Parkinson Platform Noord Nederland

We thank Sirwan KL Darweesh and colleagues for their interesting comments. We fully agree that cognitive decline can occur early in Parkinson's disease, including the prediagnostic phase, as demonstrated in the Article by Darweesh and colleagues,1 as well as our own,2 and other groups.3,4 As Darweesh and colleagues point out, investigation of the early clinical features and biomarkers associated with such early cognitive decline can provide not only information for clinical stratification and prognostication, but also help understand the underlying neurobiology of cognitive impairment in Parkinson's disease.