What Is Dysarthria?

Dysarthria is a motor speech disorder that happens when the muscles used for speaking—such as those in the lips, tongue, vocal cords, or diaphragm—become weak or difficult to control. This can lead to slurred, slow, or difficult-to-understand speech. Dysarthria itself is not a disease but a symptom of an underlying neurological or muscular condition.

The severity of dysarthria can vary from mild speech changes to severely limited communication ability, depending on the cause and muscles involved.

What Causes Dysarthria?

Dysarthria is usually caused by damage to the brain or nerves that control the muscles used in speech. Common causes include:

• Stroke
• Traumatic brain injury
• Brain tumors
• Neurological diseases, such as:
  • Parkinson’s disease
  • Amyotrophic lateral sclerosis (ALS)
  • Multiple sclerosis (MS)
  • Cerebral palsy
  • Huntington’s disease
• Infections affecting the brain (like encephalitis)
• Certain medications that affect the nervous system
• Muscle or nerve disorders

What Are the Symptoms of Dysarthria?

Symptoms can differ depending on which part of the nervous system is affected, but common signs of dysarthria include:

• Slurred or mumbled speech
• Slow or rapid speech that is hard to understand
• Soft or low-volume voice
• Nasal-sounding or strained voice
• Uneven or choppy speech rhythm
• Difficulty moving the tongue, lips, or jaw
• Trouble swallowing (sometimes occurs alongside)

How Is Dysarthria Diagnosed?

Diagnosis typically involves:

• Medical history review to identify potential causes
• Neurological examination to check for other signs of nervous system damage
• Speech-language assessment to evaluate muscle control, voice quality, and clarity
• Imaging tests (like MRI or CT scans) to look for brain injuries or abnormalities
• Blood tests if a metabolic or infection-related cause is suspected

A speech-language pathologist (SLP) plays a key role in evaluating and diagnosing dysarthria.

What Treatments Are Available for Dysarthria?

Treatment depends on the cause and severity. The main goal is to improve speech clarity and communication. Options include:

• Speech therapy – The most common treatment, focusing on strengthening muscles and improving pronunciation, breath control, and pacing.
• Communication aids – Such as speech-generating devices or smartphone apps for severe cases.
• Medications – If the cause is a condition like Parkinson’s disease or side effects from drugs.
• Surgical interventions – Rare, but may be necessary in some cases (e.g., to address facial muscle issues).

In some cases, treating the underlying condition (like a stroke or infection) can also improve dysarthria symptoms.

Can Dysarthria Be Prevented?

Dysarthria itself may not always be preventable, especially when caused by sudden events like strokes or progressive diseases. However, reducing the risk of conditions that cause it—such as managing blood pressure, avoiding head injuries, or treating infections early—can help lower the chances.

Regular checkups and early intervention are key for minimizing long-term speech difficulties.