Another genetic disease with an unknown cause is Tourette's syndrome, which causes involuntary and intense muscle contractions. Some people experience the more publicized version of the condition -- verbal outbursts or sudden cursing. Like Parkinson's, early Tourette's can result in involuntary spasms of body parts including the eyelids.

This site offers information designed for educational purposes only. You should not rely on any information on this site as a substitute for professional medical advice, diagnosis, treatment, or as a substitute for, professional counseling care, advice, diagnosis, or treatment. If you have any concerns or questions about your health, you should always consult with a physician or other healthcare professional.