Prognostic Value of Measures of the Central Hypersensitivity in Patients With Acute Low Back Pain

This study is currently recruiting participants. (see Contacts and Locations)
Verified December 2012 by University Hospital Inselspital, Berne
Sponsor:
Information provided by (Responsible Party):
University Hospital Inselspital, Berne
ClinicalTrials.gov Identifier:
NCT00892411
First received: May 1, 2009
Last updated: December 17, 2012
Last verified: December 2012
  Purpose

Background. Patients with chronic low back pain display hyperexcitability of the central nervous system (central hypersensitivity). Such hypersensitivity may occur in the acute phase and represent a risk factor for the development of chronic pain.

Objective. To determine the prognostic value of central hypersensitivity for the development of chronic low back pain.

Design. Prospective cohort study.

Setting. Primary care.

Patients. 140 individuals with acute low back pain and no history of chronic pain.

Outcomes. Primary prognostic variable will be the pain tolerance threshold at the second toe (the pressure intensity at which a further increase in pressure is deemed intolerable). Exploratory secondary prognostic variables are measures of mechanisms related to central hypersensitivity: stimulus-specific hypersensitivity (pressure, electrical, heat and cold stimulation); tissue-specific hypersensitivity (skin vs. muscle stimulation); localized vs. widespread hypersensitivity; spinal cord modulation (electrophysiological measures of hypersensitivity and changes in receptive fields); modulation at brain level (descending modulation of nociceptive input and cortical plasticity). Clinical primary outcome will be the occurrence of chronic low back pain at follow-up.

Main analysis. The investigators will use least square logistic regression models to determine the association of central hypersensitivity with prognosis.

Relevance. An understanding of the prognostic value of central hypersensitivity may allow an early stratification for treatment of individuals at risk of developing chronic low back pain. Subgroups of patients may be selected for clinical trials on novel pharmacological approaches for the prevention and treatment of central hypersensitivity.


Condition
Pain Measurement
Low Back Pain

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Prognostic Value of Measures of Central Hypersensitivity in Patients With Low Back Pain

Resource links provided by NLM:


Further study details as provided by University Hospital Inselspital, Berne:

Primary Outcome Measures:
  • Presence or absence of chronic low back pain [ Time Frame: 6 months after the acute episode ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Mechanisms of central hypersensitivity [ Time Frame: During the acute episode of low back pain ] [ Designated as safety issue: No ]

Estimated Enrollment: 140
Study Start Date: February 2009
Estimated Study Completion Date: December 2013
Estimated Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Groups/Cohorts
1
Patients With Acute Low Back Pain

Detailed Description:

Background

Prolonged afferent nociceptive input induces an increase in the excitability of central sensory neurons and plasticity changes that cause hyperexcitability of the central nervous system (central hypersensitivity. The hyperexcitable central nervous system amplifies the nociceptive signal, thereby producing an exaggerated pain response even in the presence of limited tissue damage.

Using quantitative sensory tests, central hypersensitivity has been detected in different chronic musculoskeletal pain syndromes. Patients with chronic low back pain display increased pain sensitivity and enlargement of the areas of referred pain after stimulation of tissues around and distant from the site of pain (i.e. the leg or the thumb), suggesting that widespread central hypersensitivity is associated with this condition. Functional reorganization of the cortex has been detected in different pain conditions, including low back pain. Using equal levels of sensory stimulation in patients and pain-free controls, patients with chronic low back pain showed more extensive patterns of neuronal activation in pain-related cortical areas.

An investigation on patients after a whiplash injury found that those patients with persistent moderate or severe symptoms at 6 months had displayed, soon after injury, widespread hypersensitivity. Therefore, central hypersensitivity may be an indicator of poor prognosis. An acute peripheral lesion may induce plasticity changes leading to central hypersensitivity in a subset of individuals. Such a hypersensitivity would facilitate the transition from acute to chronic pain and disability. This hypothesis has been investigated using a limited number of tests only in a limited number of individuals with whiplash injury, but not in any other condition.

Objective

To determine the prognostic value of different measures of mechanisms of central hypersensitivity in patients with acute low back pain.

Methods

140 consecutive Patients with acute low back pain, referred by general practice, will be studied prospectively. Primary prognostic variable will be the pain tolerance threshold at the second toe (the pressure intensity at which a further increase in pressure is deemed intolerable). Exploratory secondary prognostic variables are measures of mechanisms related to central hypersensitivity: stimulus-specific hypersensitivity (pressure, electrical, heat and cold stimulation); tissue-specific hypersensitivity (skin vs. muscle stimulation); localized vs. widespread hypersensitivity; spinal cord modulation (electrophysiological measures of hypersensitivity and changes in receptive fields); modulation at brain level (descending modulation of nociceptive input and cortical plasticity). Clinical primary outcome will be the occurrence of chronic low back pain at follow-up. We will use least square logistic regression models to determine the association of central hypersensitivity with prognosis.

  Eligibility

Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population

Patients with acute low back pain referred from primary care.

Criteria

Inclusion Criteria:

  • Acute low back pain < 6 weeks
  • Age 18-80

Exclusion Criteria

  • History of chronic low back pain
  • Radicular pain
  • Pregnancy
  • Breast feeding
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00892411

Contacts
Contact: Michele Curatolo, MD, PhD +41 31 632 8322 michele.curatolo@insel.ch

Locations
Switzerland
Dep. of Anesthesiology and Pain Therapy, Bern University Hospital Recruiting
Bern, Switzerland, 3010
Contact: Michele Curatolo, MD, PhD    0041-31-632 0133    michele.curatolo@insel.ch   
Principal Investigator: Monika Müller, MD, PhD         
Sponsors and Collaborators
University Hospital Inselspital, Berne
Investigators
Study Director: Michele Curatolo, MD, PhD Dep. of Anesthesiology and Pain Therapy, Bern University Hospital
Principal Investigator: Monika Müller, MD, PhD Dep. of Anesthesiology and Pain Therapy, Bern University Hospital
  More Information

No publications provided

Responsible Party: University Hospital Inselspital, Berne
ClinicalTrials.gov Identifier: NCT00892411     History of Changes
Other Study ID Numbers: KEK 103/08
Study First Received: May 1, 2009
Last Updated: December 17, 2012
Health Authority: Switzerland: Ethikkommission

Keywords provided by University Hospital Inselspital, Berne:
Neuroplasticity
Prognosis

Additional relevant MeSH terms:
Back Pain
Hypersensitivity
Low Back Pain
Pain
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Immune System Diseases

ClinicalTrials.gov processed this record on July 26, 2014