Tics Screening for Intervention

Tic Disorders

• Characterized by recurrent, unwanted, discrete, non-goal-directed, non-rhythmic movements (motor tics) or vocalizations (vocal tics)
• Distinguished from other abnormal behaviors by:
  • Repetitive and patterned character
  • Variability of type of movement/vocalization and severity
  • Association with premonitory urges
  • Partial or complete suppressibility on demand

Types of Tic Disorders

• Three types of tic disorders included in DSM-5:
  • Tourette's disorder (also called Tourette's syndrome, TS)
  • Persistent (also called chronic) motor or vocal tic disorder
  • Provisional tic disorder

Characteristics of Tics

• Highly variable within and across subjects, regarding:
  • Muscle groups involved (and thus body location)
  • Complexity
  • Interference with normal voluntary behavior
• Tics follow a cranio-caudal gradient of frequency, with:
  • Face, head, and proximal upper limbs being the most commonly affected
  • Ability to suppress tics voluntarily being maximal in the least affected areas (trunk and lower limbs)
• Tics can be classified as:
  • Simple (involving a single muscle group)
  • Complex (involving coordinated sequences or combinations of movements/vocalizations)

Premonitory Urges and Sensory Features

• Premonitory urges (PUs) are uncomfortable sensations that:
  • Build up in intensity immediately before tics
  • Are markedly alleviated immediately after tic release
• Often, linked PUs and tics occur in the same body region
• Some patients report "just-right" phenomena, reiterating actions until they feel "just right"
• Somatic hypersensitivity or site sensitization: unusual focus on external stimuli, repetitive, faint, and poorly salient

Suppression of Tics

• Ability to suppress tics varies across patients and is higher in adults than children
• Suppressing tics leads to a rise in PU intensity, but quality or severity of PUs is not associated with the ability to hold tics in
• Rewards, relaxation, physical exercise, and reduced sympathetic tone can reduce tic severity
• Psychosocial stress, raised anxiety levels, and fatigue are important precipitants of tics

Tic Disorders in Adults

• Tic-like rapid movements presenting in adulthood may be labeled as tics, but some have a functional origin
• Differ from typical "organic" tics in:
  • Female predominance
  • Sudden onset, often precipitated by minor trauma or panic attacks
  • Uncommon association with PUs or suppressibility
  • Common suggestibility
  • Lack of association with a family history of tic disorders or a personal history of ADHD or OCD

Epidemiology and Comorbidities

• Tics typically begin between 5 and 8 years of age, with 95% of cases starting between 4 and 13 years
• Severity peaks around puberty, and tics may spread beyond the cranio-cervical region
• Most prevalence studies have focused on pediatric populations, with a combined prevalence of:
  • 0.77% for TS
  • 1.61% for chronic tic disorders
  • 2.99% for transient tic disorders
  • 2.82% for all tic disorders
• Comorbidities include:
  • ADHD (affecting up to 60% of TS patients)
  • Obsessive-compulsive disorder (OCD)
  • Anxiety disorders
  • Mood disorders
  • Conduct disorder/oppositional defiant disorder
  • Autism spectrum disorder (ASD)

Pathogenesis

• Structural and functional abnormalities detected in TS patients at numerous levels of the cortico-striato-thalamo-cortical (CSTC) network
• Microscopic level: reduced numbers and gene expression within inhibitory GABAergic and cholinergic interneurons in sensorimotor parts of the striatum and internal segment of the globus pallidus
• Functional imbalance between inhibition/excitation in these structures was hypothesized

Management

• Comprehensive history and assessment using validated rating instruments are crucial in guiding management
• Education of patients and families is essential in optimizing understanding and acceptance of symptoms and identifying coping strategies
• Tics typically require active interventions when they are:
  • Stigmatizing
  • Socially or academically impairing
  • Influencing mood and self-esteem
  • Generating situational anxiety
• Pharmacological and behavioral approaches are used, with dopamine antagonist drugs being the most common treatment

Alpha-2 Agonists

• Clonidine and guanfacine are considered first-line therapy for tics in the US and Canada due to their favorable tolerability profile.
• Six RCTs demonstrated superiority of clonidine over placebo in both oral and transdermal formulations (0.05-3 mg).
• Guanfacine has a longer half-life than clonidine and can be administered once daily (0.5-4 mg).
• Two RCTs and two open-label studies confirmed the efficacy of guanfacine, especially in children with tic disorders.

