1. Transcranial Magnetic Stimulation
Julia Shannon
BME 281
October 11, 2011

2. What is it?
A procedure that uses magnetic fields to stimulate nerve cells in the brain
Relatively new
Since development, has been used in many fields of research
Use of magnets, instead of a direct electric current to the brain, allows for mapping of the cerebral cortex and its connections

3. First use
1985-Anthony Barker conducted the first successful TMS study in Sheffield, England
Stimulated muscle contraction
-conducted nerve impulses from the motor cortex to the spinal cord

4. How does it work?
A large electromagnetic coil is placed against the scalp
Uses a magnetic field to create weak electric currents that stimulate nerve cells in a region of the brain
Causes depolarization or hyper polarization in neurons

5. Clinical uses
Tested as a treatment for various neurological and psychiatric disorders
Used today to improve symptoms of depression
Stimulating the nerve cells creates mood change
Used when standard procedures have no effect
Least invasive
(doesn’t require surgery or implantation of electrodes)
164 patients with unipolar, non-psychotic major depressive disorder were treated with TMS. Within 30 days..
-1/3 reported complete resolution
-1/2 reported significant improvement

6. Procedure Doctor places coil against head- mapping signals
Increase of magnetic
dosage until fingers or
hands twitch
(motor threshold)

7. Treatments are typically given daily, for 30-40 minutes, in a span of 4-6 weeks.
Stimulation is gradual
Repetitive TMS produces longer-lasting effects which persist past the initial period of stimulation

8. Coil Types
Can differ in geometry of the coil, the type of material used
Designs of different coils used can have a big impact on the resulted stimulation
Ex: figure-eight coil results in more focal pattern of activation,
double-cone coil used for deeper stimulation

9. Risks and Side Effects Common: Less Common: Seizures, mania
Headache, scalp discomfort, tingling or twitching of facial muscles, lightheadedness
Less Common:
Seizures, mania

10. The NeuroStar, a device used for TMS, was cleared by the FDA in 2008
Improvements in symptoms may last for days/weeks/months
Other areas of research include
-rehabilitation of motor disability after stroke
-evaluating damage from strokes, spinal cord injuries, Multiple Sclerosis, and motor neuron disease
- itraoperative monitoring

11. TMS machine designed in 1992: stimulate or slow down regions of the brain so that doctors could monitor the effects of the surgery in real time
Allan Snyder- theorized that people could tap into genius-like mental ability when undergoing TMS
(Having a mental impairment would allow other mental functions to flourish)
40% of test subjects displayed extraordinary and newfound mental skills.

12. Sources
Yang, Sarah. " Neuroscientists Connect Neural Activity and Blood Flow in New Brain Stimulation Technique." University of California, Berkeley. Web. 08 Oct <
Fallon, Sean. "NeuroStar TMS Depression Therapy System First To Be Given FDA Approval." Gizmodo, the Gadget Guide. Web. 08 Oct <
"Savant for a Day." Biotele. Web. 08 Oct <
Staff, Mayo Clinic. "Transcranial Magnetic Stimulation - MayoClinic.com." Mayo Clinic. Web. 08 Oct <
"Transcranial Magnetic Stimulation." Neurology. Web. 08 Oct <
"Transcranial Magnetic Stimulation." Wikipedia, the Free Encyclopedia. Web. 08 Oct <