Diagnostic Features of Tourette Syndrome
Clinical Presentation
- The American Academy of Neurology suggests that the ability to temporarily suppress tics, followed by intensification of the premonitory sensation, is a core clinical feature that distinguishes tics from other movement disorders 1, 2
- The American Thoracic Society notes that repetitive, stereotyped movements, such as simple motor tics, are brief, repetitive movements involving discrete muscle groups 2
- The presence of core tic features, including suppressibility, variability, presence of premonitory sensation, and the characteristic waxing-waning pattern, is consistent with Tourette syndrome 1, 2, 3
- A chronic duration of symptoms, such as 2 years, fits with chronic tic disorder or Tourette syndrome rather than transient tic disorder, which resolves within one year 4
Differential Diagnosis
- The American Academy of Neurology states that subthalamic nucleus infarct causes hemiballismus, which is distinct from bilateral repetitive touching movements with premonitory sensations 2
Diagnosis and Characteristics of Tourette's Syndrome
Core Tic Symptoms
- Simple motor tics may include eye blinking, facial grimacing, head jerking, shoulder shrugging, and other brief movements 5, 6
- Simple phonic tics include throat clearing, sniffing, grunting, and other basic sounds 5, 6
Common Comorbidities to Screen For
- Attention deficit hyperactivity disorder (ADHD) - present in 50-75% of children with Tourette's 6
- Obsessive-compulsive behaviors - present in 30-60% of children with Tourette's 6
Important Diagnostic Considerations
- Boys are affected more commonly than girls, with a prevalence of approximately 1 per 1,000 male children 6
- Transient tic disorder is more common (4-24% of elementary school children) and typically resolves within a year 5, 6
Clinical Pitfalls to Avoid
- Misdiagnosing tics as habit behaviors or psychogenic symptoms can lead to inappropriate interventions 5, 6
- Excessive medical testing can cause iatrogenic harm; diagnosis is primarily clinical 5, 6
Diagnostic Criteria for Tic Disorder with Vocal and Motor Components
Core Diagnostic Criteria
- The presence of both multiple motor tics and one or more vocal tics is required for a diagnosis of Tourette Syndrome, according to DSM-5 classification, which is distinct from isolated chronic vocal or motor tic disorders 7, 8, 9
- Isolated chronic vocal tic persisting >1 year without motor tics is characteristic of Chronic Vocal Tic Disorder 7, 8
- The presence of both motor and vocal tics is diagnostic of Tourette Syndrome 7, 9