The Pathophysiology of Tics; An Evolving Story

The Role of CBGTC Synaptic Neurotransmission in the Pathophysiology of Tics

The pathophysiology of tic disorders involves an alteration in the transmission of messages through the cortico-basal ganglia-thalamo-cortical circuit. A major requirement for the passage of a message through this circuit is an intact chemically mediated synaptic neurotransmitter system (ie, neurotransmitters and second messengers). This article reviews the scientific evidence supporting the involvement of a variety of neurotransmitters (ie, dopamine, glutamate, gamma-aminobutyric acid, serotonin, acetylcholine, and the opioid system). Although there are favored neurotransmitter abnormalities, their complex interactions suggest the likelihood that several are involved in the production of tics.

The Pathophysiology of Tics: An Anatomic Review

The underlying pathophysiology of tics in Tourette syndrome is a topic of major scientific interest. To date, there is an absence of consensus among researchers regarding the precise anatomic location responsible for tics. The goal of this article is to review the current understanding of these brain circuits and data supporting specific anatomic regions. In summary, current scientific evidence supports the likelihood of multiple areas of abnormality within cortico-basal ganglia-thalamocortical (CBGTC) circuitry or their connected brain regions. A reasonable anatomic hypothesis is that a disruption anywhere within specific circuitry can ultimately lead to the development of a tic disorder.