The diagnostic hallmarks of the disease are tics. The diagnosis is made when a child has both motor and vocal tics, which start in childhood and persist for more than a year.
Tics are more or less involuntary behaviors. They may be very simple or very complex; the complex ones can be hard to recognize as tics until after some of the less dramatic ones have appeared. Common MOTOR tics are grimaces, eye blinking, shrugging, head jerking, spitting, nose rubbing, leg tapping, funny steps when walking. Common VOCAL tics are throat clearing, grunting, sniffing, coughing, repeating words, even barking or even cursing.
There are several sub-varieties of tics. A PURE MOTOR tic may go on with the patient not even aware of it. A SENSORY/MOTOR tic is one in which the patient feels a distinct need to carry out the action. Some authorities feel that most TS tics are SENSORY/MOTOR, to the point that other movement disorders should be considered if all a patient's tics are pure motor tics.
There are some VERBAL tics (vocal tics that involve words) that are rather common in TS and rather uncommon in the rest of the universe, so are worth mentioning specifically. COPROLALIA (the word means s**t-talk) is uncontrollable outbursts of profanity or obscenity. ECHOLALIA is the compulsive repetition of words or sounds made by others (there's ECHOPRAXIA, too, for mimicking actions). PALILALIA is the repetition of one's own words, often sounding as though the patient is trying to take a running start to finish a sentence.
The complexity of the tics ranges from a simple twitch to a very complicated behavior...........simply put, there's really a continuum between tics and compulsions, and it's kind of hard to draw the line between the two.
That makes it less surprising, perhaps, that many TS patients and many siblings of TS patients have lots of compulsions --- sometimes enough to meet the diagnostic criteria for obsessive- compulsive disorder (OCD).
Many TS kids also have features of ADHD (attention deficit/hyperactivity disorder), and may meet the criteria for diagnosis of that problem. RITALIN, which is used to treat ADHD, makes tics worse in about 30-40% of people with tics who get it. So a fairly common scenario is that a kid may be diagnosed to have probable or definite ADHD; Ritalin is prescribed; tics become obvious; diagnosis is refined/advanced to TS.
Many TS kids also have features of PERVASIVE DEVELOPMENTAL DISORDER (PDD) of the Asperger type. This is hard to describe succinctly --- though at a TS Support Group meeting one can just describe it as "all the social/behavioral problems common in TS, but without the tics." When Asperger described the syndrome in 1942, he called it "autistic psychopathy," but the kids are not as autistic (inwardly directed) as the ones we now customarily describe with the term "(Kanner's) Autism." You can think of them as having almost a dyslexia-like problem in learning to recognize social cues, which leads to social retardation which can be quite severe, even if the child is very bright. This leads to a huge number of school adjustment problems and the like; these are often not handled well, because school officials are often unfamiliar enough with the disorder that they haven't a clue how to deal with it. Often, they will interpret the child's intelligence as evidence that he "knows better" than to do all these things, then will punish the child for tics or for behavioral problems that are neurologic in origin. Even a teacher who is well informed about neurobehavioral disorders may have a difficult time managing such children, and they often must be taught in circumstances short of full mainstreaming.
The terminology, here gets confusing at times, and there's not universal agreement about it. Some authorities feel that PDD-like manifestations are common in TS; others prefer to think of it as two diagnoses when a TS child has a lot of such social integration trouble. This is probably not important, except that it causes concern and con- fusion (Is the diagnosis correct? Has something changed?)
Tics tend to get worse about puberty, and tend to get less severe in later life. But there's striking patient-to-patient, day- to-day and month-to-month variation. Anxiety may make the tics worse, and concentration on a task may suppress them.
TS seems to be caused by abnormalities in the metabolism of a brain messenger chemical called DOPAMINE. There are abnormal levels of this chemical in some brain areas in TS patients, and many of the helpful drugs are things that influence how the brain metabolizes dopamine. There's also a suggestion that some of the kids with the more severe PDD symptoms may have a second, related defect which has a different effect on dopamine. The genes for TS and PDD have not yet been found, so many of the details are still a bit speculative.
There are drugs which help control tics, so that the majority of TS patients can function reasonably well. The ones with PDD features may need to reach adulthood to have enough social maturity to function well, and some of them prove incapable of independent living. HALOPERIDOL (Brand name Haldol) is the front-line drug; it works quite well, but sometimes leads to too much sedation, a bit of a flat affect, or a funny syndrome of school avoidance. PIMOZIDE (Orap) is the other TS-specific drug, and is often used in patients who do poorly on Haldol. Some prefer it because it is less sedating than Haldol, and hasn't been as convincingly associated with school phobia. CLONIDINE is a blood pressure medication that also influences dopamine balance, and seems to help many patients with fewer side effects (it's sedating at first, but most folks grow tolerant of this effect). Some studies have failed to show an effect when examined rigorously, but enough individual patients seem to benefit that it probably is a matter of learning how to identify which patients are likely to do well with it. MELLARIL may be helpful for anxiety and the "hyper" state that some TS patients have, and thus may be especially helpful in school integration problems. It has anti-tic activity, too, but is less specific and potent in that regard. PROZAC may help compulsions and associated depressive symptoms. CLOMIPRAMINE may help compulsions. There are lots more.
When you start looking at the population as a whole, or just at some different families, the story gets quite a bit more complicated. First of all, the incidence of other tic disorders and other neurobehavioral disorders (ADHD, OCD, Asperger's type PDD, and others) is quite a bit higher than you'd expect in relatives of TS patients. Then, some families have a lower "penetrance" than others. And most strikingly, a lot of patients with TS have enough other neurobehavioral features to meet the usual diagnostic criteria for ADHD, OCD or PDD.
