Basal ganglia structure in Tourette’s disorder and attention deficit hyperactivity disorder: influence of comorbidity and medication use

Tourette syndrome is characterized by open motor behaviors — tics — but another crucial aspect of the disorder is the presence of premonitory urges: uncomfortable sensations that typically precede tics and are temporarily alleviated by tics. We review the evidence implicating the somatosensory cortices and the insula in premonitory urges and the motor cortico-basal ganglia-thalamo-cortical loop in tics. We consider how these regions interact...