More than a Movement Disorder: Non-Motor Features and Future Directions in Dystonia Research.

BACKGROUND: Dystonia, the third most common movement disorder, is increasingly recognised as a network disorder with both motor and non-motor symptoms. Non-motor symptoms have been shown to be key determinants of quality of life in dystonia and include anxiety, depression, sleep disturbance, cognitive dysfunction and fatigue. RESULTS: Emerging data suggests that dysfunction within cortico-striato-thalamo-cerebello-cortico circuits underpins both motor and non-motor symptoms. Genetic studies have highlighted shared gene clusters involved in synaptic function that are associated with both dystonia and psychiatric disorders. Neuroimaging studies reveal microstructural and functional alterations in patients with dystonia that correlate with non-motor symptoms. DISCUSSION: Current research into both the pathophysiology and treatment of non-motor symptoms remains limited, heterogeneous and based on small sample sizes, which restricts the strength of the conclusions that can be drawn. Evidence for targeted therapies for non-motor symptoms is scarce. CONCLUSIONS: A greater understanding of the overlap between neural pathways underpinning motor and non-motor symptoms may provide a foundation for the development of novel pharmacological and non-pharmacological therapies. As understanding advances, treatment strategies will likely adopt a holistic model that integrates pharmacological options with non-pharmacological measures, including multi-disciplinary rehabilitation and supportive therapies.