For people with SD, muscles spasms in the larynx (also known as the voice box) cause the voice to sound tight, strangled or strained. SD is a chronic condition that typically begins between the ages ...

Kennedy has a condition called spasmodic dysphonia, a neurological disorder that impacts the muscles in the voice box, also known as the larynx, according to the National Institute on Deafness and ...

That’s because he has spasmodic dysphonia, a rare neurological condition that causes the muscles affecting the ... that controls the movement of the larynx. But they're not always successful ...