Modulation of Sense of Agency With Non-invasive Brain Stimulation and Mindfulness-based Stress Reduction Therapy

Modulation of the Sense of Agency Across Different Neurological Disorders Using Non-invasive Brain Stimulation and Mindfulness-based Stress Reduction Therapy

A conversion disorder is a dysfunction of the nervous system in which no structural damage can be demonstrated. However, it must be distinguished from other psychiatric disorders such as psychosis or depression. There are a variety of signs of the disease, such as muscle paralysis, uncontrolled tremors or cramps. In rarer cases, blindness, deafness or numbness may occur. Diagnosing this complex disorder has always been a challenge for neurologists and psychiatrists.

This study investigates the effects of transcranial magnetic stimulation (TMS) on the general well-being and symptoms of conversion disorder and other neurological disorders and in comparison to healthy subjects. The TMS method allows to target specific areas of the brain by means of magnetic fields. This technique is not painful and does not have long-lasting effects.

In addition, the study investigates the effects of mindfulness-based stress reduction on the general well-being and symptoms of conversion disorder and other neurological disorders and compared to healthy subjects. This technique is not painful and has no long-lasting effects.

Furthermore, the study examines movement patterns and symptoms of patients compared to healthy controls while they are in a virtual reality.

Finally, the study examines patients' brain activity while playing a game targeting the sense of agency in real time, which is recorded with an MRI scanner.

The study includes a maximum of twelve sessions in total (ten sessions of approximately 1.5-2 hours each and two sessions each overnight). The planned study methods include TMS, (real-time and normal) magnetic resonance tomography of the brain (MRI "tube"), virtual- and augmented reality (AR/VR), questionnaires, blood, saliva, and motion sensors (e.g., fitness bracelet), and participation in the 8-week mindfulness program.

Inclusion Criteria:

Patients:

• A diagnosis of a functional disorder (such as FND, GTS, PPD, anxiety or depression or others) according to DSM-5 diagnostic and ICD-11 criteria, or
• A diagnosis of an organic neurological disorder such as stroke, multiple sclerosis (MS), neuromuscular, or movement disorder
• Aged > 16 years old
• Willing to participate in the study (by signing the ICF)
• Capable of judgement

healthy controls:

• Aged > 16 years old
• Willing to participate in the study (by signing the ICF)
• Capable of judgement

Exclusion Criteria:

• Presence of comorbid psychiatric disorders such as psychosis, current major and severe depression episode, autistic spectrum disorder
• Past surgery in the brain
• History of alcohol or drug abuse
• Botulinum toxin injection in last 3 month
• Inability to follow the procedure of the study, e.g., due to language problems
• For organic disorders only: Active severe aphasia, dementia, neglect and acute confusional state, severe pain
• For female participants: breastfeeding, pregnancy or intention to become pregnant (assessed with standard urine test prior to the enrolment in the experiment and before each visit)
• For MRI and TMS part only: Past surgery in the brain
• For MRI and TMS part only: Implanted medical devices not-compatible with MRI or TMS (e.g., cochlear implants, infusion pumps, neurostimulators, cardiac pacemakers)
• For TMS part only: History of actual or suspected epilepsy
• For TMS part only: Suspected or diagnosed labile or hypertensive blood pressure
• For Virtual Reality only: No cybersickness