Prodromal features for Parkinson's disease--baseline data from the TREND study

Area of Science:

• Neuroscience
• Gerontology
• Neurology

Background:

• Non-motor symptoms often precede motor deficits in Parkinson's disease (PD).
• These early signs, termed prodromal markers, may indicate a neurodegenerative state before clinical diagnosis.
• Depression, rapid eye movement behaviour disorder (RBD), and hyposmia are key prodromal markers for PD.

Purpose of the Study:

• To investigate the association between selected prodromal markers (depression, RBD, hyposmia) and other potential prodromal PD features.
• To assess the prevalence of additional prodromal symptoms in elderly individuals with and without these selected markers.

Main Methods:

• Analysis of data from 698 healthy individuals aged 50-80 years from the TREND study.
• Participants were classified based on the presence of one or more selected prodromal markers (SPMs).
• A 23-item questionnaire assessed other prodromal PD features, comparing groups with and without SPMs.

Main Results:

• Individuals with SPMs reported significantly more additional prodromal PD features compared to those without (median 2 vs. 4-7 features, P < 0.001).
• Participants with depression or RBD endorsed more prodromal features (5/23) than those with hyposmia (3/23, P = 0.001).
• No significant increase in prodromal features was observed when comparing individuals with two SPMs versus one SPM.

Conclusions:

• The presence of prodromal markers for PD is associated with a higher occurrence of other early PD symptoms.
• These findings suggest that depression, RBD, and hyposmia can help identify individuals at increased risk for Parkinson's disease.