Fatigue in patients with Parkinson's disease: a cross-sectional study

The purpose of this study is to ascertain the incidence of fatigue and to determine the cross-sectional associate and related variables of fatigue in patients with Parkinson's disease (PD).

A sample of 130 healthy individuals (39.23% male, mean age 64.19 ± 8.70 years) and 130 patients with PD (50.00% males, mean age 65.06 ± 9.04) were enrolled in the study. All participants were evaluated using the Fatigue Severity Scale (FSS), Mini-Mental State Examination (MMSE), Hamilton anxiety scale (HAMA), and Hamilton depression scale (HAMD). Patients with PD were assessed with the Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn & Yahr staging, the MMSE, HAMA, HAMD, the Parkinson's Disease Sleep scale-2 (PDSS-2), and Parkinson's Disease Questionnaire-39 (PDQ-39).

The PD group exhibited significantly higher scores in the FSS (p < 0.001) and demonstrated a greater susceptibility to fatigue compared to the control group. The FSS score in female patients was significantly higher than that in male patients (p = 0.003). Patients experiencing fatigue exhibited significantly higher scores on the UPDRS (p < 0.001), Hoehn & Yahr staging (p < 0.001), NMSS (p < 0.001), HAMD (p < 0.001), HAMA (p < 0.001), PDSS-2 (p = 0.012), and PDQ-39 (p < 0.001) compared to those without fatigue. Correlation analysis revealed significant associations between fatigue and NMSS, HAMD, HAMA, PDSS, PDQ-39, UPDRS, and Hoehn & Yahr stage. In the FSS-based multiple linear regression, HAMA and PDQ-39 remained cross-sectional associated with higher fatigue severity, whereas NMSS showed a borderline effect. To directly evaluate multivariable discrimination for fatigue occurrence, we constructed a combined logistic model including NMSS, HAMD, and PDQ-39. The combined model showed good discrimination (AUC 0.879, 95% CI 0.806-0.941) and acceptable calibration (Brier score 0.125), outperforming any single scale.

Patients with Parkinson's disease experience a higher incidence of distressing fatigue compared to healthy individuals. The significant prevalence of fatigue among these patients is linked to various motor and non-motor symptoms.