Parkinson's disease staging based of the non-motor symptoms scale

Objective: The Non-Motor Symptoms Scale (NMSS) is a unified instrument for assessment of non-motor symptoms (NMS) in Parkinson‘s disease (PD). Present study is aimed at exploring a PD staging based on NMS severity levels determined through NMSS. Methods: International, multicentre, cross-sectional study. Data on patients‘ sex, age, disease duration, and treatment were collected. NMSS, Hoehn and Yahr staging (HY), motor examination and motor complications scales, and the PDQ-8 were applied. NMSS scores were broken down by quartiles to establish severity levels. Chi squared, Mann-Whitney, and Kruskal-Wallis tests were applied to compare NMSS severity levels with other variables in the study. Results: The sample was composed by 750 PD patients (58.5% men; mean age: 65.98±10.33 years; disease duration: 7.37±5.64 years; HY median: 2, limits: 1-5). NMSS total score was 56.82±43.62 (range: 0-243, median: 44). NMSS levels were established as follows: level 0 (no NMS); 1 (slight): 1-7 points; 2 (mild): 8-24; 3 (moderate): 25-44; 4 (severe): 45-80; 5 (very severe): ÔëÑ81 points. No differences were detected in NMS severity level distribution by gender (p = 0.14) and age (p = 0.09). Disease duration, motor examination, motor complications, and PDQ-8 scores showed significant differences by NMSS severity levels (p < 0.0001). There was also a significant difference between HY and NMS levels (p < 0.0001). Conclusions: Severity levels, based on quartiles, can be extracted from NMSS scores and may be the basis for a staging system based on NMS. A significant difference was found between HY and NMS classifications, showing that motor and non-motor manifestations have a different pattern