Mood and energy determinants of quality of life in dystonia

Prior research has demonstrated that dystonia patients may have reductions in numerous measures of quality of life (QOL) when compared to healthy age-matched controls. However, the determinants of QOL in this patient population have not been fully specified. To address this issue, we administered the Medical Outcomes Study Short Form 36 (SF-36) questionnaire along with the Visual Analogue Mood Scale (VAMS), the Beck Depression Inventory (BDI), the Unified Dystonia Rating Scale (UDRS), and the State and Trait Anxiety Index (STAI) to 73 patients diagnosed with primary dystonia. Dystonia patients demonstrated lower QOL on all subscales of the SF-36 compared to normative healthy age-matched data. While the UDRS, a predominantly motor scale, was not significantly correlated with QOL (r = -0.19, P = 0.11), the BDI (r = -0.79, P < 0.0001), the STAI (r = -0.63, P < 0.0001) and multiple subscales of the VAMS revealed significant correlations. The tired subscale was the item most strongly correlated with overall QOL (r = -0.52, P < 0.0001), and particularly QOL related to physical function. The association of tiredness with QOL remained significant even when adjusting for the BDI and STAI scores (P < 0.0001). This study highlights the importance of mood and energy in QOL among a cohort of patients with dystonia. Further studies will be needed to determine the effect of treatment on these associations and whether disturbances in energy are related to sleep disturbances or to primary fatigue issues.