With the increasing understanding of the involvement of basal ganglia circuits in the functions of movement, cognition, emotion and motivation, the network model of dystonia posits a plausible mechanism for the co-occurrence of mental dysfunctions in dystonia-plus syndromes. Genetic mutations that alter the production of neurotransmitters and receptors can potentially affect the function of these interconnecting circuits and yield non-motor symptoms as well. This article reviews the psychiatric findings in dystonia-plus syndromes reported thus far in the literature, both in animal models and human subjects. Based on this innovative understanding of the pathophysiology, implications to treatment of combined motor and non-motor symptoms (i.e. mental dysfunctions) are also briefly discussed.
Keywords: Anxiety; cognition; depression; dystonia parkinsonism; dystonic disorders; impulse-control disorder.