Pain physician
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Opioids are broad-spectrum analgesics with potent pain-relieving qualities but also with potential adverse effects related to both short-term and long-term therapy. Researchers have attempted to alter existing opioid analgesics, utilize different routes/formulations, or combine opioid analgesics with other compounds in efforts to improve analgesia while minimizing adverse effects. Exogenous opioids, administered in efforts to achieve analgesia, work by mimicking the actions of endogenous opioids. ⋯ This notion has been supported by the observation that the quaternary compound morphine methyliodide, which does not as readily cross the bloodbrain barrier and enter the CNS, produced antinociception following intradermal administration into the hindpaw, but not when the same dose was administered systemically (subcutaneously at a distant site). With a growing appreciation of peripheral endogenous opioids, peripheral endogenous opioid receptors, and peripheral endogenous opioid analgesic systems, investigators began growing hopeful that it may be possible to achieve adequate analgesics while avoiding unwanted central untoward adverse effects (e.g. respiratory depression, somnolence, addiction). Peripherally-acting opioids, which capitalize on peripheral endogenous opioid analgesic systems, may be one potential future strategy which may be utilized in efforts to achieve potent analgesia with minimal side effects.
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Chronic headache represents a very significant public health and economic issue. One treatment modality for chronic refractory headache involves the use of subcutaneous implanted neurostimulator leads in the occipital region. Varied types of headache etiologies including migraine, transformed migraine, chronic daily headache, cluster headache, hemicrania continua, occipital neuralgia, and cervicogenic headache have been studied with peripheral nerve field stimulation and found responsive to stimulation of the suboccipital region, known commonly as occipital nerve stimulation (ONS). ⋯ ONS is a useful tool in the treatment of chronic severe headaches with at least Level IV (limited) evidence based on multiple positive studies.
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Comparative Study
Influence of psychological variables on the diagnosis of facet joint involvement in chronic spinal pain.
Facet or zygapophysial joint pain is one of the common conditions responsible for chronic spinal pain. Controlled diagnostic blocks are considered the only means of reliable diagnosis of facet joint pain, due to the inability of physical examination, clinical symptoms, radiologic evaluation, and nerve conduction studies to provide a reliable diagnosis. The prevalence of facet joint pain has been established to be 15% to 45% of patients with low back pain, 39% to 67% of patients with neck pain, and 34% to 48% of patients with thoracic pain. However, using only a single block, false-positive rates of 27% to 63% in the cervical spine, 42% to 58% in the thoracic spine, and 17% to 50% in the lumbar spine have been reported. While there are multiple reasons for false-positive results, psychological variables may also contribute to false-positive results. A lack of influence of psychological factors on the validity of controlled diagnostic local anesthetic blocks of lumbar facet joints has been demonstrated. However, no such studies have been performed in the thoracic or cervical spine. ⋯ This study demonstrated that, based on patient psychopathology, there were no significant differences among the patients either in terms of prevalence or false-positive rates in the lumbar and thoracic regions. A higher prevalence and lower false-positive rates in the cervical region were established in patients with major depression.
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Occipital nerve stimulation is an emerging treatment modality for refractory headache disorders like migraine and cluster headache. Either percutaneous or surgical leads are implanted subcutaneously in the occipital region in an effort to stimulate the distal branches of the occipital nerves (C2-3). A number of complications of this technique have been reported, such as painful direct muscle stimulation and lead migration. ⋯ One patient underwent lead removal with reimplantation 1 month later; the other was managed with excision of a granuloma at the erosion site and prophylactic antibiotics. Both patients returned to excellent headache control. Lead erosion is a possible complication of occipital stimulation; strategies to reduce the risk of lead erosion are discussed, although further studies are needed to clarify the best surgical techniques.
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More than 50% of multiple sclerosis patients experience chronic pain syndrome. We set out to determine the specific type of chronic pain that was seen in our multiple sclerosis patients. ⋯ This study suggests that multiple sclerosis patients are at a higher risk of developing complex regional pain syndrome than the general population.