of clinical course , ADHD predates the emergence of tics in most cases . Obsessive – compulsive behaviour and OCD occur in about 30-50 % of people with GTS , with these symptoms typically presenting after the tic symptoms . ¹¹ Behavioural or emotional problems — such as aggression and anger control problems , sleep disturbance and self-injurious behaviour — have been noted to occur at higher than expected levels in people with tic disorders , usually when ADHD or OCD are also present . ¹² Other behavioural or emotional disabilities — such as non-OCD anxiety , separation anxiety in particular and depression or depressive symptoms — have also been noted to occur at high levels in individuals with tic disorders . ¹³

In terms of cohorts of individuals with tic disorders , learning problems have been identified in about 30-40 % of cases . ¹⁴ Learning difficulties are substantially more likely to be present when ADHD is also present . The full ranges of specific learning disabilities are observed in children with tic disorders , although difficulties with reading and handwriting tend to predominate . ¹⁵

It has also been increasingly observed in recent years that similarities exist between GTS and autism spectrum disorders ( ASD ). ASD and Tourette syndrome are both neurobiological conditions that predomi-

Table 2 . Differential diagnoses of Tourette syndrome

Condition

Epilepsy

Tics have also been observed in individuals with intellectual disability , with the prevalence of tics appearing to increase with the severity of the disability . When individu-

Features

Associated with altered level of consciousness , not suppressible

Athetoid type of cerebral palsy ( CP ) Present from birth to three years ; associated with other features of CP

Dystonia musculorum deformans

Spasmodic torticollis ( see figures 4A and B )

Encephalitis lethargica

Huntington ’ s chorea

Tardive tourettism

Restless leg syndrome

Myoclonus

Torsion dystonia involving the legs

Spasm of muscles involving the neck

History of encephalitis

Present in third to fifth decade

History of long-term use of neuroleptics

Jerky movements of small muscle groups that cannot be controlled even temporarily

of these have distinctive clinical features and course of progression and are associated with characteristic types of movements , while tics can be differentiated using the character-

ADHD co-occurs in around 50-60 % of individuals with Tourette syndrome , higher still if subclinical symptoms of ADHD are considered .

relate to disruptive behaviour , hyperactivity , obsessive compulsive behaviours and temper outbursts rather than tics . ²⁰ Fortunately , empirically supported psychological and pharmacological treatments are available for most co-occurring conditions in Tourette syndrome , and these can be implemented in the context of tics with minimal adaptation . It is worth noting that treatment of tics alone is not thought to exert a significant beneficial impact on comorbid behavioural symptoms , while the converse may be true . Figure 5 summarises the management of a patient presenting with tics . ²

Pharmacological therapy

Although tics can attract a great deal of attention , it is not always necessary to treat them except when it is felt there is a deleterious effect on the patient ’ s social , educational or occupational functioning .

Drug therapy is , at present , the mainstay of treatment for the motor and vocal symptoms , where these are at the moderate-to-severe end of the spectrum . The medications most commonly used are alpha-adrenergic drugs and dopamine antagonists ( antipsychotics ). Since GTS is a remitting – relapsing condition , a few ‘ indicator tics ’ help assess the status of the disorder ( the term ‘ indicator tic ’ is used to denote any tic that is present

fluphenazine , topiramate and clonazepam . Clonidine is usually well tolerated ; however , it can cause dizziness and sedation . An evening dose can help with sleep disturbance , a common comorbid problem . Side effects of second- generation antipsychotics include cognitive dulling and excessive sedation , in addition to weight gain and metabolic abnormalities . Many families find the side effects unacceptable for their children and choose not to use pharmacotherapy or discontinue medication soon after initiation . It should be noted that stimulant treatment for ADHD in the context of GTS has long been controversial as it was believed to worsen tics , but it is now recognised that stimulants can be used without much deleterious impact on tic severity . ²² Careful monitoring is needed for worsening of tics and , if needed , may be combined with medication for tic symptoms . Comorbid OCD needs appropriate treatment using CBT and / or medication , such as SSRIs .

In adults , risperidone and other antipsychotic drugs would be the drug of first choice .

Specialist referral

Where GTS or a chronic tic disorder is suspected and where symptoms are severe and / or causing distress , consider referral to a specialist with experience in tic disorders .

nantly develop during childhood and mostly affect boys . Both conditions may include symptoms such as stereotypical or repetitive behaviours , ordering or arranging behaviours , as well as echolalia and echopraxia . Research conducted in Australia suggests that as many as 13 % of patients with GTS may have a comorbid ASD . ¹⁶ Tics occur in about 20-40 % of individuals with ASD , although there is significant variability in the extent of research , with a large well-controlled study reporting the occurrence of GTS in ASD to be 6.5 %. 17 In summary , the rate of GTS in ASD populations is estimated to be between 6 % and 11 %, while the rate of ASD in GTS is thought to be 4.5 % -18 %. ¹⁸

als with intellectual disability only are studied , the prevalence of tics is reported to be about 5-10 %. ¹⁹ However , when individuals with ASD and intellectual disability are considered , the prevalence of tics is much higher . ¹⁷

DIFFERENTIAL DIAGNOSES

ONE of the differential diagnoses at the early stage of GTS is that of a provisional tic disorder . These tics start between the ages of five and 10 , but they are not multiple nor persistent and remit spontaneously within weeks or months . Other conditions to consider in the differential diagnoses of GTS appear in table 2 . Most

istic features described earlier .

MANAGEMENT

THERE is no cure for GTS . The goals of treatment , therefore , are to reduce the severity , frequency and disruptive impact of symptoms ; to manage associated psychiatric and learning problems ; and to improve social functioning and quality of life . This treatment will usually be arranged by a specialist with experience in tic disorders . However , it is important for GPs to be aware of the treatment options available for patients .

Research and clinical experience suggest that , in most cases , the most disabling symptoms identified by both the children and their parents

during the assessment — the quality and nature of which would be indicative of the problem and serve as a prototype ).

In children , a trial of clonidine is often used first , especially when tics are associated with ADHD , as it can help both conditions ; this drug also has a better side-effect profile than antipsychotics . If this is ineffective , risperidone could be trialled . If risperidone is ineffective or poorly tolerated , aripiprazole , amisulpride or haloperidol may be tried . ²¹

Other drugs that have been used with some success include other second-generation antipsychotics or antiepileptics ( for example , quetiapine or olanzapine ), tetrabenazine ,

Where simple motor tics have been present for less than 12 months , and where symptoms are not causing significant distress to the patient , reassurance and monitoring is warranted to determine how the symptoms evolve .

Patient support groups

Australians with Tourette syndrome are fortunate as they have access to a strong and well-co-ordinated patient support group : the Tourette Syndrome Association of Australia ( TSAA ). The TSAA can provide support to patients , as well as information about the condition ; lists of practitioners with expertise in tic disorders in their local area ; access to