Articles: chronic-pain.
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Objectives. Electrical brain stimulation is used as a treatment for patients with intractable chronic pain and movement disorders. However, the implantation of electrodes and electrical stimulation may induce histological changes around the electrode tip. We aimed to review the histological changes in humans that were electrically stimulated in the brain. ⋯ Macroscopic lesions were present in only some cases, mostly due to pulling at the extension cable in the postoperative evaluation period preceding definite implantation of the electrode wire and stimulator. Conclusions. Electrical brain stimulation induces histological changes in some patients. According to electrical brain stimulation studies in animals, these changes can be related to the charge and charge density per phase (and their interaction).
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Introduction. Early animal and human evidence existed for a postsynaptic dorsal column (PSDC) pathway for visceral nociception that, when lesioned, decreased pain of terminal illness. There have been recent anecdotal reports in the literature that spinal cord stimulation (SCS) reduces pain of visceral nociception. We present here a review of the literature supporting a hypothesis that SCS might work by modulating information through the spinothalamic tracts (STT) and PSDC. ⋯ Conclusions. Chronic visceral nociception may be secondary to visceral sensitization and hyperalgesia and can be affected by the spinal cord and brain, the "brain-gut" axis. There is preclinical evidence and clinical anecdotes that this nociceptive information is transmitted in the central nervous system through the PSDC pathway and LSTT and that SCS decreases pain of visceral nociception. It may be that SCS works by modulation of the above pathways.
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Chronic, noncancer pain such as that associated with osteoarthritis of the hip and knee is typically managed according to American College of Rheumatology guidelines. Patients unresponsive to first-line treatment with acetaminophen receive nonsteroidal antiinflammatory drugs (NSAIDs), including cyclooxygenase-2 (COX-2) inhibitors. However, many patients may have chronic pain that is refractory to these agents, or they may be at risk for the gastrointestinal, renal, and cardiovascular complications associated with their use. ⋯ Unlike nonselective NSAIDs and COX-2 inhibitors, tramadol ER is not associated with gastrointestinal, renal, or cardiovascular complications. Although tramadol is an opioid agonist, significant abuse has not been demonstrated after long-term therapy. It is concluded that tramadol ER has an efficacy and safety profile that warrants its early use for the management of chronic pain, either alone or in conjunction with nonselective NSAIDs and COX-2 inhibitors.
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Objective. When using spinal cord stimulation (SCS) for chronic pain management, precise longitudinal positioning of the cathode is crucial to generate an electrical field capable of targeting the neural elements involved in pain relief. Presently used methods have a poor spatial resolution and lack postoperative flexibility needed for fine tuning and reprogramming the stimulation field after lead displacement or changes in pain pattern. We describe in this article a new method, "electrical field steering," to control paresthesia in SCS. ⋯ Conclusions. By means of cathodal steering on a longitudinal contact array, the group of excited DC and DR fibers, and thus paresthesia coverage, can be controlled when using SCS. With widely spaced contacts, superposition of the electrical field from each steering contact is limited. To precisely control segmental paresthesia (DR stimulation), a small contact spacing is necessary.
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Objectives. Vertebral fractures are the most common consequences of severe osteoporosis. The chronic pain from collapse of osteoporotic vertebrae affects quality of life (QoL) and autonomy of patients. The management of pain with oral or transdermal opiates can cause severe side-effects. ⋯ The mean morphine dose during the spinal trial was 11.28 mg/day, 7.92 mg/day at pump implantation, and 16.32 mg/day at one-year follow-up. Conclusions. Our results show that intrathecal administration of morphine efficiently relieves the symptoms of pain and improves QoL. Continuous intrathecal administration of morphine appears to be an alternative therapy to conventional analgesic drug delivery and has advantages in those patients who have severe side-effects with systemic administration of analgesics.