The Green Leaflet - Selected Articles


Roger D. Freeman, M.D. & Diane K. Fast, M.D., Ph.D.,

For many years we have been told by clinicians and in textbooks that Tourette Syndrome is like this or that, is associated with this or that, and should be treated like this or that, but the descriptions and recommendations haven't been in close agreement. Yet new parents and patients want to have good information. We probably all realize that at this early stage of our understanding there's no good reason to have very close agreement, and that there is much individual variation, but it could be argued that there is too much confusion that has started to accompany our great success in making TS better known.

Out of the acknowledged differences between one place and another has grown the CATS (Canadian-American TS) Database, sponsored by the TSFC. It is a truly collaborative effort that now involves not only many sites in these two North American countries, but the UK, Norway, and now Australia and Japan. So far 851 cases have been entered, we expect over 1,000 by this summer, with several other countries joining. There is no reason to believe we will not have well over 2,000 by the end of 1999, as we enter the next millennium. Some interesting results are emerging already.

The CATS database consists of the information on a one-page entry form that can be filled out about one minute after seeing a patient. It has the great advantage of brevity and simplicity, so that very busy practitioners, whether in specialty clinics, universities, or their own private offices, can participate without too onerous a burden or special funding. Thus it taps a wider than usual variety of sources of patients, and it gives back to those clinicians a new sense of participating in a world-wide effort. That this is so is proven by the rapid accumulation of data and the high level of dedication of the consortium of members. Many other ideas and projects can be piggy-backed on this network.

There are trade-offs to this simplicity, of course. At this point we have data on what clinicians report, without independent verification, so any conclusions must be tempered by that realization. Also, only one form is made out for a patient. If they later develop an additional problem, or start medication for the first time, or have new family members with tics or OCD, we will not have that information. Whatever we get is usually a minimum, not a maximum. But that was the way it was designed; to do otherwise would immensely complicate everything and exclude most of us.

Although important information has already been revealed, its most important function is to raise better questions and to provide ways to collaborate in answering them with additional, specialized efforts. It is absolutely necessary to be aware of these advantages and disadvantages to grasp what CATS is about, and what it is not.

As a registry, we can immediately find patients with certain characteristics for further study. Ordinarily very few sites (if any) would have enough patients to perform such a study, and the results would be of uncertain generalizability to the world's population. But CATS has already gone further. We would like to provide just two examples:

  1. There is an extremely wide range of findings and practices reported from different sites. You would think that the ratio of males to females (not a very subjective finding!) would be fairly consistent: not so. Although the overall average is 4 to 1, pretty much the same as reported in the literature, it varies by site from 19 to 1, to 2 to 1. Looking at those conditions commonly thought to be associated with TS, the range of comorbid ADHD is 93% down to 30%, OCD ranges from 65% to 5%, mood disorder from 55% to 4%, and anxiety disorder from 63% to 0. Looking at 4 problem areas, anger control problems range from 68% to 8%, sleep problems from 47% to 0, coprolalia from 42% to 0, and self-injurious behaviour (SIB) from 50% to 0. Sites report a range of TS Only (no other comorbidity) from 44% to 0. Obviously if one were to take any one of these extremes as "correct," one could come up with amazingly different results.
  2. There is one important generalization that obtains. If you look at persons with TS Only (wherever they come from) they have a low rate of those 4 problems named above: anger control 11%, sleep 11%, coprolalia 5%, and SIB 6%. If a patient with TS has ADHD, however, the chances of having anger control problems and coprolalia double, sleep disorder triples, and SIB is unaffected; with TS+OCD, three areas increase a bit, but SIB is 5 times more frequent; with TS+ADHD+OCD, anger control problems are 3 times more likely.

Conclusion: it thus seems that it is comorbidity which accounts for most of the high reported rates of problems (other than tics) in persons with TS.

There are many other findings based on these reports which space limitations prevent us from presenting here. Perhaps this brief sample shows part of what this research effort can accomplish, and how educating people about TS might need to be modified.

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