Prognostic Value of Measures of the Central Hypersensitivity in Patients With Acute Low Back Pain
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| First Received Date ICMJE | May 1, 2009 | ||||||||
| Last Updated Date | December 17, 2012 | ||||||||
| Start Date ICMJE | February 2009 | ||||||||
| Estimated Primary Completion Date | December 2013 (final data collection date for primary outcome measure) | ||||||||
| Current Primary Outcome Measures ICMJE |
Presence or absence of chronic low back pain [ Time Frame: 6 months after the acute episode ] [ Designated as safety issue: No ] | ||||||||
| Original Primary Outcome Measures ICMJE | Same as current | ||||||||
| Change History | Complete list of historical versions of study NCT00892411 on ClinicalTrials.gov Archive Site | ||||||||
| Current Secondary Outcome Measures ICMJE |
Mechanisms of central hypersensitivity [ Time Frame: During the acute episode of low back pain ] [ Designated as safety issue: No ] | ||||||||
| Original Secondary Outcome Measures ICMJE | Same as current | ||||||||
| Current Other Outcome Measures ICMJE | Not Provided | ||||||||
| Original Other Outcome Measures ICMJE | Not Provided | ||||||||
| Descriptive Information | |||||||||
| Brief Title ICMJE | Prognostic Value of Measures of the Central Hypersensitivity in Patients With Acute Low Back Pain | ||||||||
| Official Title ICMJE | Prognostic Value of Measures of Central Hypersensitivity in Patients With Low Back Pain | ||||||||
| Brief Summary | 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. |
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| 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. |
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| Study Type ICMJE | Observational | ||||||||
| Study Design ICMJE | Observational Model: Cohort Time Perspective: Prospective |
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| Target Follow-Up Duration | Not Provided | ||||||||
| Biospecimen | Not Provided | ||||||||
| Sampling Method | Probability Sample | ||||||||
| Study Population | Patients with acute low back pain referred from primary care. |
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| Condition ICMJE |
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| Intervention ICMJE | Not Provided | ||||||||
| Study Group/Cohort (s) | 1
Patients With Acute Low Back Pain |
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| Publications * | Not Provided | ||||||||
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* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline. |
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| Recruitment Information | |||||||||
| Recruitment Status ICMJE | Recruiting | ||||||||
| Estimated Enrollment ICMJE | 140 | ||||||||
| Estimated Completion Date | December 2013 | ||||||||
| Estimated Primary Completion Date | December 2013 (final data collection date for primary outcome measure) | ||||||||
| Eligibility Criteria ICMJE | Inclusion Criteria:
Exclusion Criteria
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| Gender | Both | ||||||||
| Ages | 18 Years to 80 Years | ||||||||
| Accepts Healthy Volunteers | No | ||||||||
| Contacts ICMJE |
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| Location Countries ICMJE | Switzerland | ||||||||
| Administrative Information | |||||||||
| NCT Number ICMJE | NCT00892411 | ||||||||
| Other Study ID Numbers ICMJE | KEK 103/08 | ||||||||
| Has Data Monitoring Committee | No | ||||||||
| Responsible Party | University Hospital Inselspital, Berne | ||||||||
| Study Sponsor ICMJE | University Hospital Inselspital, Berne | ||||||||
| Collaborators ICMJE | Not Provided | ||||||||
| Investigators ICMJE |
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| Information Provided By | University Hospital Inselspital, Berne | ||||||||
| Verification Date | December 2012 | ||||||||
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ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP |
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