Targeting Emotion Regulation in Bipolar Disorder With Intermittent Theta Burst Stimulation: A Mechanistic Study
Massachusetts General Hospital
Summary
The objective of this study protocol is to test whether intermittent theta-burst transcranial magnetic stimulation (iTBS-TMS) to the inferior parietal lobule (IPL) can strengthen functional connectivity with a key region in emotion regulation (ER) neurocircuitry (anterior insula, AI) and improve performance on ER-related tasks in patients with bipolar disorder. Individual IPL sites for stimulation will be identified through baseline, pre-TMS functional magnetic resonance imaging (fMRI) scans. Patient-specific IPL subregions showing positive functional connectivity with the anterior insula and falling within the patient-specific frontoparietal control network will be used as individualized target sites for TMS stimulation. Patients will be randomized to receive 24 sessions of active versus sham iTBS to patient-specific IPL targets (6 sessions/day, 4 days, 43,200 pulses total). Post-iTBS resting-state and task-based fMRI scans will be acquired 3 days after the final day of iTBS administration (Day 4) following identical procedures as baseline. Effects of iTBS-TMS on ER will be evaluated by comparing pre-TMS versus post-TMS functional connectivity and behavior during performance on ER tasks.
Description
The specific goal of this mechanistic study is to test whether targeted engagement of the inferior parietal lobule (IPL) using a rapid and robust form of transcranial magnetic stimulation, accelerated intermittent theta burst stimulation (aiTBS), will increase emotion regulation (ER) in patients with bipolar disorder (BD). Specifically, the Investigators will experimentally test whether stimulation the IPL with aiTBS can strengthen functional neurocircuitry supporting healthy ER, as indexed by increased IPL and anterior insula (AI) functional connectivity and improved performance on ER-related…
Eligibility
- Age range
- 24–65 years
- Sex
- All
- Healthy volunteers
- No
Inclusion Criteria: 1. Individuals of all genders 2. ages 24-65 3. Diagnostic Statistical Manual (DSM-5) defined diagnosis of bipolar I or II disorder (BD); assessed using the Mini-International Neuropsychiatric Interview (M.I.N.I.) version 7.0.2. 4. Current depressive episode, assessed using the Montgomery-Asberg Depression Rating Scale (MADRS) score ≥20, 5. Ability to provide informed consent and verifiable contact information, including current psychiatric treatment provider 6. Stable medication regimen for at least one month, which must include a mood stabilizer Exclusion Criteria: 1. c…
Interventions
- DeviceTranscranial Magnetic Stimulation (TMS)
Transcranial magnetic stimulation (TMS) is a non-invasive tool for modulating patterns of brain activation and circuit connectivity. It uses electromagnetic pulses to induce electric currents over the cortex that serve to depolarize or hyperpolarize neurons, thereby changing patterns of synaptic activity. This study uses intermittent theta burst stimulation (iTBS), an efficient TMS protocol that uses high frequency (50Hz) triplets of TMS given every 200 milliseconds (i.e. at 5 Hz).
- DeviceSham (placebo) TMS
Sham stimulation works by blocking the magnetic field with an internal spacer on the sham side of the TMS coil, allowing the operator to place the coil surface against the scalp. A brief electric pulse calibrated to the stimulator output is delivered to the scalp simultaneous to the TMS pulse to mimic the scalp sensation during the sham condition. 75 Importantly, the electric pulse is calibrated to the stimulator output to ensure a realistic sham condition.
Locations (2)
- Martinos Center for Biomedical ImagingCharlestown, Massachusetts
- University of Pennsylvania, Center for Neuromodulation in Depression and StressPhiladelphia, Pennsylvania