Identifying Pain Generators and Potentiators of Residual Complaints Following Lumbar Discectomy

NCT05022251 | Terminated

• 2 other identifiers: BC-080413F014119
• Study Type: observational
• Target: 1
• Locations: 1 country
• Sites: 1

Brief Summary

Lumbar discectomy (i.e. surgically removing a hernia) is frequently performed in Belgium to treat lumbar radiculopathy. Every year \>12,000 interventions are performed with variable long-term results. The treatment success of this procedure varies and up to 41% of the patients report post-operative persistent pain complaints, and consequently suffer from failed back surgery syndrome (FBSS). Chronic complaints in FBSS following lumbar discectomy are usually treated with symptomatic interventions (including painkillers, neuromodulation, etc), rather than from a biopsychosocial perspective. In order to develop a focused and effective treatment strategy, it is crucial to first gain insight into how persons with persistent complaints after lumbar discectomy differ from those without persistent symptoms. Different known contributing factors entail type of surgery, muscle and psychosocial impairments. Although in scientific and clinical literature it is assumed that dysfunctional pain processing also plays an important mechanistic role in FBSS, there is a lack of research to support this. However, this knowledge is crucial to depict the full mechanistic picture of pain generators and potentiators in FBSS. Therefore, we will examine whether residual complaints persisting following lumbar discectomy can be accounted for by underlying dysfunctional pain processing and whether a clinical classification algorithm can be used to identify the predominant pain mechanism in these patients.

Conditions

Lumbar Radiculopathy; Central Sensitisation

Keywords

lumbar radiculopathy; discectomy; central sensitization

Outcome Measures

Primary Outcomes (13)

• Quantitative sensory testing (QST) - electrical detection threshold

  Determination of sensory detection thresholds in response to electrical stimuli which are delivered transcutaneously over the n. suralis and n. medianus, recorded in mA.

  Change from baseline (T1) at 3 months after surgery (T2)

• Quantitative sensory testing (QST) - electrical pain threshold

  Determination of sensory pain threshold in response to electrical stimuli which are delivered transcutaneously over the n. suralis and n. medianus, recorded in mA.

  Change from baseline (T1) at 3 months after surgery (T2)

• Quantitative sensory testing (QST) - thermal detection threshold

  Determination of sensory detection thresholds in response to thermal stimuli which are delivered to the skin using a thermode, recorded in °C: * cold detection threshold * warmth detection threshold

  Change from baseline (T1) at 3 months after surgery (T2)

• Quantitative sensory testing (QST) - thermal pain threshold

  Determination of sensory pain thresholds in response to thermal stimuli which are delivered to the skin using a thermode, recorded in °C: * cold pain threshold * heat pain threshold

  Change from baseline (T1) at 3 months after surgery (T2)

• Quantitative sensory testing (QST) - discrimination between thermal stimuli

  Determination of the number of paradoxical heat sensations in response to alternating cold and warm stimuli delivered to the skin using a thermode.

  Change from baseline (T1) at 3 months after surgery (T2)

• Quantitative sensory testing (QST) - tactile detection threshold

  Determination of tactile detection threshold, assessed using Von Frey monofilaments, recorded in mN

  Change from baseline (T1) at 3 months after surgery (T2)

• Quantitative sensory testing (QST) - mechanical pain threshold

  Determination of mechanical pain threshold, assessed using pinprick stimulators, recorded in mN

  Change from baseline (T1) at 3 months after surgery (T2)

• Quantitative sensory testing (QST) - sensitivity to pressure stimuli

  Determination of pressure pain threshold, assessed using pressure algometry, recorded in kg

  Change from baseline (T1) at 3 months after surgery (T2)

• Quantitative sensory testing (QST) - temporal summation of electrical stimuli

  Determination of temporal summation in response to electrical stimuli delivered transcutaneously over the skin of the n. suralis and n. medianus. The numerical pain rating in response to these stimuli (range 0 - 100) will be recorded.

  Change from baseline (T1) and 3 months after surgery (T2)

• Quantitative sensory testing (QST) - temporal summation of mechanical stimuli

  Determination of temporal summation in response to mechanical stimuli delivered using a 256mN pinprick stimulator. The numerical pain rating in response to these stimuli (range 0 - 100) will be recorded.

