In Parkinsonism, the tremors, muscular rigidity, and reduced control over voluntary movements appear to be a function of: degeneration of neurons that use dopamine as a neurotransmitter .
Parkinsonism is characterized by the symptoms associated with Parkinson’s disease. Parkinson’s disease is a degenerative, progressive disorder that influences nerve cells in the brain. The brain’s nerve cells transmit messages that plan and control body movement and they also produce neurotransmitter dopamine. For unknown reasons, the dopamine-producing nerve cells (neurons) degenerate (die). When high amount of dopamine is lost, the symptoms of Parkinson’s disease such as tremors, muscular rigidity, and reduced control over voluntary movements occur.