Tourette's Treatment: YGTSS Analysis

Treatment for Tourette's: Essential Study Points

• A study compared three statistical methods for determining positive treatment response in Tourette's syndrome or chronic tic disorder patients, utilizing the Yale Global Tic Severity Scale (YGTSS) and Clinical Global Impression-Improvement (CGI-I) scale.
• A 25% decrease on the YGTSS Total Tic Score (TTS) predicted a positive response on the CGI-I.
• Signal detection analysis revealed that a 25% reduction in YGTSS-TTS provided optimal sensitivity (87%) and specificity (84%) for predicting positive response.
• A mixture model defined dimensional response as a 23% or greater reduction on the YGTSS-TTS.
• Behavioral intervention showed higher odds of positive response on CGI-I (OR=5.68, 95% CI=[2.99, 10.78]) compared to dimensional response (OR=2.86, 95% CI=[1.65, 4.99]).
• A 25% reduction on the YGTSS-TTS is highly predictive of positive response across all three analytic methods, but tic severity alone does not fully determine the classification of positive response for trained raters.
• A separate study found that a 35% reduction in YGTSS total tic severity score or a raw score change of 6-7 points were optimal for determining treatment response in youth with tic disorders.

Study Overview on Interventions for Tics

• Examined interventions for tics in children/youth with Tourette syndrome (TS) or chronic tic disorder (CTD).
• The study included 40 placebo-controlled trials, consisting of 32 pharmacological, 5 behavioral, 2 physical, and 1 dietary intervention.
• A GRADE approach was used to assess the certainty of evidence.

Key Findings: Effective Interventions

• α2-adrenergic receptor agonists (clonidine and guanfacine) showed moderate certainty evidence and improved tic/global scores (SMD = -0.71; 95% CI -1.03, -0.40; N = 164).
• Habit reversal training (HRT)/comprehensive behavioral intervention (CBIT) had moderate certainty evidence and improved tic/global scores (SMD = -0.64; 95% CI -0.99, -0.29; N = 133).
• Antipsychotic drugs had low certainty evidence but improved tic scores (SMD = -0.74; 95% CI -1.08, -0.40; N = 76).
• Other interventions had low/very low quality evidence or showed no conclusive benefit.
• For medication treatment of tics, first-line treatment includes α2-adrenergic receptor agonists (clonidine and guanfacine), and second-line treatment involves antipsychotics (due to the risk of harm).
• HRT/CBIT is effective, but lacks evidence comparing it alone versus combined with medication.
• Insufficient evidence supports physical and dietary interventions.

Lecture Outline

• Therapy and theory primer
• Includes a Tourette's Syndrome Outline
• Evidence-based models of therapy with TS
• Case study
• Evidence Considerations

Increasing Attribution of Mental State

• Pavlov (1901) described classical conditioning involving unconditioned and conditioned reflexes.
• Watson (1934) focused on the control and prediction of behavior.
• Skinner (1971) developed operant conditioning, emphasizing intentional actions, reinforcement (positive and negative), ratio, and immediacy of reinforcement.
• Bandura (1963) introduced social learning through observation and modeling.

Theoretical principles

• Operant Conditioning involves active behavior influenced by environmental experiences.
• Positive reinforcement increases the frequency/intensity of a behavior.
• Withdrawing positive reinforcement will reduce the behavior.
• Undesirable behavior can be extinguished by negative consequences.
• Exposure (deliberately inviting the target behavior) and response prevention (stopping the target behavior) is an effective therapeutic technique.

Tourette's Syndrome (TS) Outline

• Many therapies for young people (YP) with TS include a family component due to heavy family involvement
• Depression/anxiety/OCD are examples of comorbid disorders with individual treatment protocols
• Tics often include neck movements and can manifest as 'Woos,' lip/mouth tics, or back stretches
• Other observations:
  • Tiring/exhausting
  • Persistent

Key Characteristics of Tourette's Syndrome

• Movements are exhibited in motor tics
• Sounds/words are exhibited in phonic tics
• Symptoms have to last at least 12 months
• Quality of tics changes
• Severity of the tics 'waxes and wanes'
• Tic disorders are milder or more transient, lasting less than 12 months (DSM V)
• TS was identified by Giles de la Tourette in 1855, with a 1:3-4 female:male ratio
• 1 in 100 children have TS → ~1 in 20 have a tic disorder
• The genetic basis is complex that involves inheritance
  • 90% of identical twins are concordant for TS (ESSTS, 2011)
  • Candidate genes have been pinpointed on chromosomes 2 (O'Rourke, 2009) and 13 (Abelson et al, 2005)
• Neurological substrates:
  • Basal ganglia, thalamus, and cortex are implicated (Robertson et al, 2017)
• Excess dopamine/sensitive dopamine receptors exist in the brain
• Dopamine antagonists are effective (Haloperidol/Risperidone), and GABA is implicated
• Drugs are effective but indicated only in a minority of cases

