Basics
Description
- A tic is a sudden, repetitive, stereotyped, involuntary movement (e.g., blinking, grimacing) or vocalization (e.g., throat clearing, sniffing). Tics can be further classified as simple (e.g., nose twitching, grunting) or complex (e.g., hand gestures, jumping, echolalia). Tics characteristically change in anatomic location, frequency, type, complexity, and severity over time, although each tic has a stable appearance from one occurrence to the next. Most individuals are able to suppress their tics for brief periods of time, and some endorse having premonitory sensory urges that precede their tics. Tics typically abate during sleep but can persist in some cases.
- DSM-5 classification of tic disorders:
- Tourette syndrome (TS): Both ≥2 motor and ≥1 vocal tics have been present at some time, although not necessarily concurrently; tics have been present for >1 year since first tic onset (regardless of the duration of tic-free periods); onset <18 years
- Persistent (chronic) motor or vocal tic disorder: ≥1 motor or vocal tics but not both; tics have been present for >1 year since first tic onset; onset <18 years
- Provisional tic disorder: ≥1 motor and/or vocal tics; tics have been present for <1 year since first tic onset; onset <18 years
- Other specified tic disorder: tics causing clinically significant distress or impairment but not meeting the full criteria for a tic disorder. Provider should specify the atypical feature(s), for example, "with onset after age 18 years. "
- Unspecified tic disorder: as above, but provider chooses not to specify the reason that full criteria for a tic disorder are not met (e.g., there is insufficient information to make a more specific diagnosis)
- When there is evidence of an underlying organic etiology, a diagnosis of "other specified tic disorder " should be used.
- Pediatric autoimmune neuropsychiatric disorder associated with Streptococcus (PANDAS): a controversial entity first described in 1998. In theory, group A ²-hemolytic streptococcal (GABHS) infection triggers antibodies that cross-react with the basal ganglia and cause obsessive-compulsive disorder (OCD) symptoms and/or tics in some individuals. The National Institute of Mental Health defines PANDAS as follows:
- Presence of OCD and/or a tic disorder
- Prepubertal onset
- Sudden, explosive onset of symptoms and a course of dramatic exacerbations and remission
- Temporal relationship between symptom onset and exacerbations and GABHS infections
- Presence of neurologic abnormalities (hyperactivity, choreiform movements, tics) during exacerbations
- These diagnostic criteria do not always prove helpful in distinguishing PANDAS from other "standard " tic disorders. The high incidence of GABHS infections and high prevalence of asymptomatic carriers make it difficult to prove a link between GABHS infection and tics.
- Other autoimmune neuropsychiatric conditions with less restrictive diagnostic criteria have been proposed, including Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS) and Childhood Acute Neuropsychiatric Symptoms (CANS).
Epidemiology
- Described in almost all ethnic groups
- Affects males > females
- Typical onset is between ages 5 and 7 years.
Prevalence
- The prevalence of chronic tics and TS in school-age children is 3 " 6% and 0.1 " 1%, respectively.
- Transient tics occur in 20 " 25% of children.
Risk Factors
Genetics
No single gene has been associated with tics or TS; however, the family history is often positive for tics. The prevalence of TS in 1st-degree relatives is 10 times that in the general population.
General Prevention
Tics cannot be prevented, but educating patients, families, and school personnel about tics can minimize their impact. Aggressive management of comorbid conditions strongly influences patient outcomes.
Pathophysiology
The pathophysiology underlying tics and TS is not completely understood but is thought to involve abnormal dopamine neurotransmission within the basal ganglia. Evidence also implicates problems with serotonin, norepinephrine, and acetylcholine.
Etiology
Theory: Environmental or hormonal perturbations trigger tics in genetically susceptible individuals.
Commonly Associated Conditions
- ’ Ό50% of children with chronic motor tics or TS meet diagnostic criteria for attention-deficit/hyperactivity disorder (ADHD), and ’ Ό50% have OCD or obsessive-compulsive traits.
- Anxiety, learning disabilities (LD), oppositional defiant disorder, conduct disorder, and rage episodes are also associated with TS.
Diagnosis
The diagnosis of tics is clinical. Physical examination and ancillary studies are typically normal.
