Fatigue evaluated using the 16-item Parkinson Fatigue Scale (PFS-16) predicts Parkinson's disease prognosis

Although fatigue is an important nonmotor symptom in Parkinson's Disease (PD) patients, little is known about the pathophysiological details of fatigue in PD, and it is still unknown whether fatigue correlates with PD prognosis. In this study, we investigated whether fatigue in PD correlates with clinical manifestations, treatment, or patient prognosis.

We recruited 75 idiopathic PD patients and used the Parkinson Fatigue Scale (PFS-16) to investigate fatigue. We compared PFS-16 scores with clinical details such as age, disease duration, daily levodopa equivalent dosage, and Hoehn & Yahr (H&Y) disease stage in the 56 patients who fully completed the questionnaire.

In total, 62% of subjects suffered from fatigue, as defined by a mean PFS-16 score above 3.3. There was no correlation between PFS-16 scores and disease duration or levodopa equivalent daily dose. However, there was a significant correlation between mean PFS-16 scores and a worsening grade of H&Y staging. The comparison between patients who showed stable H&Y grades (n=26) and patients with severely aggravated H&Y grades (n=7) revealed that the most significant differences were in questions 14 and 16 in the PFS-16 (p<0.001).

Fatigue is common in PD patients, as demonstrated in the present study. The PFS-16 questionnaire may be helpful to predict disease prognosis.