TS and ADHD, Page 19

Tourette’s Syndrome and Alleged Structural Abnormalities Within the Basal Ganglia

[The following is an email reply I made to someone who apparently read my third TS essay: “Is Tourette’s Syndrome a Neurological Disorder?—A Dissenting Viewpoint.” I do not have his or her permission to post the person’s email. Therefore, I post my own response without in any way identifying him or her, and the only reference to anything he or she said is his or her contention that there is clear cut evidence of brain abnormalities within people with TS, an assertion made by a great many people. The email has only been edited to redress a few, insignificant errors of a strictly typographical nature, and to remove non-essential verbiage of a personal nature to avoid identification.]

In regard to your cited objections within your original email, you state that there is clear evidence of structural brain changes in patients with TS.

By this, I am assuming you are referring to various imaging studies including functional imaging techniques, SPECT, PET and MRI purporting to give evidence of such matters as smaller caudate volumes within the basal ganglia for subjects, children and adults, with TS and studies that evidence hypofusion (lower blood flow) to the left caudate, anterior cingulated cortex and the left dorsolateral prefrontal cortex within patients with TS when compared to control subjects.

First off, although there might be larger studies that I am not aware of, the largest such one that I am aware of consisted of 154 TS patients and 130 healthy control subjects with no history of tic disorders, including TS. I personally would prefer to see significantly larger studies replicate the results of this one (Peterson, Kane et al.) regarding purported physical abnormalities within the basal ganglia before drawing any firm conclusions and labeling such evidence as "clear cut."

Nevertheless, if I concede the pool sample is sufficient, and I concede the validity of the conclusion that TS is caused by physical abnormalities within the brain, or elsewhere within the central nervous system, drawn from such studies for the sake of argument, then one must ask: Why can’t they be used as an objective, diagnostic tool regarding TS? If they could, then we would not be having this discussion, and I would retract my views on my website and elsewhere. Click to continue:


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