Pain
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Randomized Controlled Trial
Association between clinical signs assessed by manual segmental examination and findings of the lumbar facet joints on magnetic resonance scans in subjects with and without current low back pain: A prospective, single-blind study.
The relevance of magnetic resonance imaging (MRI) findings such as facet joint (FJ) effusion and edema in low back pain (LBP) is still unknown. Therefore, we prospectively evaluated the presence of these MRI findings in the lumbar spine (Th12-S1) and their association with pain evoked by manual segmental FJ provocation tests (spinal percussion, springing, and segmental rotation tests) in 75 subjects with current LBP (≥30 days in the past 3 months) compared with 75 sex- and age-matched control subjects. FJs were considered painful, if ≥ 1 provocation test triggered LBP. ⋯ True-positive findings occurred in 16% of LBP FJs and in 2% of control FJs (P<0.01); 46 LBP subjects (61%) and 9 control subjects (12%, P<0.01) had true-positive findings. Pain on provocation and FJ effusion and/or edema were significantly correlated only in patients with LBP. In conclusion, only true-positive findings (ie, concurrent effusion and/or edema and positive provocation test results in the same FJ) discriminate well enough between control subjects and subjects with current LBP, whereas neither effusion and/or edema nor FJ provocations tests alone are suitable to detect suspected FJ arthropathy.
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Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterized by recurring abdominal pain associated with alterations in bowel habits. We hypothesized that patients with chronic visceral pain associated with IBS may have microstructural differences in the brain compared with healthy control subjects (HCs), indicative of long-term neural reorganization of chronic pain pathways and regions associated with sensory integration. In the current study we performed population-based voxel-wise diffusion tensor imaging (DTI) comparisons and probabilistic tractography in a large sample of phenotyped patients with IBS (n=33) and in HCs (n=93). ⋯ Sex differences in FA and MD were also observed in the patients but not in HCs. Probabilistic tractography in patients confirmed a higher degree of connectivity between the thalamus and prefrontal cortex, as well as between the medial dorsal thalamic nuclei and anterior cingulate cortex, and a lower degree of connectivity between the GP and thalamus. Together, these results support the hypothesis that patients with chronically recurring visceral pain from IBS have long-term microstructural changes within the brain, particularly in regions associated with integration of sensory information and corticothalamic modulation.
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Pain and sensitization are major issues in patients with osteoarthritis both before and after total knee arthroplasty (TKA) and revision TKA (re-TKA). The aim of this study was to assess sensitization in patients with and without chronic pain after re-TKAs. Twenty patients with chronic knee pain and 20 patients without pain after re-TKA participated. ⋯ Additionally, significant correlations between knee pain intensity and cuff PPTs, temporal summation, and CPM and between total duration of knee pain and temporal summation were found (P<.05). This study demonstrated widespread sensitization in patients with pain after re-TKA and highlighted the importance of ongoing nociceptive input for the chronification process. This has important implications for future revisions, and precautions should be taken if patients have widespread sensitization.
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Previous research in health and disease has shown that exposure to pain changes the density of cortical grey matter (GM). Such structural changes of the brain might, however, depend crucially on how this pain experience is evaluated and processed in the brain. In the present study we aimed to detect pain-rating patterns and underlying GM changes after the application of repetitive painful stimulation using voxel-based morphometry (VBM). ⋯ By contrast, pain habituaters did not show any density changes in the GM. Depending on the individual perception of pain during the time course of stimulation, the repetitive application of painful stimuli changed the GM density in pain-processing brain regions exclusively in those subjects who were characterised by the lack of habituation. Because VBM studies investigating patients experiencing chronic pain observed similar decreases in GM density and increasing pain ratings over time, the sensitisers in our study may have a higher vulnerability to developing chronic pain syndromes in later life.
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Quantitative sensory testing (QST) is a psychophysical method used to quantify somatosensory function in response to controlled stimuli in healthy subjects and patients. Although QST shares similarities with the quantitative assessment of hearing or vision, which is extensively used in clinical practice and research, it has not gained a large acceptance among clinicians for many reasons, and in significant part because of the lack of information about standards for performing QST, its potential utility, and interpretation of results. A consensus meeting was convened by the Neuropathic Pain Special Interest Group of the International Association for the Study of Pain (NeuPSIG) to formulate recommendations for conducting QST in clinical practice and research. ⋯ For the conduct of QST in healthy subjects and in patients, we recommend use of predefined standardized stimuli and instructions, validated algorithms of testing, and reference values corrected for anatomical site, age, and gender. Interpretation of results should always take into account the clinical context, and patients with language and cognitive difficulties, anxiety, or litigation should not be considered eligible for QST. When appropriate standards, as discussed here, are applied, QST can provide important and unique information about the functional status of somatosensory system, which would be complementary to already existing clinical methods.