Fatigue assessment of Parkinson's disease patient in clinic: specific versus holistic.

Fatigue is a frequently encountered non-motor symptom in Parkinson's disease (PD). Being a subjective definition, with no biological markers, it is difficult to describe. Its definition is influenced by the background and culture of the patient. Subtypes of fatigue are peripheral fatigue and mental fatigue. The co-existence of other non-motor symptoms in PD complicates its assessment. Fatigue could be present before, at the time of diagnosis of PD in untreated patients or during the course of the disease. Scales that can be used for evaluation include generic one for a holistic manner and those specifically designed for PD. A scale designed for fatigue should differentiate between PD patients with fatigue and those without fatigue. The next step is to choose between unidimensional which evaluate one dimension and multidimensional scales. We present the main scales which can be used for fatigue assessment and their properties. The scales are presented with some psychometric properties in non-PD population and those properties through validation in PD population. Scales have some properties which could be recommended for screening and/or rating of severity of fatigue in PD.