Dysarthria is a speech disorder that results when the muscles a person uses to speak become weakened. The condition is common among people with Parkinson’s disease.

Someone who has dysarthria and Parkinson’s may experience vocal tremors, speech that is too soft or too loud, or a monotonous vocal tone, among other symptoms.

Scientists are researching methods to alleviate dysarthria and Parkinson’s. While there currently is no cure, speech therapies and communication strategies may help people with these conditions communicate more effectively with others.

Keep reading to learn more about dysarthria and Parkinson’s, including the symptoms and treatment options.

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Dysarthria is an umbrella term for speech disorders that develop due to weakened muscles that people use to speak. These muscles are in the mouth, face, and respiratory system.

Common causes include brain injuries and neurological conditions, but dysarthria can also occur due to:

  • inflammatory conditions, such as encephalitis, meningitis, and autoimmune diseases
  • vascular conditions, such as stroke and Moyamoya disease
  • exposure to toxic elements, such as carbon monoxide, alcohol, and heavy metals

There are different types of dysarthria depending on the location of the disorder or damage. However, research suggests hypokinetic dysarthria is the type of speech disorder that doctors often associate with Parkinson’s disease.

Parkinson’s disease is one of many movement disorders, which are neurologic conditions that affect the body’s movement. They can occur when a person’s brain does not supply the basal ganglia with sufficient dopamine.

The basal ganglia are structures deep within the brain that help start and control movement. The lack of dopamine impairs the basal ganglia’s ability to release the inhibition necessary for moving. This includes impaired movement in the muscles responsible for speech and often results in dysarthria.

About 70–100% of people with Parkinson’s also experience dysarthria.

Learn more about the signs and symptoms of Parkinson’s disease.

Someone who has dysarthria may experience speech-related symptoms, such as:

  • vocal tremors
  • monotonous vocal tone
  • a voice that sounds hoarse, rough, scratchy, or nasal
  • speech that is unusually quiet or loud
  • speech that is excessively fast or slow
  • twisted vowel and consonant sounds

When a person has dysarthria due to Parkinson’s disease, they may also experience movement-related symptoms, including:

  • a slowness or difficulty with moving or walking
  • trouble balancing, falling, dizziness, or fainting
  • body stiffness
  • a stooped posture
  • facial masking, which refers to difficulties making facial expressions
  • body tremors

It is important to note that Parkinson’s disease also may include nonmovement symptoms, such as psychological changes, sleeping issues, loss of smell, constipation, and weight loss.

Current treatments for dysarthria and Parkinson’s disease include speech therapies, medical therapies, surgical procedures, or a combination of the three.

Older reviews highlight that medication tends to help more with limb function than speech improvement. However, newer research states that surgical procedures, such as deep brain stimulation, have varying outcomes.

This suggests speech therapies are the most common options for people with dysarthria and Parkinson’s.

The American Speech-Language-Hearing Association (ASHA) outlines treatments that target speech-production subsystems, including respiration, phonation, articulation, resonance, and prosody.

Someone with dysarthria and Parkinson’s might work with a speech-language pathologist on:

  • exercises to strengthen their mouth muscles
  • inhaling deeply before beginning to speak
  • using more breath to make speech louder
  • slowing down their speech
  • exaggerating articulation to make “clear” speech

The ASHA highlights communication strategies that may help people with these conditions. They include speaker strategies, such as maintaining eye contact, pointing and gesturing, and restating the message using different words. Additionally, communication-partner strategies, such as being an active listener, using specific questions for clarification, and providing feedback and encouragement, can help.

Someone with dysarthria may find Augmentative and Alternative Communication (AAC) helpful. AAC involves supplementing natural speech with unaided methods such as finger spelling, hand signs, and gestures. People may also benefit from aided AAC methods, including pictures, communication boards, and speech-generating devices. Finally, environmental modification is beneficial to everyone communicating. It involves setting the stage for clear communication and comprehension. Techniques include:

  • reducing background noise
  • making sure there is adequate lighting
  • sitting face-to-face during conversations
  • adjusting the proximity between the people conversing

Currently, there is no cure for dysarthria relating to Parkinson’s disease. However, research on ways to alleviate symptoms of both conditions continues.

In the meantime, the above treatments and management methods may help people with dysarthria and Parkinson’s better communicate with others.

Importantly, a person should notify their doctor if they start showing signs of dysarthria. A 2018 review of speech disorders in Parkinson’s disease notes that although the prevalence of speech disorders among people with Parkinson’s disease may be as high as 89%, only 3–4% receive speech therapy.

Talking with a doctor about speech therapy may help a person with Parkinson’s learn to communicate more clearly.

Dysarthria is a speech disorder that occurs when the muscles a person uses to make speech weaken. It is common among people with Parkinson’s disease.

Symptoms may include vocal tremors, speech that is too fast or too slow, and changes in vocal tone and sound.

Currently, there is no cure for dysarthria that occurs from Parkinson’s. However, there are several treatment and management options.

Some options, such as surgery, have varying outcomes. Others, such as speech therapies and other communication strategies, may be more successful at improving communication between people.