European journal of pain : EJP
-
Neuropathic pain is a chronic pain state resulting from peripheral nerve injury, characterized by hyperalgesia and allodynia. We have reported that mice with genetic impairment of IL-1 signaling display attenuated neuropathic pain behavior and ectopic neuronal activity. In order to substantiate the role of IL-1 in neuropathic pain, WT mice were implanted subcutaneously with osmotic micropumps containing either IL-1ra or vehicle. ⋯ To test whether IL-1 is involved in maintenance of mechanical allodynia, a separate group of WT mice was treated with a single injection of either saline or IL-1ra four days following SNT, after the allodynic response was already manifested. Whereas saline-treated mice displayed robust allodynia, acute IL-1ra treatment induced long-lasting attenuation of the allodynic response. The results support our hypothesis that IL-1 signaling plays an important role in neuropathic pain and in the ectopic neuronal activity that underling its development.
-
Randomized Controlled Trial
Population pharmacokinetic-pharmacodynamic modeling of ketamine-induced pain relief of chronic pain.
Pharmacological treatment of chronic (neuropathic) pain is often disappointing. In order to enhance our insight in the complex interaction between analgesic drug and chronic pain relief, we performed a pharmacokinetic-pharmacodynamic (PK-PD) modeling study on the effect of S(+)-ketamine on pain scores in Complex Regional Pain Syndrome type 1 (CRPS-1) patients. ⋯ Long-term S(+)-ketamine treatment is effective in causing pain relief in CRPS-1 patients with analgesia outlasting the treatment period by 50 days. These data suggest that ketamine initiated a cascade of events, including desensitization of excitatory receptor systems in the central nervous system, which persisted but slowly abated when ketamine molecules were no longer present.
-
Back pain is common and some sufferers consult GPs, yet many sufferers develop persistent problems. Combining information on risk of persistence and prognostic indicator prevalence provides more information on potential intervention targets than risk estimates alone. ⋯ Several factors increased risk of poor outcome in back pain patients, notably high pain and unemployment. These risks in combination with high prevalence of risk factors in this population distinguish factors that can help identify targets or sub-groups for intervention.
-
Autonomic neuropathy seems to play a central role in the development of gastrointestinal symptoms in diabetes. In order to explore the neuronal mechanisms behind the symptoms we evaluated the brain processing of painful visceral stimuli. ⋯ There is evidence of altered central processing to visceral stimulation, and both peripheral and central mechanisms seem involved. Central neuronal reorganisation may contribute to our understanding of the gastrointestinal symptoms in patients with diabetic autonomic neuropathy and this may guide development and evaluation of new treatment modalities.
-
Insensitivity to pain is a rare disorder that is commonly associated with Hereditary Sensory and Autonomic Neuropathies (HSAN I-V) resulting often in autonomic dysfunction and premature death. Very few individuals have been reported with pain insensitivity lacking such autonomic neuropathies. We performed genetic, neurologic, psychological, and psychophysical evaluations in such an individual (OMIM 243000) and her first degree relatives. ⋯ Congenital insensitivity to pain in our IC was associated with two novel SCN9A mutations which most likely resulted in a Nav1.7 channelopathy. However, in contrast to individuals with other SCN9A mutations, the observed pain insensitivity was relative and not absolute, which may be consistent with hypomorphic effects of one or both mutations. The ability to sense at least some danger signals may be advantageous and ameliorate the otherwise increased morbidity and mortality of some individuals with congenital insensitivity to pain.