Altered amygdala functional connectivity in adult Tourette's syndrome

Tourette's syndrome (TS) is a developmental neuropsychiatric disorder characterized by motor and vocal tics as well as psychiatric comorbidities. Recently, differences in maturation of cortical networks using functional connectivity metrics have been described for this disorder. However, adult data on subcortical networks are scarce. In particular, the connectivity of the amygdala, for which a role in the pathophysiology of TS has been established, has not been examined so far. We studied 15 adult TS patients (11 male, aged 30.4 +/- 9.7y) and 15 age- and sex-matched controls (11 male, aged 32.0 +/- 9.3y) in a functional magnetic resonance imaging study at 1.5T using a simple motor task. We corrected for possible confounds introduced by tics, motion and brain-structural differences as well as age, sex, and medication. Task performance was monitored by simultaneous MR-compatible video-recording. Data were analyzed using an independent component approach sensitive to functional connectivity patterns. A stable component comprising both amygdalae could be identified across all subjects. Additionally, we observed a highly significant increase in coupling between/within amygdalae in the TS group when compared to controls, although behavioral data obtained during scanning did not show significant differences. These findings are expected to add to our understanding of the functional architecture of Tourette's syndrome.