Ariane Park, MD, MPH
Andrea G. Malone, DO
DESCRIPTION
Tics are relatively brief involuntary movements (motor tics) or sounds (vocal tics) that usually are intermittent but may be repetitive and stereotypic. They fluctuate or wax and wane in frequency, intensity, and distribution. Typically tics can be volitionally suppressed, although this may require intense mental effort. Motor tics may persist during all stages of sleep. Tics typically are exacerbated by dopaminergic drugs and by CNS stimulants, including methylphenidate and cocaine.
- Premonitory feelings or sensations precede motor and vocal tics in >80% of patients. These premonitory phenomena may be localizable sensations or discomfort, or nonlocalizable, less specific, and poorly described feeling such as an urge, anxiety, and anger.
- The “intentional” component of the movement may be a useful feature differentiating tics from other hyperkinetic movement disorders.
EPIDEMIOLOGY
- Incidence/prevalence
- Reported prevalence rates have varied markedly. The frequency of tics depends on the definition of the phenotype. Transient tic disorders occur relatively commonly in children (3%–15% in different studies), and chronic motor tics occur in approximately 2%–5%, although “chronic” may extend only 2–3 years in many of these individuals.
- Because about one third of patients do not even recognize the tics, it is difficult to derive an accurate prevalence figure.
- Age
- Onset is usually in childhood.
- Sex
- Boys are much more likely than girls to have chronic tics. The male-to-female ratio in chronic motor tic disorder is approximately 5:1 (between 2:1 and 10:1 in different studies).
RISK FACTORS
- Family history of obsessive-compulsive disorder
Genetics
- Probable mixed model of inheritance, rather than simple autosomal mode of transmission.
- Tourette's syndrome is the most common cause of tics, manifested by a broad spectrum of motor and behavioral disturbances.
ETIOLOGY
Most of the tic disorders are idiopathic. The pathogenetic mechanisms of tics and Tourette's syndrome are unknown, but evidence supports an organic rather than psychogenic origin.
COMMONLY ASSOCIATED CONDITIONS
Tics may be simple or complex.
Simple Tics
- Simple tics involve only 1 group of muscles, causing a brief jerk-like movement or a single meaningless sound.
- Simple vocal tics: Throat clearing, sniffing, animal sounds (e.g., barking), coughing, yelling, hiccuping, belching
- Simple motor tics: Eye blinking, nose twitching, sticking tongue out, head turning or neck stretching, shoulder jerking, muscle tensing, flexing fingers, blepharospasm, bruxism
Complex Tics
- Complex tics consist of coordinated sequenced movements resembling normal motor acts or gestures that are inappropriately intense and timed. They may be seemingly nonpurposeful or they may seem purposeful.
- Complex vocal tics: Parts of words or phrases repeated, talking to oneself in multiple characters, assuming different intonations, coprolalia (use of profanity)
- Complex motor tics: Flapping arms, facial grimaces, picking at clothing, complex touching movements, jumping, shaking feet, pinching, poking, spitting, hair brushing
- Also classified as
- Transient (duration <12 months)
- Chronic (duration >12 consecutive months)
- Neurological examination in patients with tics is usually normal.
DIAGNOSTIC TESTS AND INTERPRETATION
Lab
Diagnosis of a tic is generally made during physical examination. If there are no other neurological findings, tics require no additional diagnostic testing. If other neurological signs or symptoms are present, further evaluation is guided by that finding.
Imaging
- Imaging studies are not needed routinely in the evaluation of patients with typical history and examination findings and are indicated only to exclude specific illnesses suggested by abnormal historical or examination findings.
- At present, no clinical utility exists for functional imaging studies in the evaluation of tic disorders.
Diagnostic Procedures/Other
Neuropsychological testing: Patients with difficulties in the school or work setting may benefit from identification of an existing learning disorder so that adaptive strategies can be devised.
DIFFERENTIAL DIAGNOSIS
MEDICATION
- DopamineD2 receptor antagonists: Chlorpromazine was reported to dramatically improve tic severity. Since then, several placebo-controlled randomized allocation studies with various neuroleptics (e.g., haloperidol, fluphenazine, pimozide) have confirmed these initial reports. On average, tic severity declines by approximately 50–80% with neuroleptic treatment.
