5.2.9 Tic Disorders

Tic Disorders

Tic disorders are neurodevelopmental disorders that typically emerge during childhood and are characterized by the presence of repetitive, involuntary, and sudden movements or vocalizations.

Prevalence/Incidence:

Tic disorders are relatively common in children and adolescents, with a prevalence of approximately 1-2% in the general population (Robertson, Cavanna, & Eapen, 2009). The incidence of tic disorders varies depending on the subtype, with transient tic disorders being the most common subtype, affecting up to 20% of children at some point in their lives (Eapen, Snedden, & Naik, 2016). 2:1 ratio of boys to girls in community-based samples. Prevalence 5–10/10,000 in European and Asian populations.

Aetiology:

Believed to result from a combination of genetic and environmental influences. Various susceptibility genes have been implicated, including connections to chromosome 2 (Eapen et al., 2016). A well-established association with psychosocial stress exists, along with increased reactivity in the HPA axis and noradrenergic system. A potential disruption in the dopamine system is also proposed. Additional factors that may contribute include prenatal and perinatal complications, exposure to androgens, heat, fatigue, and a post-infectious autoimmune process (Robertson et al., 2009).

Presentation:

Tic disorders are classified into several subtypes, including transient tic disorder, chronic motor or vocal tic disorder, and Tourette syndrome. The most common tics involve eye blinking, facial grimacing, throat clearing, and sniffing. Tics typically wax and wane in severity, and they may be worsened by stress or fatigue (Robertson et al., 2009).

Clinical Features	Description
Tourette’s syndrome	Multiple motor tics and one or more vocal tics, not necessarily occurring simultaneously; copropraxia (a tic consisting of involuntarily performing obscence or forbidden gestures, or inappropriate touching) may be present; duration over 12 months
Chronic motor/vocal tic disorder	Either motor or vocal tics, but not both; duration over 12 months
Transient tic disorder	Tics do not persist for longer than 12 months; the most common form of tic, often seen in younger children

Motor tics frequently start between the ages of 3 and 8, preceding the appearance of vocal tics by several years. Tics tend to evolve over time, with more intricate tics developing after a few years. The intensity of tics fluctuates, often exacerbated by factors such as exhaustion, emotional stress, and excitement. Tic severity typically reaches its peak during early adolescence and, for most individuals, significantly decreases by the conclusion of adolescence. While coprolalia is widely linked to this disorder in public perception, it is relatively rare and not a diagnostic requirement.

Treatments:

Treatment for tic disorders typically involves a combination of pharmacological and behavioural interventions. Medications such as antipsychotics and alpha-2-adrenergic agonists may be prescribed to reduce the frequency and severity of tics (Robertson et al., 2009). Behavioural interventions such as habit reversal therapy and cognitive-behavioural therapy may also be effective in reducing tics and improving quality of life (Eapen et al., 2016).

Outcome:

The long-term outcome of tic disorders varies depending on the subtype and severity of symptoms. Transient tic disorders typically resolve on their own within a few months, while chronic motor or vocal tic disorders may persist into adulthood (Robertson et al., 2009). Tourette syndrome is typically a lifelong condition, but many individuals with the disorder experience a reduction in symptoms during adolescence or early adulthood (Eapen et al., 2016).

	Information
Prevalence/Incidence	Prevalence rates of tic disorders in children and adolescents vary, with estimates ranging from 1% to 24% (Knight et al., 2012). Tourette syndrome, the most severe form of tic disorder, has a prevalence rate of 0.3-0.8% (Knight et al., 2012). Tic disorders are more common in boys than girls (Singer et al., 2019).
Aetiology	Tic disorders are thought to have a genetic component, with studies showing that they often run in families (Knight et al., 2012). Neurobiological factors, such as abnormalities in dopamine and serotonin neurotransmitter systems, may also contribute to the development of tic disorders (Singer et al., 2019). Environmental factors, such as stress, may exacerbate tic symptoms.
Presentation	Tic disorders are characterized by involuntary movements or sounds, known as tics. Tics can be simple (e.g. eye blinking, throat clearing) or complex (e.g. hopping, twirling). Tics can also be motor or vocal in nature. Tics are typically preceded by an urge or sensation and can be temporarily suppressed (Knight et al., 2012). Tic disorders can also be accompanied by co-occurring conditions, such as ADHD, OCD, and anxiety disorders (Singer et al., 2019).
Treatments	Behavioural interventions, such as habit reversal training and exposure with response prevention, can be effective in reducing tic severity and improving quality of life (McGuire et al., 2019). Medications, such as antipsychotics and alpha-2 agonists, may also be used to manage tic symptoms (Singer et al., 2019).
Outcome	Tic symptoms may improve with age, with many individuals experiencing significant reduction or remission of symptoms in adulthood (Knight et al., 2012). However, tic disorders can also be chronic and persistent, and can have negative impacts on social, academic, and occupational functioning (Singer et al., 2019). Early identification and intervention can improve outcomes and reduce the impact of tic symptoms on daily life (McGuire et al., 2019).

