Can a screening questionnaire accurately identify mild Parkinsonian signs?

BACKGROUND

Mild parkinsonian signs (MPS) are early features that, when present, increase the risk of neurodegenerative disease and mortality. Current methods to identify MPS are limited to neurological examination. Our objective was to assess the ability of a 9-item Parkinson's Disease Screening Questionnaire (PDSQ), which has high sensitivity in the detection of overt Parkinson's disease (PD), to detect MPS.

METHODS

Measures including the PDSQ, Unified Parkinson's Disease Rating Scale and University of Pennsylvania Smell Identification Test were administered to 267 participants without neurodegenerative disease. Two published definitions of MPS were used to classify cases.

RESULTS

PDSQ scores were higher for cases compared to controls (p < 0.001 for the first case definition and 0.07 for the second). However, the questionnaire had low sensitivity (47 and 59%) and specificity (62 and 63%) in the detection of MPS. Adding factors such as age, gender and smell test score to the questionnaire in a predictive model only marginally improved the test characteristics.

CONCLUSION

The results show the screening questionnaire does not accurately identify MPS. More accurate tests are needed to improve the detection of this early syndrome which can lead to motor disability, neurodegenerative disease and mortality.