The motor speech disorder dysarthria is a condition in which nerve damage weakens the muscles used for speech. People with dysarthria have difficulty speaking. Their speech may be slurred, breathy, strained, or otherwise difficult to understand.

This article answers your biggest questions about dysarthria, including:

• What is dysarthria?
• What causes dysarthria?
• What are the different types of dysarthria?
• What are the early signs and symptoms of dysarthria?
• How does dysarthria affect adults?
• How is dysarthria diagnosed and treated?
• How can someone with dysarthria communicate more clearly?
• What are tips for listeners while talking to someone with dysarthria?
• Where can I find help for dysarthria?

What is dysarthria?

Dysarthria is a motor speech disorder. A person with dysarthria may be unable to control the muscles used for articulation, speed, and pitch of speech, generally due to nerve damage.

Dysarthria is not the same as aphasia, although each is a communication disorder, and you can have the conditions at the same time. Dysarthria is a speech impairment or speech disorder, while aphasia is an expressive language disorder or specific language impairment where the person has difficulty understanding words or putting them together in a sentence. 

What causes dysarthria?

A nerve, brain, or muscle disorder may cause dysarthria as the muscles that control the mouth, tongue, larynx, or vocal cords become weak or paralyzed. 

Developmental dysarthria is the result of brain damage during fetal development or at birth. Conditions like cerebral palsy, epilepsy, or carbon monoxide exposure can cause developmental dysarthria in young children. 

Acquired dysarthria is the result of brain damage later in life. Stroke, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS, or Lou Gehrig’s disease) are common causes of acquired dysarthria.

Other conditions that may lead to dysarthria include:

• Brain cancer
• Brain injury
• Brain tumor
• Cerebral palsy
• Guillain-Barre syndrome
• Head injury
• Huntington's disease
• Lyme disease
• Multiple sclerosis
• Muscular dystrophy
• Myasthenia gravis
• Severe spinal injury
• Traumatic brain injury
• Wilson's disease

Dysarthria can also be a side effect of certain medications, like certain sedatives or epilepsy medications. 

What are the different types of dysarthria?

Beyond categorization as developmental or acquired, dysarthria can appear as one of six types: 

• Ataxic dysarthria, caused by damage to the cerebellum, which helps coordinate muscle movement. A person with ataxic dysarthria may have trouble pronouncing letters and emphasizing the right parts of a word when speaking.
• Flaccid dysarthria, caused by damage to the lower motor neurons. This causes speech to be breathy and nasal.
• Hyperkinetic dysarthria, caused by damage to the basal ganglia, the brain structure responsible for muscle movement. Hyperkinetic dysarthria causes fast, hyper-sounding, and often unpredictable speech.
• Hypokinetic dysarthria is also caused by damage to the basal ganglia, but with hypokinetic dysarthria, speech is slowed, monotone, or rigid.
• Spastic dysarthria, caused by damage to the upper neurons on one or both sides of the brain. This causes speech to be strained or harsh.
• Mixed dysarthria includes a mix of two or more of the other five types.

What are the early signs and symptoms of dysarthria?

The primary symptom of dysarthria is unclear or garbled speech. Other symptoms include:

• Difficulty moving the mouth, tongue, or lips.
• Slurred speech.
• Unusually slow or unusually fast speech.
• Difficulty controlling voice volume.
• A nasal, strained, or monotone voice.
• Hesitation in talking.
• Speaking in short bursts instead of complete sentences.

How does dysarthria affect adults?

Dysarthria can cause communication problems that lead to social difficulties, depression, and social isolation. It can also cause problems at work or in school, particularly in roles that require public speaking. 

Depending on the severity of the disability, people with dysarthria may qualify for certain protections under the Americans with Disabilities Act (ADA). The ADA protects people with disabilities from discrimination in the workplace, on public transit, and in public businesses. 

Ask your employer about potential accommodations for dysarthria, such as using email and text messages instead of phone calls or face-to-face meetings. 

There are many technologies that can help people with dysarthria communicate. An easy first step is a cell phone with accessibility features designed for dysarthria. Many people with dysarthria find programs like text-to-speech apps helpful for communication.

How is dysarthria diagnosed and treated?

Generally, the first test for dysarthria is a physical exam from a primary care physician (PCP) or speech-language pathologist (SLP). Depending on the results of the physical exam, doctors may call for further testing to find the underlying cause of the dysarthria symptoms.

This series of tests may include:

• MRI or CT scans of the brain, head, or neck to check for physical abnormalities.
• An electroencephalogram (EEG) to check for abnormalities in brain activity.
• Electromyography to test the electrical function of the muscles and nerves.
• Blood or urine tests to see if there is an infection or inflammation.
• A spinal tap, also known as a lumbar puncture, to check for tumors or infections.
• Barium or videofluoroscopic swallow studies to test the muscles used for swallowing. 

Dysarthria treatment depends on the cause, severity, and type of dysarthria. Treatment options include:

• Speech and language therapy to improve communication and, if possible, regain normal speech.
• Speech strategies to give the best chance of being heard and understood.
• Surgery, if necessary to remove a tumor or fix an injury that’s causing dysarthria.
• Nonverbal communication strategies, like writing or sign language.
• Other accommodations and modification strategies for school or the workplace.

How can someone with dysarthria communicate more clearly?

Much of managing dysarthria symptoms involves finding new or adaptive methods of communication. These might include:

• Using hand gestures or sign language.
• Writing by hand. 
• Typing on a computer or cell phone.
• Using text-to-speech software. 

In some dysarthria cases where the underlying condition also affects the muscles used to write and type, people with dysarthria can use tools like alphabet boards to communicate via touching and pointing. 

When speaking, many people with dysarthria find they communicate more clearly by:

• Speaking slowly.
• Using short phrases.
• Pausing between sentences to check for listener comprehension.
• Starting a conversation with a single word so the listener knows what you’re talking about. For example, saying “travel” before discussing travel logistics.

What are tips for listeners while talking to someone with dysarthria?

Friends, family, or coworkers of people with dysarthria can make communication easier by:

• Eliminating background noise, such as turning off the TV or moving to a quieter room.
• Facing the speaker and sitting close enough to understand visual cues.
• Making eye contact.
• Ensuring good lighting.
• Asking yes or no questions.
• Repeating what they’ve said to make sure you understand.

If you don’t understand someone with dysarthria, do not pretend you do. This can be frustrating and embarrassing for both the speaker and the listener. Instead, ask them to repeat themselves or find an alternate communication method like writing down what they’re trying to say. 

Where can I find help for dysarthria?

Your primary doctor is an excellent first step to receive testing for dysarthria. In addition, Ability Central has a searchable database of non-profits that can help with everything from diagnosis to treatment.

For more information on conditions that impact speech, see: 

• Aphasia and Dysphasia: Why Do People Stop Using and Understanding Language?
• Expressive Language Disorder: Symptoms, Challenges, and Treatments
• What Should I Do After a Muteness Diagnosis?
• Receptive Language Disorder: Why Can’t I Understand What People Say?