Cellular and Molecular Pathology in Tourette Syndrome

Abstract This chapter summarizes the available literature and data on pathological findings in Tourette syndrome. In severe, unremitting Tourette syndrome, there are decreases in somatostatin-positive/nitric oxide synthase–positive interneurons, fast spiking parvalbumin-positive/γ-aminobutyric acid-ergic interneurons, as well as tonically active cholinergic interneurons in the caudate nucleus and putamen. There is also a prominent increase in inflammation throughout the basal ganglia along with activation of microglial cells. Overall, neuroimaging studies suggest that the basal ganglia, a set of nuclei situated deep within the cerebral cortical hemispheres, are a central component of the pathophysiology of TS. These findings are discussed in light of current views on the pathogenic mechanisms underlying tic disorders.