Description of Tourette Syndrome

Tourette syndrome is a tic disorder.
Tics are any sudden, rapid, recurrent, non rhythmic, involuntary action or vocalization.
Unlike the tic disorder Chronic Tic Syndrome, Tourette’s sufferers display both motor and vocal tics.

It is not a well-understood condition.
Everyday, new things are discovered that totally throws off everything we’ve learned so far.

The usual place to go for a consistent and up to date definition of Tourette’s is DSM or ICD. DSM (Diagnostic service manual) is what doctors use for diagnosing their patients in the U.S. and is probably the book used most often for Tourette's. It is filled with the criteria one must satisfy in order to be said to have a condition. Every once and a while the DSM is revised.

The criteria here are for DSM IV:

  1. both multiple motor and one or more vocal tics have been present at some time during the illness, although not necessarily concurrently.
  2. The tics occur many times a day (usually in bouts) nearly everyday or intermittently throughout a period of more than one year, and during this period there was never a tic-free period of more than three consecutive months.
  3. The disturbance causes marked distress or significant impairment in social, occupational or other important areas of functioning.
  4. The onset is before age 18 years.
  5. The disturbance is not due to the direct physiological effects of a substance (e.g., stimulants) or a general medical condition (e.g., Huntington’s disease or a post viral encephalitis).
The next DSM (DSM V) is not expected out until 2006, but there has been a revision called DSM IV-TR. DSM IV-TR does not include criteria #3 as it has been decided a diagnosis of Tourette syndrome can still be made even if the tics do not cause distress or social impairment. DSM III listed the age of onset as before 21. It is expected that DSM V will return to this figure.

The ICD is used extensively in Europe and Australia (although Australia uses DSM and ICD interchangeably).  The structure is slightly different.  First you must satisfy the criteria for a general tic disorder (F95) and only then can the diagnosis be narrowed to Tourette syndrome (F95.2).  The definition is:

"A form of tic disorder in which there are, or have been, multiple motor and one or more vocal tics, although these need not have occurred concurrently.  Onset is almost always in childhood or adolescence.  A history of motor tics before development of vocal tics is common; the symptoms frequently worsen during adolescence, and it is common for the disorder to persist into adult life.
The vocal tics are often multiple with explosive repetitive vocalisations, throat clearing, and grunting, and there may be the use of obscene words or phrases.   Sometimes there is associated gestural echopraxia, which may also be of an obscene nature (copropraxia).  As with motor tics, the vocal tics may be voluntarily suppressed for short periods, be exacerbated by stress, and disappear during sleep."

[ Back to contents ] [ Index page ]

1