We appreciate the comments expressed by Chen and colleagues concerning our recent review on the onset of PD.1 We agree that the research on early nonmotor manifestations of PD may improve our understanding of the natural history of PD and may uncover distinct clinical subtypes of PD. Thus, increasing the knowledge of nonmotor symptoms may contribute to individualized management of PD and may improve response to treatment and prognosis.
Savica R, Rocca WA, Ahlskog JE. Prospective Research on Parkinson Nonmotor Symptoms—Reply. Arch Neurol. 2011;68(1):135-138. doi:10.1001/archneurol.2010.333