suppressibility of tics
in Tourette syndrome:
in children and
Aribert Rothenberger*MD, Department of Child and
Adolescent Psychiatry, University of Göttingen, Göttingen,
*Correspondence to final author atthe Department of
Child and Adolescent Psychiatry, University of Göttingen,
von-Siebold-Str. 5, D - 37075 Göttingen, Germany.
Although premonitory sensory phenomena (PSP) and
suppressibility of tics (SPT) are important in Tourette
syndrome not only when behavioural therapeutic approaches in
children are considered, there is a lack of developmental
information on these phenomena. Therefore, a cross-sectional
survey of these factors in children and adolescents was carried
out. Rates of PSP and SPT were gathered using a questionnaire
for the assessment of Tourette syndrome. The 254 outpatients
(212 males, 42 females) with Tourette syndrome investigated
had an age range of 8 to 19 years, normal intelligence, and
diagnosis according to DSM-IV-TR/ICD-10. To test for
developmental effects, the total group was stratified into three
age groups (8 to 10, 11 to 14, and 15 to 19 years). Data were
statistically evaluated using χ2tests. Of the 254 participants,
37% reported PSP, while 64% were able to suppress their tics.
Only a subgroup of 119 patients gave unequivocal answers to
both questions and only 60% of these experienced both PSP and
SPT. Statistically significant stepwise increases were found at
two different age levels. One was around 10 years (PSP ‘Yes’ or
‘No’ and SPT), the other around age 14 (PSP ‘Yes’). There was
no influence of tic duration and age at tic onset on PSP/SPT. The
reported data suggest that PSP is experienced rarely in younger
children with Tourette syndrome and is not a necessary
prerequisite for SPT. Increasing PSP with age merely seems to
reflect cognitive development rather than intrinsic aspects of
Tourette syndrome. In children under 10 years of age, SPT might
require more awareness of tics than in older age groups.
Developmental aspects of PSP and SPT should be taken into
consideration when studies of cognitive behavioural treatment for
children and adolescents with Tourette syndrome are planned.
Recent clinical investigations have revealed that many patients
with Tourette syndrome report a variety of premonitory sen-
sory phenomena (PSP) immediately preceding their motor
and/or vocal tics. Such phenomena include uncomfortable
bodily and cognitive sensations. These are described as focal
tension, pressure, tickling, cold, warmth, or paresthesias
localized to discrete anatomical regions related to the tic in
question or as a generalized inner tension or anxiety, or
both; these sensations are often experienced as a sensory
urge for motor discharge (e.g. like an urge to stretch one’s
shoulder or a need to clear one’s throat). The internal strug-
gle to control these PSP can be as debilitating as the tics
themselves. A neurophysiological basis of these sensory
urges might be that sensory motor and primary motor corti-
cal inputs converge on the medium spiny projection neu-
rones (Leckman 2002). Individuals have reported that PSP
typically ‘drive’ the motor act of the tics and, after completing
the tic, a sensation of temporary relief and stopping of the
PSP frequently seems to occur (Leckman et al. 1993, 2002;
Miguel et al. 2001).
These phenomena are probably more frequently reported
by adolescents and adults than by younger children. Based
on general but uncontrolled clinical observations, Leckman
and coworkers (2001) remarked that young children under
the age of 10 years with simple tics (e.g. eye blinking, quick
head jerk) usually do not have PSP , or are totally unaware of
these sensations. In their earlier retrospective cross-sectional
study, Leckman and colleagues (1993) found that the mean
age at which the respondents (mostly adults with Tourette syn-
drome) first became aware of PSP was around 10 years, which
averaged about 3 years after the onset of tics. Nevertheless,
some children report PSP as early as at age 6 to 7 years, while
many adolescents do not report PSP at all. Hence, the age-spe-
cific prevalence of PSP in Tourette syndrome and its meaning
for the disorder in childhood remains to be determined.
