Dopamine replacement therapies, such as the dopamine precursor levodopa, typically lead to the relief of symptoms but lose their potency as the disease progresses.

Most Parkinson's therapies, including deep brain stimulation and a precursor to the neurotransmitter dopamine called levodopa, ease tremors and rigidity.

Other dopamine-based therapies have since been developed, but levodopa is the gold standard for relieving the motor symptoms of Parkinson's.