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Prefrontal cortex Supplementary motor area

Caudate nucleus

Ventral anterior thalamus

infections and immunological triggers , maternal stress during pregnancy and gestational smoking ) that could trigger the priming of microglia , the immune cells in the brain . ⁶

Subsequent triggers — such as streptococcal infection , psychosocial stressors or toxins — could activate an autoimmune or autoinflammatory response involving the microglia precipitating symptom onset . Thus , tics , OCD and ADHD could be precipitated by Group A streptococcal infection , which is referred to as paediatric autoimmune neuropsychiatric disorder associated with streptococcal infection ( PANDAS ). And when such symptoms result from other infectious agents such as Lyme disease , mycoplasma , mononucleosis and the H1N1 flu virus , the term paediatric acute-onset neuropsychiatric syndrome ( PANS ) is used . ^{7 , 8}

However , there is ongoing debate as to whether this may have a direct aetiological role or merely precipitates tics in a predisposed individual and triggers symptom onset or modulates the presenting symptoms ( for example , tics , obsessive compulsive behaviours ).

DIAGNOSIS

Signs and symptoms

TICS are the hallmark of GTS . Tics are rapid , repetitive and involuntary movements of the body ( motor tics ) or the phonic system ( vocal tics ). Tics that last less than one year are referred to as transient tic disorder or provisional tic disorder . Up to 20 % of children are reported to develop tics lasting only a few weeks or months . ⁹ According to DSM-5 or ICD-10 code F95.0 , when motor or vocal tics , but not both , continue for more than one year , these are referred to as a chronic tic disorder . And when motor and vocal tics co-occur for over one year , this indicates GTS ( see box 1 ).

The types and details of the various tics that may be present in GTS appear in table 1 .

The tic can be differentiated

Box 1 . Diagnostic criteria for GTS in DSM-5

• Both multiple motor and one or more vocal tics are present at some time during the illness , although not necessarily concurrently .

• The tics may wax and wane in frequency but have persisted for more than one year since first tic onset .

• The onset is before 18 years of age .

• The disturbance is not due to the direct physiological effects of a substance or a general medical condition .

Source : DSM-5 ¹

Table 1 . Common tics and related behaviours

Simple ( see figures 2 and 3 )

Complex

Related behaviours

Motor tics

Source : Eapen V 2013 ³

Blinking , raising the eyebrow , eye rolling , nasal twitch or flare , upper or lower lip movements , mouth to the side , facial grimace , shoulder shrug , arm flex or extend , tongue protrusion , head nod , neck stretch , chin on chest or shoulder , torso – thorax twist , abdominal contractions , leg or feet movements , tapping

Forced touching of self , others or objects , puffing or blowing , lick , smell , spit , stamp , hop , jump , skip , turn , bend , kick , hit , unusual gait ( walking ), feet shuffling , flapping arms , twirling around , tensing muscle groups , thrusting movements , twirling hair , adjusting clothing

Self-injurious behaviours : punching or poking self , biting , picking skin or scabs Copropraxia : involuntary obscene gesturing , touching private parts of self or others Coprographia : writing obscenity Echopraxia : copying or repeating other people ’ s actions or movements Palipraxia : repetition of last act or movement Non-obscene socially inappropriate behaviours : making socially inappropriate statements or comments , kissing self or others

from other habits and mannerisms based on the fact that the tic is typically preceded by an ‘ inner urge ’ and / or a premonitory somatic sensation ,

Vocal tics

Grunt , throat clear , cough , bark , growl , snort , squeak , shriek , scream , low- or high-pitched sounds , noisy or unusual breathing , sniffing , humming , whistling , hoot , hiss , pant , wail , gasp , click , yelp , burp , raspberries , yell , moan , ugh – ah – eh – ooh sounds

Making animal-like sounds , barely audible muttering , changing the pitch or volume of voice , assuming different characters or intonations

Echolalia : repeating what others say Palilalia : repeating only the last word Coprolalia : involuntary swearing , uttering obscenities Internal tics : bladder or bowel tics Stimulus-induced tics : tics precipitated by events in the environment , including seeing or talking about tics

such as an itch , stretch or tightness at the site that is relieved by the tic . See box 2 for the characteristic features of tics . Ironically , the ability of people

Box 2 . Features of tics associated with GTS

• Tics are often preceded by an ‘ inner urge ’ and / or premonitory somatic sensation .

• Tics have a waxing and waning course .

• One type of tic may be ‘ replaced ’ by another over time .

• Stress and anxiety typically worsen tics .

• Tics can be suggestible ( ie , they may be triggered by talking about tics or observing tics in other people ).

• Voluntary suppression is possible for a period , which may be followed by ‘ rebound ’ tics .

with tic disorders to voluntarily suppress the tic , although at the expense of mounting inner tension , can lead to misinterpretation by others that tics are under voluntary control . Other associated features — such as coprolalia and copropraxia , etc — only occur in about

5-30 % of patients , but when present , they can be stigmatising and impair functioning . ²

ASSESSMENT

A KEY role of the GP is to be alert to the possibility of a tic disorder in patients and refer them to a paediatrician or child and adolescent psychiatrist for an opinion where symptoms are severe and / or causing distress to the patient .

Always take a detailed medical and psychiatric history for comorbidities and perform thorough physical and neurological examinations . Pay special attention to the evaluation of comorbid disorders , such as obsessive – compulsive symptoms or disorder , ADHD , disruptive behaviours ,

Voluntary suppression is possible for a period , which may be followed by ‘ rebound ’ tics . learning disorders , depression and anxiety .

Assessment of GTS includes involvement of family members ( both for eliciting family history of tics or related behaviours and for psychoeducation and being part of the management plan ), teachers and significant others who are impacted by the child ’ s symptoms and whose reactions in turn affect the symptoms . The characteristic features described earlier with a waxing and waning nature of the tics are so distinctive that a diagnosis can be made on history alone . Despite this , diagnostic difficulties can occur . At the time of first onset , children are often referred to multiple specialists for possible eye , nose or throat problems , or the problem is dismissed as ‘ nervousness ’ ( for example , a ‘ nervous twitch ’). In the absence of a careful history and exam , tics should not be explained away by informing parents that their child will outgrow them . When the tics persist , such reassurance may create a mistaken belief that a nervous disposition is causing the tics or that the child could stop the tics if only they were to try harder . Unfortunately , it is still not uncommon for children to be undiagnosed for many years .

COMORBIDITY

IT has been frequently observed that , for children and adults with tic disorders , comorbidity is the rule rather than the exception , with only 10-15 % of people with tic disorders having only tics ( that is , pure tics ) without any comorbidities . ¹⁰ Foremost among these comorbidities is ADHD . Epidemiological studies indicate that ADHD co-occurs in around 50-60 % of individuals with Tourette syndrome , higher still if subclinical symptoms of ADHD are considered . In terms