A<unk>  is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving oscillations or twitching movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds,<unk> unk, and legs. Most<unk> s occur in the hands. In some people, a<unk>  is a symptom of another neurological disorder. A very common<unk>  is the teeth chattering, usually induced by cold temperatures or by fear.
Tremor
Seizure
Pallor
Catalepsy
Catatonia
Paratonia
Clonus
Psychomotor agitation