Exploring the fatigue phenomenon in individuals with Parkinson's disease: an Italian multicenter cross-sectional...

Fatigue is a common and disabling non-motor symptom in Parkinson's disease (PD), significantly affecting patients' quality of life. However, it is often underdiagnosed due to its subjective nature and the lack of a clear definition, hindering the development of effective treatments.

This study aims to investigate the prevalence of fatigue and its associations with sociodemographic factors, disease severity, levodopa equivalent daily dosage (LEDD) and motor, non-motor, and cognitive symptoms in an Italian cohort of patients with PD.

An observational cross-sectional study was carried out in three Italian centers from January to May 2024. One hundred PD patients (H&Y ≤ 4) were assessed using validated tools: Parkinson Fatigue Scale (PFS), Fatigue Severity Scale, and Modified Fatigue Impact Scale. Motor and non-motor signs and symptoms, cognitive status, and LEDD were analyzed using non-parametric tests and Spearman's correlations. Fatigue prevalence was determined based on PFS score ≥ 3.09.

Fatigue was present in 36% of patients, more prevalent in women and more severe in those with H&Y > 2. Fatigue correlated strongly with non-motor symptoms (MDS-UPDRS Part I; ρ > 0.6, p < 0.001) and moderately with motor complications (0.4 < ρ < 0.5, p < 0.001), but weakly with disease duration, LEDD and age (ρ < 0.3, 0.002 < p < 0.05). Significant intercorrelations among fatigue scales supported their ability to consistently measure the fatigue construct.

Fatigue in PD is a multidimensional phenomenon influenced mainly by non-motor symptoms. Gender-specific differences and the association with disease progression underscore the need of comprehensive and integrated management strategies to address this challenging symptom.