Next-Gen Olfactometry System for Olfactory Testing in Parkinson's Disease and High-Risk Individuals

Olfactory impairment is a key prodromal symptom of Parkinson's disease (PD), yet conventional Japanese olfactory tests require controlled rooms and time-consuming manual procedures, restricting large-scale use. The Next-gen Olfactometry System (NOS) provides rapid, semi-automated assessment.

We evaluate the clinical utility of the NOS as an efficient screening tool for PD-related olfactory dysfunction.

Twenty-three patients with PD, 21 high-risk individuals (≥2 prodromal symptoms), and 20 low-risk controls underwent NOS testing (recognition and detection thresholds and a composite score). Results were compared with the Odor Stick Identification Test for Japanese (OSIT-J) to evaluate correlation and discriminative ability.

NOS recognition and detection thresholds correlated moderately with OSIT-J (r = -0.676 and r = -0.516, both P < 0.001). NOS recognition thresholds were significantly worse in PD than in either risk group, but did not differ between risk groups. NOS detection thresholds and OSIT-J scores showed a graded decline-worst in PD, intermediate in high-risk, and best in low-risk-with every pairwise contrast significant. The NOS indices may discriminate between the PD and high-risk groups, as well as between the PD and low-risk groups. In the exploratory analysis, NOS recognition thresholds correlated moderately with the dopamine transporter single-photon-emission computed tomography specific binding ratio in the high-risk group.

NOS indices showed moderate agreement with OSIT-J. Although NOS did not surpass OSIT-J in discrimination between high- and low-risk individuals, its rapid, semi-automated workflow makes it a practical option for large-scale olfactory screening in prodromal PD.