Neural Mechanisms of the Sensorymotor Circuit in Sensory Phenomena in OCD

Official title

Neural Mechanisms of the Insula-Supplementary Motor Area Circuit in Sensory Phenomena in Obsessive-Compulsive Disorder

Overview

The goal of this clinical study is to investigate the neural mechanisms of abnormal sensory phenomena in patients with Obsessive-Compulsive Disorder and to evaluate whether modulation of the insula-supplementary motor area circuit can improve these symptoms. The study will include adult patients with OCD (with or without sensory phenomena) and healthy volunteers. The main questions it aims to answer are: * Do patients with OCD show abnormal activity in the insula-SMA circuit compared with healthy controls? * Is this abnormality associated with the presence and severity of abnormal sensory phenomena? * Can low-frequency rTMS targeting the Supplementary Motor Area improve sensory phenomena and obsessive-compulsive symptoms? Researchers will compare an on-line rTMS group (viewing body-focused videos during stimulation) with an off-line rTMS group (resting during stimulation) to evaluate whether task engagement enhances treatment effects. Participants will: * Complete clinical assessments and behavioral tasks. * Undergo EEG and fMRI assessments. * Receive low-frequency rTMS targeting the Supplementary Motor Area. * Repeat assessments after the intervention.

Detailed description

Phase 1:

This part adopts a cross-sectional design. A total of 30 patients with Obsessive-Compulsive Disorder with sensory phenomena, 30 OCD patients without sensory phenomena, and 30 healthy controls will be recruited. Clinical assessments will be conducted, including evaluation of the severity of sensory phenomena, as well as obsessive-compulsive, depressive, and anxiety symptoms. Resting-state functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) data will be collected. In addition, during a body-focused video task designed to activate the insula-SMA circuit, task-based fMRI-EEG data will be simultaneously acquired.

Phase 2:

This part adopts a randomized parallel controlled design. Based on the 30 OCD patients with sensory phenomena included in Phase 1, an additional 30 patients will be recruited, resulting in a total of 60 OCD patients with sensory phenomena. After completing baseline clinical scale assessments, behavioral tasks, fMRI, and EEG data collection, participants will be randomly assigned to an on-line group or an off-line group. Both groups will receive low-frequency repetitive transcranial magnetic stimulation (rTMS) targeting the Supplementary Motor Area for six consecutive days, with five sessions per day. In the on-line group, participants will watch body-focused sensory videos during each stimulation session, whereas the off-line group will remain at rest during stimulation. After completion of the intervention, clinical scale assessments, behavioral tasks, and fMRI and EEG data collection will be repeated.

Interventions

• Device repetitive transcranial magnetic stimulation (rTMS)
  Repetitive transcranial magnetic stimulation (rTMS) will be delivered at 1 Hz with a total of 1,200 pulses per session, administered five times per day for six consecutive days. Target localization will be based on each participant's T1-weighted structural MRI, using a neuronavigation system to establish an individualized head model and identify the Supplementary Motor Area. The stimulation intensity will be set at 110% of the individual resting motor threshold (RMT).

Primary outcome measures

• Change in Yale-Brown Obsessive Compulsive Scale(Y-BOCS) score [Time frame: Up to 6 days]

Secondary outcome measures (8)

• Change in Sensory Phenomena Scale (SPS) score [Time frame: Up to 6 days]
• Change in Beck Depression Inventory(BDI) score [Time frame: Up to 6 days]
• Change in Beck Anxiety Inventory (BAI) score [Time frame: Up to 6 days]
• Change in Perceived Stress Scale(PSS) score [Time frame: Up to 6 days]
• Change in Obsessive-Compulsive Inventory-Revised (OCI-R) score [Time frame: Up to 6 days]
• Change in Obsessive Beliefs Questionnaire (OBQ) score [Time frame: Up to 6 days]
• Change in Intolerance Of Uncertainty Scale (IUS-12) score [Time frame: Up to 6 days]
• Change in Intolerance Of Not Just Right Experiences Questionnaire Revised, (NJRE-Q-R) score [Time frame: Up to 6 days]

Eligibility criteria

Inclusion criteria

OCD with abnormal sensory phenomena

• Meet the diagnostic criteria for Obsessive-Compulsive Disorder according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
• Aged 18-55 years.
• Score ≥16 on the Yale-Brown Obsessive Compulsive Scale, indicating moderate to severe symptoms.
• Score >6 on the Sensory Phenomena Scale (SPS), indicating moderate to severe sensory phenomena.
• Right-handed.
• Either medication-free or on stable medication for at least 8 weeks.

OCD without abnormal sensory phenomena

• Meet the diagnostic criteria for Obsessive-Compulsive Disorder according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
• Aged 18-55 years.
• Score ≥16 on the Yale-Brown Obsessive Compulsive Scale.
• Score ≤6 on the Sensory Phenomena Scale (SPS).
• Right-handed.
• Either medication-free or on stable medication for at least 8 weeks.

Exclusion criteria

• Meeting diagnostic criteria in Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition for psychiatric disorders other than OCD or obsessive-compulsive personality disorder.
• OCD symptoms so severe that required assessments cannot be completed.
• Presence of severe suicidal ideation or high suicide risk.
• Pregnant women or women planning pregnancy in the near future.
• History of epilepsy or any medical condition that may induce seizures or intracranial hypertension.
• Contraindications to MRI, such as metallic implants.
• Clinically significant medical illnesses or abnormal laboratory findings.
• Inability to complete study procedures due to severe symptoms, low cognitive functioning, or poor cooperation.

Healthy Controls Inclusion criteria

• No current or past psychiatric disorders meeting diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.
• Aged 18-55 years.
• Right-handed. Exclusion criteria

1\. Pregnant women or women planning pregnancy in the near future. 2. History of epilepsy or any medical condition that may induce seizures or intracranial hypertension.

3\. Presence of severe suicidal ideation or high suicide risk. 4. Contraindications to MRI, such as metallic implants. 5. Clinically significant medical illnesses or abnormal laboratory findings. 6. Inability to complete study procedures due to severe symptoms, low cognitive functioning, or poor cooperation.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

China · 1 center

• Shanghai Mental Health Center — Shanghai

Identifiers

NCT: NCT07480408 · SP-OCD

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