Dysarthria

Overview

Dysarthria happens when the muscles used for speech are weak or are hard to control. Dysarthria often causes slurred or slow speech that can be difficult to understand.

Common causes of dysarthria include conditions that affect the nervous system or that cause facial paralysis. These conditions may cause tongue or throat muscle weakness. Certain medicines also can cause dysarthria.

Treating the underlying cause of dysarthria may improve your speech. You also may need speech therapy. For dysarthria caused by prescription medicines, changing or stopping the medicines may help.

Symptoms

Symptoms of dysarthria depend on the underlying cause and the type of dysarthria.

Symptoms may include:

• Slurred speech.
• Slow speech.
• Not being able to speak louder than a whisper or speaking too loudly.
• Rapid speech that is difficult to understand.
• Nasal, raspy or strained voice.
• Uneven speech rhythm.
• Uneven speech volume.
• Monotone speech.
• Trouble moving your tongue or facial muscles.

When to see a doctor

Dysarthria can be a sign of a serious condition. See a healthcare professional right away if you have sudden or unexplained changes in your ability to speak.

Causes

Dysarthria can be caused by conditions that make it hard to move the muscles in the mouth, face or upper respiratory system. These muscles control speech.

Conditions that may lead to dysarthria include:

• Amyotrophic lateral sclerosis, also known as ALS or Lou Gehrig's disease.
• Brain injury.
• Brain tumor.
• Cerebral palsy.
• Guillain-Barre syndrome.
• Head injury.
• Huntington's disease.
• Lyme disease.
• Multiple sclerosis.
• Muscular dystrophy.
• Myasthenia gravis.
• Parkinson's disease.
• Stroke.
• Wilson's disease.

Some medicines also can cause dysarthria. These may include certain sedatives and seizure medicines.

Risk factors

Dysarthria risk factors include having a neurological condition that affects the muscles that control speech.

Complications

Complications of dysarthria may come from having trouble with communication. Complications may include:

• Trouble socializing. Communication problems may affect your relationships with family and friends. These problems also may make social situations challenging.
• Depression. In some people, dysarthria may lead to social isolation and depression.