrupt or finish sentences for the person with PPAOS unless asked.
  • Avoid correcting speech unless the person wants help.
  • Involve the person with PPAOS in conversations as much as possible.
  • Repeat back or summarize what was said to confirm understanding. For example, "You're saying you want water. Is that right?"

It also may help to:

  • Reduce background noise and distractions.
  • Keep writing tools or devices nearby.
  • Focus on the message and not on how it sounds.

Support groups

Some medical centers and organizations offer support groups for people with motor speech conditions and their families. Support groups can provide education, encouragement, practical coping strategies and shared experiences. Ask your healthcare professional or speech-language pathologist about local or online support options.

Preparing for an appointment

Primary progressive apraxia of speech (PPAOS) usually develops gradually. A neurologist and a speech-language pathologist may evaluate you.

To prepare:

  • Bring a list of medicines and supplements you take.
  • Consider bringing a family member or friend to help with communication.
  • Write down symptoms or concerns ahead of time.

Questions family members may ask

  • Is apraxia temporary or long-lasting?
  • What's the most likely cause of these speech issues?
  • What tests are needed?
  • What treatments are available for PPAOS, and which do you recommend?
  • Are there services available, such as speech-language therapy or home health assistance?
  • Are communication supports or assistive devices helpful?
  • How can we best support communication at home?

What your healthcare professional may ask

  • When did the symptoms of the speech issues begin?
  • Is speech harder to understand at certain times, such as when you are tired or stressed or speaking quickly?
  • Do you understand what others say to you?
  • Do others understand what you're saying?
  • Have you noticed changes in your speech, such as the way you move your jaw, tongue and lips to make speech sounds, or changes in the sound of your voice?
  • Is it hard to plan or coordinate mouth movements for speech?
  • Have there been changes in writing, typing or non-speech movements?

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