From the Guidelines
Tics are brief, intermittent, involuntary or semivoluntary movements or sounds.
Characteristics of Tics
- Tics are typically shorter in duration than other movement disorders, such as paroxysmal kinesigenic dyskinesia (PKD) attacks 1
- They can be motor tics, which are movements, or phonic tics, which are sounds, such as coughing, throat clearing, or sniffing 1
- Tics are often characterized by their suppressibility, distractibility, suggestibility, variability, and the presence of a premonitory sensation 1
Types of Tics
- Simple tics: brief, sudden movements or sounds, such as blinking or coughing
- Complex tics: longer, more complex movements or sounds, such as vocalizations or gestures
- Phonic tics: vocalizations, such as coughing, grunting, or squeaking
Diagnosis and Treatment
- Tics are a clinical hallmark of Tourette syndrome, a neurobehavioral disorder that can also present with other symptoms, such as attention deficit disorder or obsessive-compulsive behavior 1
- Diagnosis of tics or tic disorders, such as Tourette syndrome, requires ruling out other biological or genetic disorders that may cause similar symptoms 1
- Treatment of tics may involve dopamine receptor-blocking drugs, such as haloperidol or pimozide, which have been shown to be effective in controlling tics in patients with Tourette syndrome 1
From the Research
Definition of Tics
- Tics are stereotyped repetitive involuntary movements or sounds, frequently preceded by premonitory sensations or urges 2, 3, 4
- They are characterized by sudden, rapid, recurrent, nonrhythmic movement or vocalization 3, 4
- Tics can be simple or complex, and can affect one or more muscles producing simple or complex movements 5
Types of Tics
- Motor tics: involuntary movements that can affect one or more muscles 5
- Vocal tics: involuntary sounds or vocalizations 3, 4
- Simple tics: brief, isolated movements or sounds 3
- Complex tics: longer, more complex movements or sounds 3
Pathophysiology of Tics
- Tics are thought to be related to altered neurotransmitter function within the CNS, especially dopaminergic mechanisms 3
- Dysfunction of basal ganglia-thalamo-cortical projections affects sensorimotor, language and limbic cortical circuits 5
- Abnormalities in brain GABA and dopamine function have been found in patients with Tourette Syndrome 6
Clinical Presentation and Epidemiology
- Tics often begin in childhood and can persist into adulthood 4, 6
- The onset of tics usually occurs at approximately 7 years of age 3
- Up to 10% of children have at least a transient tic disorder, and the accepted prevalence figure for Gilles de la Tourette Syndrome (GTS) is 0.05-3% 3
- Tics are frequently associated with comorbid neuropsychiatric symptoms, such as attention deficit hyperactivity disorder and obsessive compulsive disorder 3, 6