Neuromodulation : journal of the International Neuromodulation Society
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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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Objectives. In Europe, patients with acute pelvic pain are transported to the hospital in an ambulance without an emergency physician. We hypothesized that transcutaneous electrical nerve stimulation (TENS) would be an effective noninvasive procedure for pain treatment. Methods. We conducted a prospective, randomized, blinded study where 100 women were randomly assigned into a real- or a sham-TENS group. ⋯ Results. Compared to sham TENS, patients with active TENS felt that their pain was reduced by half after treatment (p < 0.01), anxiety scores significantly decreased (p < 0.01), heart rate and arteriolar vasoconstriction decreased significantly (p < 0.01), and nausea (p < 0.01) was lessened. Overall satisfaction with the received care was significantly higher (p < 0.01). Conclusion. TENS is a safe, rapid, and effective analgesic treatment for acute pelvic pain.
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Clinical neurophysiology has always played an important interventional role throughout the perioperative stages in functional neurosurgery. On the one hand, some neurophysiologic procedures have become an integrated part of neurosurgery. On the other hand, in deep brain stimulation, although the surgical electrode implantation is an essential step, the therapeutic effects are actually produced by electrically modulating the physiologic activity of the brain. We review the topic of neurophysiologic intervention in the deep brain stimulation for movement disorders by presenting the evidence derived from our own experiences based on an integrated group located at two hospitals in London and Oxford, UK, and mainly covering tremor caused by multiple sclerosis, Parkinson's disease and dystonia.
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Objectives. To study the impact of personality traits on the effect of neurostimulation in patients with chest pain and normal coronary arteries. Materials and Methods. Using the Dutch personality questionnaire, we retrospectively studied the personality traits in 33 patients treated with neurostimulation, either transcutaneous electrical nerve stimulation or spinal cord stimulation after 5 years. Neurostimulation was successful in 21 patients. ⋯ In univariate analyses, low scores at the "social inadequacy" scale and the use of calcium antagonists were associated with beneficial outcome of neurostimulation. In multivariate analysis low scores at the "social inadequacy" scale remained an independent predictor for beneficial neurostimulation outcome, when adjusted for other variables. Conclusion. Personality traits are a determining factor in the evaluation of neurostimulation for patients with chest pain and normal coronary arteries.
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Objective. The safety and efficacy of intrathecal (IT) ziconotide was studied in a randomized, double-blind, placebo-controlled trial. Materials and Methods. Patients (169 ziconotide, 86 placebo) with severe chronic nonmalignant pain unresponsive to conventional therapy and a visual analog scale of pain intensity (VASPI score) ≥ 50 mm were treated over a 6-day period in an inpatient hospital setting. Initial starting dose was 0.4 µg/hour and was titrated to analgesia or intolerance (maximum dose 7.0 µg/hour). ⋯ During the initial titration phase, a significantly greater percentage of patients in the ziconotide group compared to the placebo group reported AEs, including abnormal gait, amblyopia, dizziness, nausea, nystagmus, pain, urinary retention, and vomiting. Conclusion. Ziconotide provided significant analgesia in patients for whom conventional therapy failed. However, there was a considerable incidence of ziconotide-associated AEs due to the rapid titration and high doses administered.