Tremor
Tremor is an unintentional, somewhat rhythmic, muscle movement involving to-and-fro movements (oscillations) of one or more parts of the body. It is the most common of all involuntary movements and can affect the hands, arms, head, face, vocal cords, trunk, and legs. Most tremors occur in the hands. In some people, tremor is a symptom of another neurological disorder. A very common kind of tremor is the chattering of teeth, usually induced by cold temperatures or by fear. Tremor is generally caused by problems in parts of the brain that control muscles throught the body or in particular areas, such as the hands. Neurological disorders or conditions that can produce tremor include multiple sclerosis, stroke, traumatic brain injury and neurodegenerative diseases that damage or destroy parts of the brainstem or the cerebellum.
