What Causes Speech Impairment?

Conditions list medically reviewed by George Krucik, MD, MBA

Adult speech impairments include any symptoms that cause an adult to have difficulty with vocal communication. Examples include slurred, slowed, hoarse, stuttered, or rapid speech. Depending on the underlying cause of your speech impairment, you... Read More

Adult speech impairments include any symptoms that cause an adult to have difficulty with vocal communication. Examples include slurred, slowed, hoarse, stuttered, or rapid speech. Depending on the underlying cause of your speech impairment, you may also experience other symptoms, such as:

  • drooling
  • weakened facial muscles
  • trouble remembering words
  • expressive language deficits
  • sudden contraction of your vocal muscles

If you experience a sudden onset of speech impairment, get medical care right away. It may be a sign of a serious underlying condition, such as a stroke.

Common types of adult speech impairment

There are many different types of speech impairment and speech disorders, including:

  • aphasia, the inability to express and comprehend language
  • dysarthria, slurred or choppy speech
  • spasmodic dysphonia, which can cause your voice to be hoarse, airy, and tight
  • vocal disturbances, changes in the sound and ease of your speech causes by any factor that changes the function or shape of your vocal cords

Causes of adult speech impairment

Different types of speech impairment are caused by different things. For example, you may develop a speech impairment as a result of:

  • a stroke
  • a traumatic brain injury
  • a degenerative neurological or motor disorder
  • an injury or illness that affects your vocal cords
  • dementia

Depending on the cause and type of speech impairment, it may occur suddenly or develop gradually.

Aphasia

If you’re having trouble thinking of words or pronouncing them correctly, you may be experiencing aphasia. It may be a symptom of brain damage, for example, caused by a stroke.

Other potential causes of aphasia include:

  • head trauma
  • brain tumor
  • cognitive degenerative conditions, such as Alzheimer’s disease

Dysarthria

Dysarthria can occur when you have trouble moving the muscles of your lips, tongue, vocal folds, or diaphragm. It can result from degenerative muscle and motor conditions, such as multiple sclerosis, muscular dystrophy, cerebral palsy, or Parkinson’s disease.

Other potential causes include:

  • stroke
  • head trauma
  • brain tumor
  • Lyme disease
  • facial paralysis, such as Bell’s palsy
  • tight or loose dentures
  • alcohol consumption

Spasmodic dysphonia

Spasmodic dysphonia involves involuntary movements of your vocal cords when you speak. This condition results from abnormal brain functioning. The exact cause is unknown.

Vocal disturbances

Your vocal cords and ability to speak can be negatively affected by a variety of activities, injuries, and other conditions, such as:

  • throat cancer
  • polyps, nodules, or other growths on your vocal cords
  • the ingestion of certain drugs, such as caffeine, antidepressants, or amphetamines

Using your voice incorrectly or for prolonged periods of time can also result in a hoarse vocal quality.

Diagnosing adult speech impairment

If you experience a sudden onset of impaired speech, seek medical attention right away. It might be a sign of a potentially life-threatening condition, such as a stroke.

If you develop impaired speech more gradually, make an appointment with your doctor. It may be a sign of an underlying health condition. Unless your speech impairment is caused by using your voice too much or a viral infection, it probably won’t resolve on its own and may worsen. This is why it’s important to get a diagnosis and begin treatment as soon as possible.

To diagnose your condition, your doctor will likely start by taking a complete medical history and evaluating your symptoms. They’ll likely ask you a series of questions to hear you talk and assess your speech. This can help them determine your level of comprehension and speaking ability. It can also help them learn if the condition is affecting your vocal cords, your brain, or both.

Depending on your medical history and symptoms, your doctor may order one or more tests, such as:

  • brain scans using X-rays, CT scans, or MRI scans
  • electrical current tests
  • blood tests
  • urine tests

Treatments for adult speech impairment

Your doctor’s recommended treatment plan will depend on the underlying cause of your speech impairment. It may involve an evaluation by a neurologist, otolaryngolist or speech-language pathologist.

Your doctor may refer you to a speech-language pathologist who can teach you how to conduct exercises to strengthen your vocals cords, increase vocal control, improve articulation, and expressive and receptive communication. In some cases, they may also recommend assistive communication devices. For example, they may advise you to use an electronic device to translate typed messages into verbal communication.  

In rare cases, you may need surgery or other medical procedures.

Aphasia

To help treat aphasia, your doctor will try to address the underlying cause of your symptoms. If it’s caused by a stroke, for example, they may prescribe medications and surgery. You may also receive a comprehensive cognitive-linguistic evaluation by a speech-language pathologist.

Dysarthria

If you’re diagnosed with dysarthria, your doctor will likely encourage you to undergo speech therapy. Your therapist may prescribe exercises to help improve your breath control and increase your tongue and lip coordination.

It’s also important for your family members and other people in your life to speak slowly. They need to give you ample time to respond to questions and comments.

Spasmodic dysphonia

There’s no known cure for spasmodic dysphonia. But your doctor can prescribe treatments to help alleviate your symptoms. For example, they may prescribe botulinum toxin injections (Botox) or surgery to your vocal cords. This may help reduce spasms.

Vocal disorders

If you’re diagnosed with a vocal disorder, your doctor may advise you to limit the use of your vocal cords to give them time to heal or prevent further damage. They may advise you to avoid caffeine or other drugs that can irritate your vocal cords. In rare cases, you may need surgery or other medical treatments.

Preventing adult speech impairment

Some types and causes of adult speech impairment are impossible to prevent. But you can take steps to lower your risk of developing other types of impaired speech. For example:

  • don’t overuse your voice by screaming or placing stress on your vocal cords
  • lower your risk of throat cancer by avoiding smoking and second-hand smoke
  • lower your risk of brain injury by wearing a helmet when riding your bike, protective gear when playing contact sports, and a seatbelt when traveling in motor vehicles
  • decrease your risk of stroke by exercising regularly, eating a well-balanced diet, and maintaining healthy blood pressure and blood cholesterol levels
  • limit your consumption of alcohol

If you develop unusual vocal symptoms, seek medical attention. Early diagnosis and treatment may improve your long-term outlook and help prevent complications. Ask your doctor for more information about your specific condition, treatment options, and outlook.

If you’re diagnosed with a speech or vocal disorder, always carry an identification card with the name of your condition. Also, keep your emergency contact information in your pocket at all times. This can help you prepare for times when you may not be able to communicate your health condition and needs to others.

Medically reviewed by Sara Minnis, MS, CCC-SLP on November 3, 2016Written by Suzanne Allen


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This feature is for informational purposes only and should not be used to diagnose. Please consult a healthcare professional if you have health concerns.