Neuromodulation : journal of the International Neuromodulation Society
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Objectives To retrospectively analyze by indices of success, patients with chronic complex pain, including, axial low back pain, receiving dual spinal cord stimulation (SCS) systems. Methods Eighteen patients with dual spinal cord stimulators have been retrospectively and nonrandomly analyzed. The preponderance of patients in our study group had failed back surgery syndrome (FBSS). ⋯ Thirteen (81%) patients with dual lead SCS therapy were willing to repeat the SCS implant procedure. Complications occurred in 43.7%. Conclusions Dual spinal cord stimulation is appropriate and efficacious for treating complex pathology and complex pain that including pain of the low, axial back.
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Objective Low intensity and low frequency electromagnetic field stimulation (EMFs) provides substantial pain relief in patients with various chronic pains. The aim of this study was to examine the effects of EMFs on the activity of thoracic spinal neurons responding to noxious visceral stimuli. Materials and Methods Extracellular potentials of single T(3) -T(4) spinal neurons were recorded in pentobarbital anesthetized male rats. ⋯ Even after termination of EMFs, the suppression of spinal neuronal activity lasted for 1-2 hr. In contrast, excitatory responses of 7/18 (39%) neurons to esophageal distension were inhibited, five (28%) were excited and six (33%) were not affected by EMFs. Conclusions Results showed that EMFs generally reduced nociceptive responses of spinal neurons to noxious cardiac chemical stimuli, whereas it was not effective for nociceptive responses to esophageal mechanical stimulation.
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The present experiments were performed on rat colon to study neurogenic and myogenic elicited propulsion induced by 0.3 and 30 msec long current pulses. The colon segments were stimulated sequentially and randomly. The obtained contractions displaced the intraluminal content in individual propulsion steps. ⋯ When inhibiting cholinergic transmission by atropine, the propulsion induced by 0.3 msec pulses was blocked, while partially inhibited when using 30 msec pulses. Inhibiting nitric oxide synthesis by N(G) -nitro-L-arginine methyl ester (L-NAME) blocked propulsion induced by both of the pulse durations. In conclusion, electrical stimulation induces propulsion when using both 0.3 and 30 msec long pulses; stimulation using 0.3 msec pulses activates neurons, whereas 30 msec pulses depolarize muscles; in the absence of nitrergic transmission, propulsion cannot be induced by electrical stimulation.
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Objective The purpose of this study was to test if the F-response can be repressed volitionally. Normally, the F-response is used for clinical diagnostics but it also has an important influence on the design of a neural prosthesis involving functional electrical stimulation (FES) and the use of volitional myoelectric signal (MES) for control. Methods Ten neurologically normal subjects were trained to reduce the level of the F-response from the anterior tibial muscle. ⋯ From the first to the last session of a trial, the change was found not significant. Conclusion The level of the F-response may change locally, but there is no indication that a subject can volitionally learn to repress the response, even when given feedback information about the actual level. Therefore the F-waves in the myoelectric signal from a stimulated muscle has to be accounted for when designing devices using a stimulated muscle response for myoelectric control such as eliminating the F-interval from the recorded signal.