Tics are involuntary and repetitive sounds (vocal tics) or movements (motor tics) that can be rapid, sudden, recurrent, and nonrhythmic .
They are due to an urge or sensation that eases after performing the movement or the sound.
1. What Are the Types of Tics?
1.1. Primary Tics
- Transient tic disorder
Transient tic disorders are motor or vocal tics that last for less than a year.
- Chronic tic disorder
Chronic tic disorders are motor or vocal tics that last for more than a year.
- Adult-onset tic disorder
Adult-onset tic disorder is a recurrent childhood tic disorder; however, this subtype can be classified as a secondary tic disorder if it is due to acquired conditions such as encephalitis or head trauma .
- Tourette syndrome
It is characterized by both vocal and motor chronic tics that are sudden and repetitive such as blinking, clearing throat, grunting, or facial movements .
The genetic causes of Tourette’s Syndrome are unknown; however, some cases are associated with mutations in genes such as SLITRK1, CNTNAP2, and HDC.
SLITRK1 is a protein found in the membrane of neurons where it is involved in the regulation of synapses.
CNTNAP2 is a protein found in the membrane of the neurons where it plays a role in axons, while HDC is an enzyme involved in the function of the neurotransmitter histidine.
1.2. Secondary Tics
Secondary tics can be associated with the following disorders and conditions:
- Global Brain Developmental Disorder
This disorder is due to neurodevelopmental anomalies that lead to delays in the development of social and communication skills, such as autism, mental retardation (intellectual disability), and Pervasive developmental disorders (PDD).
Examples of infections that affect the nervous system such as:
It is an inflammation of the brain caused by a viral infection.
Creutzfeldt-Jacob disease is a progressive neurodegenerative disease affecting the brain and causing cognitive disorders such as memory loss, changes in behavior, and ataxia (uncoordinated movements)
The disease is due to the accumulation of a glycoprotein known as a prion, which functions in the brain are not well known .
Post-streptococcal disorders are autoimmune disorders that happen following infections with a type of bacteria known as Staphylococcus pyogenes.
- Genetic and Neurodegenerative Diseases
Neuroacanthocytosis is a group of genetic disorders characterized by anomalies of red blood cells (acanthocytosis) and movement disorders .
Hallervorden-Spatz syndrome is a rare neurodegenerative disease characterized by the accumulation of iron in a part of the brain known as basal ganglia causing its damage .
Carbon monoxide poisoning .
- Brain injury
- Immune Disorders of the Central Nervous System (CNS)
Antiphospholipid Antibody Syndrome
This syndrome is characterized by the production of antibodies against phospholipids in the body which increases the risk of blood clots and thrombosis .
Sydenham’s Chorea is a neurological disorder that affects children after an infection with a group A beta-hemolytic streptococcus (GABHS) .
- Psychiatric Disorders
Schizophrenia is a complex and severe mental health disorder that is classified as a type of psychosis. It is characterized by significant alterations in thoughts, perception, mood, and behaviors .
Psychogenic tics are characterized by the sudden onset of brief motor tics that are due to an urge or sensation that can be suppressed. Psychogenic tics can be due to the body’s response to stress .
2. What Are the First Signs of Tics?
The initial evaluation of tics is difficult as other disorders may have similar signs such as attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), dyskinesis, stereotypies, or tourettism .
3. Do Tic Disorders Go Away?
An improvement in individuals affected by tics is generally observed by adolescence or early adulthood; therefore, waiting for a period of time can lessen the severity of the tics.
4. How Are Tics Treated?
Most individuals with tics do not seek treatment and education of the affected individual, family, and school environment (e.g., school personnel) about the causes of tics is the initial intervention .
This educational approach can prevent such as embarrassment, bullying, anger, self-harm, and social isolation.
- Non-pharmacological treatment
The aim of this therapy is to help the affected individuals to manage their tics and reduce their severity.
This intervention involves awareness training and competing response training.
The awareness training request from the affected individual to name the tic loud, while in the competing response training, the affected individual learns to do a new behavior every time the tic manifests .
- Pharmacological treatment
Although most prescribed medications for tics are not approved by the US FDA (Food and Drug Administration), Tics-suppressing medications such as alpha-2-agonists, dopamine blocking agents, are used for severe cases of tics to help individuals with tics with their daily life .
Tic disorders can be primarily associated with Tourette’s syndrome but can also be related to physical and mental disorders, brain injury, drugs, or intoxications. Fortunately, an improvement in individuals affected by tics is generally observed by adolescence or early adulthood. Meanwhile, some of the affected individuals may suffer from embarrassment, bullying, and isolation, due to a lack of education on the causes of tics.
Therefore, is essential that the affected individual learn how to manage the tics in everyday life to reduce associated discomfort, stress, and anxiety.
The education of the family and people in close contact with the affected individual can also significantly reduce embarrassment and bullying through better understanding the difficulties facing an individual with a tic disorder.