Spasmodic dysphonia is caused by abnormal functioning of the brain, particularly in the basal ganglia, an area responsible for coordinating muscle movements. It is a neurological disorder involving involuntary spasms of the vocal cord muscles, which disrupt normal voice production. The exact cause is unknown, but it may have genetic components and can be triggered or worsened by factors such as upper respiratory infections, injury to the larynx, prolonged voice use, psychological stress, or other neurological diseases. Women and middle-aged individuals are more commonly affected, and it may run in families. The disorder is considered a type of focal dystonia affecting speech muscles.
