Transcranial Magnetic Stimulation Effects on Pain Perception

Not Applicable

Completed

Conditions: Gastric Bypass Surgery Pain Management

Interventions: Device: Real TMS 45 min
Device: Sham TMS 45 min
Device: Real TMS 4 Hours
Device: Sham TMS 4 Hours

Registration Number: NCT01861574

Lead Sponsor: Medical University of South Carolina

Brief 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)

Detailed Description: To test whether rTMS over the left prefrontal cortex significantly reduces post-operative pain and PCA use following gastric-bypass surgery relative to sham and an active control, in a mood- independent manner. Note that the active control is still mentioned in the aims and hypotheses, but was apparently removed from the study design.

To determine the effects of timing (one immediately following surgery and one 4 hours later) and dose of TMS (0, 1, or 2 sessions of active rTMS) on post-operative pain and PCA use; To determine the effects of TMS on post-surgical recovery time (time to discharge) and clinical outcomes at 1-month, 3- months and 6-months follow-up. Again an active control is mentioned, though this was removed from the design. It appears that this aspect of the proposal was not edited to reflect the new study design.

In the new design, 108 participants received two 20 minute sessions of 10 Hz rTMS (110% of motor threshold) over the left dorsolateral prefrontal cortex (one immediately following surgery and one 4 hours later). Participants were randomly assigned to receive two sessions of real rTMS, two sessions of sham, 1 real then 1 sham, or 1 sham then 1 real rTMS treatments.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 108

Inclusion Criteria

Adult gastric by-pass patients 18 to 60 years old

Exclusion Criteria

Non gastric by -pass patients.

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Real then Sham TMS	Real TMS 45 min	Participants in the Real then Sham TMS group receive 20 minutes of Real TMS 45 minutes after gastric-bypass surgery and then 20 minutes of Sham TMS 4 hours after surgery.
Both Real TMS	Real TMS 4 Hours	Participants in the Both Real TMS group receive 20 minutes of Real TMS 45 minutes after gastric-bypass surgery and then another 20 minutes of Real TMS 4 hours after surgery.
Both Real TMS	Real TMS 45 min	Participants in the Both Real TMS group receive 20 minutes of Real TMS 45 minutes after gastric-bypass surgery and then another 20 minutes of Real TMS 4 hours after surgery.
Sham then Real TMS	Sham TMS 45 min	Participants in the Sham then Real TMS group, receive Sham TMS 45 minutes after gastric-bypass surgery and 20 minutes of Real TMS 4 hours after surgery.
Sham then Real TMS	Real TMS 4 Hours	Participants in the Sham then Real TMS group, receive Sham TMS 45 minutes after gastric-bypass surgery and 20 minutes of Real TMS 4 hours after surgery.
Real then Sham TMS	Sham TMS 4 Hours	Participants in the Real then Sham TMS group receive 20 minutes of Real TMS 45 minutes after gastric-bypass surgery and then 20 minutes of Sham TMS 4 hours after surgery.
Both Sham TMS	Sham TMS 45 min	Participants in the Both Sham TMS group, receive Sham TMS 45 minutes after gastric-bypass surgery and then another 20 minutes of Sham TMS 4 hours after surgery
Both Sham TMS	Sham TMS 4 Hours	Participants in the Both Sham TMS group, receive Sham TMS 45 minutes after gastric-bypass surgery and then another 20 minutes of Sham TMS 4 hours after surgery

Primary Outcome Measures

Name	Time	Method
Patient Controlled Analgesia (PCA) Hydromorphone Usage	Post-Op Hour 0 through 48	PCA pump usage values were reported by concentration in mg/mL. Post operative PCA pump usage was tracked 0-48 hours after surgery. The PCA pump usage was downloaded from the PCA pump after discharge from the hospital and values were reported in mg/mL (concentration in mg/mL). The PCA pump data were averaged over Post-operative hours 0-48 (total PCA pump usage post-operatively) and the mean PCA pump usage was calculated and reported in mg/mL for all groups (4).
Sensory Dimension of McGill Pain Questionnaire	Check Up 1, Check Up 2, Check Up 3, and Check Up 4	Participants completed the McGill Pain Questionnaire-short form (MPQ) at Check Up 1, Check Up 2, Check Up 3, and Check Up 4. Check Up 1 \& 2 occurred on Post-Op Day 1. Check Up 1 occurred immediately after surgery. Check Up 2 occurred 4 hours after Check Up 1. Check Up 3 \& 4 occurred on Post-Op Day 2, 4 hours apart. The MPQ has two pain dimensions: 1.Sensory subscale with 11 words, and 2.Affective subscale with 4 words from the original MPQ. The range of scores for the affective dimension of pain is 0-12. The range of scores for the sensory dimension of pain is 0-33. The maximum total score for the sensory dimension is 33. Higher scores are indicative of worse pain on the sensory dimension of pain.
Affective Dimension of McGill Pain Questionnaire	Check Up 1, Check Up 2, Check Up 3, and Check Up 4	Participants completed the McGill Pain Questionnaire-short form (MPQ) at Check Up 1, Check Up 2, Check Up 3, and Check Up 4. Check Up 1 \& 2 occurred on Post-Op Day 1. Check Up 1 occurred immediately after surgery. Check Up 2 occurred 4 hours after Check Up 1. Check Up 3 \& 4 occurred on Post-Op Day 2, 4 hours apart. The MPQ has two pain dimensions: 1.Sensory subscale with 11 words, and 2.Affective subscale with 4 words from the original MPQ. The range of scores for the affective dimension of pain is 0-12. The maximum total score for the Affective dimension is 12. Higher scores are indicative of worse pain on the affective dimension of pain.

Secondary Outcome Measures

Name	Time	Method
Confidence Ratings of Guessing TMS Condition Assignment	After Second TMS Treatment (Check up 4)	After participants guessed their TMS condition; whether they received real or sham TMS, They were then asked to rate the confidence in their guess. Ratings were on a scale of 0-10 where 0=complete guess and 10=absolutely sure. Results below include the mean confidence ratings of those that guessed the TMS condition correctly and those that guessed incorrectly.
Correctly Guessed Assignment Condition at 4 Hours	After second TMS treatment (Check up 4)	Participants were asked to guess whether they received real or sham TMS after each rTMS session. The results below report the percentage or participants that correctly guessed TMS Condition after the second TMS treatment, 4 hours after surgery.