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Offset Mechanisms in Evaluation of Lumbar Medial Branch Blocks

OMEGA Study: Offset Mechanisms in Evaluation of Lumbar Medial Branch Block

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05961800
Acronym
OMEGA
Enrollment
40
Registered
2023-07-27
Start date
2023-07-05
Completion date
2028-06-01
Last updated
2026-07-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Analgesia, Facet Joint Pain, Pain, Chronic, Pain, Procedural

Keywords

lumbar, medial branch block, offset analgesia, onset hyperalgesia, QST, quantitative sensory testing

Brief summary

This study examines the relationship between central nervous system (CNS) mechanisms of pain inhibition and the pain relief that occurs following a lumbar medial branch block (MBB).

Detailed description

This study examines the relationship between central nervous system (CNS) mechanisms of pain inhibition and the pain relief that occurs following a commonly-performed nerve block used to diagnose and treat chronic low back pain. Patients scheduled for lumbar medial branch blocks as part of routine clinical care will arrive to clinic prior to the block for quantitative sensory testing procedures that measure CNS pain modulation. Patients will then undergo treatment as usual with their block, subsequently reporting low back pain intensity in a pain diary.

Interventions

BEHAVIORALCutaneous Probe

A computer-controlled probe delivers temperatures to the skin to measure pain, offset analgesia and onset hyperalgesia.

BEHAVIORALQuantitative Sensory Testing

Standard methods involving pinprick, pressure, heat, and cold applied to the skin are used to measure sensation and pain

BEHAVIORALComputer Tasks

Quantitative Sensory Testing (QST) and computer tasks are used to measure changes in pain intensity.

Sponsors

University of Pittsburgh
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE

Intervention model description

Quantitative Sensory Testing

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Scheduled for lumbar MBB in UPMC Pain Management clinics * Age \> 18 years old * Predominantly axial chronic low back pain at least 3 months on a daily basis * Must meet the minimum criteria for cognitive function using the PROMIS 2-item cognitive screener (\>3) * Low back pain intensity of \> 3/10 * Willing and able to receive study-related phone calls

Exclusion criteria

* History of spine surgery at the level of the lumbar MBB * Active worker's compensation or litigation claims * New pain and/or psychiatric treatments within 2 weeks of enrollment * Not fluent in English and/or not able to complete the questionnaires * Any clinically unstable systemic illness that is judged to interfere with the study

Design outcomes

Primary

MeasureTime frameDescription
Offset analgesia and onset hyperalgesiaduring this portion of the study visit (30 minutes)Pain intensity difference during heat stimuli measured on a 0-100 sliding scale (0 is no pain, 100 is the most intense pain imaginable) at baseline
Low back pain intensity changeImmediately after lumbar medial branch block and up to 16 hours after lumbar medial branch blockPatients respond to the question "How would you rate your back pain right now?" from 0 (no pain) to 10 (worst imaginable pain) to see how intense their back pain is each hour after the lumbar medial branch block.

