What Is Dysarthria?

Medically Reviewed by Zilpah Sheikh, MD on December 07, 2023
5 min read

Dysarthria is a condition in which the part of your brain that controls your lips, tongue, vocal cords, and diaphragm doesn't work well. It's hard for you to move those muscles the right way.

This condition comes in two forms:

  • Developmental dysarthria happens from damage to a growing baby's brain in the womb or at birth. Cerebral palsy is one possible cause. Developmental dysarthria affects children.
  • Acquired dysarthria happens from damage to the brain later in life. A stroke, Parkinson's disease, or a brain tumor is the possible cause. This type affects adults.

People with dysarthria can think and understand language. But they have trouble talking because of weakness in the muscles that control speech.

Some people with dysarthria have only minor speech problems. Others have so much trouble getting their words out that other people may not be able to understand them very well. A speech-language therapist can help improve speaking skills.

The six types of dysarthria are divided by causes or symptoms. They include:

  • Spastic dysarthria is caused by damage to nerve cells in the central nervous system that affect movement. It makes the voice sound harsh.
  • Hypokinetic dysarthria happens from damage to a part of the brain called the basal ganglia that controls movement. Speech is slow and never changes pitch.
  • Hyperkinetic dysarthria is also from damage to the basal ganglia. In this case, speech is fast and changes a lot.
  • Ataxic dysarthria happens from damage to the cerebellum, a part of the brain that helps muscles move. It can cause problems in the way you pronounce words.
  • Flaccid dysarthria affects the lower motor neurons that send signals to your muscles to move. Your speech may sound nasal.
  • Mixed dysarthria is the most common type. It's a mixture of other types, such as spastic plus flaccid.

Damage to the parts of the brain that control speech causes dysarthria. Any of these conditions can cause this type of damage:

  • Amyotrophic lateral sclerosis (ALS) or Lou Gehrig's disease
  • Brain tumors
  • Cerebral palsy
  • Dementia
  • Guillain-Barre syndrome
  • Huntington's disease
  • Lyme disease
  • Multiple sclerosis (MS)
  • Muscular dystrophy
  • Myasthenia gravis
  • Parkinson's disease
  • Side effects of certain medicines, such as epilepsy drugs
  • Stroke
  • Traumatic brain injury
  • Wilson's disease

Prevalence of dysarthria

The likelihood of getting dysarthria depends on the cause. This condition affects:

  • 30% of people with ALS
  • 25%-50% of people with MS
  • 70%-100% of those with Parkinson's disease
  • 8%-60% of people who have had a stroke
  • 10%-65% of those with traumatic brain injury

Depending on the cause, dysarthria can make your speech:

  • Flat
  • Have an uneven rhythm
  • Higher- or lower-pitched than usual
  • Jerky
  • Monotone
  • Mumbled
  • Nasal or whiny
  • Raspy
  • Slow or fast
  • Slurred
  • Soft like a whisper
  • Strained

Because dysarthria can make it harder to move your lips, tongue, and jaw, it can be harder for you to chew and swallow. Trouble swallowing can cause you to drool.

If you suddenly have a hard time speaking, you might be having a stroke. Call 911 right away. But if it's been happening for a while, see a speech-language pathologist (SLP). They'll ask about any diseases you have that could affect your speech.

They'll also want to check the strength of the muscles in your lips, tongue, and jaw as you talk. They might ask you to:

  • Stick out your tongue
  • Make different sounds
  • Read a few sentences
  • Count numbers
  • Sing
  • Blow out a candle

Tests for dysarthria

You might need some tests, including:

  • Imaging tests like MRI or CT scans
  • Blood or urine tests
  • Brain and nerve tests like electroencephalogram or electromyography
  • Spinal tap to check for infection
  • Swallowing study to check for problems when you swallow

Treatment will depend on the cause of your dysarthria, the type, and your symptoms. Your speech might get better after you treat the cause.

If you still have dysarthria, you might see a SLP who will teach you:

  • Exercises to strengthen the muscles of your mouth and jaw
  • Ways to speak more clearly, such as talking more slowly or pausing to catch your breath
  • How to control your breath to make your voice louder
  • How to use devices like an amplifier to improve the sound of your voice

Your therapist also will give you tips to help you communicate, such as:

  • Carry a notebook or smartphone with you. If someone doesn't understand you, write or type what you want to say.
  • Make sure you have the other person's attention.
  • Speak slowly.
  • Talk face-to-face if you can. The other person will be able to understand you better if they can see your mouth move.
  • Try not to talk in noisy places, like at a restaurant or party. Before you speak, turn down music or the TV or go outside.
  • Use facial expressions or hand gestures to get your point across.
  • Use short phrases and words that are easier for you to say.

Your therapist will work with your family to help them understand you better. They may suggest that your loved ones:

  • Ask if they don't understand something
  • Give you time to finish what you have to say
  • Look at you when they talk with you
  • Repeat the part they understood so you don't have to say the whole thing again
  • Try not to finish your sentences for you
  • Talk to you as they would with anyone else
  • Continue to involve you in conversation

Dysarthria can affect many parts of your life. When you have trouble speaking clearly, you may be less able to communicate with loved ones. This can affect your relationships with family and friends.

It's common for people with dysarthria to feel alone and depressed. That's why it's so important to get treatment from a speech-language therapist and see a mental health professional if you feel alone or sad.

Dysarthria is a problem with parts of your nervous system that affects speech. It comes in several types that each affect speech in different ways. In speech therapy, you can learn exercises and tips to help you communicate more easily.

What is the main cause of dysarthria?

Damage to the brain from a condition like Parkinson's disease, a stroke, an injury, or MS can cause dysarthria.

How do people with dysarthria speak?

How speech changes depends on the type of dysarthria. The voice might sound breathy, nasal, slurred, fast, slow, out of rhythm, very loud, or very quiet.

What is an example of dysarthria speech?

Someone with dysarthria may speak slowly, haltingly, and at the same pitch (monotone).