Motor disorders (tic disorders, stereotypic movement)

Tic Disorders - Twitch, Shout, Repeat

• Definition: Sudden, rapid, recurrent, nonrhythmic motor movements or vocalizations. Often preceded by a premonitory sensory urge and are temporarily suppressible.
• Course: Typically wax and wane; worsen with stress, anxiety, or fatigue.

Types of Tics:

• Simple Motor: Eye blinking, head jerking, shoulder shrugging.
• Simple Vocal: Throat clearing, sniffing, grunting.
• Complex Motor: Facial gestures, jumping, touching objects.
• Complex Vocal: Repeating words (echolalia), uttering obscenities (coprolalia).

Diagnosis (Onset before age 18):

• Tourette's Disorder: ≥2 motor tics AND ≥1 vocal tic for >1 year.
• Persistent (Chronic) Tic Disorder: EITHER motor or vocal tics (not both) for >1 year.
• Provisional Tic Disorder: Tics present for <1 year.

⭐ A majority of patients with Tourette's disorder have comorbid ADHD or OCD; always screen for these conditions.

Management:

• First-line: Psychoeducation and behavioral therapies like Habit Reversal Therapy (HRT).
• Pharmacotherapy (for severe/distressing tics): Alpha-2 agonists (guanfacine, clonidine), VMAT2 inhibitors, or antipsychotics.

Stereotypic Movement Disorder - Rock, Sway, Soothe

• Repetitive, seemingly driven, and purposeless motor behavior starting in the early developmental period.
  • Examples: Hand flapping, body rocking, head banging, self-biting.
• Behavior interferes with social/academic function or leads to self-injury (requiring protective measures).
• Not attributable to a substance or other neurological/mental disorder (e.g., OCD, trichotillomania).
• Differentiated from tics (more rhythmic/prolonged) & autism (can be comorbid if movements are severe).

⭐ Often associated with intellectual disability, genetic syndromes (e.g., Rett syndrome), or severe sensory deprivation (blindness, deafness).

Differential Diagnosis - What's That Wiggle?

• Tics: Sudden, rapid, non-rhythmic, and stereotyped. Crucially, they are partially suppressible.
  • Simple: Eye blinking, throat clearing.
  • Complex: Copropraxia (obscene gestures), echopraxia (imitating movements).
• Stereotypies: Rhythmic, repetitive, driven-appearing movements. Typically not suppressible.
  • Common in autism: Hand flapping, body rocking.
• Other Ddx: Consider chorea (dance-like), athetosis (writhing), dystonia (sustained postures), myoclonus (brief, shock-like jerks).

⭐ The transient, voluntary suppressibility of tics is a key feature that distinguishes them from chorea or dystonia, which cannot be consciously controlled in the same way.

Management Flow - Taming the Tics

• Initial Steps: Psychoeducation, reassurance, and watchful waiting are key for all tic disorders. Treatment is only initiated if tics are causing significant distress or functional impairment.
• First-Line Therapy: Behavioral interventions are preferred.
  • Habit Reversal Therapy (HRT): Core component. Involves awareness training and developing a competing response to the tic.
  • Comprehensive Behavioral Intervention for Tics (CBIT): HRT + functional analysis and relaxation techniques.

⭐ Exam Favorite: Behavioral therapy (CBIT/HRT) is the first-line treatment for Tourette syndrome and persistent tic disorders causing functional impairment, NOT medication. Pharmacotherapy is reserved for when behavioral approaches are insufficient or unavailable.

• ADHD requires inattention and/or hyperactivity-impulsivity before age 12 in ≥2 settings; treat with stimulants.
• Autism Spectrum Disorder involves impaired social communication and restricted, repetitive behaviors.
• Tourette Syndrome needs multiple motor and ≥1 vocal tics for >1 year before age 18; often co-occurs with ADHD/OCD.
• Stereotypic Movement Disorder features rhythmic, purposeless movements (e.g., head banging), unlike the brief, sudden nature of tics.