Secondary

MeasureTime frameDescription
Duration of low back painBaselineParticipant self-reports the number of years they have experienced low back pain. The number of years for each participant will be reported.
PEG: A Three-Item Scale Assessing Pain Intensity and InterferenceBaselineAssessment for self-reported average pain and pain interference within past 7 days. Responses range from 0 (no pain) to 10 (pain as bad as you can imagine). Total scores range from 0-30, and higher scores indicate more pain interference.
Baseline Back Pain IntensityBaselineAssessment for determining how much a person hurts with a question ranked on a 11-point scale, from "0 = no pain" to "10 = worst imaginable pain." The minimum raw summed score is 0 and the maximum score is 10. Lower raw response scores suggest lower pain intensity and better outcomes.
PROMIS Pain Interference 4aBaselineAssessment for self-reported consequences of pain with 4 questions ranked on a 5-point scale, from "not at all" to "very much". The minimum raw summed score is 4 and the maximum score is 20. Lower scores suggest better outcomes.
PROMIS Physical Function- 6bBaselineAssessment for self-reported capability with 6 qualitatively scaled questions ranked on a 5-point scale, from "without any difficulty" to "unable to do" or "not at all" to "cannot do." The minimum raw summed score is 6 and the maximum score is 30.
PROMIS Sleep Disturbance 6aBaselineAssessment for self-reported perceptions of sleep quality and sleep depth with 6 questions ranked on a 5-point scale. The minimum raw summed score is 6 and the maximum score is 30. Lower scores suggest better outcomes.
6-item Pain Catastrophizing ScaleBaselineStandardized survey score assessing pain perception before the study procedures begin. Rumination subscale score ranges from 0-16. Magnification subscale score ranges 0-12. Helplessness subscale score ranges from 0-24. Total score can be calculated by summing subscales. Total score ranges from 0-52, with higher scores indicating more pain catastrophizing.
Patient Health Questionnaire (PHQ-2)BaselineThe PHQ-2 inquires about the frequency of depressed mood and anhedonia over the past two weeks. The PHQ-2 includes the first two items of the PHQ-9. A PHQ-2 score ranges from 0-6. The authors identified a score of 3 as the optimal cutpoint when using the PHQ-2 to screen for depression. If the score is 3 or greater, major depressive disorder is likely.
PROMIS 4-item DepressionBaselineAssessment for self-reported negative mood and views of self with 4 questions ranked on a 5-point scale, from "never" to "always". The minimum raw summed score is 4 and the maximum score is 20. Lower t-scores suggest better outcomes.
PROMIS 4-item AnxietyBaselineAssessment for self-reported fear, anxious misery, hyperarousal, and somatic symptoms with 4 questions ranked on a 5-point scale, from "never" to "always". The minimum raw summed score is 4 and the maximum score is 20. Lower scores suggest better outcomes.
Areas of Pain Body MapBaselineThe digital body figure contains 36 anterior regions and 38 posterior regions on which participants can mark areas in which they experience chronic pain. The number of pain areas each participant recorded will be reported, with a possibility of 74 total regions.
Treatment ExpectancyBaselineAssessment for the subject's expectations of treatment effec prior to lumbar medial branch block. Scores range from 0 (not at all) to 4 (very much), with total scores ranging from 0-24. Higher scores indicate higher expectations of the low back pain treatement.
Patient Global Impression of ChangeImmediately after lumbar medial branch blockThe subject's impression of the impact of the lumbar medial branch block on their pain and function will be measured with a 7-item scale (1 = very much worse, 2 = much worse, 3 = minimally worse, 4 = no change, 5 = minimally improved, 6 = much improved, 7 = very much improved).
Situational pain catastrophizing scale (S-PCS)Immediately after lumbar medial branch blockStandardized survey score assessing pain perception immediately following the lumbar medial branch block. Scores range from 0-24, with higher scores representing more pain catastrophizing.
Pain intensity during QSTduring this portion of the study visit (60 minutes)Changes in pain intensity during quantitative sensory tests measured on a 0-100 sliding scale (0 is no pain, 100 is the most intense pain imaginable)
Baseline back pain intensitybaselinePatients respond to the question "How would you rate your back pain on average?" from 0 (no pain) to 10 (worst imaginable pain) to see how intense their back pain is before the lumbar medial branch block.
Back pain intensity after lumbar medial branch blockImmediately after lumbar medial branch block and up to 16 hours after lumbar medial branch blockPatients respond to the question "How would you rate your back pain right now?" from 0 (no pain) to 10 (worst imaginable pain) to see how intense their back pain is each hour after the lumbar medial branch block.

Countries

United States

Contacts

CONTACTMaya L Maurer, BS
mam708@pitt.edu412-665-8052
CONTACTBenedict J Alter, MD, PhD
alterbj@upmc.edu412-677-0575
PRINCIPAL_INVESTIGATORBenedict J Alter, MD, PhD

University of Pittsburgh

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 28, 2026