Tic Disorders 8/3/2017

A tic is defined as a sudden, rapid, non-rhythmic, repetitive movement. There are motor tics and vocal tics. Examples of motor tics include: eye blinking, grimacing, nose wrinkling, tongue protruding, shoulder shrugging, head rolling and body writhing. Examples of vocal tics include: throat clearing, sighing, smacking sounds, sucking sounds, coughing and hiccupping. Sometimes it can be difficult to distinguish between a tic and a compulsion or a tic and an involuntary movement that is a side effect of a medication. A compulsion is linked directly with an obsessive worry and is done to relieve anxiety, unlike a tic.

It is also important to assess for other medical conditions, including Huntington’s disease, Wilson’s disease, substance abuse, and head trauma, which can cause tics. Patients with developmental disorders can sometimes present with stereotypic movements, which are tic-like mannerisms that have a soothing effect. Many patients with tics report that they do not know when the tic is coming on, whereas others report a premonition.

Tourette syndrome is defined as multiple motor and vocal tics at some time during the course of the illness, beginning before age 18, that cannot be explained by another medical condition. The tics have to be occurring mostly daily for at least one year, but concurrent motor and vocal tics are not required for the diagnosis. Chronic tic disorder is defined as either multiple motor or vocal tics, but not both, at some time during the course of the illness for a period of at least one year. Transient tic disorder is defined as multiple motor and/or vocal tics occurring most days for at least 2 weeks but not for longer than 12 consecutive months.

When assessing for a tic disorder it is important to ask about onset and course of symptoms, current severity of motor and vocal tics, presence of premonitory sensations and capacity for tic suppression, overall burden caused by the tics, and previous treatments. Symptoms checklists can be useful during the assessment process.

There are no lab studies or imaging studies that are useful for diagnostic purposes of Tourette syndrome but some may have a role of rule out possible medical causes of the tics. Co-morbid disorders include Attention-Deficit/Hyperactivity Disorder (ADHD), Obsessive-Compulsive Disorder (OCD), learning disabilities (LD) and other behavioral difficulties. In many cases, these co-occurring disorders may be of greater clinical importance than the tics symptoms, and therefore drive the treatment.

Medication treatments for tic symptoms include: alpha-agonists, atypical antipsychotics, and traditional antipsychotics. The alpha-agonists include clonidine (01.mg-0.4mg) and guanfacine (1-4mg), both of which have been used for years for the treatment of tics. The primary side effects to monitor include sedation, hypotension, and dry mouth. It is important to caution patients to not stop the medication abruptly because it could result in rebound hypertension. In the atypical antipsychotic class, the agents with stronger dopamine blockade, like risperidone (0.5-3mg/day), are more effective for treatment of tics. With these agents, the most concerning side effects include metabolic effects, weight gain, and sedation. In the traditional antipsychotic class, haloperidol (1-4mg/day) and pimozide (2-8mg/day) have been well studied for treatment of tics, with primary side effects including sedation and extrapyramidal movements. In general, medication may not be indicated for mild tics, and clonidine or guanfacine might be a good first line agent for moderate tics, given the potential side effects of the antipsychotic agents.

Treatment for co-morbid disorders will not be discussed in detail here, but it is important to address treatment of co-morbid ADHD and a tic disorder. There is some evidence that the stimulant medications, which are used typically to treat ADHD, can worsen tics. Therefore, it might be worthwhile to first try clonidine or guanfacine (both available now in extended-release forms) to treat both the ADHD and tic disorder, but it also can make sense to try a stimulant to treat the ADHD, particularly if it is more impairing for the patient. Another option is to use a stimulant as the primary treatment for the ADHD and adjunctive guanfacine or clonidine for the tic disorder. Alternatives include other non-stimulants, like atomoxetine or bupropion.

Non-pharmacological treatments for tic disorders include cognitive behavioral therapy, specifically habit reversal, which helps patients become more aware of premonitions and improve tic suppression.

It is our hope that this primer on tic disorders is helpful for providers in the primary care setting.



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