Tics and Tourette syndrome: SAQ

Question 1 (10 marks)

Outline how you would confirm the diagnosis in this child, the features that distinguish his movements from mimics, and the investigation you would perform. (10 marks)

Model answer

Diagnosis (4 marks). The child has Tourette disorder by DSM-5 criteria. He has multiple motor tics (eye-blinking, grimacing, shoulder-shrugging) plus at least one vocal tic (throat-clearing), present for over one year (18 months), with onset before age 18, in the absence of a substance or medical cause. Motor and vocal tics need not occur at the same time, and coprolalia is not required. The diagnosis is entirely clinical, made on the history and on home video, and the family history of paternal childhood tics supports it. [2]

Phenomenology distinguishing a tic from mimics (4 marks). The defining features that separate his tics from stereotypies and other movement disorders are the premonitory urge, the mounting tension relieved only by the movement, the brief suppressibility with rebound, and the waxing-and-waning, body-shifting course. A stereotypy, by contrast, is rhythmic, fixed, and purposeful-appearing and lacks the urge and suppressibility. The inattentive restlessness he shows at school is the motor restlessness of comorbid attention-deficit or hyperactivity disorder, which is a separate phenomenon from his discrete tics and which coexists in about 60 per cent of children with Tourette. [2] [6]

Investigation (2 marks). No routine blood test, scan, or electroencephalogram is indicated for a child with a typical history and a normal examination; the diagnosis is clinical and over-investigation causes harm. I would request home video to confirm the movements in their natural setting and would grade severity clinically, reserving any targeted test for an atypical feature such as a focal deficit, regression, or a fixed rather than fluctuating course. [2]

Question 2 (10 marks)

Outline your management of this child, including the role of behavioural therapy and pharmacotherapy, and the management of his comorbidities. State the prognosis you would give the family. (10 marks)

Model answer

Principles (1 mark). Management is stepped and aims at function rather than tic elimination. The tics and the comorbid attention-deficit or hyperactivity disorder and obsessive-compulsive disorder are assessed and treated in parallel, because the comorbidities usually cause more impairment than the tics. [2]

Behavioural therapy (3 marks). The first active treatment for impairing tics is Comprehensive Behavioural Intervention for Tics, or CBIT, a structured behavioural therapy built on habit reversal training that teaches the child to detect the premonitory urge and to perform a competing response. The Piacentini randomised trial showed CBIT significantly reduces tic severity compared with supportive therapy, and it is endorsed as first-line by the American Academy of Neurology and European guidelines. I would refer him for CBIT and would begin psychoeducation and school accommodation. [1] [2]

Pharmacotherapy (3 marks). If behavioural therapy is inadequate, the preferred first drugs are the alpha-2 agonists clonidine or guanfacine, chosen first because they also treat attention-deficit or hyperactivity disorder and have a safer profile than antipsychotics. Clonidine is started low and titrated with blood-pressure monitoring. The antipsychotics risperidone and aripiprazole are the strongest tic suppressants and are reserved for moderate to severe impairment with metabolic and extrapyramidal monitoring, started low and titrated to effect. [2] [5]

Comorbidities and prognosis (3 marks). His attention-deficit or hyperactivity disorder is managed with behavioural strategies and, if needed, with stimulant or non-stimulant medication, and the modern evidence shows stimulants do not routinely worsen tics, so effective treatment should not be withheld. His obsessive-compulsive symptoms are treated with cognitive behavioural therapy using exposure and response prevention, with a selective serotonin reuptake inhibitor for moderate to severe obsessive-compulsive disorder. The prognosis for the tics is favourable: tic severity peaks around 10 to 12 years and improves for most children through adolescence, though obsessive-compulsive symptoms may persist. I would counsel the family that treatment targets function, that tics fluctuate, and that the long-term outlook is good. [6] [11]