Parkinson’s disease (PD) is a progressive, neurological disease that mainly affects movement but can also affect cognition. Parkinson’s disease results from the destruction of nerve cells in a part of the brain called the basal ganglia.
Different parts of the brain work together by sending signals to each other to coordinate all of our thoughts, movements, emotions, and senses. When we want to move, a signal is sent from the basal ganglia to the thalamus and then to the cerebral cortex, all different parts of the brain. Nerve cells in the brain communicate by using chemicals. A chemical (neurotransmitter) called dopamine is produced in a group of cells called the substantia nigra and is essential for normal movement. When the cells die, they can no longer produce and send dopamine, so the signal to move doesn’t get communicated. By the time a person starts to experience motor symptoms of Parkinson’s, they’ve already lost approximately 50% of their dopamine producing cells. People may experience non-motor symptoms from loss of other neurotransmitters up to ten years before motor symptoms are noticed.