The Effect of Right dlPFC cTBS on Acute Measures of Anxiety, Functional Connectivity, and TMS-evoked BOLD Responses.
University of Pennsylvania
Summary
The right dorsolateral prefrontal cortex (dlPFC) is increasingly being targeted with transcranial magnetic stimulation (TMS) to reduce anxiety expression; however, there is little mechanistic evidence supporting an optimized treatment protocol. Thus, the objective of the current project is to develop an interleaved TMS/fMRI that can assess the effect of neuromodulatory (potentially therapeutic) TMS protocols on neural and behavioral measures related to anxiety expression. PUBLIC HEALTH RELEVANCE: These results will yield direct evidence that 1 Hz and cTBS modulate brain activity associated with anxiety expression and regulation, thus informing novel TMS based anxiety treatments.
Description
The right dorsolateral prefrontal cortex (dlPFC) is increasingly being targeted with transcranial magnetic stimulation (TMS) to reduce anxiety expression in anxiety disorders, depression, and posttraumatic stress disorder (PTSD). However, we lack the basic evidence to determine critical details regarding the optimal stimulation parameters including the dose, target, and protocol. In addition, there is little mechanistic evidence for why any particular right dlPFC target/dose/protocol should be effective for a given set of patients. Indeed, there is little consensus as to whether such mechanist…
Eligibility
- Age range
- 18–50 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * Able to give their consent * Right-handed * Individuals receiving therapy for anxiety must be stable on their regimen for at least 4 weeks prior to study enrollment. Exclusion Criteria: * Non-english speaking * Any significant medical or neurological problems * Current or past non-anxiety-related psychiatric comorbidity, active or history of active suicidal ideation * Alcohol/drug problems in the past year or lifetime alcohol or drug dependence * Medications that act on the central nervous system * History of seizure * History of epilepsy * Increased risk of seizure fo…
Interventions
- DeviceActive TMS
Subjects will receive a continuous 1800 pulse cTBS train to the right dlPFC at 100% of motor threshold. The train will consist of 50 Hz bursts, repeated at intervals of 200 ms (5 Hz) for 40 sec.
- DeviceSham TMS
Subjects will receive a series of 100 single pulses to the right dlPFC at 100% of motor threshold. Pulses will be randomly jittered and have an average interpulse interval of 6 ± 4 seconds. Single pulses delivered in such a fashion have been shown to have little or no neuromodulatory effect on subsequent cortical excitability.
Location
- University of PennsylvaniaPhiladelphia, Pennsylvania