State vs. Trait Alterations in Low Back Pain

NCT06412484 | Recruiting DMC

• 1 other identifier: CRPP Renewal
• Study Type: observational
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

The primary goal of this study is to investigate whether different alterations observed in patients with non-specific episodic low back pain (compared to healthy volunteers), detected using several assessments: psychophysical and neurophysiological testing, imaging, and blood sampling, are dependent or independent of the presence and type of pain experienced at the time of investigation.

Conditions

Low Back Pain

Keywords

Trait vs. State Alterations

Outcome Measures

Primary Outcomes (12)

• Mechanical Detection Threshold (MDT)

  A reduced psychophysical QST battery will be performed in 3 body areas: most painful (MP), adjacent to MP, and a control area. MDT will be assessed with Von Frey filaments applied to the skin (mN). Subject reports when tactile input is detected.

  1 - 6 months

• Mechanical Pain Threshold (MPT)

  A reduced psychophysical QST battery will be performed in 3 body areas: most painful (MP), adjacent to MP, and a control area. MPT will be assessed with pin-pricks (mN) applied to the skin. Subject reports when the stimulus feels sharp or blunt.

  1 - 6 months

• Mechanical Pain Sensitivity (MPS)

  A reduced psychophysical QST battery will be performed in 3 body areas: most painful (MP), adjacent to MP, and a control area. MPS will be assessed with pin-pricks and Q-tip, cotton swab, and brush applied to the skin. Subjects rate stimuli on scale of 0-100. In our protocol only 3 blocks.

  1 - 6 months

• Wind-Up Ratio (WUR)

  A reduced psychophysical QST battery will be performed in 3 body areas: most painful (MP), adjacent to MP, and a control area. WUR will be assessed with a pin-prick, which is applied 10 times in 10 seconds. Subjects rate the series on scale of 0-100. In our protocol, only 3 series.

  1 - 6 months

• Vibration Detection Threshold (VDT)

  A reduced psychophysical QST battery will be performed in 3 body areas: most painful (MP), adjacent to MP, and a control area. VDT will be assessed with a tuning fork applied to a bony prominence. Subject reports when the vibration can't be felt anymore.

  1 - 6 months

• Pressure Pain Threshold (PPT):

  A reduced psychophysical QST battery will be performed in 3 body areas: most painful (MP), adjacent to MP, and a control area. PPT will be assessed with an algometer (kg), applied to a muscle. Subject reports when pressure becomes painful.

  1 - 6 months

• Sympathetic Skin Responses (SSRs)

  Neurophysiological assessement of sweat activity in response to pain will be recorded with cap electrodes located at the hand. Painful heat stimulation will be applied with a thermode of the Pathway Medoc System. A train of 15 heat stimuli, with an inter-stimulus interval of 13-17 seconds, will be applied. The thermode baseline temperature will be 42ºC and during the stimulation the temperature will quickly ramp up to 52 ºC. Subjects are asked to rate the perception of the stimulus using a pain scale of 0-100. This procedure will be done two times: one at the most painful area of the patients, and the corresponding body area in the matched healthy volunteer, and at the volar forearm as a control pain-free area. This readout is a proxy for sympathetic nervous system activity.

  1 - 6 months

• Conditioned Pain Modulation (CPM)

  CPM measures the modulation of a noxious test stimulus by another noxious conditioning stimulus applied at a remote body region. In this study, test stimuli of different modalities (pressure, superficial mechanical, heat or electrical stimuli) will be applied at different body regions before and after or before, during and after a cold water bath or neutral water bath (hand immersion) as conditioning stimulus. Changes in test stimuli read-outs (during-before or after-before) will serve as CPM measure. Negative changes represent inhibitory, positive changes facilitatory CPM effects. For all test stimuli read-outs, CPM effects will be expressed as percentage changes. Test stimuli read-outs include: pain ratings on a scale of 0: no pain, to 100: most intense pain; perception thresholds and pain thresholds (in kg for pressure).

  1 - 6 months

• Brain resting state Magnetic Resonance Imaging (rsMRI)

  Measure of the brain's spontaneous activity acquired during resting state using a 7T Siemens scanner.

  1 - 6 months

• Lumbar Magnetic Resonance Imaging

  Structural resonance image of lumbar spine section acquired using a 3T Siemens scanner.

  1 - 6 months

• Brain Magnetic Resonance Spectroscopy (MRS)

  Imaging method that allows the detection of concentration of certain metabolites in the brain. This data will be acquired using a 3T Phillips scanner.

