Neuromodulation : journal of the International Neuromodulation Society
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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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Objectives. Sacral root stimulation (SRS) is a technique to restore the idiopathic overactive bladder (IOB). However, its mechanism of action is yet to be elucidated. Hence, we studied whether SRS restored IOB through the mechanism of spinal neuromodulation. ⋯ This spinal excitability decreased and bladder function improved after SRS, an effect that outlasted actual stimulation by at least 30 min. Conclusions. Our results showed that spinal excitability was increased in response to somatic nociceptive afferents in IOB patients. SRS restored bladder function, at least, in part, through spinal neuromodulation.
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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.
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It is still debated which neuroimaging technique should be preferred in targeting the subthalamic nucleus (STN) for implantation of stimulating electrodes. In the present study, we systematically analyzed the different imaging techniques and their outcome in reports describing original data on bilateral STN stimulation in advanced Parkinson's disease. Five different imaging techniques to target the STN for implantation of stimulating electrodes were reported: magnetic resonance imaging (MRI), MRI in combination with ventriculography, MRI in combination with computed tomography (CT), CT, and CT in combination with ventriculography. We found that patients who underwent STN deep brain stimulation with MRI (regardless the use of an additional imaging technique) had a significantly better Unified Parkinson's Disease Rating Scale motor score (mean improvement 58%) as compared to patients who underwent STN deep brain stimulation with CT imaging (regardless the use of an additional imaging technique; mean improvement 47%).