  Change from baseline (T1) and 3 months after surgery (T2)

• Quantitative sensory testing (QST) - spinal hyperexcitability

  Determination of spinal hyperexcitability using the nociceptive flexion reflex (NFR; sensitization of spinal cord neurons), recorded in mA

  Change from baseline (T1) and 3 months after surgery (T2)

• Quantitative sensory testing (QST) - temporal summation of spinal hyperexcitability

  Determination of temporal summation of the nociceptive flexion reflex (NFR; sensitization of spinal cord neurons), recorded using a numeric pain rating scale (range 0 - 100)

  Change from baseline (T1) and 3 months after surgery (T2)

• Quantitative sensory testing - conditioned pain modulation

  Determination of condition pain modulation (aka. pain inhibits pain) by means of a heterotopic noxious counterstimulation paradigm. Test stimuli comprise of pressure pain threshold assessments and application of a heat stimulus (using a thermode) corresponding to a temperature eliciting a visual analog scale rating of 5/10. Test stimuli will be applied before, during and after the conditioning stimulus which is the immersion of the hand in a hot circulating water bath of 45.5°C.

  Change from baseline (T1) and 3 months after surgery (T2)

Secondary Outcomes (20)

• Central sensitization inventory

  Baseline (T1)

• Central sensitization inventory

  3 months after surgery (T2)

• Douleur Neuropathique 4 Questionnaire

  Baseline (T1)

• Douleur Neuropathique 4 Questionnaire

  3 months after surgery (T2)

• Pain catastrophizing scale

  Baseline (T1)

Study Arms (2)

Lumbar radiculopathy

Lumbar radiculopathy patients (n=122), classified as ASA I to II without any symptoms of spinal cord compression (i.e. bilateral leg pain), who are scheduled for a first-time, single-level, unilateral lumbar discectomy.

Procedure: Lumbar discectomy

Healthy controls

Sex, age, and BMI-matched healthy, pain-free control subjects (n=122) will be recruited for study participation.

Interventions

Lumbar discectomy PROCEDURE

surgically removing a hernia

Lumbar radiculopathy

Eligibility Criteria

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

Study Population

Lumbar radiculopathy patients scheduled for first-time, single level, unilateral lumbar discectomy. Sex, age, and BMI matched healthy controls.

You may qualify if:

• Dutch speaking
• Body mass index below 35kg/m²
• Lumbar radiculopathy patients, classified as ASA I to II without any symptoms of spinal cord compression (i.e. bilateral leg pain), who are scheduled for a first-time, single-level, unilateral lumbar discectomy
• Healthy, pain-free controls (score 0 on a visual analogue scale from 0 to 100)

You may not qualify if:

• Female participants will be excluded if pregnant, lactating or \<1 year postnatal
• Having (a history) of severe medical disorders either respiratory (e.g. cystic fibrosis), orthopedic (e.g. whiplash trauma), neurologic (e.g. cerebrovascular incident), cardiovascular (e.g. severe hypertension), endocrinological (e.g. diabetes), psychiatric (e.g. post-traumatic stress disorder
• Having a history of spinal surgery (e.g. discectomy), spinal traumata (e.g. vertebral fracture) or severe spinal deformities (e.g. spondylolisthesis)
• Having a pacemaker or defibrillator
• Healthy controls will be excluded if having suffered low back pain in the preceding year of score 2 or higher on the visual analog scale and which limited their activities of daily living or for which they consulted a (para)medic.

Sponsors & Collaborators

• University Ghent: lead
• Research Foundation Flanders: collaborator

Study Sites (1)

Ghent University (Hospital)

Ghent, Belgium

Location

MeSH Terms

Conditions

Radiculopathy

Condition Hierarchy (Ancestors)

Peripheral Nervous System Diseases; Neuromuscular Diseases; Nervous System Diseases

Study Officials

• Jessica Van Oosterwijck, PhD

  Ghent University; Research Foundation Flanders

  STUDY DIRECTOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 12, 2021
• First Posted: August 26, 2021
• Study Start: October 1, 2021
• Primary Completion: October 31, 2023
• Study Completion: October 31, 2023
• Last Updated: December 20, 2023

Record last verified: 2023-12

Locations

BE (1)