Parkinson's Disease

The symptoms of Parkinson's disease result from a deterioration of the metabolic pathways in the area of the brain called the substantia nigra. Cells in this part of the brain produce dopamine, a chemical that transfers messages in the brain. Lack of dopamine disrupts the ability of the brain to direct or control movements normally.

Using an imaging drug that is like dopamine (18F-DOPA), the PET scan will show changes in this dopaminergic systems. In Parkinson's disease, the PET scan shows a characteristic pattern of reduced uptake for 18F-DOPA, and it begins to appear very early in the course of the disease.

This enables doctors to know if the gradually increasing symptoms that may be a tremor, gait disturbance, or others are the result of Parkinson's disease or some other cause. Therapy can be started at its earliest possible stage.

PET can indicate with a high degree of accuracy if a movement disorder is Parkinson's disease or another type of disorder.