Parkinson's Disease is a progressive movement disorder marked by tremors, rigidity, slow movements (bradykinesia), and posture instability. It occurs when cells in one of the movement-control centers of the brain begin to die for unknown reasons.

PD was first noted by British physician James Parkinson in the early 1800s.

Usually beginning in a person's late fifties or early sixties, Parkinson disease causes a progressive decline in movement control, affecting the ability to control initiation, speed, and smoothness of motion. Symptoms of PD are seen in up to 15% of those ages 65–74, and almost 30% of those ages 75–84.

Most cases of PD are sporadic. This means that there is a spontaneous and permanent change in nucleotide sequences (the building blocks of genes). Sporadic mutations also involve unknown environmental factors in combination with genetic defects. The abnormal gene (mutated gene) will form an altered end-product or protein. This will cause abnormalities in specific areas in the body where the protein is used. Some evidence suggests that the disease is transmitted by autosomal dominant inheritance. This implies that an affected parent has a 50% chance of transmitting the disease to any child. This type of inheritance is not commonly observed. The most recent evidence is linking PD with a gene that codes for a protein called alpha-synuclein. Further research is attempting to fully understand the relationship with this protein and nerve cell degeneration.

Tim Donahoe has been a patient of Dr. Omar Gonzalez since April of 2007.

Background: Tim was employed by a home medical equipment company. He was the face for his employer with approximately 70 doctors. On a visit with a rural GP, he noticed a twitch in one of his fingers. His GP sent me to the motor function clinic at Barnes Hospital in St. Louis, Mo. where he was diagnosed with Parkinson's. Seeking a second opinion and in denial Tim went a year without treatment. That was July of 2001. He was 46 years old and at the top of his health and conditioning. He played mandolin and guitar in two bands, competed in track and field at a national level, and strength trained for his competitions. At this time Tim was bench pressing 245 lbs, deadlifted 445 lbs, and squat of 405 lbs.