Parkinson's disease is a neurodegenerative disorder involving loss of neurons that release dopamine in the striatum. To compensate for the loss of dopamine, patients are typically prescribed levodopa medication which is converted to dopamine by the enzyme Aromatic L-Amino Acid Decarboxylase (AADC). As Parkinson's disease progresses, levodopa therapy becomes less effective and is associated with motor fluctuations, involuntary movements and other complications.