Prevalence of Prodromal Symptoms of Parkinson's Disease in the Late Middle-Aged Population.

BACKGROUND

The prodromal phase of Parkinson's disease (PD) can last up to 20 years and is characterized by a variety of non-motor symptoms.

OBJECTIVE

To determine the prevalence of a selection of non-motor symptoms known to be associated with an increased risk of developing PD in a late middle-aged population-based sample and to determine their association with motor function.

METHODS

At a mean age of 60.3 years, 775 subjects were recruited from the Longitudinal Aging Study Amsterdam (LASA). Hyposmia, cognitive impairment, patient-reported constipation, possible REM-sleep behavior disorder, depression, and anxiety were indexed as known PD risk factors. Additionally, 1) the PD screening questionnaire, 2) four physical performance tests, and 3) a functional limitations questionnaire, were used to determine whether the presence of two or more PD risk factors was associated with reduced motor function.

RESULTS

The prevalence of single risk factors ranged between 3 and 13%. Approximately 11% of subjects had two or more PD risk factors. Motor functioning of subjects with two or more PD risk factors was significantly worse than performance of subjects without or with a single risk factor (all p values≤0.001).

CONCLUSION

Approximately 11% of the late middle-aged population has two or more known PD risk factors. Among these subjects self-perceived PD symptoms and reduced physical performance are more prevalent, suggesting that at least some of these subjects may be in the prodromal phase of PD.