This has made it quite tough to pin down the genetic basis of TS precisely --- a minor change in diagnostic criteria used in a study may have a major impact on the results, for example, of the "linkage" studies one does to try to find out which chromosome carries the gene. In other words, it might make a big difference if quirky old Uncle Fred with his facial grimaces is called "unaffected" or "affected," or is assigned to some intermediate category like "possible" or "probable." There are a number of ways that one can try to approach this problem, and a number of possible explanations that might turn out to be correct. For example, there might well be a single TS gene, but it might not in every family have exactly the same chemical thing wrong with it. Or there may be just one flavor of TS gene, but there may be other genes that have a big role to play in how strongly the TS gene is evident clinically. Both of these may be true in some scenarios. A popular concept is that there is in fact a specific TS gene, that it is important in the way the body makes the brain messenger chemical dopamine, and that it causes tics and compulsions. Interacting with this gene to determine the features of an individual patient are other genes which influence the way dopamine is metabolized in the brain once it's made (a candidate for one such gene is the one for the Dopamine D2 receptor gene, linked to a piece of DNA known as the A1 allele --- this one's been identified, lives on chromosome #3, and appears more commonly in patients with a wide variety of neurobehavioral disorders than in normals). But there are LOTS of confounding factors and biases which make it very hard to be sure if it's itself important, or just sits on a chunk of DNA that containe OTHER stuff that's important. For some of the associations, the data aren't even holding up, so the original finding may have been a false lead (See the June, 1993, issue of Scientific American)
In an article in the May, 1993, issue of the Journal of Laboratory and Clinical Medicine, Dr. Ben J. van de Wetering of the University of Rotterdam --- a TSA- funded researcher ---reviews the search for the genetic basis of TS, along with a more general discussion of the devilish problem of trying to work with a disease which is obviously inherited, but in which the diagnosis is a bit ambiguous. The article is aimed at a medical/scientific audience, and is fairly heavy going for the layperson. Nonetheless, it is potentially of great value to TS caregivers, as it stresses the genetic nature of TS and the probability that many of the associated behaviors are genetically determined, too. Like Dr. Frith's book, reviewed elsewhere in this newsletter, it may be useful in resolving the disease-manifestation-versus-delinquency squabbles that arise all too frequently in the school or workplace integration of TS patients. For people with a bit of a science background, it is a good "read," as well. TSAhas some reprints available; the journal is a major one, and thus is present in almost every medical library.
Among the behavioral problems common in children with Tourette Syndrome are those which could be classified as features of "High-Functioning Autism" or "Pervasive Developmental Disorder (PDD) of the Asperger Type." These behavioral difficulties may become problems well before tics appear or are recognized, so a fair number of children first are diagnosed as having Asperger Syndrome or an autism variant, then later have that diagnosis refined to Tourette Syndrome when more well-recognized TS problems emerge. Between 15 and 30% of children initially diagnosed as having Asperger Syndrome are ultimately diagnosed as having TS.
Asperger himself was a child psychiatrist in Vienna, who described his syndrome (which he called "autistic psychopathy") at almost the same time that Kanner described the more severely autistic syndrome we now call by the name of "autism." Because he published in Austria when it was a province of Nazi Germany, his work did not get widespread attention at the time --- furthermore, his championing of the rights and value of a group of children at risk of extermination by Nazi ideologues had to be done cautiously. As a result, his initial description (his tenure thesis at the University of Vienna in 1942) was never translated into English. Ironically, my wife and I were about 30% finished with just such a translation when this book appeared --- it includes a very good translation of more than 2/3 of that thesis. It also includes a number of reviews by noted scholars on topics related to Asperger Syndrome, autism, and neurobehavioral disorders more generally. There are many detailed case descriptions of behavioral patterns we all will recognize.
The book is scholarly, and is really intended for a professional audience. But it is also written in most sections quite clearly, and is therefore accessible to people who have a bit of background in the area and know some of the related jargon ----- lots of parents, teachers, and social workers dealing with TS kids will find this book quite readable. The value of this book for TS parents is in understanding the behavioral features that don't fit the textbook descriptions of TS. Asperger and Frith (and some of the other contributors) have been interested in management strategies as well as physiology, so there's some practical meat, here. Perhaps even more important in some cases will be its value in convincing reluctant school officials that some very complex abnormal behaviors are likely to be part of a child's neurobehavioral syndrome (and beyond his or her easy control), rather than just delinquency that ought to be punished. We have used it quite effectively in a couple of cases in which a classroom teacher understood and accepted the problems well (essentially learning by observing the child), but in which a social worker, principal, special-education teacher --- or even nurse or pediatrician ---favored simple and sometimes severe punishment for compulsive behaviors.
Finally, reading this book will give parents a bit of insight into why their children may have passed through some intermediate diagnoses on the way to their ultimate recognition as having TS. It isn't always that the first examining physicians were negligent, inattentive, ill informed or wrong......it's pretty often the case that nonspecific symptoms, with more common explanations available, dominated the picture (or were all that were present) early in the course.
Your bookstore probably won't have this in stock, but can order it from Cambridge University Press; if you have any trouble, go through a specific medical book store (e.g. Enrica Fish Books, 814 S.E. Washington, Minneapolis 55414; 612-623- 0707).