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.