Objective: To identify odorants within the UPSIT that effectively distinguish PD patients from healthy controls and to examine their associations with motor and non-motor symptoms.
Background: Olfactory dysfunction is one of the prodromal symptom of Parkinson’s disease (PD). While the University of Pennsylvania Smell Identification Test (UPSIT) is a reliable tool for staging dysfunction, its length can be time-consuming. Recent studies suggest specific odorant subsets may serve as efficient biomarkers for alpha-synucleinopathy.
Method: Healthy controls (N=98) and PD patients (N=121) underwent UPSIT testing. The PD group received comprehensive motor (MDS-UPDRS) and non-motor (MMSE, MoCA, PDSS, BDI, BAI, QUIP-RS, NMSS, PDQ-39) assessments. Logistic regression identified significant odorants. Items with the highest odds ratios (Exp[B]) were evaluated using ROC curve analysis for shortened test performance. Multiple regression analyzed associations between specific odorant scores and clinical symptoms.
Results: Most odorants significantly differentiated PD from controls, except for pizza, menthol, gasoline, and pine. A 12-item subset-selected based on the highest Exp(B) values-achieved an optimal Youden index with a sensitivity of 0.878 and a specificity of 0.934 at a cutoff score of 8.5. In the PD group, the score for these 12 odorants significantly correlated with cognitive performance (MoCA: r = 0.264, p = 0.003; MMSE: r = 0.262, p = 0.004). Regarding motor features, lower scores were significantly associated with the akinetic-rigid phenotype (r = -0.192, p = 0.035), whereas no significant association was found with the tremor-dominant phenotype.
Conclusion: A 12-item abbreviated olfactory test demonstrates high sensitivity and specificity for PD screening. The association between specific odor loss and cognitive dysfunction, as well as the akinetic-rigid motor phenotype, suggests that these odorant subsets may reflect disease severity and specific clinical progression patterns.
To cite this abstract in AMA style:
YH. Lin, TC. Fang, MH. Chang, YJ. Guo. Identification of Discriminative Odorants for Parkinson’s Disease and Their Clinical Correlates: A Population-Specific Short-Form Approach [abstract]. Mov Disord. 2026; 41 (suppl 1). https://www.mdsabstracts.org/abstract/identification-of-discriminative-odorants-for-parkinsons-disease-and-their-clinical-correlates-a-population-specific-short-form-approach/. Accessed October 1, 2026.« Back to 2026 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/identification-of-discriminative-odorants-for-parkinsons-disease-and-their-clinical-correlates-a-population-specific-short-form-approach/