Many people experience a sudden jolt just as they fall asleep, and scientists say there is a simple explanation behind the strange sensation.

Chorea and hemiballismus are both forms of involuntary movement disorders. Hemiballismus can cause sudden, violent, and flinging motions. Chorea can cause irregular, spontaneous, and nonrepetitive ...

Chorea is an involuntary movement disorder that causes irregular muscle movements. It occurs due to the overactivity of dopamine in the brain, which can have many causes. Treatment and outlook both ...