Tics can sometimes be suppressed by voluntary effort of
will for short periods of time ranging from a few minutes up
to a few hours (Jankovic 1997). This, however, is usually
uncomfortable and stressful. After a while, the urge to move
becomes often uncontrollable, and a period of voluntary
suppression is usually followed by series of tics. Degrees of
control vary and the ability to modify or suppress tics usually
improves with age. It is assumed that the awareness of PSP
can facilitate tic suppression in some individuals. This was
true for 24 of 132 (18%) participants in the study by Leckman
and colleagues (1993). On the other hand, clinical experience
suggests that many individuals are able to suppress their tics
for a variable and mostly short period of time, without exact-
ly knowing how they succeed to control their tics. However,
the premonitory sensory phenomenon itself cannot be sup-
pressed and, in fact, may build up over time. Further, PSP are
an essential part of the behavioural treatment approach for
Tourette syndrome. The most promising behavioural thera-
py seems to be habit reversal training, a treatment form con-
ceptually similar to exposure plus response prevention.
Here, the individual learns to use the PSP for preventing the
actual tic performance through a competing motor response
or by shaping strategies to reduce the intensity and intrusive-
ness of the tics. The latter approach may be especially valu-
able when working with younger children (Piacentini and
Chang 2001). It has still to be shown whether the treatment
model approach by Evers and van de Wetering (1994), based
Developmental Medicine & Child Neurology 2003, 45: 700–703
on awareness training and a tic-specific tension-reduction
technique, can effectively reduce and/or modify motor tics
and even PSP .
Through the use of these strategies for tic control, patients
are trained to become aware of, recognize, and label their PSP .
Hence, maturational effects of both tic and PSP awareness as
well as suppression of tics may play an important role for plan-
ning behavioural and cognitive treatment approaches in chil-
dren and adolescents with Tourette syndrome. Unfortunately,
until today such data are not available for this age range.
Therefore, the objective of this study was to use a cross-
sectional design to investigate the developmental aspects of
PSP before tics, the suppressibility of tics (SPT) during child-
hood, and the relation between both factors, in order to
improve our knowledge and understanding of children with
Tourette syndrome, to develop better age-related diagnostic
procedures, and to optimize our therapeutic approaches.
On the basis of numerous clinical interviews with patients over
many years, a worldwide clinical exchange with other special-
ized physicians (Freeman et al. 2000), and a review of the avail-
able literature, a questionnaire (available on request from the
senior author) was developed to gather information on all rele-
vant aspects of Tourette syndrome. After a brief introduction,
the questionnaire was answered by young persons with
Tourette syndrome and/or their parents within the framework
of the patient’s clinical assessment at the institution.
With respect to their PSP and SPT, the participants were
asked to report whether the behaviour was actually present
or not: ‘Do you feel a kind of pre-sensation immediately
before the tic?’, ‘Are you able to suppress tics for a while?’.
Here, they could answer ‘Yes’, ‘No’, or ‘Don’t know’. As most
children and adolescents had difficulties in further describ-
ing the character of their PSP and the way they suppress their
tics, no additional information could be evaluated within
this study. While the interpretation of the ‘Don’t know’
answers would be equivocal, only the more clearly defined
answers ‘Yes’ or ‘No’ are presented. Content validity and cri-
terion validity against a psychiatric interview can be regarded
All children and adolescents (n=254, 212 males, 42 females;
mean age 11.6 years, SD 3.1years; age range 8 to 19 years) with
normal intelligence had been referred to our own depart-
ment (n=135) or to other outpatient clinics in Germany.
They were diagnosed by best estimate as having Tourette syn-
drome on the basis of DSM-IV-TR (American Psychiatric
Association 2000) and ICD-10 criteria (World Health
Organization 1990). Clinical diagnosis was made by experi-
enced and child and adolescent psychiatrists. Mean age at tic
onset was 6.7 (SD 2.8) years; mean tic duration was at 5.8 (SD
3.5) years. Tic severity was moderate to high by overall clini-
To test for developmental effects the total group was strat-
ified into three age groups (8 to 10, 11 to 14, and 15 to 19
years; see Table I), as suggested by both the interpretation
from Leckman and colleagues (1993, 2001) that there might
be a critical period for tic awareness around age 10 years, and
because early and late adolescence reflect different stages of
cognitive and physical development.
