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Tourette’s Syndrome and Tics

The word "tic" has been used for at least four centuries to refer to a variety of sensory and motor conditions. For example, "tic douloureux" refers to a pain syndrome. Today, the term tic is best applied to a subgroup of movement disorders characterized by rapid and irregularly repetitive movements that usually involve the head and neck muscles, including the voice apparatus. Tics may manifest as a symptom of various different conditions and, thus, have been broadly classified.

Transient idiopathic tics are extremely common in children, with up to 13 percent of boys and 11 percent of girls manifesting tics of sufficient frequency or severity as to require medical attention. Typical age at onset is seven years. For most children, tics spontaneously resolve within one year after onset. Transient tics rarely begin after age 17, so new-onset tics in adults, especially those over age 50, should alert the physician.

Chronic idiopathic tics, which comprise the true "tic disorders," also emerge during childhood but are less prevalent than transient tics.

Classification of Tic Disorders

Idiopathic

Transient tic disorder

Chronic tic disorder (motor or vocal tics)

Tourette's syndrome (motor and vocal tics)

Adult-onset tic disorder (rare)

Symptomatic

Basal ganglia disease (e.g., Sydenham's chorea) Metabolic insults (e.g., carbon monoxide poisoning, hypoglycemia)

Drug-induced tics (e.g., amphetamines, cocaine, neuroleptics)

Congenital tics (e.g., rubella, birth anoxia, Asperger's syndrome, Rett syndrome)

Genetic tics (e.g., fragile X syndrome, Down syndrome, XYY syndrome, XXX+9p syndrome)

Psychiatric tics (e.g., schizophrenia, obsessive-compulsive disorder)

has an incidence of 59 per 10,000 persons.29 With chronic tic disorders, tics may improve during adolescence and reappear in later adulthood. In some patients, tics persist and can result in a lifetime of disability. Chronic tic disorder includes a genetic component; male first-degree relatives have up to a 30 percent higher risk.

CLINICAL PRESENTATION

Younger children are frequently unaware of tics. When brought to medical attention by a teacher or parents, the chief complaint is often termed "hyperactivity.'' Periods of inattention in these patients may be indicative of epilepsy, especially if tics.

Tics manifest as habitual behaviors or mannerisms, such as winking, facial grimacing, head-jerking or shoulder-shrugging, or, less commonly, as directed movements, such as the hand wiping the nose. Complex tics consist of a series of simple tics in succession or complicated behaviors performed repetitively. Occasionally, tics may cause self-injury, such as slapping one's own face or biting one's own hand. Vocal tics range from brief sounds, such as that made when clearing the throat.

Adults and children over age 10 may complain of a sensation, such as an itch, that creates an urge to perform the tic movement. These patients may report that although they can voluntarily suppress the tics, the effort involved in doing so creates a build-up of tension that becomes unbearable. Eventually, the tension must be "released" by performing the tic. However, the relief thus produced is only temporary, and the patient soon experiences the sensation and urge again; this process may be repeated up to several hundred times a day. Tics often occur in bouts throughout the day, with exacerbations developing during periods of anxietyor public exposure and momentary relief during relaxed or pleasurable activities. Tics occur less frequently during a febrile illness or with alcohol intake.

Patients with tics may have associated behavioral disorders that compound the level of disability caused by the tics. Attention-deficit/hyperactivity disorder, obsessive-compulsive disorder and affective disorders are common comorbid conditions. Thus, obtaining a comprehensive medication history is particularly important for both children and adults who present with tics. Methylphenidate (Ritalin) may have been prescribed for a child with a tic disorder in an attempt to control the hyperactivity and inattention that often accompany tics. However, use of this stimulant may worsen tics.

Differential Diagnosis of Tic Disorders in Adults

Disorder

Body part affected

Clues to diagnosis

Blepharospasm

Bilateral eyelids

Bilateral blinking or closing of eyes

Hemifacial spasm

Unilateral facial muscles

Limited to one side of the face

Focal epilepsy

Any body part

Rhythmic pattern, presence of an aura, characteristic EEG findings

Myoclonus

Arms, trunk

Jerks occur singly

Tremors

Head, limbs (upper more than lower)

Tremors are continuous

Huntington's chorea

Trunk, limbs

Movements are not suppressible, positive family history

Sydenham's chorea

Trunk, limbs

Movements are not suppressible, antecedent streptococcal infection, positive ASO titers

Athetosis

Trunk, proximal limbs

Slow writhing movements

Akathisia

Limbs more than trunk

Pacing, getting in and out of a chair, etc.

Dystonias

Neck, limbs

Fixed abnormal postures

Tardive dyskinesia

Mouth, tongue

History of drug exposure

Hemiballismus

Proximal limbs (upper more than lower)

Abnormal MRI results in subthalamic region

Wilson's disease

Proximal limbs (upper more than lower)

Positive family history, characteristic blood and urine copper study findings, Kayser-Fleischer rings

TOURETTE'S SYNDROME

In 1885, Gilles de la Tourette published the first reports of patients exhibiting "... motor incoordinations and ... inarticulate shouts accompanied by articulated words with echolalia and coprolalia .... ' Tourette's syndrome begins in early childhood with simple motor tics that are limited to a single muscle group, such as eye-blinking or head-jerking. Within one year after onset, complex motor tics appear, consisting of more elaborate facial grimacing and shoulder and hand movements. Repetition of one's own behaviors (palimimia) and imitation of others' behaviors or movements (echomimia).