Timely identification of individuals at risk for neurodegenerative diseases such as Parkinson disease (PD) is increasingly important as more neuroprotective agents are investigated. Improving early diagnosis may facilitate access to clinical trials now and prepare for the future availability of disease-modifying treatments. Early diagnoses may also facilitate pharmacologic and nonpharmacologic therapies with the potential to improve quality of life.1 In addition, an early diagnosis is important for families and caregivers to understand the symptoms their loved ones may be experiencing and prepare for the future.2