How can parkinson's disease effect the nervous system?

Attacks One Location: Parkinson's disease is a degenerative condition caused by the death of Dopamine producing neurons in an area of the brain known as the substantia nigra. The reason for cell death is unknown. As Dopamine is essential in the use and control of one's muscles early symptoms include tremors, rigidity and difficulty walking. As it progresses, cognitive, behavioral and emotional problems are common.