Dystonia is caused not by a single malfunctioning brain structure, but because of many complications in the brain networks that connect areas of the brain that control movement. Investigators at Baylor College of Medicine published a study examining the interactions of several such brain areas, the inferior olive and the cerebellum, in dystonia.
Using genetically modified mice, they blocked neurons in the inferior olive from signaling to the cerebellum. The mice developed a dystonic movement disorder with twisting limb movements and tremor, demonstrating that dysfunction in signaling between these brain structures is a mechanism that may cause dystonia. Remarkably, the investigators were able to reverse the movement disorder symptoms with drugs, and—most notably—with deep brain stimulation of the cerebellum. Researchers have been increasingly interested in clarifying the role of the cerebellum in dystonia and what that might mean for novel therapies.
The most common target for deep brain stimulation in human dystonia patients is the subthalamic nucleus, part of the basal ganglia but this study intriguingly points to the cerebellar nuclei as potential surgical targets.
White JJ, Sillitoe RV. Genetic silencing of olivocerebellar synapses causes dystonia-like behaviour in mice.Nat Commun. 2017 Apr 4;8:14912.