Effects of Transcranial Magnetic Stimulation (TMS) and Stimulus Controllability on Pain Perception
Condition: Chronic Pain
MeSH terms: Chronic Pain
Study type: Interventional

Summary: 
      Although transcranial magnetic stimulation (TMS) is now considered a minimal risk
      intervention, is approved for the treatment of depression, and is widely used around the
      world, little is known about mechanisms of action of prefrontal rTMS for depression or pain.
      There is some evidence that the prefrontal cortex is involved in perception of control and
      may moderate the effects of perceived controllability on emotional reactivity to painful
      stimuli. The present study aims to investigate the effects of prefrontal rTMS and perceived
      controllability on pain perception in healthy adults.
    

Detailed description: 
      Transcranial magnetic stimulation (TMS) is a minimally invasive brain stimulation technology
      that can focally stimulate the brain of an awake individual.1,2 A localized pulsed magnetic
      field transmitted through a figure-8 coil (lasting only microseconds) is able to focally
      stimulate the cortex by depolarizing superficial neurons3,4 which induces electrical currents
      in the brain.5 If TMS pulses are delivered repetitively and rhythmically, the process is
      called repetitive TMS (rTMS).

      rTMS over the prefrontal cortex has been shown to produce temporary analgesic effects in
      healthy adults using laboratory pain methods and in patients with chronic pain of various
      etiologies. However, little is known about mechanisms of action.

      Evidence from functional MRI studies suggests that participants' perceived controllability
      over pain stimuli is associated with decreased pain experience and decreased activation of
      cortical and subcortical areas involved with pain perception.6 Perceived controllability may
      involved prefrontal cortical circuits and may be involved in inhibition of limbic system
      responses to painful stimuli.

      To date, no studies have investigated the interaction between prefrontal TMS and perceived
      controllability on pain perception in healthy adults. Building on extensive pilot work and
      experience in the area of laboratory pain assessment and TMS in the Brain Stimulation
      Laboratory at MUSC, the investigators propose to investigate the effects of perceived
      controllability and prefrontal TMS on pain perception in healthy adults. This study may help
      determine whether TMS can be used to stimulate a cortical area thought to be involved in
      perceived controllability, thus enhancing one's sense of controllability and thereby
      substantially reduce pain intensity and unpleasantness.

      Although transcranial magnetic stimulation (TMS) is now considered a minimal risk
      intervention, is approved for the treatment of depression, and is widely used around the
      world, little is known about mechanisms of action of prefrontal rTMS for depression or pain.
      There is some evidence that the prefrontal cortex is involved in perception of control and
      may moderate the effects of perceived controllability on emotional reactivity to painful
      stimuli. The present study aims to investigate the effects of prefrontal rTMS and perceived
      controllability on pain perception in healthy adults.
    

Intervention name(s): Operator Role Real TMS; Receiver Role Real TMS; Operator Role Sham TMS; Receiver Role Sham TMS; All Participants Operator Role
Intervention type(s): Device; Device; Device; Device; Device
Intervention description(s): In two of the four visits, the participant will be assigned to the operator condition receiving Real TMS. The participant will be assigned a partner and both participants will participate in a numeric-combination-guessing task. Performance on this task will be directly related to the painfulness of a series of thermal stimuli that participants receive. The "operator's" performance will control the painfulness delivered to both participants. Each participant will play each role twice.; In two of the four visits, the participant will be assigned to the receiver condition receiving Real TMS. The participant will be assigned a partner and both participants will participate in a numeric-combination-guessing task. Performance on this task will be directly related to the painfulness of a series of thermal stimuli that participants receive. The "receiver's" performance on the task will be unrelated to his/her stimulus painfulness. Each participant will play each role twice.; In two of the four visits, the participant will be assigned to the operator condition receiving Sham TMS. The participant will be assigned a partner and both participants will participate in a numeric-combination-guessing task. Performance on this task will be directly related to the painfulness of a series of thermal stimuli that participants receive. The "operator's" performance will control the painfulness delivered to both participants. Each participant will play each role twice.; In two of the four visits, the participant will be assigned to the receiver condition receiving Sham TMS. The participant will be assigned a partner and both participants will participate in a numeric-combination-guessing task. Performance on this task will be directly related to the painfulness of a series of thermal stimuli that participants receive. The "receiver's" performance on the task will be unrelated to his/her stimulus painfulness. Each participant will play each role twice.; All participants in Operator Role (Receiving real or sham TMS)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Other
Keywords: Pain