Tic disorders are relatively common in children and adolescents and can have a significant impact on quality of life. While the exact cause of tic disorders is not known, a combination of genetic and environmental factors is thought to play a role. Treatment typically involves a combination of medication and behavioural interventions, and the long-term outcome varies depending on the subtype and severity of symptoms.

An Understanding of How Tic Disorders Relate to Behaviours (e.g. Self-harm, Refusal to Attend School etc.) and Contexts (e.g. Pre-school Behaviours)

Tic disorders can have a significant impact on a child’s behaviour, both in terms of their interactions with others and their ability to engage in everyday activities. In this response, we will discuss how tic disorders can relate to behaviours such as self-harm and refusal to attend school, as well as how they may present in preschool-aged children.

Self-harm: Self-harm refers to intentional behaviours that cause physical harm to oneself. While self-harm is not a symptom of tic disorders per se, research suggests that individuals with tic disorders may be at increased risk for self-injurious behaviours. In some cases, tics themselves may cause physical harm, such as repetitive head-banging or hitting oneself. In other cases, the emotional distress associated with tic disorders may lead to self-harm as a coping mechanism (Woods et al., 2011). It is important for clinicians to be aware of the potential risk for self-harm in individuals with tic disorders and to address this issue as part of the treatment plan.

Refusal to attend school: Refusal to attend school is a common problem among children with tic disorders. Research suggests that up to 50% of children with Tourette syndrome may experience school refusal at some point (Baron-Cohen et al., 1999). School refusal can be related to a number of factors, including anxiety, social isolation, and difficulties with attention and concentration. In some cases, tics themselves may interfere with a child’s ability to participate in school activities, leading to frustration and avoidance behaviours (Woods et al., 2011). Treatment for school refusal may involve a combination of behavioural interventions such as exposure therapy and cognitive-behavioural therapy, as well as medication to manage tics and associated symptoms.

Preschool behaviours: Tic disorders can also present in preschool-aged children, although a diagnosis can be challenging in this population. Preschool-aged children with tic disorders may exhibit a range of behaviours, including repetitive motor movements, vocalizations, and compulsive behaviours such as hand-washing or arranging objects in a particular way (Baron-Cohen et al., 1999). These behaviours may interfere with the child’s ability to participate in social activities and may be mistaken for other developmental or behavioural disorders. It is important for clinicians to be aware of the potential for tic disorders in preschool-aged children and to consider this diagnosis in cases where repetitive behaviours are present.

In conclusion, tic disorders can have a significant impact on a child’s behaviour, both in terms of their interactions with others and their ability to engage in everyday activities. Clinicians should be aware of the potential for self-harm and school refusal in individuals with tic disorders and should consider the possibility of tic disorders in preschool-aged children who exhibit repetitive behaviours.

References:

1. Knight, T., Steeves, T., Day, L., Lowerison, M., & Jette, N. (2012). Prevalence of tic disorders: a systematic review and meta-analysis. Pediatric Neurology, 47(2), 77-90.
2. McGuire, J. F., Piacentini, J., Scahill, L., Woods, D. W., Villarreal, R., Wilhelm, S., … & Walkup, J. T. (2019). Bothersome tics in patients with chronic tic disorders: Characteristics and individualized treatment response to behavior therapy. Behaviour research and therapy, 116, 87-95.
3. Singer, H. S., Morris, C., Grados, M., & Glaze, D. (2019). PANDAS and PANS in school-aged children: Diagnosis and treatment. Pediatric Clinics, 66(6), 1019-1035.
4. Eapen, V., Snedden, C., & Naik, U. (2016). Tic disorders: From pathophysiology to treatment. Journal of Neuropsychiatry and Clinical Neurosciences, 28(1), 11-17.
5. Robertson, M. M., Cavanna, A. E., & Eapen, V. (2009). Gilles de la Tourette syndrome and disruptive behavior disorders: Prevalence, associations, and explanation of the relationships. Journal of Neuropsychiatry and Clinical Neurosciences, 21(4), 356-364.
6. Baron-Cohen, S., Scahill, V. L., & Izaguirre, J. (1999). The prevalence of Gilles de la Tourette syndrome in children and adolescents with autism: a large scale study. Psychological Medicine, 29(6), 1151-1159.
7. Woods, D. W., Piacentini, J. C., & Chang, S. (2011). Managing tic disorders: A guide for parents and professionals. Oxford University Press.