What is huntington's disease?

Huntington's disease (HD) is an inherited disorder that causes nerve cells (neurons) in parts of the brain to gradually break down and die. The disease attacks areas of the brain that help to control voluntary (intentional) movement, as well as other areas. People living with HD develop uncontrollable dance-like movements (chorea) and abnormal body postures, as well as problems with behavior, emotion, thinking, and personality.

For example, uncontrolled movements in the person's fingers, feet, face, or torso. These movements are signs of chorea. They can get more intense when the person is nervous or distracted; as HD progresses, the person's movements can become more extreme and obvious.

Symptoms of HD typically appear in middle-aged people (adult HD). They can also appear in children (juvenile HD), but this is rare. The disease gets worse over time.

Early signs of HD can vary, but often include mild clumsiness or problems with balance or movement, cognitive or psychiatric symptoms (problems with thinking or emotion), and changes in behavior.

For some people, chorea can make it harder to walk, which increases the chances of falling. Some people with HD do not develop chorea; instead, they may become rigid (stiff) and move very little or not at all. This condition is called akinesia. Other people may start out with chorea but become rigid as the disease progresses.

In addition to chorea, some individuals have unusual fixed (unchanging) postures, which is known as dystonia. The two movement disorders (akinesia and dystonia) can blend or alternate.

Credit:  National Institute of Neurological Disorders and Stroke.