Stuttering & Parkinson’s: Searching for Links

There is much talk about a connection between stuttering and Parkinson’s disease (PD). Many in online PD communities have mentioned stuttering when talking about speech difficulties. But evidence is scarce because there is not much research on this topic.¹

PD is a motor disorder with no known cause or cure. PD symptoms happen because of damage to neurons in a certain portion of the brain. This damage causes lower production of dopamine. Dopamine is a chemical produced by your cells and is important for smooth, purposeful movements.²

How PD affects speech

The lack of dopamine causes motor symptoms. It also affects the face muscles used to produce smooth, productive speech. Motor symptoms may include:²

• Tremor
• Rigidity
• Difficulty balancing
• Bradykinesia (slowness of movement)

PD affects everyone differently. Changes in speech look different for everyone and may include:^1,2

• Hypophonia: breathy or soft speech
• Tachyphemia: speech that is difficult to understand because it is:
  • Slurred
  • Mumbled
  • Rapid
• Monopitch: a monotone voice caused by a loss of:
  • Tone
  • Pitch
  • Volume
• Difficulty finding the right words

Types of stuttering

Stuttering is a speech disorder. It involves the involuntary repetition of sounds or words. There are 2 main types of stuttering: developmental and acquired. Palilalia is a condition that has similar symptoms to stuttering and is linked to advanced PD.^3-5

Developmental stuttering

Developmental stuttering is the most frequent type of stuttering. It typically develops in children. Children generally grow out of their stuttering. But research has shown that stuttering can come back in some people after a brain illness or injury.³

Acquired and neurogenic stuttering

One type of acquired stuttering is neurogenic stuttering. It is a rare speech disorder that develops in adults with no history of stuttering. It usually happens after a brain injury or illness.^3,5,6

Neurogenic stuttering affects the rhythm of speech and can happen at any part of saying a word. Other symptoms include:³

• Involuntary lengthening or repetition of a sound
• Halting or interrupted speech
• Difficulty producing words

The exact cause of neurogenic stuttering is not known. But it has been linked to several brain conditions, such as:⁵

• Stroke
• Traumatic brain injury
• Epilepsy
• Multiple sclerosis
• PD

Stuttering with PD: palilalia

Unlike stuttering, palilalia has been definitively linked to PD. Like stuttering, palilalia is not under the speaker’s control. Older people with advanced stages of PD are more likely to experience it. People with palilalia repeat syllables, words, or phrases at high speed and low volume.^5,7

How is palilalia treated?

People who stutter or experience palilalia should work with a speech pathologist. Speech pathologists are medical professionals who treat speaking and swallowing disorders. They use methods such as:^5,8

• Vocal exercise (this may not work for people with severe PD)
• Practicing breath control
• Practicing muscle control

More research on palilalia is needed

There have been few studies specifically on stuttering in people with PD. There is not enough evidence to make a direct connection between stuttering and PD. However, some people with PD say there is a link.⁵

To find out more about stuttering or palilalia and what may be causing it, make an appointment with a speech pathologist. They can help you get a clear diagnosis and make a treatment plan.