Other Medications

• Tetrabenazine is a presynaptic dopamine depletor that acts by blocking the vesicular VMAT2 protein and displays minor postsynaptic D2 blockage.
• Baclofen and topiramate were found to be moderately effective in two medium-sized double-blind RCTs on patients of different ages.
• Botulinum toxin type A injections are useful for treating persistent, simple motor tics located to the upper face or neck, as well as for vocal tics, including coprolalic utterances.
• Delta-9-tetrahydrocannabinol, the main active compound of cannabis, has been tested in two small RCTs on adults with TS, showing a modest, but promising, benefit on some outcome measures and acceptable tolerability.

Behavioral Therapies

• Habit reversal training (HRT) is a highly effective treatment approach for tics, built on awareness training, competing response training, and social support.
• Six RCTs and other smaller observational studies demonstrated the efficacy of HRT in diminishing tic severity.
• Comprehensive Behavioral Intervention for Tics (CBIT) is an extension of HRT that complements it with function-based assessment, relaxation training, and psychoeducational interventions.
• CBIT has been shown to be highly effective in two large multi-site RCTs, with sustained improvements for more than 6 months and amelioration of familial distress, obsessive-compulsive symptoms, and anxiety.

Other Therapies

• Exposure and response prevention (ERP) is a behavioral therapy that has been adapted for tic treatment, relying on prolonged exposure to urges associated with sustained suppression of tics.
• Cognitive psychophysiological model has been tested in an open trial, aiming to change the background activity against which tics occur and treat associated metacognitive and perfectionist beliefs.
• Mindfulness-based stress reduction programs, aerobic exercise sessions, and neurofeedback modulation of EEG oscillatory activity have been tested in preliminary open-label studies, but controlled trials are lacking.

Neuromodulation Strategies

• Deep brain stimulation (DBS) remains the only active intervention that is extensively being investigated for adult TS patients who are deemed refractory to pharmacological and behavioral interventions.
• The main patient selection criteria for DBS in TS include refractoriness to pharmacological and behavioral interventions, severe tic symptoms, and presence of comorbid conditions.
• The most frequently used targets for DBS in TS are the centromedian/parafascicular-substantia periventricularis-nucleus ventralis oralis internus crosspoint of the thalamus and the globus pallidus pars interna.

Assessment Plan in Tourette's Syndrome

• Demographics to be considered: age, gender, ethnicity, education level, SES, and marital status
• Tic evaluation involves:
• Yale Global Tic Severity Scale
• Premonitory Urge for Tics Scale (PUTS)
• Engaging and listening to parents/partners
• Contextual Factors
• Comorbidities to be assessed:
• OCD
• ADHD
• Anxiety/depression
• Disruptive behaviors
• Autism
• Area of functioning to be evaluated:
• Engaging and listening to parents/partners
• Academic and professional proficiency
• Hobbies and recreational interests
• Aspirations

Decision Tree for the Treatment of Tics

• Tics assessment leads to:
• Psychoeducation
• No indication for treatment, with monitoring
• Indication for treatment with preference for behavioral treatment
• Symptom-focused behavioral therapy
• If still an indication for treatment, then:
• Pharmacotherapy
• If indication for treatment with preference for pharmacological treatment, then:
• Pharmacotherapy + behavioral therapy
• Polypharmacotherapy

Abbreviations

• CY-BOCS: [Children]Yale-Brown Obsessive-Compulsive Scale
• SNAP: Swanson, Nolan and Pelham questionnaire
• SCARED: Screen for Child Anxiety and Related Emotional Disorders
• BDI: Beck Depression Inventory
• BAI: Beck Anxiety Inventory
• DBRS: Disruptive Behavior Rating Scale
• ASSQ: Autism Spectrum Screening Questionnaire
• PUTS: Premonitory Urge for Tics Scale
• OCD: Obsessive-compulsive disorder
• GTS-QOL: Generalized Tic Syndrome Quality of Life Scale

Understanding Tics and Other Primary Tic Disorders

• Premonitory Sensation: an uncomfortable tension in the neck muscles, temporarily relieved by performing an abrupt 'head flick' movement
• Obsessive Thought: an intrusive thought accompanied by raised anxiety levels, temporarily relieved by performing a series of voluntary routine actions
• Risk-taking or Sensation-seeking: a mental urge to act out a specific behavior, potentially leading to self-harm, but with an immediate gratification

DSM-5 Criteria for Tic Disorders

Tourette's Syndrome (TS)

• Must have two or more motor tics and at least one vocal tic
• Must have had tics for at least a year
• Must have tics that begin before the age of 18
• Must have symptoms not due to taking medicine or other drugs, or due to having another medical condition

Persistent (Chronic) Motor or Vocal Tic Disorder

• Must fulfill the same criteria as TS, apart from the first criterion
• Must have one or more motor tics or vocal tics, but not both

Provisional Tic Disorder

• Must fulfill the same criteria as persistent, chronic tic disorder
• Tics have been present for no longer than 12 months in a row