Quality of life in isolated dystonia – a cross-sectional study

Objective: To evaluate the relationship between health-related quality of life (HR-QoL) and both physical and psychiatric factors in a large, international, multi-centre cohort of isolated dystonia patients.Background: HR-QoL, which is reduced in isolated dystonia compared to population-based samples, is not only determined by motor but also non-motor symptoms [1]. As depression, generalized anxiety disorder (GAD) and social anxiety disorder (SAD) are highly prevalent in dystonia patients [1-6], we hypothesize that psychiatric rather than dystonic symptoms predict HR-QoL.Method: 603 isolated dystonia patients were prospectively enrolled in the cross-sectional Natural History Dystonia Coalition multicenter study. HR-QoL (RAND 36-Item Health Survey), symptoms respectively severity of depression and GAD (Hospital Anxiety and Depression Scale, HADS) and SAD (Liebowitz Social Anxiety Scale, LSAS) were evaluated. Dystonia severity and dystonic tremor were examined using a standardized video protocol and the Burke-Fahn-Marsden Dystonia Rating Scale. Patients with botulinum toxin (BoNT) treatment were enrolled at least two months after their last injection. Statistical predictors of HR-QoL were obtained from a saturated path analysis, BoNT-associated changes of HR-QoL over one year were also evaluated using a non-parametric analysis of variance.Results: Mean HR-QoL of the 603 dystonia patients (mean age: 55.6 ± 12.5 years, female n=404) was 64 ± 22%. In 22% of patients HADS-D was > 7/21, in 37% HADS-A was > 7/21 and in 44% LSAS was > 30/144. All eight QoL subscales were negatively related to intensity of depression, GAD and SAD (all p ≤ .001). Dystonia severity was negatively associated with physical functioning, physical and emotional role functioning, and social functioning (all p ≤ .001), whereas presence of tremor was negatively associated with physical functioning and pain (all p ≤ .006). Older age was associated with better emotional well-being and vitality (all p ≤ .006). Sex was not associated with HR-QoL. Patients with initiated (n = 35) and without (n=37) BoNT therapy experienced an improvement of HR-QoL (total score) and dystonia severity over one year (all p ≤ .025).Conclusion: HR-QoL in isolated dystonia is strongly associated with psychiatric and physical features. Standard therapy regimens, such as BoNT focus on motor improvements, while comprehensive care of dystonia patients should address both physical and mental aspects of health.References: 1. Slawek J, Friedman A, Potulska A, et al. Factors affecting the health-related quality of life of patients with cervical dystonia and the impact of botulinum toxin type A injections. Funct Neurol. 2007;22(2):95-100. 2. Lewis L, Butler A, Jahanshahi M. Depression in focal, segmental and generalized dystonia. J Neurol. 2008;255(11):1750-1755. 3. Gundel H, Wolf A, Xidara V, Busch R, Ceballos-Baumann AO. Social phobia in spasmodic torticollis. J Neurol Neurosurg Psychiatry. 2001;71(4):499-504. 4. Kuyper DJ, Parra V, Aerts S, Okun MS, Kluger BM. Nonmotor manifestations of dystonia: a systematic review. Mov Disord. 2011;26(7):1206-1217. 5. Moraru E, Schnider P, Wimmer A, et al. Relation between depression and anxiety in dystonic patients: implications for clinical management. Depress Anxiety. 2002;16(3):100-103. 6. Fabbrini G, Berardelli I, Moretti G, et al. Psychiatric disorders in adult-onset focal dystonia: a case-control study. Mov Disord. 2010;25(4):459-465