Causes and Development of Tourette Syndrome in Humans

What is Tourette syndrome?

Tourette Syndrome commonly known as Tourette's is a kind of Neuropsychiatric disorder that causes people to make certain movements or sounds called tics that they couldn't control. A tic is an involuntary body movement or vocal sound that is repeatedly made, rapidly and suddenly. It is a kind of Dyskinesia, which is the general medical term given to impairments of voluntary movements. Some identified tics are blinking of eyes, coughing, throat clearance, etc. Tics begin before the age of 18 yrs typically between 4-6 years, remains at its peak and decreases during adolescence. However, most tics disappear, but in 1% population tic persists in adulthood.

Types of Tics

Generally, There are two kinds of tics present:

• Motor Tics are movements which include arm or head jerking, blinking of eyes, making of face, etc. Complex motor tics involve multiple muscle groups that tends to be slower and purposeful in appearance (e.g: hopping, jumping, etc.) and

• Vocal Tics or phonic tics are sounds which include throat clearing and Yelping. Complex vocal tics are words that may or may not be recognisable but that consistently occur out of text (e.g.: Swear Words, ethnic slurs, etc.)

Symptoms of Tourette Syndrome

The main symptoms of Tourette syndrome are the tic. Some of the symptoms are so mild that they are not noticeable while others happen often and are quite common. Stress, excitement, sick can make the symptoms worse.

Medications for tics is not necessary. Education is an important part of the treatment plan. In other words, explanation and reassurance alone are often sufficient treatment. Many individuals bearing Tourette disease go undiagnosed and never seek any medical cure.

Conditions Associated with Tourette Syndrome

The most common condition of Tourette syndrome connected with half of the children's are Attention Deficit Hyperactivity Disorder (ADHD) and Obsessive Compulsive Disorder (OCD). Both of these disorders were observed before school age. In addition, Also individuals with Tourette Syndrome may also have depression, anxiety and several behavioural changes.
Developmental disability is not a feature of Tourette Syndrome, However, ADHD can disrupt learning process in children specially in the poor grade.

Causes of Tourette Syndrome

The actual cause of Tourette syndrome is not known, however, evidence suggests that both genetic and environmental factors are involved. A person with Tourette syndrome has about 50% chance of passing the gene to one of his or her children, but Tourette is a condition of variable expression and incomplete penetrance. Thus not everyone who carries the genetic vulnerability will show symptoms, and the people in the same family may show different symptoms.

Environmental exposures during the prenatal period, perinatal stages and postnatal life can contribute to the development and course of Tourette Syndrome. Perinatal events like mental stress, maternal smoking and obstetric complications may lead to increase the severity of tics which leads to Tourette's disease.

Chemicals in the brain that are responsible for nerve impulse transmission may also be involved in such syndrome. These agents are known as Neurotransmitters. They include Dopamine, serotonin and norepinephrine.
Childhood infection (Streptococcal infection) may be one of the causes of Tourette syndrome. To fight infection the immune system produces antibodies which interact with brain tissue thereby affecting the normal develpment of the brain.

The pathophysiology of Tourette syndrome indicates that the tics are a result from dysfunction in cortical and subcortical regions, the thalamus, the basal ganglia and frontal cortex.

Diagnosis of Tourette Syndrome

The first step in confirming the diagnosis of Tourette syndrome is to rule out all the possible causes of child's symptoms. These symptoms include allergies if they are sniffing and coughing and vision problem if they are blinking more than usual.

It is quite necessary to find out other symptoms that cause tic-like behaviours. These symptoms include learning behaviour, involuntary muscle spasms, etc.
Treatment of Tourette Syndrome

In general, there is no cure for Tourette syndrome. In fact there are many techniques that are used to manage the tics that are caused due to the syndrome. However, medications and treatments are available if the symptoms of tics are pain or injury, interfere with school or social life, etc. Education is one of the most important treatments of this disease.