Pain Inhibition and Facilitation in Recurrent Low Back Pain

Pro-Nociceptive and Anti-Nociceptive Mechanisms Across an Episode of Recurrent Low Back Pain

This study evaluates psychophysical measures of pain inhibition and facilitation, along with cortical responses to different sensory stimuli, in patients with recurrent low back pain and matched healthy individuals.

Study Overview

• Status: Completed
• Conditions: Healthy; Recurrent Low Back Pain

Detailed Description

Pain inhibitory and facilitatory mechanisms have been suggested to play a role in the development of persistent low back pain; however, there is still debate on when changes in these mechanisms occur. Similarly, evoked cortical responses can reflect neuroplastic changes in pain processing regions, which are also thought to play a role in the transition to persistent pain, but there is also debate on when these neuroplastic changes develop relative to low back pain. Therefore, this study will use patients with an intermediary clinical pain state, recurrent low back pain, and matched healthy control participants, to investigate within and between subject differences in pain inhibitory, facilitatory and neuroplastic mechanisms.

• Study Type: Observational
• Enrollment (Actual): 60

Contacts and Locations

Study Locations

• Denmark
  • Aalborg, Denmark, 9000
    • CNAP, SMI, Aalborg University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Population recruited from university, college, and wider Aalborg community

Description

Inclusion:

• Healthy men and women
• Aged 18-60 years
• No previous back pain OR >1 previous episode of low back pain in past 12 months
• No current back pain OR Pain in the region posteriorly between the inferior border of the 12th rib and the lower gluteal fold (low back pain) at time of recruitment lasting >24 hours
• Able to speak, read and understand English

Exclusion:

• Pregnancy
• First episode of low back pain
• Low back pain associated with menstruation
• Chronic low back pain (continuous pain episode for >3 months)
• Currently seeking active treatment for low back pain
• Red flags symptoms
• Drug addiction defined as the use of cannabis, opioids or other drugs
• Current or previous neurologic, musculoskeletal, mental, or other illnesses which may affect the trial
• Current or previous chronic or recurrent pain condition other than low back pain
• Current regular use of analgesic or other medication which may affect the trial
• Lack of ability to cooperate
• Recent history of acute pain particularly in the lower limbs (unless related to LBP)
• Abnormally disrupted sleep in 24 hours preceding experiment

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Recurrent Low Back Pain Patients; Participants experiencing a current episode of their recurrent non-specific low back pain at the time of recruitment.
Healthy Volunteers; Participants matched in age and gender to one of the recurrent low back pain patients, with no significant past low back pain, chronic pain or other relevant medical disorders.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Conditioned Pain Modulation	Pressure pain threshold (kPa) as test stimulus before compared to during a pressure conditioning stimulus on the lower leg	Day 0 vs. Day 28
Temporal Summation of Pain	Pain rating (VAS) change over a series of 10 repeated mechanical stimuli	Day 0 vs. Day 28

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pressure Pain Thresholds	Threshold of pain detection (kPa) with handheld algometry over the low back and distant sites	Day 0 vs. Day 28
Thermal Pain Thresholds	Hot and cold pain detection thresholds (degrees)	Day 0 vs. Day 28
Two Point Discrimination	The smallest distance (mm) for which two separate points can be distinguished over the low back	Day 0 vs. Day 28
Proprioceptive Weighting	Center of pressure displacement during 1-minute of quiet standing	Day 0 vs. Day 28
Sensory Evoked Potentials	EEG signals recorded in response to laser and electrical stimuli applied to the back	Day 0 vs. Day 28

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Affective Regulation	Pressure pain ratings pre, during and post affective image set	Day 0 vs. Day 28
Attentional Regulation	Pressure pain ratings pre, during and post computerised attention-demanding task	Day 0 vs. Day 28

Collaborators and Investigators

• Sponsor: Aalborg University
• Investigators: Principal Investigator: Megan E McPhee, BPhty MSc, Aalborg University

Publications and helpful links

General Publications

• McPhee ME, Graven-Nielsen T. Positive affect and distraction enhance whereas negative affect impairs pain modulation in patients with recurrent low back pain and matched controls. Pain. 2022 May 1;163(5):887-896. doi: 10.1097/j.pain.0000000000002442.

Study record dates

Study Major Dates

• Study Start (Actual): April 10, 2018
• Primary Completion (Actual): December 14, 2018
• Study Completion (Actual): December 14, 2019

Study Registration Dates

• First Submitted: March 7, 2018
• First Submitted That Met QC Criteria: March 7, 2018
• First Posted (Actual): March 13, 2018

Study Record Updates

• Last Update Posted (Actual): December 11, 2020
• Last Update Submitted That Met QC Criteria: December 10, 2020
• Last Verified: December 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Pain; Neurologic Manifestations; Disease Attributes; Back Pain; Low Back Pain; Recurrence
• Other Study ID Numbers: N-20170034

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No