What is the approach to diagnosing and treating a new onset tic?

Diagnosis and Management of New Onset Tics

The diagnosis and treatment of new onset tics requires a systematic approach that first distinguishes between tic disorders and somatic/psychogenic cough, followed by appropriate behavioral and/or pharmacological interventions based on tic severity and impact on quality of life.

Diagnostic Approach

Initial Assessment

• Determine if the movements meet criteria for tics:
  • Sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations
  • Presence of premonitory urge (sensation before tic)
  • Temporarily suppressible
  • Distractible and suggestible
  • Variable in intensity and frequency 1

Differential Diagnosis

1. True Tic Disorder vs. Somatic Cough/Psychogenic Tic

   • For somatic cough disorder, patient must meet DSM-5 criteria including excessive thoughts about symptoms, persistent anxiety, and symptoms lasting typically >6 months 1
   • Tic cough shares core features of tics including suppressibility, distractibility, and premonitory sensation 1
   • Note: Nighttime presence or barking/honking quality should not be used to diagnose or exclude somatic or tic cough 1

2. Rule out secondary causes:

   • Medication side effects
   • Neurological conditions
   • Autoimmune processes
   • Infection (including PANDAS)

3. Evaluate for common comorbidities:

   • Obsessive-compulsive disorder (OCD)
   • Attention deficit hyperactivity disorder (ADHD)
   • Anxiety disorders
   • Depression 2

Classification

• Provisional Tic Disorder: Tics present for less than 1 year
• Chronic Tic Disorder: Single type of tic (motor OR vocal) for more than 1 year
• Tourette Syndrome: Both motor AND vocal tics for more than 1 year 2

Treatment Algorithm

Step 1: Education and Monitoring

• Provide education about tics and their natural course
• Explain that many tics are transient and may resolve without treatment
• Monitor for 4-6 weeks to assess severity, impact, and trajectory

Step 2: Behavioral Interventions (First-Line)

• Comprehensive Behavioral Intervention for Tics (CBIT) is recommended as first-line treatment when available 3

  • Combines habit reversal training (HRT) to address urge-tic relationship
  • Includes functional intervention to identify and neutralize environmental triggers
  • Has demonstrated acute and durable efficacy 3

• For children with somatic cough disorder, non-pharmacologic trials of hypnosis or suggestion therapy are recommended 1

Step 3: Pharmacological Treatment (For moderate-severe tics)

When behavioral therapy is insufficient or unavailable:

1. Alpha-2 Agonists (first-line pharmacotherapy):

   • Clonidine
   • Guanfacine
   • Particularly useful when ADHD is comorbid 4

2. Dopamine Modulators (second-line):

   • Pimozide: Start at 0.05 mg/kg (children) or 1-2 mg/day (adults)
   • Titrate every third day to maximum 0.2 mg/kg, not exceeding 10 mg/day
   • Requires baseline ECG and periodic monitoring 5
   • Note: For doses above 4 mg/day in adults or 0.05 mg/kg/day in children, CYP2D6 genotyping should be performed 5

3. Other options:

   • Tetrabenazine 4
   • Second-generation antipsychotics 2

Special Considerations

Adult-Onset Tics

• New-onset tics in adults are uncommon and warrant thorough evaluation 6
• More likely to have secondary causes than childhood-onset tics
• May cause significant social embarrassment and require more aggressive treatment 6

Comorbidity Management

• Address comorbid conditions (ADHD, OCD, anxiety) as they often cause more distress than the tics themselves 4
• Treatment approach may need modification based on comorbidities

Treatment Monitoring

• Periodic attempts should be made to reduce medication dosage to see if tics persist
• Allow 1-2 weeks after dose reduction to distinguish withdrawal effects from return of symptoms 5
• Continue to monitor for side effects, particularly with dopamine modulators

Prognosis

• Less than 25% of individuals continue to have moderate or severe tics into adulthood 2
• Many tics improve or resolve with time, particularly those with onset in childhood

Remember that the goal of treatment is to improve quality of life and reduce functional impairment, not necessarily to eliminate all tics.