This research aims to uncover the Mechanisms of pain relief through the FDA-cleared peripheral transcutaneous magnetic stimulation (pTMS) device by MagVenture. 50 people with chronic pain (post-surgical or post-traumatic) will be identified and recruited. The eligibility for participation in the study will be evaluated by a series of pain and mental health questionnaires followed by quantitative sensory testing (QST) to assess response to noxious heat, cold, and pressure stimuli. Blood will be drawn to isolate plasma, serum, and leukocytes. Participants will then undergo pTMS at the site of pain for four consecutive days. At the end of the therapy, pain testing will be done again, followed by blood withdrawal to assess the changes in plasma and leukocyte levels of mediators of pain. It is anticipated that pTMS will increase mediators of pain relief and reduce inflammatory mediators. Risks: It is possible that a few participants may not respond to pTMS therapy. However, plasma analysis of mediators of pain may help stratify these participants into responders vs. non-responders. Risks associated with the study are minimal and mainly involve discomfort associated with pain testing. The importance of knowledge gained includes understanding pain relief mechanisms by medical devices such as pTMS, which will result in better pain management.
Chronic pain (pain lasting ≥3 months) is a debilitating condition associated with depression, dementia, increased risk of suicide, decreased productivity, and substance abuse. Opioids continue to be a crucial part of pain management. However, the misuse of prescription opioids has led to a shift towards injectable opioids such as heroin, with nearly 80% of new heroin users reporting prior use of prescription opioids. Further, co-morbid substance abuse can exacerbate pain symptoms despite pharmaceutical treatment, revealing the limitations of current pain management strategies. Due to tolerance, people with a history of opioid dependence often need higher doses of opioids to treat acute pain and long-term opioid use paradoxically worsens chronic pain. From a public health perspective, there is an increased chance of transmitting and acquiring hepatitis B and C due to opioid use-related engagement in risky behaviors. Moreover, the economic burden of untreated pain in the US is estimated to be more than $100 billion per year. Therefore, there is an urgent need to develop novel therapeutic strategies and reduce reliance on opioids. Peripheral Transcutaneous Magnetic Stimulation (pTMS) is a non-invasive method of relieving pain by stimulating the target area with magnetic pulses. The magnetic field pulse passing into the body induces a voltage difference between any two points, which creates an electric field and causes electrons to flow between these two points. The magnetic field can penetrate deep tissue, such as spinal nerve roots or muscles. No mechanical contact is necessary, making pTMS applicable to patients with extreme hypersensitivity or allodynia to skin touch. pTMS is FDA-cleared for post-traumatic and post-surgical chronic pain. However, to date, no clear evidence has emerged about pTMS's potential mechanism of pain relief, which has moderated its applicability and acceptability. The study will require recruiting patients over the phone, followed by an on-site visit, which includes patient interaction, blood collection, pain study, performing pTMS therapy at the site of pain, and patient monitoring. Three more on-site visits on consecutive days will include pTMS therapy. The last (fourth) visit will include specimen collection and a pain study. The first and the fourth visits will take 2.5 hours, while the second and the third visits will require 30 minutes. The participants will be followed over the phone every 30 days till the completion of the study to inquire about their wellness.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
50
MagVenture Pain Therapy System: It is an FDA-cleared magnetic stimulator system that provides brief and focused magnetic pulses to non-invasively stimulate peripheral nerves and provide relief of chronic intractable, post-traumatic, and post-surgical pain for patients 18 years or older. It is a relatively new technique in the US for pain relief in the clinical setting and thus not very widespread yet. Evidence shows Magnetic Peripheral Nerve Stimulation to have a promising average pain relief of up to 87%\*. Using magnetic pulses, MagVenture Pain Therapy engages sensory, pain, and motor fibers mechanistically to recondition the central nervous system by eliminating noxious pain signals to the brain, reducing chronic neuropathic pain for responsive patients. \*Bedder M, Parker L.: Magnetic Peripheral Nerve Stimulation (mPNS) for Chronic Pain, 2023
Ambulatory Care Center, Florida International University
Miami, Florida, United States
RECRUITINGPressure Pain Assessment
Pressure Pain Threshold. A handheld probe (Algomed, Medoc) with a small (less than ½ inch wide) rubber tip will be used to apply pressure to the participant's forearm and shoulder. The pressure will slowly increase, and the participant will be asked to click a button when they first feel pain as a result of the pressure stimulation. The pressure will be removed as soon as the participant presses this button. This particular algometer will be used because it provides the examiner with visual feedback to maintain a consistent application rate, which is critical for maintaining high inter-examiner reliability. To assess the pressure pain threshold, the examiner will apply a constant rate of pressure, and the participant will be instructed to press a button when the sensation first becomes painful, at which time the device records the pressure in kilopascals. Higher kilopascals would suggest less pressure pain.
