Neuromodulation : journal of the International Neuromodulation Society
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Objectives. Identification, delimitation, and stereotactic localization of the human nucleus accumbens (Acc) in order to allow its accurate definition and three-dimensional targeting on magnetic resonance imaging (MRI) enabling its use for deep brain stimulation. Methods. Magnetic resonance imaging and anatomical coronal serial cuts were performed on 24 Acc from human cadaver brains perpendicular to the anterior commissure-posterior commissure line; identification, localization, and determination of its dimensions and three-dimensional stereotactic coordinates. ⋯ The stereotactic coordinates were obtained every millimeter along its length. Conclusion. It was possible to identify well the human Acc, define its limits and establish its three-dimensional coordinates as potential MRI-guided stereotactic target.
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Objectives. This study aims to assess the safety and efficacy of long-term intrathecal (IT) ziconotide infusion. Materials and Methods. In this prospective study, 155 patients with severe chronic pain (48 with malignant pain, 107 with nonmalignant pain) who had been responsive to short-term IT ziconotide in a double-blind, placebo-controlled study received long-term, open-label IT ziconotide monotherapy. Efficacy assessments included the mean percentage change on the visual analog scale of pain intensity from baseline in the study of origin; safety was monitored by adverse event (AE) reports, periodic laboratory tests, and vital sign measurements. ⋯ The mean IT ziconotide dose remained stable over 12 months in the 31 patients who participated in the study for ≥ one year. Ziconotide-related AEs were reported in 147 out of 155 patients (94.8%); 39.4% of patients discontinued treatment because of AEs, the majority of which were considered ziconotide related. Conclusions. Ziconotide IT monotherapy provided patients with analgesia for 12 months in this open-label study, with an acceptable benefit/risk profile and no evidence of tolerance.
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Objectives. This study aims to explore the relationship among the levels of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) produced by cortical glial cells, and identify any correlation between neuromodulation and brain lateralization. Material and Methods. Cortical glial cells from Balb/c neonatal mice were cultured in vitro and the effects of treating or not treating these cells from both hemispheres with lipopolysaccharide (LPS) (10 µg/mL) for 24 hours were tested. The levels of IL-1β, IL-6, and TNF-α in left and right cortical glial cell cultures and the time course of any changes were compared. ⋯ Conclusion. Lipopolysaccharide increases cytokine production in both cerebral cortices, three cytokines have different expression time course within 72 hours, but only IL-1β in right cortex and IL-6 releasing is time-dependent, and more so on the right side than the left in 24 hours. We proposed the increased immunosuppressive activity of right cortex was due to the higher expression of IL-1β, TNF-α, and IL-6 in the right cortical glial cells, whereas there would be more immunoenhancement activity of the left cortex due to the lower levels of these three kinds of cytokines, this being a less pronounced effect than that on the right side. One of the reasons for the brain lateralization may be the different production of cytokines by the cortical glial cells on either side.
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Introduction. Subcutaneous, occipital nerve stimulation has emerged as a potentially effective treatment modality for patients with refractory headache disorders. The purpose of this study was to document occipital stimulation characteristics in 10 patients status post implantation of an occipital nerve stimulator. Methods. All possible electrode combinations were tested in each patient, and sensory threshold, discomfort threshold, and associated paresthesia maps were noted. ⋯ The associated paresthesia maps demonstrated that most patients felt stimulation as expected in the occipital regions; trigeminal distribution stimulation occurred but only in a minority of patients. Half of the patients experienced ≥ 50% reduction in headache frequency or severity. Conclusions. These results should aid in clinical decision-making and manufacturing requirements for this modality; larger, prospective studies will be needed to determine the safety and efficacy of stimulation techniques for headache disorders.
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Objective. For targeting the subthalamic nucleus (STN), we attempted to quantify the changes in multiple cell activities by computing the neural noise level and multiple-cell spike density (MSD). Methods. We analyzed the neural noise level and MSD by stepwise recording at every 0.25-mm increment during the final tracking in 90 sides of 45 patients with Parkinson's disease. The MSD was analyzed with cut-off levels ranging from 1.2- to 2.0-fold the neural noise level in the internal capsule or zona incerta in each trajectory. ⋯ The ventral boundary was identifiable, however, from a decrease in the neural noise ratio in only 70 sides (78%). In contrast, both the dorsal and ventral boundaries were clearly identified from an increase and a decrease in the MSD, respectively, in all of the 90 sides. Conclusion. MSD analysis by semimicroelectrode recording represents a useful, practical, and apparently reliable means for identifying the boundaries of the STN.