For statistical evaluation of differences between rates in
the three age groups, pairwise group comparisons were per-
formed with χ2tests using the Yates correction. Statistical sig-
nificance was set at p≤0.05. To evaluate the association
between PSP and SPT, a descriptive approach was used by
calculating relative risk values and comparing them between
groups, using χ2tests with the Yates correction.
Premonitory Sensory Phenomena and Suppressibility of Tics Tobias Banaschewski et al.
Table I: Characteristics of different age groups of patients
with Tourette syndrome (n=254), mean (SD)
Variable Age group (y)
8–10 15–19 ANOVA
Age at investigation, y
Age at tic onset, y
Tic duration, y
9.1 (0.8) 12.6 (1.1) 16.6 (1.5)
5.7 (2.2)7.1 (2.7)
3.4 (2.1)5.5 (2.7)
Table III: Suppressibility of tics (SPT) in three different age
SPTAge group (y)
‘Yes’, %48 66 7964
‘Yes’, percentage of patients who could temporarily suppress
their tics; pvalues, Yates-corrected χ2test.
Table II: Awareness of premonitory sensory phenomena
(PSP) in three different age groups (n=251 due to three
participants with missing data)
PSPAge group (y)
‘Yes’ + ‘No’, %34 56 6852
‘Yes’, %2434 5737
‘Yes’ + ‘No’, percentage of patients who could give an unequivocal
answer; ‘Yes’, percentage of patients aware of any premonitory
sensory phenomena (PSP); pvalues, Yates-corrected χ2test.
The percentage of PSP and SPT reports for each age group
and the p values for group comparisons are presented in
Tables II and III.
Details of the statistical relation between PSP and SPT
within each age group are seen in Table IV .
There was no statistically significant influence of age at
investigation, age at tic onset, or tic duration on the investi-
gated parameters (PSP and SPT) in any of the PSP or SPT sub-
groups within the three different age groups.
This is the first cross-sectional survey of children and adoles-
cents with Tourette syndrome which investigated the devel-
opmental aspects of PSP and SPT. Of 254 participants
between 8 and 19 years, 37% reported PSP and 64% could
suppress their tics. While only a subgroup of 119 patients
gave unequivocal answers to both questions: 60% of these
experienced both PSP and SPT.
The percentage of PSP reported in this study is clearly
lower than the values of Kurlan and colleagues (1989) with
PSP reported in 74% of 35 adult patients with Tourette syn-
drome, and in 93% of 132 mostly adult respondents with
Tourette syndrome in a study by Leckman and colleagues
(1993). However, a look at the results of the three different age
groups studied (8 to 10 years, 11 to 14 years, and 15 to 19
years) shows that the rates for awareness of PSP increased
from childhood to adolescence. Statistically significant steps
were found at two different age levels. When both unequivo-
cal ‘Yes’ and ‘No’ answers for PSP were taken into considera-
tion (i.e. the child was clearly aware whether or not they
experienced PSP), the essential maturational step could be
observed between the group of age 8 to 10 years and the 11 to
14 year olds (34, 56, and 68% for the three age groups respec-
tively). This supports the assumption of Leckman and cowork-
ers (1993, 2001) that the age around 10 years plays an
important role for tic awareness, and shows clearly that within
the natural course of Tourette syndrome tic awareness
increases with age without being dependent on tic duration
and age at tic onset, i.e. development of PSP seems to merely
reflect cognitive development rather than intrinsic aspects of
On the other hand, the percentage of clear ‘Yes’ answers
only (24, 34, and 57% for the three age groups respectively)
was lower, compared to the ‘Yes’ and ‘No’ answers for PSP ,
and identified a significant developmental step around age
14 years. The 57% awareness of PSP in late adolescence is still
lower than the above mentioned values in adult patient
groups with Tourette syndrome (74% to 93%). Hence, aware-
ness training for tics within the framework of behavioural
therapy seems to be most challenging for children under the
age of 14 years and might adversely influence compliance if
attempted in these young individuals.
