Low Back Pain, Zygapophyseal Joint Arthritis
Conditions
Keywords
low back pain, zygapophysial joint arthritis, endogenous opioids, lumbar medial branch block
Brief summary
This study will study pain relief after spine injections that are used to guide care. Some improvements in pain from a procedure might be from placebo effect rather than the physiological effect of the procedure. The study will use naloxone to reverse the effect of the body's internal placebo system after a spine injection, so the placebo effect and the injection effect can be measured separately. This process may improve the understanding of spine injections and their ability to guide pain care.
Detailed description
Nerve blocks are commonly used in pain medicine to diagnose painful conditions and predict response to invasive procedures and surgeries. Placebo responses may cripple clinicians' ability to interpret responses to nerve blocks and guide patient care, when reported pain relief is due to placebo rather than the nerve block. Existing methods to assess placebo response in clinical practice are limited and indirect. The area that is most explored is in the diagnosis of pain from the facet joints of the spine and relies on an indirect signal from repeated diagnostic injections. Lumbar medial branch radiofrequency neurotomy (LMBRN) is commonly used to treat low back pain and can lead to large improvements in pain and disability. There is a high failure rate of LMBRN even after a series of controlled prognostic injections called lumbar medial branch nerve blocks (LMBB) with local anesthetic. The discrepancy between response to LMBB and LMBRN has been attributed to the confounding of pain relief from the nerve block with pain relief from the placebo response. Endogenous opioids (EO), substances produced within the human body that bind to opioid receptors and produce opioid analgesia, are likely responsible for most of the placebo response caused by LMBB. This study will use naloxone, an opioid receptor antagonist, to completely block the activity of EOs in patients. First, the pain relief after LMBB will be recorded - this is a combination of the effect of the nerve block and EO released in the placebo response. Normal saline will be infused, as an internal control for the state of receiving an infusion. Naloxone will then be infused, reversing EO-dependent placebo analgesia - the analgesia remaining will be from the nerve block. Finally, clinical outcomes from LMBRN will be collected to determine whether using naloxone with LMBB can improve prediction of outcomes with LMBRN. Naloxone will be used to probe a mechanism of procedurally-induced endogenous-opioid mediated placebo analgesia. No IND is pursued in this study. These data will provide detailed parameters of placebo response from LMBB, improving interpretation of LMBB for estimation of prevalence of zygapophyseal joint pain and for prognostication of LMBRN. Furthermore, if this methodology of EO reversible analgesia is feasible for investigation of placebo from LMBB, it will be more broadly investigated in diagnostic and prognostic injections used in interventional pain management.
Interventions
After assessment of response to lumbar medial branch block, 8 ml normal saline will be infused through IV over several minutes. 10 minutes will pass, and response to lumbar medial branch block procedure will be re-assessed. After this step, naloxone infusion will occur (see next intervention)
DRUGNaloxone infusion
After infusion of normal saline and re-assessment of response to lumbar medial branch block procedure, 8 milligrams of naloxone will be infused over several minutes. Then after 10 minutes, response to lumbar medial branch block procedure will be re-reassessed for the final time.
