Table of Contents

• What is [18F]-ALTANSERIN?
• Purpose of the Study
• How is [18F]-ALTANSERIN Used?
• Eligibility Criteria
• Study Objectives
• Potential Benefits

What is [18F]-ALTANSERIN?

[18F]-ALTANSERIN is a special type of medication called a radiotracer. It’s not a treatment for any disease, but rather a tool used in medical imaging to help researchers and doctors understand certain brain functions better.^[1]

This substance is designed to bind to specific receptors in the brain called serotonin 5-HT2A receptors. Serotonin is a chemical messenger in the brain that plays a role in mood, behavior, and other brain functions. By attaching to these receptors, [18F]-ALTANSERIN allows researchers to see how these receptors are distributed and functioning in the brain using a special imaging technique called Positron Emission Tomography (PET).^[1]

Purpose of the Study

The main purpose of using [18F]-ALTANSERIN in this study is to investigate its potential in understanding Tourette Syndrome, also known as Tourette Disorder or Gilles de la Tourette’s disorder. Tourette Syndrome is a condition that causes people to make involuntary sounds or movements called tics.^[1]

Specifically, researchers are interested in understanding how the serotonin system in the brain might be involved in controlling impulsivity in people with Tourette Syndrome. Impulsivity refers to acting without thinking about the consequences, which can be a challenge for some people with this condition.^[1]

How is [18F]-ALTANSERIN Used?

[18F]-ALTANSERIN is administered as an injection. Here’s what you can expect if you participate in this study:^[1]

• The radiotracer will be injected into your arm through a small tube called a catheter.
• The injection will continue for about 2 hours before the imaging begins.
• The dose is calculated based on your body weight, approximately 2.6 MBq/kg (megabecquerels per kilogram) with a 10% variation.
• You will have two PET scans during the study: one when you’re not taking any neuroleptic medication (a type of medication often used to treat Tourette Syndrome), and another when you’re on a stable dose of neuroleptic medication.

Eligibility Criteria

To participate in this study using [18F]-ALTANSERIN, you need to meet certain criteria. Here are some of the key requirements:^[1]

• You must be diagnosed with Tourette Disorder according to the DSM-5 (a manual used by healthcare professionals to diagnose mental health conditions).
• You should be between 18 and 65 years old.
• You must be a member of a social security scheme in France.
• You need to provide informed consent, which means you understand and agree to participate in the study.
• You should already have a scheduled treatment with a medication called aripiprazole.
• Your tics should be manageable enough to allow you to undergo PET and fMRI scans.
• If you’re a woman, you must use effective contraception throughout the study.

There are also conditions that would prevent you from participating, such as having certain psychiatric conditions, taking drugs that affect serotonin (like some antidepressants), or having medical devices that are not compatible with MRI or PET scans.^[1]

Study Objectives

The researchers have several goals for this study using [18F]-ALTANSERIN:^[1]

1. To understand how the availability of serotonin 5-HT2A receptors in the brain relates to changes in impulsivity in adults with Tourette Syndrome when they start treatment.
2. To explore how these receptors relate to other behavioral changes in people with Tourette Syndrome during treatment.
3. To investigate how brain activity (measured by fMRI) relates to changes in impulsivity and other behaviors in people with Tourette Syndrome during treatment.

Potential Benefits

While [18F]-ALTANSERIN itself is not a treatment, the information gathered from this study could potentially lead to several benefits:^[1]

• Better understanding of how Tourette Syndrome affects the brain, particularly in relation to impulsivity.
• Insights into how current treatments for Tourette Syndrome work at a brain level.
• Potential development of new treatments that target the serotonin system to help manage symptoms of Tourette Syndrome.
• Improved methods for diagnosing and monitoring Tourette Syndrome using brain imaging techniques.

It’s important to note that this is a research study, and the direct benefits to participants may be limited. However, the knowledge gained could help many people with Tourette Syndrome in the future.^[1]