Exploring DBS Efficacy in Treatment-refractory Tourette's Syndrome

The primary purpose of this study is to investigate the effect of deep brain stimulation (DBS) in patients with Treatment-refractory Tourette's syndrome (TR-TS) implantation targeting the Antero-medial globus pallidus interna (GPi), Antero-medial globus pallidus interna (amGPi), Postero-ventrolateral GPi (pvGPi), Centromedian nucleus, substantia periventricularis and nucleus ventro-oralis internus (Cm-Spv-Voi), Centre median nucleus and nucleus ventro-oralis (Cm-Voi), or Nucleus Accumbens/ Anterior Limb of Internal Capsule (NA-ALIC), or other unreported nuclei targets.

Tourette's Syndrome (TS) is a neurodevelopmental disorder characterized by repetitive, involuntary movements and vocalizations known as tics. It typically manifests in childhood and may persist into adulthood. The prevalence of TS varies globally, affecting approximately 1% of the population. Males are more commonly affected than females, and there is a broad spectrum of symptom severity. Treatment-refractory Tourette's Syndrome (TR-TS) refers to cases where standard therapeutic interventions, such as behavioural therapy and medications, have shown limited effectiveness. TR-TS prevalence is relatively lower but highlights the challenges in managing severe and persistent symptoms. In a comprehensive survey of diverse neuromodulation therapies, targeting specific nuclei with DBS has the most potential for TR-TS with apparent symptoms. The stimulation targets of DBS for patients with obsessive-compulsive disorder include GPi, amGPi, pvGPi, Cm-Spv-Voi, Cm-Voi, and NA-ALIC. However, the DBS case reports are limited and lack high-quality, evidence-based medical evidence. So, this cohort study focuses on the effectiveness of DBS-targeted GPi, amGPi, pvGPi, Cm-Spv-Voi, Cm-Voi, NA-ALIC, or other unreported nuclei targets on TR-TS.

Another goal of this program is to study the neuronal activity of the GPi, amGPi, pvGPi, Cm-Spv-Voi, Cm-Voi, and NA-ALIC, or other unreported nuclei targets, respectively. At the same time, some subjects are presented with a task involving an unexpected reward. This separate study is an option and will not affect current study participation.

Some participants will also be invited to join a related study that involves positron emission tomography (PET) scanning to determine how the stimulation changes activity in the brain. Participation in the separate PET study is optional and will not affect current study participation.

Eligibility Criteria:
Inclusion Criteria:

1. aged 18-65;
2. able to provide written informed consent;
3. have a diagnosis of Tourette's syndrome according to the Statistical Manual of Mental Disorders-Fourth Edition-Text Revised (DSM-IV-TR) criteria and confirmed by the Mini-International Neuropsychiatric Interview Chinese version 5.0;
4. with a YGTSS of at least 35 for at least 12 months before surgery, while YGTSS- Total Motor≥15;
5. must have failed conventional medical treatment at adequate therapeutic doses of three classes of medication lasting for at least three months;
6. must not be suitable for behavioural intervention or that this intervention is inappropriate or unsuccessful;
7. have been on stable comorbid conditions without suicidal ideation for at least six months.

Exclusion Criteria:

1. presence of other psychotic disorders;
2. have a treatment history that includes electroconvulsive therapy (ECT), modified electroconvulsive therapy (MECT), transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), DBS, and transcranial magnetic stimulation (TMS);
3. presents a suicide risk (defined as a HAMD-17 score of ≥3 on suicide-related items);
4. experience difficulty in effectively communicating with investigators;
5. with a history of traumatic brain injury (TBI);
6. with intracranial or cardiovascular stents;
7. substance abuse within the past six months;
8. unstable neurological or coagulation disorders;
9. women who are pregnant, lactating, or of childbearing potential who refuse the use of reliable contraception during the study;
10. have been involved in other clinical studies within three months before enrollment in this study;
11. any conditions considered by the study group.