Parkinson's disease -- a chronic disorder that causes a progressive loss of nerve cell function in the part of the brain that controls muscle movement--is an incurable neurological condition with debilitating symptoms. Over 1.5 million Americans are affected, and the numbers continue to grow. From the first moment of her Parkinson's diagnosis, author Jackie Christensen took charge and educated herself on every aspect of her condition. Now, as a "patient-expert,"...