The Pathophysiology of Tourette Syndrome

When we talk about the pathophysiology of a certain disease, we mean to say the study of abnormal functions in the body and how disease processes work. For Tourette syndrome, looking at the structures of the brain and other important chemicals that said to be responsible for the disorder is also a consequential review.

It is widely reported that the pathophysiology for Tourette syndrome had not been fully understood. Dr. Kirk Frey and Dr. Roger Albin presented that there were only limited insights as to what abnormalities could have been underlying Tourette syndrome when traditional neuroimaging techniques were used. They also said that because there were only a few persons diagnosed with Tourette syndrome who die early in life, they were limited to a few post-mortem brains to study and that these brains came mostly from adults. Nevertheless, most researches point out to neurotransmitters in the brain, their circuitry and a few structures that are responsible for the make up of Tourette syndrome.

Considering neurotransmitters in the brain, researches say that Tourette syndrome is a result from an abnormal activity in a chemical in the brain called dopamine. Neuroimaging studies revealed that dopamine is produced excessively in persons with the disorder. Dopamine is a kind of neurotransmitter in the brain. Aside from norepinephrine, dopamine is a catecholamine responsible for controlling movements and regulating hormonal responses. Dopamine is also the one responsible for psychiatric symptoms such as psychosis.

There are three specific circuits it undergoes. First, the regulation of bodily movements. Dopamine is involved in the production of tics in a person with Tourette syndrome. The excessive amount of dopamine that regulates in the structures of the brain, is said to be one of the emerging causes of the reproduction of the repetitive, uncontrollable body movements. Whereas in a person who exhibits rigidity in muscle movements or there is difficulty in moving is equated to practically absence of dopamine circulating.

The second circuitry is for emotion and cognition. Abnormalities in this system of circuitry are the one responsible for the production of psychotic manifestations.

The third is for the regulation of the endocrine system. Its primary action for this organ is to direct the release of hormones into the bloodstream.

Information about dopamine is essential in the understanding of where it actually goes wrong in the brain in the case of Tourette syndrome. Knowing that its excessive reproduction is important in connecting the occurence of tics of people with Tourette syndrome is essential as well. The circuitry passes through deep within the brain in a structure called the basal ganglia. But because all the circuits inside the brain happen simultaneously, it also involves not only the basal ganglia but also some other parts of the brain such as the cortical, subcortical regions of the brain, the thalamus and frontal cortex, all are located deep within the fore brain. Each structure has its own function in the transmission of the neurotransmitters in the brain. All is described to be but one whole operating system. In an article written by Steve Olson, he mentioned that the operating system described in a person with Tourette syndrome, according to Dr. Jonathan Mink, a neuroscientist in the University of Rochester Medical Center in New York, is in a way buggy. This description again goes back to studies from neuroimaging techniques that demonstrated abnormality in dopamine release, dopamine reception and pathways involved in the transmission of this neurotransmitter.