Efficacy of Behavioural Intervention, Antipsychotics, and Alpha Agonists in the Treatment of Tics Disorder in Tourette's Syndrome

Abstract

Tourette's Syndrome (TS), in which patients have sudden, repeated, involuntary twitches and movements, called tics, is a condition of the nervous system. They can be motor, vocal, simple, or complex tics. It can be physically, emotionally, mentally, and socially distressing and challenging for those suffering from it. Usually, it is accompanied by various comorbidities like attention-deficit hyperactivity disorder, obsessive-compulsive disorder, and sleep disorders. A variety of environmental and genetic factors are also associated with tics in TS like the first-degree relatives are more at risk of developing TS.TS is heterogeneous with complicated patterns of inheritance and phenotypic manifestations. There is a strong association between common single nucleotide polymorphisms (SNP, s) in the SLITRK1 gene and TS. Environmental factors like prenatal, postnatal, and perinatal factors directly influence tics in TS. These factors are low birth weight, intrauterine growth retardation (IGR), and various infections. The treatment of TS can be broadly classified into non-pharmacological and pharmacological treatment. Non-pharmacological therapy includes various behavioural interventions that can be helpful in situations when patients are tolerant of medical treatments. Psychoeducation and counselling play an essential role in the treatment of TS. It is vital to give a proper understanding to the patient and their family about the disease. Cognitive-behavioral intervention for tics, cognitive-behavioral therapy, exposure and response prevention, relaxation techniques, deep brain stimulation, and habit reversal training are the commonly used therapies for tics. These therapies have shown good efficacy because it improves the Yale Global Tic Severity Scale score (YGTSS) significantly. And they show effectiveness in patients who are irresponsive to medical treatment. The main lines of medical treatment are antipsychotics and alpha agonists. Typical (haloperidol, pimozide) or atypical (aripiprazole, risperidone, olanzapine) Antipsychotics differ in their side effects, efficacy, and tolerance in different age groups of children. Haloperidol was the first drug approved by the Food and Drug Administration for tics, but later on, new developments and improvements were made as far as drug therapy is concerned. The alpha-agonist most commonly used is clonidine which is also available in the form of adhesive patches. Another alpha agonist which is also widely used is guanfacine. Botulinum toxin and baclofen have also shown efficacy in dealing with tics in TS with other comorbidities. We will review in this article all the main lines of treatment and their effectiveness in TS.

Keywords: alpha agonists; antipsychotics; behavioural interventions; behavioural therapy; movement disorders; non-pharmacological treatment; pharmacological treatment; pharmacotherapy; tics disorder; tourette's syndrome.

Figure 1. Treatment of Tourette’s syndrome

The two main lines of treatment is non-pharmacological and pharmacological. The non-pharmacological treatment is psychoeducation and behavioural intervention, which mainly includes comprehensive behavioural intervention for tics (CBIT), habit reversal training (HRT) and deep brain stimulation (DBS). The pharmacological treatment includes mainly antipsychotics (Aripiprazole, Risperidone, Haloperidol, Pimozide) and Alpha agonists (Clonidine, Guanfacine), Baclofen and Botulinum toxins are also used in some cases for the treatment of Tourette’s syndrome. The idea of the figure has been adopted from the articles "Tourette syndrome: A mini-review" and "A review of the current treatment of Tourette syndrome" [1,2].

Figure 2. Behavioural interventions for TS mainly includes: 1) Psychoeducation and counselling 2) DBS (deep brain stimulation) 3) ERP (Exposure Response Prevention) 4) CBIT (comprehensive behavioural intervention for tics), which includes HRT (Habit Reversal Therapy), Relaxation training and different functional interventions.

The idea of the figure has been adopted from the article "Tourette syndrome: A mini-review "[1].