Neuromodulation : journal of the International Neuromodulation Society
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Electrical signals can be recorded using long-term implanted nerve cuff electrodes in human peripheral nerves. Reliable detection of sensory nerve signals is essential if such signals are to be of use in sensory-based functional electrical stimulation neural prosthetics as a replacement for artificial sensors (switches, strain gauges, etc.). In this review, the signal characteristics of the sensors, the nerve interface, signal processing, and an example of human application to restore motor functions are described.
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Objective. This study examines, in a retrospective fashion, the effects of intraspinal infusion therapy, primarily using opioids, in the treatment of recalcitrant noncancer pain in a sample of 29 consecutive patients. Patients were, on average, 58 years of age having had one surgery, with a pain duration of 221 months. ⋯ Side effects remain fairly common and require continued attention. Their presence, however, did not appear to deter from the patient's overall sense of satisfaction. Acquiring information from significant others and clinic staff may be a useful adjunct in interpreting the overall outcome.
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Objectives To determine the toxicity window for the continuous intrathecal administration of dextrorphan, dextromethorphan, and memantine via an implanted delivery pump. Materials and Methods Using 48 sheep with programmable continuous intrathecal infusion systems we determined the behavioral, motor, neurological, and histopathological changes produced by a 43-day continuous infusion study of dextrorphan, dextromethorphan, and memantine dissolved in 0.9% NaCl. Daily doses of each N-methyl-D-aspartate (NMDA) antagonist were 0.013, 0.051, 0.203, 0.510, 0.811, and 2.533 mg/kg/day, flow rates ranged from 13.25 ml/day to 0.051 ml/day at a concentration of 10 mg/ml. ⋯ However, infusion of dextrorphan, dextromethorphan, and memantine at the higher doses (> 0.051 mg/kg/day) produced dose-dependent negative behavioral, motor, and histopathologic changes as indicated by a series of nonparametric statistical analyses. The minimal toxic doses were dextrorphan dose 3, dextromethorphan dose 1 and memantine dose 1. This study suggests that continuous intrathecal infusion of dextrorphan, dextromethorphan, and memantine via an implantable pump system can cause significant toxicities at the higher doses studied.