The prodromes of Parkinson's disease

• Published in: The European journal of neuroscience Vol. 49; no. 3; pp. 320 - 327
• Main Authors: Rees, Richard Nathaniel, Noyce, Alastair John, Schrag, Anette
• Format: Journal Article
• Language: English
• Published: France Wiley Subscription Services, Inc 01.02.2019; John Wiley and Sons Inc
• Subjects: Anosmia; Diagnosis; Early Diagnosis; GBA; Humans; LRRK2; Movement disorders; neurodegenerative disease; Neurodegenerative diseases; Parkinson Disease - diagnosis; Parkinson's disease; Pathology; Prodromal Symptoms; REM sleep; REM sleep behavioural disorder; Risk groups; Sleep disorders; Special Issue; Tom Isaacs Special Issue; Tremor; REM sleep behavioural disorder; neurodegenerative disease; LRRK2; GBA; anosmia
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.14269

Whilst the diagnosis of Parkinson's disease (PD) 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 PD, a diverse range of non‐motor and motor features can occur. Individually they do not allow a diagnosis of PD, 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 PD 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 PD pathology. In addition, we discuss the information on prodromal features from ongoing studies aimed at detecting prodromal PD in the general population. It is likely that better delineation of the clinical prodromes of PD and their progression in these high‐risk groups will improve understanding of the underlying pathophysiology.