High prevalence of self-reported non-motor symptoms and lack of correlation with motor severity in adult patients with idiopathic isolated dystonia

Background Although abnormal movements and postures are the hallmark of dystonia, non-motor symptoms (NMS) are common and negatively affect quality of life. Objectives The aim of this study was to screen dystonia patients for NMS and analyze their association with clinical parameters, including motor disability. Methods Adult patients with idiopathic isolated dystonia were interviewed and examined. Dystonia severity was evaluated with the Fahn-Marsden Dystonia Rating Scale and the presence of NMS was assessed using a list of 29 complaints. Results A hundred and two patients (63.7% female) were enrolled. Dystonia began after 20 years of age in 61.8% and was focal or segmental in 82.8% of patients. Only eight patients (7.8%) had no NMS and 59.8% reported more than five. The most prevalent NMS were pain (72.5%) and anxiety (63.7%), followed by difficulty recalling information (44.1%), sadness/anhedonia (41.2%), and difficulty falling asleep (38.2%). No correlation was found between the total number of NMS and dystonia severity ( p = 0.18) or regular botulinum toxin use ( p = 0.66). The majority of NMS domains correlated with each other. Conclusions Our results confirm a high prevalence of NMS among dystonia patients, even in those with mild motor disability. The pathophysiology of NMS in dystonia remains to be completely understood.