  1 - 6 months

• Blood Sample

  Blood sample of approximately 14 ml will be drawn, in a total of 3 tubes: PAXGene blood RNA tube, Serum tube, and K2 EDTA tube. This will allow analysis of inflammatory molecules (i.e. cytokines) and cell concentrations (i.e. immune cells).

  1 - 6 months

Secondary Outcomes (11)

• Anxiety and Depression

  1 - 6 months

• Pain Catastrophizing

  1 - 6 months

• Pain Sensitivity

  1 - 6 months

• Pain Self Efficacy

  1 - 6 months

• Back Awareness

  1 - 6 months

Study Arms (2)

Low Back Pain (LBP) Patients

LBP patients will undergo three study visits, at moments at which their pain status is different: a) "pain-free", b) low back pain (clinically relevant), c) experimental pain (clinically irrelevant). Measures will be repeated in each visit, to understand the influence / relationship of pain state on possible mechanistic alterations observed in LBP compared to HCs.

Behavioral: Pain Free Session; Behavioral: Low Back Pain Session (= clinically relevant pain); Behavioral: Experimental Pain Session (= clinically irrelevant pain)

Healthy Controls (HCs)

HCs will undergo one single visit, equivalent to patients' "pain-free" visit.

Behavioral: Pain Free Session

Interventions

Pain Free Session BEHAVIORAL

On a day in which participants don't have any pain or a pain ranging from 0-2 (on a numerical rating scale of 0-10), they will undergo all the study measures (see primary outcome measures for detail): clinical exam, QST, SSRs, CPM, rsMRI, lumbar MRI, MRS, and blood sample.

Healthy Controls (HCs); Low Back Pain (LBP) Patients

Low Back Pain Session (= clinically relevant pain) BEHAVIORAL

On a day in which patients have an ongoing typical low back pain episode of an intensity of 3 or more (on a numerical rating scale of 0-10), they will undergo all the study measures (see primary outcome measures for detail), except the lumbar MRI: clinical exam, QST, SSRs, CPM, rsMRI, MRS, and blood sample.

Low Back Pain (LBP) Patients

Experimental Pain Session (= clinically irrelevant pain) BEHAVIORAL

On a day in which participants don't have any pain or a pain ranging from 0-2 (on a numerical rating scale of 0-10), an experimental pain state will be induced using a high concentration (8%) Qutenza patch, containing capsaicin. All the study measures will be performed (see primary outcome measures for detail), except the lumbar MRI and blood sample: clinical exam, QST, SSRs, CPM, rsMRI, MRS.

Low Back Pain (LBP) Patients

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population consists of people that suffer from non-specific low back pain, meaning that their pain cannot reliably be attributed to a specific pathology and radiographic abnormalities correlate poorly with patients' symptoms. Participants should suffer from chronic episodic low back pain, meaning that they have had back pain pain for at least more than 3 months, with recurrent fluctuating pain episodes.

You may qualify if:

• German or English proficiency
• Informed consent
• Low back pain for more than 3 months
• Low back pain clinically not attributable to "red flags" (e.g. infection, fractures, inflammation)
• Fluctuating course of pain (with on and off pain periods).

You may not qualify if:

• Inability to give informed consent / follow study instructions (e.g. due to language problems)
• Major medical or psychiatric condition. E.g. severe heart disease, diabetes, autoimmune disorders, rheumatic disorders, major depressive disorder, etc.
• Symptomatic radiculopathy, manifested through motor and/or sensory deficits / or signs of nerve root involvement on lumbar MRI.
• Back operation
• BMI \> 30
• Pregnancy

Sponsors & Collaborators

• Schweinhardt Petra: lead

Study Sites (1)

Balgrist Campus

Zurich, 8008, Switzerland

RECRUITING

Biospecimen

Retention: SAMPLES WITH DNA

Blood serum

MeSH Terms

Conditions

Low Back Pain

Condition Hierarchy (Ancestors)

Back Pain; Pain; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Petra Schweinhardt

  University of Zurich

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Petra Schweinhardt

CONTACT

+41 44 386 57 24; petra.schweinhardt@balgrist.ch

Beatriz Chozas Barrientos

CONTACT

+41 77 809 72 12; beatriz.chozasbarrientos@balgrist.ch

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Prof. Dr. Med. PhD

Study Record Dates

• First Submitted: January 22, 2024
• First Posted: May 14, 2024
• Study Start: October 1, 2023
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: May 14, 2024

Record last verified: 2024-05

Locations

CH (1)