Spasmodic dysphonia is a neurological condition that causes certain muscles in the “voice box,” or larynx, to spasm, often making the voice sound raspy, strained or breathy.
Robert F. Kennedy Jr. started developing symptoms of the condition in 1996, when he was making most of his income from speaking engagements. He said he went from being able to speak to “large halls without any amplification” to having a chronic vocal tremor.
“I think it makes it problematic for people to listen to me,” he said during a town hall last year. “I cannot listen to myself on T.V.”
The chronic condition, which is more common among women than men, is thought to result from problems in the part of brain that helps coordinate the movement of muscles.
Roughly 500,000 people in North America have been diagnosed with the condition, with the onset typically occurring when people are middle-aged, without an obvious explanation.
The condition may run in families, although a specific gene for spasmodic dysphonia has not yet been identified.
There is currently no known cure, although Botox injections and voice therapy may help reduce symptoms.
