Editorial: Models, mechanisms, and maturation in developmental dystonia

Dystonia, characterized by involuntary over-contractions or co-contractions of muscle groups, is the third most common movement disorder and afflicts an estimated 300-400 million individuals worldwide. Despite the convergence of this group of disorders on a phenotype of abnormal muscle activity, the underlying pathophysiology of dystonia has proven to be wide-ranging, diverse, and as a result difficult to effectively treat. This reality is reflected in the clinic, where dystonia poses great diagnostic and therapeutic challenges. However, major inroads have been made in defining the causes of individual etiologies of dystonia, with mounting efforts rising to meet the therapeutic demands of developing therapies to treat this group of devastating disorders. Specifically, the identification of disease-causing mutations in inherited, often childhood-onset, forms of dystonia has opened the door to generate experimental models to understand the genetic and neural network culprits that cause dystonia. This insight has started to elucidate commonalities in the molecular and neural pathways underlying genetically distinct forms of dystonia. However, despite these advances, there are still many outstanding questions in the field. For example, why do genetic forms of dystonia often present early in life? What protects against symptom development in non-manifesting carriers with dystonia-causing genetic mutations? Does neurodevelopmental maturation contribute to symptom acquisition, and does this role of maturation reflect a critical therapeutic window? And most importantly, how can we exploit our current understanding of the mechanisms that underlie dystonia to design effective therapies and successful new treatments? These questions helped stimulate and inspire the collection of current papers.