History
- Document a description of the patient 's past and current tics, including age of onset, type, anatomic location(s), duration, number, frequency, complexity, severity, and exacerbating or alleviating factor(s).
- Determine the degree to which the tics are causing interference and/or impairment.
- Assess for commonly associated conditions.
- In prepubertal patients with severe, sudden-onset OCD symptoms and/or tics, inquire about recent GABHS infections.
Physical Exam
Physical examination is usually normal. Tics may not be seen; thus, it may be necessary to depend on history. Having the child intentionally reproduce the sound(s) and/or movement(s) of concern and/or having the parents provide video can aid in differentiating tics from other movement disorders.
Diagnostic Tests & Interpretation
Lab
There is little evidence to support routine testing for GABHS in children suspected of having PANDAS. Throat cultures should be obtained in children with symptoms of pharyngitis.
Diagnostic Procedures/Other
Diagnosis depends largely on history. Diagnostic tests are unnecessary. Psychological testing may elucidate comorbid conditions (ADHD, OCD, LD).
Differential Diagnosis
- Certain simple tics (eye blinking, sniffing, throat clearing) may be mistaken for allergy symptoms, whereas complex tics may be mistaken for purposeful, voluntary movements.
- Stereotypies are patterned, episodic, repetitive, purposeless, rhythmic movements. The movements are constant in pattern and location, without variation over time.
- Chorea is characterized by rapid, random, purposeless movements that often have a "dance-like " quality. Unlike tics, chorea is not stereotyped.
- Dystonia is characterized by repetitive, sustained muscle contractions that cause abnormal postures and movements, often with a twisting quality. Dystonic tics result in sustained postures and can be difficult to distinguish from dystonia; however, the presence of a premonitory urge suggests the former diagnosis.
- Myoclonus is a sudden, brief, shock-like movement. It is not suppressible and is not associated with a premonitory sensation.
- Automatisms, seen in some forms of epilepsy, may look like tics but are neither associated with premonitory sensations nor under partial voluntary control. EEG is normal in children with tics but may be abnormal in those with seizures.
- Hemifacial spasm (HFS) is a rare condition that results in frequent, involuntary muscle contractions involving one side of the face. Early cases of HFS may be difficult to distinguish from motor tics, but HFS is limited to one side of the face, and the spasms last longer than tics.
Treatment
Many tics do not interfere with children 's lives and therefore do not require specific treatment. Educating the child and family about tics is often sufficient. Clinical decisions must take comorbid symptoms into account, and treatments must target the most impairing symptoms first. The waxing and waning nature of tics confounds treatment; it may take weeks to identify whether an intervention is helping.
Medication
- Mild/occasional tics: Medication is not needed.
- Moderate or severe:α-2 Agonist or dopamine antagonist may reduce severity/frequency.
- With OCD: Selective serotonin reuptake inhibitors can be helpful. Fluoxetine, fluvoxamine, and sertraline appear to be equally effective.
- With ADHD:α-2 Agonist may help hyperactivity/impulsivity. Consider addition of a stimulant if symptoms are refractory or if inattention is the primary complaint.
- PANDAS: As above. There is insufficient evidence to support the use of long-term antibiotics and/or immunomodulation.
First Line
- Clonidine and guanfacine are used off-label as 1st-line treatments for tics. Both are available in immediate- and extended-release forms.
- Clonidine: Start 0.05 mg at bedtime. Increase by 0.05 mg/week to effect, side effects, or a maximum of 0.4 mg/day, divided 3 or 4 times/day. Available as a tablet and transdermal patch.
- Guanfacine: Start 0.5 mg at bedtime. Increase by 0.5 " 1 mg/week to effect, side effects, or a maximum of 3 mg/day, divided twice a day.
- Sedation and orthostatic hypotension are common initial adverse effects, more so with clonidine than guanfacine.
- Avoid abrupt discontinuation, which can cause rebound hypertension.
Second Line
- Antipsychotic medications are considered 2nd-line treatments. Weight gain is common with all antipsychotic medications, but the atypical agents are generally preferred because they are better tolerated overall and are less likely to cause extrapyramidal side effects.
- Commonly used atypical agents include risperidone, aripiprazole, ziprasidone, and olanzapine.
