Tourette Syndrome - Initial Diagnosis

Page Contents

• Overview
• Presentations
• Diagnostic Criteria
• Practice Guidelines
• Differential Diagnosis
• History And Examination
• Resources

Overview

Tourette syndrome (TS) is a clinical diagnosis for which there is no test available. Mild TS is possibly as common as 1 in 100 people and related chronic motor or vocal tic disorders (that don't meet all the clinical criteria for TS) are even more common (and commonly overlooked). Transient tics are a very common phenomenon, occurring in up to 1 in 4 children, but typically are mild and short-lived. A detailed medical history and physical exam should include overall assessment of the tics and their impact on academic, social, organizational, family, and general health functions. Careful questioning for co-morbid conditions is critical. The relative impact of co-morbid factors on self-esteem and quality of life should be defined.

Presentations

The tics in TS typically first emerge between 4 and 7 years of age and, over time, may evolve from simple to complex and from just motor to motor and/or phonic. Associated behavioral or neurodevelopmental conditions may precede, occur with, or begin after the tics have emerged.

Diagnostic Criteria

There is no diagnostic test to confirm TS. The following criteria from the DSM-IV-TR ([American: 2000]) must be met to make a diagnosis of TS:

• both multiple motor tics and one or more vocal tics have been present at some time during the illness, although not necessarily concurrently; (A tic is a sudden rapid, recurrent, nonrhythmic, stereotyped motor movement or vocalization.)
• the tics occur many times a day (usually in bouts) nearly every day or intermittently throughout a period of more than 1 year, and during this period there was never a tic-free period of more than 3 consecutive months;
• the onset is before age 18 years; and
• the disturbance is not due to the direct physiological effects of a substance (e.g., stimulants) or a general medical condition (e.g., Huntington disease or post-viral encephalitis).

Most patients with TS (>90%) have one or more associated behavioral or neurodevelopmental conditions. These conditions may include:

• ADHD (in approximately 50%);
• OCD (in approximately 30%);
• Learning problems (in approximately 20%);
• Anxiety (in approximately 30%);
• Sleep problems;
• Depression;
• Anger dysregulation; and
• Pervasive developmental disorders, including autism and Asperger syndrome.

Practice Guidelines

Scahill L, Erenberg G, Berlin CM Jr, Budman C, Coffey BJ, Jankovic J, Kiessling L, King RA, Kurlan R, Lang A, Mink J, Murphy T, Zinner S, Walkup J.
Contemporary assessment and pharmacotherapy of Tourette syndrome.
NeuroRx. 2006;3(2):192-206. PubMed abstract

Differential Diagnosis

• Other tic disorders: Chronic non-TS tic disorders have either motor or vocal tics, but not both. They may be just as disturbing or disabling as TS. Transient tic disorders of childhood resolve completely within one year of onset. TS may remit for weeks to months but generally returns. It is difficult to differentiate these tic disorders without benefit of hindsight, as chronic motor tics without vocal tics may later evolve into bona fide TS. These categorical distinctions likely reflect our incomplete understanding of chronic tic disorders, or that these are simply arbitrary distinctions of conditions along a spectrum of symptoms and severity.
• Seizures: Generalized seizures are accompanied by a loss of consciousness, while complex partial seizures are associated with alterations in consciousness and responsiveness. Some partial seizures could be mistaken for tics, but these are generally not suppressible and are not preceded by a premonitory urge. Eyelid flickering (myoclonus) seen with absence seizures could resemble tics but in absence seizures there is loss of consciousness, no suppressibility, and no premonitory urge.
• Substance exposure: Psychiatric medications are unlikely to cause tics but they can be associated with other movement problems, such as restlessness. Stimulant medications do not cause tics, although in a minority of patients they may exacerbate them. Tics have been reported with carbamazepine and rarely other medications. Prolonged use of some neuroleptics may result in tardive dyskinesia, a neurologic syndrome which manifests as many kinds of repetitive purposeless movements, some of which may appear tic-like. These may include lip-smacking, grimacing, and rapid eye-blinking, and may occur in the extremities as well as the face. Medication adjustments are usually necessary when tardive dyskinesia is noted.
• Spasms: Muscle spasms, such as blepharospasms or spasmodic torticollis, may be confused with TS, but the characteristics of tics in TS should allow differentiation.
• Stereotypies are repetitive movements, postures, or utterances and are frequently seen in children with Pervasive Developmental Disorders or Rett syndrome, but can also be observed in typically developing children. Examples include hand-flapping, rocking, and twirling. Among children with communication limitations, stereotypies and complex tics may be indistinguishable.
• Postviral encephalitis: Differentiated by history.
• Sydenham chorea is a neurological disorder of childhood resulting from an auto-immune reaction to infection with Group A beta-hemolytic streptococcus (GABHS), which also causes rheumatic fever. This condition is characterized by involuntary movements of the face, arms, and legs, as well as clumsiness, emotional volatility, and difficulty concentrating. It is typically seen in children from about 5 to 15 years old, affects girls more than boys, and may appear from several weeks to many months after strep infection. There is no treatment, and the chorea usually resolves after weeks to months. Symptomatic management of chorea is rarely necessary.
• PANDAS, an acronym for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections, is perhaps best described as a somewhat controversial currently theoretical construct. It is postulated as either 1) a dramatic increase in symptoms in children already known to have tics or obsessive compulsive symptoms or 2) as an appearance of such symptoms in children without prior history, following a Group A beta-hemolytic streptococcal infection. See the DSM IV-TR [American: 2000] for more information. No diagnostic criteria are uniformly accepted as definitive for this putative condition.
• Wilson disease is an autosomal recessive genetic disorder that prevents the body from disposing of extra copper leading to a buildup of copper in the brain and/or the liver. Physical exam findings due include tremor and tic-like movements, incoordination of speech, swallowing, and gait, and behavioral changes. If the liver is also involved, jaundice, ascites, and other systemic symptoms may be present. Physical exam findings also include Kayser-Fleischer rings due to copper accumulation in the eye. Laboratory findings show decreased copper and ceruloplasmin levels in the blood, increased urinary excretion of copper, and copper accumulation in the liver. Since Wilson disease is treatable, there should be a low threshold for screening for this disorder by measuring serum ceruloplasmin, which is low in Wilson disease. If abnormal, more accurate testing is performed by measuring copper levels in a 24h specimen of urine, blood or in a sample obtained by liver biopsy.

History And Examination

Resources

Authors

Page Bibliography

American Psychiatric Association.
Diagnostic and Statistical Manual of Mental Disorders DSM-IV-TR (Text Revision).
4th edition (June 2000) ed. Washington, DC: American Psychiatric Association; 2000. 0890420254