Sponsors
International Pain and Spine Intervention Society
Middle Tennessee Research Institute
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Intervention model description
prospective, within-subject
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Capable of understanding and providing consent in English and capable of complying with the outcome instruments used * ≥3 months low back pain with persistent limiting symptoms despite conventional treatment (physical therapy and oral medications) * Low back pain NRS ≥ 4/10 in intensity on 7-day average and at time of lumbar medial branch block
Exclusion criteria
* Daily use of opioid medications or recreational drugs, or if using opioids PRN, report of opioid use within the 3 days prior to participating in the protocol * Positive urine drug screen for opioid medication on the day of naloxone administration * Allergy to naloxone * Refusal of or failure to place IV * Previous LMBB or LMBRN * Known spine condition that may affect the ability to diagnose or treat facet pain or lead to spine surgery (e.g. instability, severe spinal stenosis, radiculopathy, previous spine operation resulting in alteration of anatomy targeted by LMBB or LMBRFN) * Active medical condition that would limit the safety of naloxone administration (e.g. severe kidney or liver failure, unstable cardiac disease, infection, severe coagulopathy) * Psychiatric, medical, neurologic, or pain-related disorder that may compromise the ability of the patient to accurately report changes in low back pain * Requirement for procedural sedation to tolerate LMBB
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Endogenous opioid-dependent placebo analgesia | 10 minutes after naloxone infusion | Endogenous opioid-dependent placebo analgesia is defined as change in analgesia after lumbar medial branch block #1 (measured by numeric pain rating scale) after infusing naloxone |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in low back pain score after Lumbar Medial Branch Radiofrequency Neurotomy | Baseline, then 6 weeks, 3 months, 6 months after Lumbar Medial Branch Radiofrequency Neurotomy | Change in Numeric Pain Rating Scale score for low back pain after Lumbar Medial Branch Neurotomy |
| Change in McGill Pain Questionnaire-2 after Lumbar Medial Branch Radiofrequency Neurotomy | Baseline, then 6 weeks, 3 months, 6 months after Lumbar Medial Branch Radiofrequency Neurotomy | Change in McGill Pain Questionnaire-2 score after Lumbar Medial Branch Radiofrequency Neurotomy |
| Change in MQS-III after Lumbar Medial Branch Radiofrequency Neurotomy | Baseline, then 6 weeks, 3 months, 6 months after Lumbar Medial Branch Radiofrequency Neurotomy | Change in MQS-III score after Lumbar Medial Branch Radiofrequency Neurotomy |
| Change in Patient-Reported Outcomes Measurement Information System-29 after Lumbar Medial Branch Radiofrequency Neurotomy | Baseline, then 6 weeks, 3 months, 6 months after Lumbar Medial Branch Radiofrequency Neurotomy | Change in Patient-Reported Outcomes Measurement Information System-29 score after Lumbar Medial Branch Radiofrequency Neurotomy |
| Saline-reversible analgesia | 10 minutes after saline infusion | Saline-reversible analgesia is defined as change in analgesia after lumbar medial branch block #1 (measured by numeric pain rating scale) after infusing saline |
| Change in low back pain score after Lumbar Medial Branch Block #2 | Approximately 2 weeks after Lumbar Medial Branch Block #1, and before Lumbar Medial Branch Radiofrequency Neurotomy | Change in Numeric Pain Rating Scale score for low back pain after Lumbar Medial Branch Block #2 |
Other
| Measure | Time frame | Description |
|---|---|---|
| Fluoroscopy evaluation for procedural integrity, displacement - Lumbar Medial Branch Radiofrequency Neurotomy | during Lumbar Medial Branch Radiofrequency Neurotomy procedure | Fluoroscopic images of Lumbar Medial Branch Radiofrequency Neurotomy will be collected to document procedural integrity. This specific measure is the (x,y) coordinates of the proximal and distal ends of the radiofrequency cannula tip minus the (x,y) coordinates of the proximal and distal bounds of the target structure. |
| Fluoroscopy evaluation for procedural integrity - Lumbar Medial Branch Block | during Lumbar Medial Branch Block procedure | Fluoroscopic images of Lumbar Medial Branch Blocks will be collected to document procedural integrity. This measure is a binary (yes,no) describing whether the tip of the procedure needle is in contact with the anatomical target on each of the procedural images. |
| Fluoroscopy evaluation for procedural integrity, distance - Lumbar Medial Branch Radiofrequency Neurotomy | during Lumbar Medial Branch Radiofrequency Neurotomy procedure | Fluoroscopic images of Lumbar Medial Branch Radiofrequency Neurotomy will be collected to document procedural integrity. This measure is the number of radiofrequency cannula widths between the anatomical target and the radiofrequency cannula. |
Countries
United States
Contacts
Primary ContactWilliam E Rivers, DO
Outcome results
None listed