What's the difference between essential tremor and Parkinson's?

What's the difference between essential tremor and Parkinson's?

Neal Hermanowicz (Director of the Movement Disorders Program) gives expert video advice on: What are some of the other names for Parkinson's?; Who is at most risk for getting Parkinson's? and more...

Essential tremor is not regarded as a neurodegenerative disease, meaning that when we look at the brains of people with essential tremor there's not structural change that has been identified. Even when you look carefully, if you take sections from the brain of somebody with essential tremor who has passed away and look at it under a microscope, we don't see any kind of structural change. So there's some sort of chemical or circuit anomaly that is contributing to essential tremor, but it is not causing a structural change; no loss of certain brain cells or neurons that we do see in Parkinsons disease. The clinical presentation is often different. The tremor of Parkinsons disease is most often on one side of the body, right or left side, initially, then later, perhaps after a couple of years it may show up on the opposite side. The tremor of Parkinsons disease is classically thought of as being at rest when people are not using their hands. In contrast, essential tremor usually begins on both sides, both hands, and is more evident to people when they are actually using their hands, when they go to put a key in a lock or lift a cup of coffee to their lips for example, or eat soup with a spoon, then the tremor becomes apparent, but at rest the tremor is much less or even absent.