Transcranial Magnetic Stimulation (TMS)

BIRC houses a MagVenture MagPro X100 transcranial magnetic stimulation (TMS) stimulator with:

  • Localite TMS Navigator system
  • Biphasic and monophasic waveforms
  • Flat and 120º butterfly coils
  • Liquid-cooled active/sham butterfly coil
  • Theta burst capability up to 100Hz
  • 2-channel Biopac system for EMG recording

TMS training

All research staff conducting TMS sessions will complete the required BIRC TMS Safety Training course prior to using TMS.

  • All new operators must pass the BIRC online MRI safety training. This requirement applies even if MRI is not part of the study protocol. Additional hands-on training is required before conducting MRI studies.
  • All new operators and assistants must review the BIRC TMS handbook, the TMS manuals (stimulator, coil, and Localite system), complete an in-person safety training and hands-on introduction to the system and safety issues, and pass a written exam on basic operations, safety and screening considerations, and emergency procedures. Contact the BIRC Associate Director to schedule training.
  • All new operators must pass a practical safety and operations test in the TMS lab.
  • New operators are required to setup and practice at least 5 TMS sessions under approved supervision using the protocol specific to their study and document these sessions. Training documentation will be maintained by the BIRC Associate Director. Operators will be directed to obtain additional training and/or practice if the session is not conducted to the satisfaction of BIRC staff.

Please contact BIRC for more information. Training consists of written and applied tests and at least 5 supervised sessions of your specific protocol. TMS sessions must be conducted by at least two researchers.

TMS Safety and Screening

Participant Screening

  • Every participant must complete and sign a TMS screening form immediately prior to every session. Review the screening criteria carefully with the participant. If there is any uncertainty about eligibility, do not conduct TMS. A sample screening form is available.
  • Individuals with pacemakers or other electronic medical devices are not permitted in the TMS room during procedures.

Safety Precautions

  • Earplugs are required for all persons present during a TMS session
  • Researchers should properly fit the participant's earplugs. Do not rely on participants to form their own earplugs. Review proper earplug insertion at https://www.youtube.com/watch?v=3S6dthcSVIM
  • Two people must be present during TMS procedures. Both must have completed the initial TMS safety briefing and orientation session and at least one must be an authorized investigator who has satisfactorily completed all training.

Seizure Response

Seizure is a risk associated with repetitive TMS. Make sure you properly screen your participants and follow safety guidelines for maximum stimulation frequency, pattern, duration, and power level.

  • One person should call 911, note the time the seizure began, and be prepared to provide access to EMS.
  • The other person should:
  • Remove harmful objects and equipment from the person’s surrounding area
  • If the person is in a chair, gently pull chair back away from metal instruments
  • Loosen tight clothing from around the neck
  • Cushion the head as possible
  • Do NOT place anything or any fingers anywhere near the mouth
  • Do not attempt to hold the person down
  • Remain calm, seizures almost always stop after a few minutes
  • Observe what is happening, how long, etc—this can help the person later
  • If a person is having trouble breathing, turn them on their side in the recovery position
  • After a seizure, stay with the person until paramedics arrive
  • If there is concern that the person was injured, do not move the person
  • Do not leave a person who has had a seizure alone, even if the seizure has ended.
  • These roles should be agreed on prior to the session.

Normally, a TMS-induced seizure will be brief and the seizure will end within a few minutes, although the person may be disoriented. Rapidly recurring seizures or a seizure lasting more than 5 minutes are medical emergencies.

Seizures are considered an adverse event and must be reported to the IRB and the BIRC as soon as possible and within 2 days. You may be required to report AEs to other agencies, such as your project sponsor or the FDA. Project activities should be suspended while the protocol risk is evaluated.

Usage

Inspect Equipment

  • All TMS components are plugged into the isolation transformer on the cart. Check that the plugs are firmly in and that there are no cracks, visible wires or other apparent damage to the cords that could create an electrical hazard. This includes the stimulator, chair, vacuum pump, and cooling pump. If any possible damage is identified, do not use the equipment and notify the Associate Director.
  • Check the coil you are using for cracks and warping before use. Each coil also has an expiration date printed on the orange plug. The liquid cooled coil has a pulse counter that will be active after plugging it in. If the coil you want to use has expired (or the pulse counter of the liquid cooled coil shows a value less than the number of pulses in your protocol), do not use the equipment.
    Be careful not to roll the TMS cart over cords! The cart is heavy and can crush or break wires.