Dysphonia and Other Speech Problems in MS

Learn About Dysphonia and Other Ways MS Affects Speech

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Dysphonia is difficulty speaking due to reduced control of the muscles of your lips and mouth, tongue, throat, and/or vocal cords.

In multiple sclerosis (MS), dysphonia often means trouble controlling the volume of speech, meaning speaking too softly to be heard or more loudly than is appropriate. Other examples of dysphonia include hoarseness, raspy speech, or a change in pitch when you try to talk.

Dysphonia Is One Form of Dysarthria

If you have MS or know someone who has it, you may be aware that there are many ways this disease can affect the ability to speak clearly. These speech problems, including dysphonia, are grouped under the term dysarthria: speech problems due to reduced control of the muscles used in speech, often as a result of nerve damage.

  • Dysphonia is considered a form of dysarthria because these conditions involve the same muscles, structures, and nerve pathways used in speaking.

Dysarthria affects 41% to 51% of people with MS and is the most common disorder of communication in those with this disease. It’s usually mild; however, symptom severity reflects the extent of nerve damage.

MS-related dysarthria is most likely to affect your rate of speaking, the understandability of your speech, and its natural conversational flow. Examples include:

  • Slurred speech, with problems pronouncing words
  •  “Scanning” speech, in which you speak very slowly, with long pauses between words and even between syllables of a word  
  • “Explosive” speech, with episodes of loud, rapid speech production

What Causes Speech Problems in MS?

MS-related dysarthria typically results from nerve damage that weakens the muscles of your lower face, lips, tongue, and throat.

Most commonly, the cause is multiple small areas of damage in either of the two large lobes of your brain. Another possible cause is damage to your brainstem, an area of nerves between your brain and your cervical (neck area) spinal cord.

Other forms of MS-related dysarthria are believed to result from damage to the cerebellum, the part of the brain at the back of your skull.

Rarely, speech disturbances in MS result from aphasia, loss of ability to understand or express speech that may be related to memory loss. (The term aphasia also applies to inability to communicate using written words or to understand them.) Aphasia from MS may be temporary or permanent.

The Three Types of Dysarthria in MS

Doctors diagnose three different types of dysarthria in people with MS:

  • Spastic dysarthria, mainly featuring muscle stiffness or tightness
  • Ataxic dysarthria, mainly featuring loss of muscle movement control
  • Mixed dysarthria, which combines features of both the spastic and ataxic types

Mixed dysarthria is most common in people with MS. Why? Because this disease typically affects multiple areas of your nervous system. In mixed dysarthria, nerve damage may involve your brain’s white matter and/or cerebellum, your brainstem, and/or your spinal cord.

What Can Be Done to Improve Speech in MS?

A speech-language therapist can provide exercises to strengthen the muscles involved in speech or to improve your breathing by helping to relax them, as well as techniques for slowing rapid speech, pausing properly between words, and pronouncing words clearly and correctly.

No medications are available that directly help improve MS-related speech problems. However, medications that relieve symptoms such as muscle stiffness or tightness (spasticity) may provide some speech improvement.


Speech difficulties. Multiple Sclerosis Association of America (2013).

Miller PH. Dysarthria in multiple sclerosis. National Multiple Sclerosis Society (2011).