Parkinson disease Parkinson disease is an insidiously progressive disease. The typical onset is age 60 years. A stiffness like arthritis. The tremor is more prominent in the hands, is present when the hands are relaxed, or at rest and is asymmetrical. Rigidity, tremor, and slowness result, primarily, from a loss of dopamine in a region of the brain called the striatum.
Dopamine is a chemical which facilitates the flow of impulses from nerve cells.
If you trip and start falling, and if you're postural reflexes are normal, you're able to rapidly and without thinking adjust your body and limbs to stop falling. In Parkinson disease, your postural reflexes are lost and if you trip, you're unable to stop falling. Essential tremor is diagnosed by a physician after taking a history and performing an examination. If you tremble, have not seen a physician, and wonder whether you have essential tremor you can complete the Tremor Questionnaire . The questionnaire is not a substitute for a visit to your physician.