Pain
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Patients with borderline personality disorder, mostly female, exhibit severe autoaggressive behavior, namely an intentionally performed, nonsuicidal self-injury and severe blunting of pain perception, the mechanism of which is hitherto not understood. Because the nociceptive system displays a high degree of plasticity, the aim of this study was to analyze the relationship of pain perception to self-injurious behavior. Pain perception of mechanical and chemical noxious stimuli was studied by quantitative sensory testing in 22 patients (15 female, 7 male) with borderline personality disorder (BPD) according to DSM-IV and 22 age- and gender-matched controls. ⋯ Blunting of pain sensation was significantly predicted by the recency of self-injurious behavior (multiple r=0.58). In line with recent data, we suggest an excess of endogenous antinociception in BPD patients resulting from self-inflicted multiple injuries. This exaggerated pain control is conceived to operate via an uncoupling of the evaluative or emotional-affective from the sensory-discriminative dimension of pain.
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This study sought to determine whether mothers of young people with chronic abdominal pain (CAP) compared to mothers of pain-free children show a pain recognition bias when they classify facial emotional expressions. One hundred demographically matched mothers of children with CAP (n=50) and control mothers (n=50) were asked to identify different emotions expressed by adults in 2 experiments. In experiment 1, participants were required to identify the emotion in a series of facial images that depicted 100% intensity of the following emotions: Pain, Sadness, Anger, Fear, Happiness, and Neutral. ⋯ Mean response times for CAP and control groups did not differ significantly. Mothers of children with CAP did not report more anxiety, depression, and anxiety sensitivity compared to control mothers. It is concluded that mothers of children with CAP show a pain bias when interpreting ambiguous emotional expressions, which possibly contributes to the maintenance of this condition in children via specific parenting behaviours.
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Clinical Trial
Compound action potentials recorded in the human spinal cord during neurostimulation for pain relief.
Electrical stimulation of the spinal cord provides effective pain relief to hundreds of thousands of chronic neuropathic pain sufferers. The therapy involves implantation of an electrode array into the epidural space of the subject and then stimulation of the dorsal column with electrical pulses. The stimulation depolarises axons and generates propagating action potentials that interfere with the perception of pain. ⋯ The minimally invasive recording technique we have developed provides data previously obtained only through microelectrode techniques in spinal cords of animals. Our observations also allow the development of systems that use neuronal recording in a feedback loop to control neurostimulation on a continuous basis and deliver more effective pain relief. This is one of numerous benefits that in vivo electrophysiological recording can bring to a broad range of neuromodulation therapies.
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Migraine is a common and disabling neurological disease. The pathomechanism that underlies the disorder is not entirely understood, and reliable biomarkers are missing. In the current analysis we looked for microstructural alterations of the brain white matter in migraine patients by means of diffusion-weighted magnetic resonance imaging. ⋯ In the same region we also found increased mean diffusivity and increased radial diffusivity. The probabilistic tractography showed connection of this cluster to other parts of the pain network (orbitofrontal cortex, insula, thalamus, dorsal midbrain). We speculate that these findings reflect maladaptive plastic changes or white matter disintegration.