Transcranial Magnetic Stimulation Effects on Pain Perception

Summary

The purpose of this research study is to investigate the effects of Transcranial Magnetic Stimulation on pain perception. TMS is a non - invasive technique that uses electromagnetic pulses to temporarily stimulate specific brain areas in awake people (without the need for surgery, anesthetic, or other invasive procedures)

Conditions

• Gastric Bypass Surgery Pain Management

Interventions

DEVICE

Real TMS 45 min

Real TMS 45 minutes after surgery, first determined resting motor threshold (rMT) by starting with 40% of the machine output and 0.5 Hz stimulus frequency. The coil was positioned over the motor cortex and then adjusted until each pulse results in movement of the right thumb. The machine output was then adjusted to the lowest intensity that reliably produces thumb movement. Parameter estimation by sequential testing was used to determine the amount of machine energy necessary to visibly move the thumb 50% of the time. rMT was assessed before each rTMS treatment. The left prefrontal cortex was the cortical target for rTMS treatment. The EEG-10-20 system was used to locate the prefrontal cortex (F3).

DEVICE

Sham TMS 45 min

Sham TMS 45 minutes after surgery used specifically designed rTMS coil that produces auditory signals identical to real (active) TMS coils but is shielded so that actual stimulation does not occur. The eSham system was used to mimic sensations of real rTMS. This system produces mild tingling on the scalp underneath the sham rTMS coil, making it difficult in differentiating between real and sham. The amount of electrical stimulation necessary to match real rTMS pulses was determined using an algorithm (parameter estimation by sequential testing). All subjects underwent the sham titration at the beginning of every rTMS session regardless of group assignment. The left prefrontal cortex was the cortical target for rTMS treatment, located using the EEG-10-20 system.

DEVICE

Real TMS 4 Hours

Real TMS 4 hours after surgery, first determined resting motor threshold (rMT) by starting with 40% of the machine output and 0.5 Hz stimulus frequency. The coil was positioned over the motor cortex and then adjusted until each pulse results in movement of the right thumb. The machine output was then adjusted to the lowest intensity that reliably produces thumb movement. Parameter estimation by sequential testing was used to determine the amount of machine energy necessary to visibly move the thumb 50% of the time. rMT was assessed before each rTMS treatment. The left prefrontal cortex was the cortical target for rTMS treatment. The EEG-10-20 system was used to locate the prefrontal cortex (F3).

DEVICE

Sham TMS 4 Hours

Sham TMS 4 hours after surgery used specifically designed rTMS coil that produces auditory signals identical to real (active) TMS coils but is shielded so that actual stimulation does not occur. The eSham system was used to mimic sensations of real rTMS. This system produces mild tingling on the scalp underneath the sham rTMS coil, making it difficult in differentiating between real and sham. The amount of electrical stimulation necessary to match real rTMS pulses was determined using an algorithm (parameter estimation by sequential testing). All subjects underwent the sham titration at the beginning of every rTMS session regardless of group assignment. The left prefrontal cortex was the cortical target for rTMS treatment, located using the EEG-10-20 system.

Sponsors & Collaborators

• Medical University of South Carolina

  lead OTHER

Principal Investigators

• Jeffrey Borckardt · Medical University of South Carolina

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2005-02-28

Primary Completion

2011-06-30

Completion

2011-06-30

Countries

• United States

Study Locations