Understanding Tics

• Tics are usually experienced as involuntary and 'pointless' but recognizable actions
• There is a release of tension/sense of satisfaction that occurs after the tic
• Can be suppressed for periods of time
• It is suggestable

Simple vs. Complex Tics

• Simple tics:
  • Fast, small movements (eye blink, grimace) or sounds (grunts or sniff)
• Complex:
  • Slower, more noticeable movements (kissing, curtsy) or words as opposed to sounds that may be taboo
  • 10-17% of young people have coprolalia (swearing)

The Premonitory Urge

• Is preceded by an urge
• The degree of awareness has wide variations
• Can be experienced as aversive (itch/tension/tingle)
• Reduces tension and relieves discomfort, making the tic highly reinforcing

Natural History and Comorbidity

• Classically, onset ~6 years old (ESSTS, 2011)
• Often tics start around the head and neck, progressing from simple to complex over time
• The tic will resolve to a degree in early adolescence for the majority of TS cases
• Positive outcome occurs if 'pure' TS picture, tic onset is younger and less severe
• By adulthood ~30% still have tics (ESSTS, 2011)
• There is presence or absence of noticing tics
• Common comorbidities =
  • OCD (30-50%)
  • ADHD (50-60%)
  • Rage episodes are reported in 80%
• There is shared genetic component to TS/ADHD/OCD
• Up to 5-15% may have ASD
• LD are more common than in the general population
  • dyspraxia
• ~30% also experience mood/anxiety disorders
• Estimates vary, but only around 15% of TS cases are 'pure'
• A good amount of of those cases Lifetime prevalence of >TWO additional conditions → 60%

Evidence-Based Models of Therapy

• Functional Tics:
  • Sudden onset
  • Often don't respond to medications
  • Remit suddenly and are runs in with increased stress/recent events
• Classic Tics:
  • Onset usually gradual, starting around 5/6 years
  • Tic severity often responds to tic medication/behavioural therapy
    • Rarely remit suddenly
    • Wax and waning pattern, impacted by stressors
    • Runs in families

Treatment Options for Tourette’s Syndrome

• Stage 1: Always offer psychoeducation
• Stage 2: Can include Behavioural treatment and or medication
• The European clinical guidelines emphasize this approach

Behavioral Therapies for Tourette’s Syndrome.

• Comprehensive Behavioral Intervention for Tics (CBIT)
• Habit Reversal Training (HRT)
• Exposure and Response Prevention (ERP)

Behavioral Theories

• Operant Conditioning
  • Has active behavior -Positive Reinforcement
    • Withdrawn reinforcement
• Exposure response prevention is an effective therapeutic technique

Awareness Training

• Record/acknowledge a tic - session work
  • Which muscle groups are involved? and deconstruct the tic
• Include the premonitory urge
• Identify the core of the tic - when is it 'done', and consider the first tic in a complex chain

Competing Response Training

• behavior that is physically incompatible with the tic and less noticeable
• Ex. Grunting - deep breathing Body jerk - Chris - back against wall
• Using your body alone to compete without the use of any props or clothing etc.

Praise and Reinforcements during training

• Usually from a parent -The effort of performing the CR should be praised.
• ex extrinsic reward becoming intrinsic
• Contingent on carrying out CR - tic frequency is not relevant
• Not rewarding ‘no tics’
• Can prompt (in agreed way) to do CR

Outcomes

-Objective pre and post measurements are key

• Aim for 30% reduction in tic is seen as a meaningful

Stereotypies vs. Tics

• In Tourette's Syndrome, physical tics are involuntary
• The onset of stereotypies occurs at earlier ages than tics (6-7 years)
• Stereotypies are more consistent in times whereas tic wax and wane
• Tics tend to be rapid and random whereas stereotypies are more rhythmic

Case Study: Josh

-Josh was 14, parents/sibs/peers laughed

• Significant history of TS, OCD, ADHD
• The School would respond by allowing Josh to watch YouTube video
• He would exhibit Vocal and motor tics
• His final diagnosis was a YGTSS score of 85 (high)
• Final Treatments -CBIT - selected:ADHD picture and the tic hierarchy -high level of positive reinforcement at home and school -HRT: Competing response -breathing technique

When Is Treatment Succseful

• Is tic SEVERITY the best barometer of clinical change?
• If impacting functioning - YES -if tics are managed, do we have to consider the co-occurring conditions too?