Time frame: 1. On Day 1 (Baseline) 2. On Day 4 (post therapy)
Thermal (Heat) pain
Thermal (Heat) (Threshold, pain, and tolerance) will be assessed using TSA2 Air device from Medoc: A slowly increasing heat stimulus that the participant can terminate by pressing a button when it becomes painful or intolerable. The participant would press the button when they first feel warm (threshold), pain, or can no longer tolerate the heat. Lower heat indices indicate higher thermal sensitivity.
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post therapy)
Thermal (Cold) Pain
Thermal (Cold) (Threshold, pain, and tolerance) will be assessed using TSA2 Air device from Medoc: A slowly decreasing cold stimulus that the participant can terminate by pressing a button when it becomes painful or intolerable. The participant would press the button when they first feel cold (threshold), pain, or can no longer tolerate the cold. Higher cold indices indicate higher thermal sensitivity.
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post therapy)
Temporal Heat Summation
Temporal heat summation will be measured using TSA2 Air device. A series of 5 brief heat pulses (about 2 seconds in duration) will be given, and the participant will be asked to rate how painful each heat pulse feels on a scale from 0 to 100. These heat pulses will be repeated at different temperatures (44° C, 46° C, and 48° C). The participant can stop the procedures at any time so that they do not experience unacceptable pain. Greater pain ratings indicate more pain
Time frame: 1. On day 1 (Baseline) 2. On Day 4 (Post therapy)
Conditioned Pain Modulation
Conditioned pain modulation (CPM) will be tested by TSA2 Air Device. The standard thermode will be placed on the left hand, and the heat pain rating will be assessed at 46 degrees. Then the right hand will be immersed in cold water for 30 seconds. The Heat pain test will be performed again on the left hand to assess Pain modulation. A normal response would indicate a decrease in heat pain on the left hand after immersing the right hand in cold water.
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post Therapy)
McGill Pain Questionnaire-Short Form
Description: 15 descriptors (11 sensory; 4 affective) using an intensity scale ranging from 0-3 on the pain scale (0 = no pain, 1 = mild pain, 2 = moderate pain, or 3 = severe pain) A higher number indicates more pain
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post therapy)
Brief Pain Inventory
A set of 4 Pain Questionnaire: Worst pain in last 24 hours: (1-10) Least pain in last 24 hours (1-10) Pain on average (1-10) Pain right now (1-10) Total possible score: 40 A higher number indicates more pain
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post therapy)
Present Pain Index
A pain score of current pain on the scale of 0-5 A higher number indicates more pain
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post therapy)
Visual Analogue scale
A visual pain scale of 1-100 A higher number indicates more pain
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post therapy)
PHQ-9
Patient Health Questionnaire (depression screening) Scores : 0-27 A higher number indicates greater depression
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post therapy)
GAD-7
General Anxiety Disorder 7 items scored between 0-3. Score: 0-21 A higher number indicates more anxiety
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post therapy)
Vascular Reactivity Index (VRI)
A vascular function test using the Vendys Endothelix device Measures Vascular function Score: 0-3 (VRI) The higher the number, the better the vascular function.
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post therapy)
Measuring Endogenous Opioids in Plasma
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20 ml of blood will be drawn to isolate plasma and peripheral leukocytes in pg/ml. Lower endogenous opioids indicate more pain.
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post therapy)
Measuring Inflammatory cytokines in Plasma
A 20 ml blood sample will be collected, and plasma cytokines will be measured in mg/ml. Higher plasma cytokines indicate more pain
Time frame: 1. On Day 1 (Baseline) 2. On Day 4 (Post Therapy)
Measuring endogenous opioids in peripheral immune cells.
A 20 ml blood sample will be collected, and endogenous opioids will be measured in pg/mg protein. Lower endogenous opioids would indicate more pain
Time frame: 1. On day 1 (Baseline) 2. On day 4 (Post Therapy)