Motor function and the probability of prodromal Parkinson's disease in older adults

Identification and characterization of Parkinson's disease (PD) in its prodromal stage is crucial.

The objective of this study was to investigate the association between motor function and the probability of prodromal PD in a community-dwelling older population.

We used data from a population-based cohort of older adults (HELIAD study). Subjective motor function was evaluated with a 12-item motor symptoms questionnaire and objective motor function indirectly with a physical activity questionnaire and two gait speed tests. The probability of prodromal PD was calculated according to the Movement Disorder Society research criteria for n = 1731 without PD. Regression multiadjusted models were used to investigate the associations between each motor measure and prodromal PD probability.

For each unit increase in motor symptoms score and for each kcal/kg/day lower energy expenditure (corresponding to 20 minutes of light walking/day for a 75-kg man) there was a 27% and 3% higher probability for prodromal PD, respectively (P < 0.001). Having at least one subjective motor symptom increased the odds of having possible/probable prodromal PD (n = 49; P < 0.05). Including subjective and indirect motor variables in the same model showed that both (symptoms and physical activity) contributed significantly to the model (P < 0.01). Excluding subthreshold parkinsonism from the calculation showed that gait speed less than 0.8 m/s was also associated with a higher prodromal PD probability score (P < 0.001).

Subjective motor symptoms as well as simple objective motor measures of physical activity or gait speed are associated with a higher probability of prodromal PD in older adults. These data may serve to enable the early identification of prodromal PD cohorts, particularly if they are confirmed in longitudinal studies. © 2019 International Parkinson and Movement Disorder Society.