- Typical antipsychotics (haloperidol, pimozide) are potent but are associated with troublesome side effects; therefore, they should only be used for those with refractory, disabling tics. Common side effects: sedation, weight gain, metabolic syndrome, and galactorrhea. Serious side effects: extrapyramidal reactions, neuroleptic malignant syndrome, and tardive dyskinesia.
Alert
Poor metabolizers of pimozide may be at increased risk for QT prolongation and cardiac arrhythmias; therefore, the FDA has stated that CYP2D6 genotyping should be performed before exceeding 4 mg of pimozide in adults or 0.05 mg/kg/day in children and that the dose of pimozide should not be increased earlier than 14 days in patients who are known CYP2D6 poor metabolizers.
Additional Therapies
General Measures
There is no evidence that lifestyle changes or restriction of activities modify the course of tic disorders.
Additional Therapies
- A recent randomized controlled trial of children and adolescents with TS and chronic tic disorder demonstrated that a comprehensive behavioral intervention " consisting of awareness training, competing response training, relaxation training, and social support " resulted in greater improvement in tic severity than supportive therapy and education alone. The effect size of the intervention was on par with that of medication.
- Focal motor (or vocal) tics, especially those that are dystonic, may be treated with botulinum toxin injections to the affected muscles.
Surgery/Other Procedures
Recent experimental data have shown deep brain stimulation (DBS) as a potential treatment for adults with severe and refractory tics.
Ongoing Care
Diet
There is no evidence that dietary modifications alter the course of tic disorders.
Patient Education
The Tourette Syndrome Association (www.tsa-usa.org) is a valuable resource for information. There are many local chapters.
Prognosis
Although common, tics cause impairment in a minority of children. Peak severity occurs in preadolescence. Most patients have partial or complete resolution of tics as adults. Long-term outcome depends on associated comorbidities.
Complications
Tics can be emotionally distressing and can result in social disability. Injuries " due to complex tics, compulsions, impulsivity, inattention, and other factors " may be more common in patients with TS than in the general population. Chronic, repetitive, and forceful tics can cause musculoskeletal problems (e.g., cervical spine arthritis, disc herniation) or other neurologic problems (e.g., cervical myelopathy, stroke secondary to vertebral artery dissection).
Additional Reading
- Mink JW, Walkup J, Frey KA, et al. Patient selection and assessment recommendations for deep brain stimulation in Tourette syndrome. Mov Disord. 2006;21(11):1831 " 1838. [View Abstract]
- Piacentini J, Woods DW, Scahill L, et al. Behavior therapy for children with Tourette disorder: a randomized controlled trial. JAMA. 2010;303(19):1929 " 1937. [View Abstract]
- Shprecher D, Kurlan R. The management of tics. Mov Disord. 2009;24(1):15 " 24. [View Abstract]
- Snider LA, Seligman LD, Ketchen BR, et al. Tics and problem behaviors in schoolchildren: prevalence, characterization, and associations. Pediatrics. 2002;110(2, Pt 1):331 " 336. [View Abstract]
- Tourette 's Syndrome Study Group. Treatment of ADHD in children with tics: a randomized controlled trial. Neurology. 2002;58(4):527 " 536. [View Abstract]
Codes
ICD09
- 307.20 Tic disorder, unspecified
- 307.23 Tourette 's disorder
- 307.21 Transient tic disorder
- 307.22 Chronic motor or vocal tic disorder
ICD10
- F95.9 Tic disorder, unspecified
- F95.2 Tourette 's disorder
- F95.0 Transient tic disorder
- F95.1 Chronic motor or vocal tic disorder
- F95.8 Other tic disorders
SNOMED
- 568005 Tic disorder (disorder)
- 5158005 Gilles de la Tourette 's syndrome (disorder)
- 56573006 Transient tic disorder (disorder)
- 7794004 Chronic motor tic disorder (disorder)
FAQ
- Q: Can a child with tics and ADHD be treated with stimulant medication?
- A: Although there have been concerns of stimulants making tics worse, there is no evidence that stimulants cause chronic tics. Furthermore, several recent studies have shown that treatment of ADHD with stimulants does not worsen tics and may lead to improvement.
- Q: Should mild tics be treated if they lead to teasing?
- A: The best approach is to educate the child, parents, and teacher about tics. The child can be armed with a response to questions, such as "Those are tics. They are just something I do, and I can 't help it. "