The Onset of Nonmotor Symptoms in Parkinson's disease (The ONSET PD Study)

ABSTRACT Nonmotor symptoms (NMS) in Parkinson's disease (PD) can precede onset of motor symptoms. Relationship between premotor symptoms onset and motor features is limited. Our aim is to describe the presence and perceived onset of NMS in PD as well as their possible association with motor phenotype. Presence and onset of NMS were assessed by a custom‐made questionnaire in 109 newly diagnosed untreated PD patients and 107 controls from 11 Spanish and Austrian centers. Seventeen of thirty‐one NMS were more common in patients than controls (P