Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Whilst the diagnosis of Parkinson's disease (<jats:styled-content style="fixed-case">PD</jats:styled-content>) relies on the motor triad of bradykinesia, rigidity and tremor, the underlying pathological process starts many years before these signs are overt. In this prodromal phase of <jats:styled-content style="fixed-case">PD</jats:styled-content>, a diverse range of non‐motor and motor features can occur. Individually they do not allow a diagnosis of <jats:styled-content style="fixed-case">PD</jats:styled-content>, but when considered together, they reflect the gradual development of the clinical syndrome. Different subgroups within the prodromal phase may exist and reflect different underlying pathology. Here, we summarise the evidence on the prodromal phase of <jats:styled-content style="fixed-case">PD</jats:styled-content> in patient groups at increased risk of PD with well described prodromal features: patients with idiopathic rapid eye movement sleep behaviour disorder, patients with idiopathic anosmia and families with monogenic mutations that are closely linked to <jats:styled-content style="fixed-case">PD</jats:styled-content> pathology. In addition, we discuss the information on prodromal features from ongoing studies aimed at detecting prodromal <jats:styled-content style="fixed-case">PD</jats:styled-content> in the general population. It is likely that better delineation of the clinical prodromes of <jats:styled-content style="fixed-case">PD</jats:styled-content> and their progression in these high‐risk groups will improve understanding of the underlying pathophysiology.</jats:p>