Articles: chronic-pain.
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Objectives. Although the load impedance of a pulse generator has a significant effect on battery life, the electrical impedance of contact arrays in spinal cord stimulation (SCS) has not been extensively studied. We sought to characterize the typical impedance values measured from common quadripolar percutaneous SCS contact arrays. Methods. In 36 patients undergoing percutaneous trial stimulation for various chronic pain conditions, bipolar impedance between adjacent contacts of 64 leads with 9 mm center-to-center spacing was measured in two different vertebral level regions, cervical (C3-C7) and lower-thoracic (T7-T12). ⋯ Conclusions. Results from finite-difference mathematical modeling of SCS suggest that the difference in tissue impedance related to vertebral level may be due to the dorsoventral position of the lead in the epidural space. The presence of a larger space between the triangularly shaped dorsal part of the vertebral arch and the round shape of the dural sac in the lower-thoracic region increases the likelihood that the stimulating lead will not make dural contact, and thus "see" an increased impedance from the surrounding epidural fat. This implies that the energy requirements for stimulation in the thoracic region will be higher than in the cervical region, at least during the acute phase of implant.
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Assessment and management of pain for nursing home residents is frequently reported to be inadequate, yet few studies have used objective criteria to measure the quality of care related to pain. ⋯ Infrequent or incomplete physician pain assessment and treatment and inaccurate documentation by licensed nurses limits evaluation of pain care quality based on medical record review alone. A brief resident interview identified participants reporting symptoms of chronic pain not documented in the medical record and those with a preference for medication. Initial targeting of residents with self-reported pain maximizes the efficiency of the standardized scoring system described in this study. Focusing on explicit process measures clearly identifies areas for improvement and represents an important step in assessing the quality of pain care in the NH.
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Ziconotide is an N-type calcium channel (NCC) blocking conopeptide, acting primarily at the NCC-rich dorsal horn. Reported here is an early experience with intrathecal ziconotide in a 55-year-old man with chronic pain resulting from failed back surgery. ⋯ The dosing regimen, onset and resolution of adverse events, and improvement on the primary efficacy measure, the Visual Analog Scale of Pain Intensity, are discussed. Overall, the patient responded positively to ziconotide.
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Postherpetic neuralgia (PHN) is defined as pain that persists 1 to 3 months following the rash of herpes zoster (HZ). PHN affects about 50% of patients over 60 years of age and 15% of all HZ patients. Patients with PHN may experience two types of pain: a steady, aching, boring pain and a paroxysmal lancinating pain, usually exacerbated by contact with the involved skin. ⋯ Although antiviral agents are appropriate for acute HZ, and the use of neural blockade and sympathetic blockade may be helpful in reducing pain in selected patients with HZ, there is little evidence that these interventions will reduce the likelihood of developing PHN. Postherpetic neuralgia remains a difficult pain problem. This review describes the epidemiology and pathophysiology of PHN and discusses proposed mechanisms of pain generation with emphasis on the various pharmacological treatments and invasive modalities currently available.
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Zhonghua yi xue za zhi · Oct 2005
[Analgesic effect of intrathecal transplant of immortalized rat astrocyte strain genetically modified by human preproenkephalin gene on rat chronic neuropathic pain].
To observe the analgesic effect of intrathecal transplant of immortalized rat astrocyte genetically modified by human preproenkephalin gene (IAST/hPPE) on chronic neuropathic pain. ⋯ Intrathecal transplant of IAST/hPPE cells could alleviate the allodynia-like behaviour after chronic neuropathic pain, which is associated with enkephalin secreted continuously from the grafts and conducted via opiate receptors.