Apraxia of Speech: Signs of Neurodegenerative Disease
Author: Mayo Clinic
Published: 14 Feb 2016 - Updated: 5 Jul 2026
Publication Details: Peer-Reviewed | Research, Study, Analysis
Table of Contents:
Synopsis - Definition - Introduction - Main - FAQ's - Insights, Updates - Related Content
Synopsis: This information from Mayo Clinic draws on more than a decade of study by neurologist Keith Josephs and speech pathologist Joseph Duffy to explain how primary progressive apraxia of speech can be an early sign of degenerative neurologic disease rather than a simple speech problem. It is authoritative because it reflects federally funded clinical research, with findings the team has published in journals including Brain, Neurology, and the American Journal of Alzheimer's Disease and Other Dementias, and it is genuinely useful for patients, families, seniors, and clinicians because the condition is so often mistaken for Alzheimer's disease, ALS, or even a psychological issue. By describing the symptoms, the difference between apraxia and aphasia, and the value of getting an accurate diagnosis early, the material helps readers recognize warning signs and understand what therapy and communication options can realistically offer.*
At a Glance
- 1 - Apraxia of speech caused by a stroke often stays stable or improves, unlike the primary progressive form that worsens over time.
- 2 - Producing speech activates about 100 muscles between the lungs and lips to create at least 14 distinct sounds per second for a listener to understand.
- 3 - An abnormal buildup of tau protein, also linked to Alzheimer's disease, has been found in the brains of people with apraxia of speech, though the exact cause of the progressive form remains unknown.
- Topic Definition: Apraxia of Speech
Apraxia of speech is a neurological disorder that disrupts the brain pathways responsible for planning and sequencing the muscle movements needed to talk, so a person knows exactly what they want to say but cannot reliably coordinate the sounds to say it. It can appear in children as childhood apraxia of speech, or in adults as an acquired condition following a stroke, and in its primary progressive form it steadily worsens and is tied to degenerative neurologic disease. Unlike aphasia, which affects a person's ability to understand or use language itself, apraxia is a problem of speech programming, though the two conditions can occur together, and its hallmark signs include slow, halting speech, groping movements of the mouth, and inconsistent errors that come and go.
Introduction
Misspeaking might draw a chuckle from family and friends. But then, it keeps happening. Progressively, more and more speech is lost. Some patients eventually become mute from primary progressive apraxia of speech, a disorder related to degenerative neurologic disease.
Two Mayo Clinic researchers have spent more than a decade uncovering clues to apraxia of speech. Keith Josephs, M.D., a neurologist, and Joseph R. Duffy, Ph.D., a speech pathologist, presented "My Words Come Out Wrong: When Thought and Language Are Disconnected from Speech" at the American Association for the Advancement of Science annual meeting in Washington, D.C.
Main Content
Because patients and even medical professionals don't recognize apraxia of speech, treatment typically is sought in later stages of the disease, says Dr. Josephs. As apraxia progresses, it frequently is misdiagnosed as Alzheimer's disease or amyotrophic lateral sclerosis. One patient received vocal cord injections of Botox by a physician who thought the issue was muscle spasms of the larynx. Apraxia of speech even has been diagnosed as a mental illness.
"Because it first presents as 'just' a speech problem, some people are told, 'This is in your head.' We've seen that. It's unfortunate," Dr. Josephs says.
When it's caused by a stroke, apraxia of speech typically does not worsen and may get better over time. But, apraxia of speech often is ignored as a distinct entity that can evolve into a neurologic disorder, causing difficulty with eye movement, using the limbs, walking, and falling that worsens as time passes.
"I don't want the take-home message to be that this condition is benign," warns Dr. Josephs. "It is a devastating disease, in some sense worse than Alzheimer's disease, which typically spares balance and walking until very late in the disease course. It may start with the person simply being unable to pronounce a few words. Six years later, they are in a diaper, can't speak or walk, and are drooling."
The benefit to getting an early and correct diagnosis is that people can receive appropriate therapy.
"It would be good if people recognized that changes in speech can be the first signs of neurologic disease," Dr. Duffy says. "An important part of treatment is providing information about the condition."
While speech therapy doesn't reverse or halt the progression of apraxia, it can develop compensations for producing better sounds. People with apraxia of speech also can use computers or text for alternate means of communicating.
Both the value and complexities of speech often are underappreciated. "Speech connects us to the world," Dr. Duffy says.
Speech is a complex brain-body achievement, these researchers note. It first requires selecting appropriate words and organizing them into a coherent message. This message activates 100 muscles between the lungs and lips to produce at least 14 distinct sounds per second that a listener can comprehend. A problem with speech programming - directing the muscles and structures that move - is apraxia.
Symptoms of Apraxia Can Include:
- Slow speech rate.
- Impaired rhythm of speech.
- Groping of the mouth to make sounds.
- Better automatic speech, such as greetings, compared with purposeful speech.
- Inconsistent mistakes, such as saying a word or sound correctly sometimes and not others.
Apraxia of speech differs from aphasia, a language disorder that interferes with a patient's ability to understand or use words. Patients, however, can have apraxia of speech and aphasia. While the cause of primary progressive apraxia of speech has not been determined, an abnormal accumulation of tau protein - a factor also contributing to Alzheimer's disease - has been found in the brains of those with apraxia of speech who have died.
About the Research
Mayo Clinic has received National Institutes of Health grants, for which Dr. Josephs is the primary investigator, to focus on apraxia of speech in the context of neurodegenerative cognitive and motor disorders. Drs. Josephs, Duffy and fellow researchers have published articles about their findings in Brain, the American Journal of Alzheimer's Disease & Other Dementias, Neurology and the Journal of Neurology.
Frequently Asked Questions
NOTE: Researched FAQ's by Disabled World (DW)
Is apraxia of speech the same as a stutter?
No, a stutter involves the repetition or prolongation of sounds within otherwise planned speech, while apraxia of speech is a disorder of planning and sequencing the muscle movements needed to form words at all.
Can children outgrow childhood apraxia of speech?
Childhood apraxia of speech does not typically resolve on its own, but with consistent, specialized speech therapy many children make significant progress in their ability to communicate over time.
How is apraxia of speech diagnosed?
Diagnosis is usually made by a speech-language pathologist who evaluates how a person plans and produces sounds, and in progressive cases neurologists may use imaging and cognitive testing to rule out related conditions.
What is the difference between apraxia and dysarthria?
Dysarthria results from weakness or poor control of the speech muscles themselves, whereas apraxia stems from difficulty planning the movements even when the muscles are physically capable of working.
What communication tools help people with progressive apraxia of speech?
People can use augmentative and alternative communication aids such as text-based devices, tablets, computers, and picture or symbol boards to supplement or replace spoken language as the condition advances.
Insights, Analysis, and Developments
Editorial Note: The most sobering thread running through this research is how easily a subtle change - a few mispronounced words that once earned a laugh - can be dismissed by patients and doctors alike until the disease has advanced well beyond the point of easy intervention, and while therapy cannot stop the progression, the researchers make a persuasive case that naming the condition early gives families time to plan, adapt their communication, and understand what lies ahead rather than being blindsided by a misdiagnosis of something else entirely.*Attribution/Source(s): This peer reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally authored by Mayo Clinic and published on 14 Feb 2016, this content may have been edited for style, clarity, or brevity.
* Editorial additions by Ian C. Langtree.