Apraxia of Speech Progression to Neurodegenerative Disease

Author: Mayo Clinic
Published: 2016/02/14 - Updated: 2022/06/09
Topic: Neurological Disorders - Publications List

Page Content: Synopsis - Introduction - Main

Synopsis: Progressively, with apraxia of speech, a disorder related to degenerative neurologic disease, more and more speech is lost, with some patients eventually becoming mute. Because patients and even many medical professionals don't recognize apraxia of speech, treatment typically is sought in the later stages of the disease. As apraxia progresses, it frequently is misdiagnosed as Alzheimer's disease or amyotrophic lateral sclerosis.

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.

Main Item

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.

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.

Attribution/Source(s): This quality-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 2016/02/14, this content may have been edited for style, clarity, or brevity. For further details or clarifications, Mayo Clinic can be contacted at mayoclinic.org NOTE: Disabled World does not provide any warranties or endorsements related to this article.