Challenge Case Report: Tic Disorder in an Adult

Diagnosis and Treatment

JB’s semivoluntary movements, associated with preceding urges, temporary relief, and brief suppressibility, are consistent with tics. Considering tic onset before age 18 years, the presence of multiple motor and phonic tics, tic persistence beyond 1 year, and the lack of any other possible etiology for his symptoms, JB was diagnosed with Tourette syndrome (TS). Because of the moderate severity of the tics and interference with daily life, both pharmacologic and nonpharmacologic treatments were recommended. Guanfacine was prescribed and a referral made for comprehensive behavioral intervention for tics (CBIT)/habit reversal training (HRT) for tics. JB was also referred to psychiatry for further evaluation and management of anxiety that has recently flared and contributed to tic severity.

Follow-up

At a 4-month follow-up visit, JB reported that tic severity and frequency had improved by roughly 50% with the initiation of low-dose guanfacine and completion of 4 of 8 scheduled CBIT/HRT sessions. JB had also established care with a psychiatrist, who has gradually discontinued clonazepam, and recently started working with a psychotherapist for anxiety. In general, JB was happy with the improvement in tics and felt their function at work was improved.

Discussion

Tics are semivoluntary, purposeless movements that are typically rapid, arrhythmic, and stereotyped. The movements are classically preceded by a premonitory sensation or urge and associated with relief after the tic is performed.¹ Tics are commonly temporarily suppressible, but this is often associated with a building urge to perform the tic.

TS is a neurodevelopmental disorder of unclear etiology characterized by the presence of at least 1 motor and 1 phonic tic with onset before age 18 years that lasts over 1 year, according to diagnostic criteria.² TS affects an estimated 0.3% to 1% of the population and is more common in men but occurs in all sexes/genders.² Onset of tics is typically between age 4 and 8 years. TS is often familial; first-degree relatives of individuals with tic disorders have a significantly higher risk of TS or other chronic tic disorders.^8,9

In TS, tic frequency and severity tend to wax and wane over the years, with roughly 20% of TS cases persisting into adulthood.¹⁰ Individuals have their own unique set of tics; different tics may develop or abate over the lifespan.

Comorbid attention deficit disorder (40%-60%) and OCD (20%-40%) are strongly associated with TS, occurring at rates more than 10 times higher than in the general population.^11-14 Anxiety (50%-70%) and depression (50%-60%) are frequently present as well.¹³

Clinically, tic severity and frequency can be assessed through history taking and examination. Tics can negatively affect an individual’s quality of life by causing social or emotional distress, physical discomfort, or impaired function (in work, driving, sleeping, or other activities of daily living). When tics are causing these impairments, treatment should be initiated.

The initial intervention recommended is CBIT, specifically HRT, which is typically an 8-session treatment with a trained provider based on tic awareness, development of competing response incompatible with tic execution, and relaxation training.¹⁰ Efficacy in reducing tic severity and improving quality of life has been established in randomized control trials (RCTs).^15,16

Pharmacologic therapy should be considered when behavioral therapy is not an option (owing to insurance, limited provider availability, and other barriers to access), has been completed but there is residual tic burden, or tics are severe or need to be addressed quickly. On average, medications reduce tic symptoms by 25% to 50%.¹⁷ There are 3 categories of medications for tics as follows.

Nondopaminergic Agents. The nondopaminergic alpha-2-agonists clonidine and guanfacine are first-line treatments. Clonidine has been used to treat TS for over 30 years with efficacy compared with placebo demonstrated in several RCTs.^5,6 Common side effects include sedation, bradycardia, hypotension, and dry mouth. Guanfacine has a lower risk of sedation and hypotension compared with clonidine and has also been shown to be superior to placebo in RCTs.^5,7 Topiramate, an antiseizure medication with GABAergic properties, has also been shown to effectively reduce tics in 1 clinical RCT.⁴

Dopamine Receptor Blockers. As classic dopamine receptor blockers, multiple typical and atypical antipsychotics are approved for tic treatment. Although RCT results support efficacy in tic reduction, these agents are typically reserved for severe or refractory tics owing to undesirable side-effect profiles. Antipsychotics carry the risk of tardive dyskinesia (TD), which can compound the distress and treatment complexity for people with TS.

Dopamine-Modulating Vesicular Monoamine Transporter-2 (VMAT-2) Inhibitors. The VMAT-2 inhibitors offer an alternative to antipsychotics with a better side effect profile and no risk of TD. Although the classic VMAT-2 inhibitor tetrabenazine and newer-generation deutetrabenazine and valbenazine have open-label data showing tic treatment efficacy, RCT results have not corroborated these findings and all are used on an “off-label” basis for tic treatment.^18,19

Importantly, in addition to directly addressing tic severity and frequency with CBIT and/or medications, an individual’s co-morbidities (eg, obsessive-compulsive disorder, attention deficit disorder, anxiety, or depression) should be adequately addressed (with psychiatry referral and pharmacotherapy as needed) to optimize tic improvement.