The clinical symptoms in Tourette syndrome (TS) change with age. In order to examine the course of a disease, longitudinal studies are an important tool. Cortico-striato-thalamo-cortical pathways are believed to be involved in the pathophysiology of TS, but knowledge on the influence of the development of the brain during childhood on the development of clinical symptoms is scarce. The patients with remission of tics and the patients with persistent tics might represent two different phenotypical variants of TS and thus represent two different pathophysiological mechanisms in TS.

In this chapter, we focus on longitudinal aspects of the development of TS from clinical and neuroradiological perspectives. Firstly, we describe the clinical development and course of tics and comorbidities and secondly the findings of neurodevelopmental brain imaging studies in TS. Brain imaging studies have shown similar areas in the brain involved in TS in both children and adults. Increased volume of posterior prefrontal cortex and thalamus have been found in both children and adults, and microstructural changes in corpus callosum. Differences between pediatric and adult cross-sectional clinical populations have been shown in volume of corpus callosum. Changes in parallel diffusivity in thalamus, caudate nucleus and frontal lobe have been found to be most pronounced in patients with persisting tics compared with patients with remission of tics and healthy controls. Therefore, these areas might be most interesting to examine in further studies in order to explore the possibility of different phenotypes regarding the course of TS.