- Haloperidol (Haldol): FDA indication for treatment of tics
- Pimozide (Orap): FDA indication for treatment of tics
- Fluphenazine (Prolixin): Effective anti-tic drug
- If these 3 drugs fail to adequately control tics, then risperidone (Risperdal), thioridazine (Mellaril), trifluoperazine (Stelazine), molindone (Moban), or thiothixene (Navane) can be tried.
- It is not clear whether some of the new atypical neuroleptics, such as clozapine and olanzapine, will be effective in the treatment of tics or other manifestations of Tourette's syndrome.
- Clonidine: This drug has been used frequently to treat tics. However, no proof exists for anti-tic efficacy after several small trials. A meta-analysis concluded that clonidine has clear efficacy. It may be most appropriate as a first agent in patients with problematic attention deficit hyperactivity disorder (ADHD) and mild tics.
- Mild-to-moderate tic disorder medications
- Pimozide is superior to Haldol in 1 double-blind study
- Fluphenazine is another good choice
- Clonidine (Catapres) 0.05 mg PO b.i.d. to 0.1 mg PO q.i.d.
- Severe tic disorder medications: Neuroleptic preparations
- Haloperidol (Haldol) 0.5–4 mg PO q.h.s.
- Pimozide (Orap) 1–8 mg PO q.h.s.
- Risperidone (Risperdal)
- Precautions
- Use the lowest dose of medication that achieves acceptable tic suppression.
- Neuroleptics may be associated with various extrapyramidal side effects, including dystonia, akathisia, and tardive dyskinesia, in up to 20% of children.
- Sedation, depression, weight gain, school phobia, tardive dyskinesia, hepatotoxicity, prolongation of QT interval with pimozide, akathisia, and acute dystonic reaction.
- Contraindications
- None of these drugs should be used if there is a known hypersensitivity.
- Pimozide is contraindicated in patients with the long QT syndrome because it may prolong the QT interval. There are a few reports of deaths when pimozide is used in conjunction with macrolide antibiotics, so this drug combination should be avoided.
- Alternative drugs
- Benzodiazepines: Retrospective reports suggest that benzodiazepines, such as clonazepam, reduce tic severity in some patients. The effect is less than that of neuroleptics and is probably nonspecific. Clonazepam (Klonopin) 0.25 mg PO b.i.d. to 1 mg PO t.i.d.
- Botulinum toxin injections in motor tics: Botulinum toxin injections may improve urges or sensory tics, as well as observable tics, and may be the treatment of choice for patients with a single, especially problematic, dystonic tic.
- Tetrabenazine: This is a presynaptic dopamine-depleting agent. It has not been reported to cause tardive movement disorders. A retrospective report noted “marked” clinical improvement in 57% of 47 patients with tics. It is not available in the US.
- Guanfacine: This agent was tested in a 2001 randomized controlled trial in children with both ADHD and chronic tic disorders. The drug showed clear superiority to placebo in reduction of both ADHD and tic symptoms, with few adverse effects. It also has been shown to be efficacious in adults with non-tic ADHD.
- An open trial using nicotine patch indicates that nicotine may suppress tics in patients not treated with D2 receptor-blocking drugs.
ADDITIONAL TREATMENT
General Measures
- The goal of treatment should not be to completely eliminate all tics but to achieve a tolerable suppression.
- First step is proper education of the patient, relatives, and teachers about the nature of the disorder.
- Counseling and behavioral modification may be sufficient for mild symptoms.
- Medication should be considered when symptoms begin to interfere with activities of daily living.
COMPLEMENTARY AND ALTERNATIVE THERAPIES
Symptomatic treatment
- Symptomatic treatment consists of behavioral management:
- Positive reinforcement
- Target behaviors
- Skill deficiencies
- Behavior excesses
SURGERY/OTHER PROCEDURES
There are a few reports of patients with severe motor and phonic tics controlled by high-frequency deep brain stimulation
IN-PATIENT CONSIDERATIONS
Admission Criteria
Admission for management of tics is rarely necessary.
FOLLOW-UP RECOMMENDATIONS
Patient Monitoring
Because a medication for tics may not have any impact on obsessions or compulsions, and medications for ADHD may worsen tics in some patients, the selection of medications and combination of medications can become quite complex in a situation with associated or comorbid conditions.
PATIENT EDUCATION
PROGNOSIS
- The prognosis for children who develop this disorder between the ages of 6 and 8 is good.
- Symptoms may last 4–6 years and then disappear without treatment in early adolescence.
- When the disorder begins in older children and there is no remission or reduction of symptoms well into the 20s, a chronic, lifelong disorder may be anticipated.
