European journal of pain : EJP
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The present study is the first demonstration of prolonged nociceptive behavior in the trigeminal region following compression of the trigeminal ganglion in rats. Experiments were carried out on male Sprague-Dawley rats mounted onto a stereotaxic frame under pentobarbital sodium anesthesia. For compression of the trigeminal ganglion, a 4% agar solution (8microl) was injected into the trigeminal ganglion through a stainless steel injector (24 gauge), which extended 2mm beyond the end of a guide cannula (21 gauge). ⋯ Although mechanical allodynia and hyperalgesia appeared bilaterally, the ipsilateral side was significantly more sensitive. Intraperitoneal treatment with carbamazepine significantly blocked mechanical allodynia produced by compression of the trigeminal ganglion. These findings suggest that prolonged nociceptive behavior following compression of the trigeminal ganglion may mimic trigeminal neuralgia in this animal model.
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Randomized Controlled Trial
Perioperative ketamine does not prevent chronic pain after thoracotomy.
Thoracotomy is often responsible for chronic pain, possibly of neuropathic origin. To confirm preclinical studies, the preventive effects of perioperative ketamine were tested in a randomized, double-blind, placebo-controlled clinical trial on persistent neuropathic pain after thoracotomy. Eighty-six patients scheduled for thoracotomy under standardised general anaesthesia were randomised to receive either ketamine (1 mg kg(-1) at the induction, 1 mg kg(-1) h(-1) during surgery, then 1 mg kg(-1) during 24 h; n=42) or normal saline (n=44). ⋯ Ketamine improved immediate postoperative pain, but the groups were similar in terms of neuropathic pain and intake of analgesics, 6 weeks (NPSI score: ketamine: 1.25 [0-4.125]; placebo: 1 [0-4]) and 4 months after surgery. Thus, ketamine given in 24-h infusion failed to prevent chronic neuropathic pain after thoracotomy. Other perioperative preventive long-lasting treatments or techniques could be tested in this context.
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Randomized Controlled Trial
Cannabinoid-induced effects on the nociceptive system: a neurophysiological study in patients with secondary progressive multiple sclerosis.
Although clinical studies show that cannabinoids improve central pain in patients with multiple sclerosis (MS) neurophysiological studies are lacking to investigate whether they also suppress these patients' electrophysiological responses to noxious stimulation. The flexion reflex (FR) in humans is a widely used technique for assessing the pain threshold and for studying spinal and supraspinal pain pathways and the neurotransmitter system involved in pain control. In a randomized, double-blind, placebo-controlled, cross-over study we investigated cannabinoid-induced changes in RIII reflex variables (threshold, latency and area) in a group of 18 patients with secondary progressive MS. ⋯ The visual analogue scale score for pain also decreased, though not significantly. Conversely, the H/M ratio measured before patients received cannabinoids remained unchanged after therapy. In conclusion, the cannabinoid-induced changes in the RIII reflex threshold and area in patients with MS provide objective neurophysiological evidence that cannabinoids modulate the nociceptive system in patients with MS.
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Randomized Controlled Trial Comparative Study Clinical Trial
Effectiveness of a behaviour graded activity program versus conventional exercise for chronic neck pain patients.
Chronic neck pain is a common complaint in the Netherlands with a point prevalence of 14.3%. Patients with chronic neck pain are often referred to physiotherapy and, nowadays, are mostly treated with exercise therapy. It is, however, unclear which type of exercise therapy is to be preferred. ⋯ In both BGA and CE some patients reported recovery from complaints and daily function but the proportion of recovered patients did not exceed 50% during the 12-month follow-up period. Both groups showed clinically relevant improvements in physical secondary outcomes. International Standard Randomised Controlled Trial Number: ISRCTN88733332.