A Rapid Motor Task-Based Screening Tool for Parkinsonism in Community-Based Studies.

Area of Science:

• Neurology
• Biostatistics
• Environmental Health

Background:

• Parkinsonism prevalence in developing nations is poorly understood due to limited access to neurologists.
• Objective motor task-based tests are needed for accessible parkinsonism screening.

Purpose of the Study:

• To develop and validate a parkinsonism screening tool for non-clinician administration.
• To predict Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3) scores using objective motor tasks.

Main Methods:

• A population-based sample in South Africa (N=315, age >40) from a manganese-exposed community was assessed.
• Linear regression models predicted UPDRS3 using Purdue grooved pegboard and kinematic-UPDRS3 motor tasks.
• Model validation included internal testing and external validation in a non-exposed cohort.

Main Results:

• Motor task measures (pegboard, hand rotation, finger tapping) strongly correlated with UPDRS3 scores.
• The predictive model demonstrated high accuracy (AUCs 0.81-0.91) for UPDRS3 cutoffs in internal validation.
• External validation showed good performance (AUC 0.85) for UPDRS3 ≥ 10 in a non-exposed cohort.

Conclusions:

• An objective motor task-based predictive model effectively assesses parkinsonism severity.
• This tool shows promise for widespread parkinsonism screening in diverse populations.
• The model's performance is robust across manganese-exposed and non-exposed communities.