Friedman JH, Brown RG, Comella C, Garber CE, Krupp LB, Lou JS, Marsh L, Nail L, Shulman L, Taylor CB; Working Group on Fatigue in Parkinson’s Disease. (2007). Fatigue in Parkinson’s disease: a review. Movement Disorders. 2007 Feb 15;22(3):297-308 NonMotor Symptoms ,
This article was a review of the literature discussing fatigue in PD. Fatigue has been recently more recognized in PD patients. Fatigue is not currently measured by the Unified Parkinson’s Disease Rating Scale (UPDRS) but is often experienced by the PWP. The UPDRS is one of the most common instruments used by treatment providers to monitor PD symptoms; future revisions have indicated that fatigue will be included in the assessment tool. It is unclear why PD patients experience fatigue. Studies have shown that fatigue in PD is not always related to disease severity or motor dysfunction. Some PWP indicated that they felt fatigued prior to the diagnosis of PD. Studies have shown that fatigue often co-occurs with other nonmotor symptoms, which makes it difficult to tease out if one is causing the other (e.g. sleep problems, depression, anxiety). Fatigue has been studied in animal models and may be related to dopamine depletion (a chemical in the brain whose depletion causes PD symptoms). Studies have shown that exercise in those animals had less dopamine loss. Researchers have also studied fatigue in cancer and multiple sclerosis to help understand fatigue in PD. It is also unknown what causes fatigue in those diseases as well. In cancer studies aerobic exercise was shown to improve fatigue but researchers don’t fully understand the process of why. Also in multiple sclerosis they found that fatigue was linked to patient perceptions of their general health and control over their disease. More research needs to be done to better understand fatigue in PD. There currently are not consistent answers as to why the PWP does or does not experience fatigue or how best to treat it.