2-Minute Neuroscience: Tourette Syndrome

Summary

Tourette syndrome is a neurological disorder characterized by involuntary movements or sounds known as tics. These tics can be simple or complex, with complex tics including actions like involuntary use of obscene language (coprolalia), which occurs in less than 20% of cases. The disorder is thought to involve the basal ganglia, structures in the brain responsible for inhibiting unwanted movements. In Tourette syndrome, faulty inhibition in the basal ganglia leads to uncontrolled actions. The combination of increased motor activity and reduced inhibition is believed to underlie the tics, but further research is needed to fully understand the disorder's neural mechanisms.

Takeaways

• 😀 Tourette syndrome is characterized by involuntary movements or sounds called tics.
• 😀 Tics are classified into simple and complex types, with simple tics involving one muscle group and complex tics being more elaborate.
• 😀 Simple tics can include actions like eye blinking or throat clearing.
• 😀 Complex tics can involve more complicated actions, such as reaching to touch something or using obscene language (coprolalia).
• 😀 Coprolalia occurs in less than 20% of cases of Tourette syndrome.
• 😀 The neuroscience of Tourette syndrome is not fully understood, but the basal ganglia are believed to play a key role.
• 😀 The basal ganglia, which include the caudate, putamen, globus pallidus, substantia nigra, and subthalamic nucleus, are involved in controlling movement and suppressing unwanted actions.
• 😀 The basal ganglia are hypothesized to help inhibit neurons in the thalamus from sending unwanted movement signals to the motor cortex.
• 😀 In Tourette syndrome, faulty inhibitory mechanisms in the basal ganglia may lead to the execution of movements that the patient wishes to suppress.
• 😀 The disorder may result from a combination of high motor activity that generates habitual behavior patterns and low inhibitory activity that fails to suppress those behaviors.
• 😀 More research is needed to fully understand the neural circuitry underlying Tourette syndrome.

Q & A

What is Tourette syndrome characterized by?

Tourette syndrome is characterized by recurrent involuntary movements or sounds known as tics.

How are tics in Tourette syndrome classified?

Tics in Tourette syndrome are classified into two types: simple and complex. Simple tics involve one group of muscles, while complex tics are more elaborate.

Can you give examples of simple tics?

Simple tics may include actions like eye blinking or throat clearing.

What are complex tics in Tourette syndrome?

Complex tics are more elaborate and may involve actions like reaching out to touch something or the involuntary use of obscene language, known as coprolalia.

How common is coprolalia in individuals with Tourette syndrome?

Coprolalia, the involuntary use of obscene language, is associated with Tourette syndrome but occurs in less than 20% of cases.

What is the role of the basal ganglia in Tourette syndrome?

The basal ganglia are thought to play an important role in Tourette syndrome, particularly in their hypothesized role in suppressing unwanted actions.

What brain structures make up the basal ganglia?

The basal ganglia include the caudate, putamen, globus pallidus, substantia nigra, and subthalamic nucleus.

How are the basal ganglia involved in movement control?

The basal ganglia are involved in inhibiting neurons in the thalamus, preventing them from sending undesired movement-related signals to the motor cortex, which helps control voluntary movement.

What happens when the basal ganglia’s inhibitory mechanisms fail in Tourette syndrome?

When inhibitory mechanisms in the basal ganglia fail, unwanted signals reach the cortex, causing movements or actions (tics) that the individual might prefer to suppress.

What is the relationship between motor activity and inhibition in Tourette syndrome?

In Tourette syndrome, there is an abnormal combination of high motor activity generating habitual movements and low inhibitory activity that would normally prevent these movements, leading to tics.

Is the exact neural circuitry underlying Tourette syndrome fully understood?

No, the exact neural circuitry underlying Tourette syndrome is not fully understood, and more research is needed to clarify it.