What Is Spasmodic Dysphonia / Laryngeal Dystonia?
Spasmodic dysphonia, also called laryngeal dystonia, is a voice disorder. Spasmodic dysphonia is characterized by involuntary spasms or movements in the muscles of the larynx, which causes the voice to break, and have a tight, strained, or strangled sound.
Difficulties that result from spasmodic dysphonia range from occasional problems with saying a word or two to complete inability to communicate.
Spasmodic dysphonia most often affects women, particularly between the ages of 30 and 50.
Voice and speech
Speech is a complex process that starts with muscle movement, which involves phonation (voice); respiration (breathing process); and articulation (throat, palate, tongue, lips, and teeth).
These muscle movements are initiated, coordinated, and controlled by the brain, and monitored through hearing and touch.
Voice production, or phonation, is generating and modulating sound as part of the speech process.
Voice is created in the vocal cords (or vocal folds) of the larynx.
The larynx, often referred to as the voice box, is a two-inch long tube-shaped organ located in the neck at the top of the trachea (windpipe).
The cartilage in front of the larynx is sometimes called the "Adam's apple." The vocal cords (or vocal folds) are two bands of muscle that form a "V" shape inside the larynx.
The area of the larynx where the vocal cords are located is called the glottis. The area above the cords is called the supraglottis, and the area below the cords is called the subglottis. The epiglottis is a flap at the top of the trachea that closes over the larynx to protect it from food that is swallowed into the esophagus.
Breath enters the body through the nose or mouth, and then travels to the larynx, trachea, and into the lungs. It exits along the same path. Normally, no sound is made by the vocal cords during breathing or exhaling.
When a person talks, the vocal cords tighten, move closer together, and air from the lungs is forced between them. This makes them vibrate and produces sound.
Source: National Institute on Deafness and Other Communication Disorders