So far, age-specific frequencies of suppressibility of tics
were not available in research, although Leckman and cowork-
ers (1993) found that 18% of their mostly adult patients took
advantage of PSP for the suppression of their tics. Hence, we
cannot directly compare our developmental data to previous
literature reports. We found a statistically significant increase
of SPT rates around age 10 years (48, 66, and 79% for the three
age groups respectively), while there was no significant differ-
ence between the age groups concerning the coincidence of
both PSP and SPT, although children under 10 years of age
tended to show a stronger association between these two phe-
nomena. Whether this suggests that successful suppression of
tics needs more awareness of tics in children as compared to
adolescents may be confirmed by future studies.
In any case, the reported data suggest that PSP is not a nec-
essary prerequisite for SPT, as only 37% of patients with
Tourette syndrome reported PSP , while 64% were able to
suppress their tics. Notably, only 60% of the patients with
unequivocal answers to both questions experienced both
PSP and SPT. While some children are not aware of sensory
motor precursors before tics, and thus may not be able to vol-
untarily counter-regulate single tics in a one-by-one fashion,
they still seem to be able to use spontaneously other, more
general, tic inhibiting strategies (e.g. relaxation, focussing
on reading a book, doing homework, sports, following
teacher’s lessons) to prevent the occurrence of tics for a cer-
tain amount of time or in certain situations (e.g. at school).
The behavioural observation of PSP before tics and the
SPT may reflect the neuronal development of several, proba-
bly different networks involved in the pathophysiological
background of Tourette syndrome. While PSP appears to
employ a network of sensory motor structures with a special
role of medial motor areas including the supplementary
motor area (Hallett 2001), SPT has been shown to include a
complex pattern of changes in functional fMRI involving the
basal ganglia, thalamus, and frontal cortex (Peterson 2001).
A limitation of the study is that standardized clinical rating
scales were not employed for the assessment of Tourette syn-
drome in the overall sample. A further limitation is that data
concerning the reliability of the answers are lacking. Future
research concerning the relation between developmental
psychopathology, cognitive development, and brain matura-
tion seems necessary in order to achieve the deeper under-
standing of the pathophysiological background, which is
needed for further improvements in diagnosis and treatment
of Tourette syndrome.
This study addressed the ability to suppress tics as a
dichotomous trait, which one might have or not since most
children and adolescents had difficulties to further describe
the character of their PSP and the way they suppress their
tics. However, it seems to be more adequate to conceive
Developmental Medicine & Child Neurology 2003, 45: 700–703
Table IV: Coincidence of awareness of premonitory sensory
phenomena (PSP) and suppressibility of tics (SPT) in three
different age groups
PSP + SPT Age group (y)
5248 77 60
2.751.10 1.29 1.34
‘Yes’, percentage of patients who reported both PSP and SPT (100%=
subgroup of n=119 with ‘Yes’ or ‘No’ answers to both questions).
Relative Risk, relative risk of reporting suppressibility with versus
without awareness of PSP (there was only a tendency for a higher
relative risk in the 8–10 year olds).
Premonitory Sensory Phenomena and Suppressibility of Tics Tobias Banaschewski et al.
suppressibility of tics as a dimensionally graded ability with
varying degrees of control in terms of duration and success
of tic suppression. Future research is also needed to investi-
gate whether and how contextual factors might modify the
suppressibility of tics, and to what extent this ability is related
to tic severity and the type of tics.
Accepted for publication 4th June 2003.
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