Effects of a multimodal pain therapy on neurotransmitter turnover and functional connectivity in patients with chronic back pain.
- Conditions
- chronic back painM54.0M54.2M54.3M54.4M54.5M54.6M54.8M54.9Panniculitis affecting regions of neck and back
- Registration Number
- DRKS00009849
- Lead Sponsor
- Arbeitsgruppe medizinische PhysikInstitut für diagnostische und interventionelle Radiologie (IDIR)
- Brief Summary
Functional reorganisation of the salience network (SN) has been proposed as one of the key pathomechanisms associated with central nociceptive processing in the chronic pain state. Being associated with an altered functional connectivity within the SN, these processes have been hypothesized to result from a loss of inhibitory function leading to node hyperexcitability and spontaneous pain. Combined resting-state BOLD functional magnetic resonance imaging (MRI) and 1H-MR spectroscopy was applied to chronic back pain patients and healthy subjects to assess deviations from functional integrity (weighted closeness centrality [wCC], derived from resting-state functional MRI), oscillatory BOLD characteristics (spectral power), and neurotransmitter levels (GABA+, glutamate+glutamine) in 2 key SN nodes, anterior insular (aInsR) and anterior mid-cingulate cortices. In addition, examinations were repeated in chronic back pain patients after a 4-week interdisciplinary multimodal pain treatment and in healthy subjects after 4 weeks to explore longitudinal, treatment-mediated changes in target variables. The aInsR and, to a lesser extent, the anterior mid-cingulate of patients exhibited significantly reduced wCC accompanied by a spectral power shift from a lower to a higher frequency band, indicating a desynchronization of their neuronal activity within the SN, possibly because of increased spontaneous activations. Without revealing neurotransmitter differences, patients alone showed significant positive associations between local GABA+ levels and wCC in aInsR, suggesting a stronger dependence of node synchronization on the inhibitory tone in the chronic pain state. However, this needs to be explored in the future using magnetic resonance spectroscopy techniques that are more sensitive to detecting subtle neurotransmitter changes and also allow multifocal characterization of neurotransmitter tone.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Complete
- Sex
- All
- Target Recruitment
- 71
(1) chronic back pain since 6 months or more with pain intensity of more than 3 (11-step NRS) that cannot be adequately ascribed to any somatic impairment
(2) Age between 20-65 years
(3) Right-handedness
(4) suitability for MRI assessment
(5) written informed consent
(1) primary somatic pain origns (e.g. herniated disc), which can be adressed with other dedicated therapeutic approach
(2) sensomotoric deficits of affected back area or corresponding nerve roots (i.e. symptoms of radicular pain)
(3) serious neurological or acute psychiatric comorbidities, cerebral abnormailities or brain developement deficits
(4) substance addiction
(5) benzodiazepine medication
Study & Design
- Study Type
- observational
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method resting-state fMRI (functional connectivity) and MEGA-PRESS MR-spectroscopy (GABA and glutamate concentrations) focussing the insular and anterior cingular cortex as well as the medial prefrontal cortex: <br>(1) Comparison of neurotransmitter concentrations and functional connectivity patterns between patients and healthy controls at baseline.<br><br>(2) Comparisons of neurotransmitter changes and changes in functional connectivity between therapy group and waiting group at baseline and 4 weeks later.
- Secondary Outcome Measures
Name Time Method Pain intensities (numeric rating scales), pain interference (Pain Disability Index), pain catastrophizing (Pain Catastrophizing Scale), pain experience (Short Form McGill pain questionnaire), quality of life (SF-12), symptoms of depression (Hospital Anxiety and Depression scale): <br><br>(1) therapy induced changes in questionnaire in the therapy group and compared to waiting group between baseline and 4 weeks later (2) correlative analysis of changes in neurotransmitter concentration and functional connectivity and questionnaire data