As published in New York's Tic Talk.
Tourette syndrome, as I have already explained is NOT an illness. It is not like the flu or chicken pox in that it can not be transmitted by sneezing on someone or by getting a blood transplant. But it is catching, and I'll explain with real life examples:
Example 1: Two brothers, one 8 and the other 15 have Tourette syndrome. Their mother has noticed over the years that the two brothers tend to have similar tics at the same time. Watching closer she notices that when one child develops a new tic, the other seems to unconsciously mimic it. This second child, or the recipient of the new tic never displays the tic while away from his brother.
Example 2: A young woman has a family history of Tourette syndrome. Her father, though never diagnosed, is a fairly straightforward Chronic Ticcer. One day, the father admits to a doctor that when his daughter has a bad tic day, he feels restless and uncomfortable. A couple of days later the daughter notices that during a really bad episode of her tics, her father's usually subtle and infrequent tics have increased in severity. Over the next few weeks she watches him and realises that a bad episode of her tics will increase the frequency of his tics - and vice versa. The tics performed by the father and the daughter are not the same, but the severity seems quite closely linked.
Example 3: A young boy, about 7 years old, has Tourette syndrome. In his class is another boy, this one autistic. The teacher of the Touretter has noticed that this boy has begun to mimic the autistic boy's behaviours in class. This mimicry does not appear to follow the Touretter home, and the child's mother was startled to learn of his behaviour. When asked, the boy was aware of a need to perform these movements, a feeling similar to his other tics...but it was clear from his explanation that this was not echopraxia.
Example 4: I'm not going to give a specific case of this, because every Touretter I've talked with has seen this happen at least once. When a Touretter is around "normal" people, occasionally the other person will echo their tics. When "normal" people catch Tourette syndrome it is always very slight, but still a form of mimicry. Actions that are often mimicked are finger tapping, rubbing cutlery or glasses, head flicking, eye blinking and toe tapping. These are all normal fidgeting actions that "normal" people perform many times a day, but if a Touretter starts tapping his finger on the table the other person will, more often than not, start doing it as well. This can be extremely funny...try it sometime!
So why does this happen?
One of the most cutting edge theories on human relationships
could have the key to this one.
A long standing mystery about
Homo Sapiens Sapiens is how they can tell how others of their species are
feeling. In an attempt to answer this, a group of scientists studied the
brainwave patterns of people performing an action and also the brainwave
patterns of those observing the action. What they found was sympathetic
firing. That is, when person A watches person B lifting a box, person
A's brain fires in exactly the same way it would if person A were lifting
the box. The impulse is just much weaker.
So this could be used to explain examples 1 and 3. Remember that, in Touretters, brain signals are magnified in intensity due to high levels of dopamine receptors and low serotonin. This means signals too weak to be expressed in "normal" people will be expressed in Touretters. So in examples 1 and 3, the boys who "catch" tics from the others are probably finding that their sympathetic firings in response to the observation of the other boys are being magnified until the movements are expressed.
Example 2 is a bit different. The tics that are "caught" by the father differ from those of the daughter. In this case the father is probably picking up on the stress the daughter is under and it makes him uncomfortable enough that he must tic as well. I'm afraid I'm not objective enough to be able to tell whether tics make the majority of people uncomfortable or whether this situation is different because it's a family thing. It would be interesting to find out if this happens between unrelated ticcers.
Example 4 tells me one thing, the GTS spectrum, discussed in greater detail on another page, includes "normal" people. Because Tourette's is multi-gene, it is likely that most people in this world have one or a couple of those genes without the trigger one. Everyone knows an obsessive person who does not have OCD or a fidgety person without any tic disorder. The lines between these things are getting more and more blurred!