Neuromodulation : journal of the International Neuromodulation Society
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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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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.
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Objectives Intraspinal drug delivery via indwelling pump is an effective means of treating refractory pain. Before a patient is selected for pump implantation, an intraspinal drug delivery trial must be performed to establish side-effects and efficacy profiles. No consensus protocol currently exists for such trials. ⋯ Nearly half (45%) of the respondents use the continuous intrathecal infusion technique to select patients for permanent implants. Conclusions Trial practices vary widely in terms of patient selection, medication choice, technique, and efficacy evaluation. We hope that our findings will encourage a concerted effort to evaluate existing trial protocols in order to establish a reliable standard of care.
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Objectives The objective of this paper is to report the clinical protocols that we have developed and used for titrating constant flow implantable pumps to an effective dose in de novo pain and spasticity pump patients and, thereby, highlight the similarities and differences in our techniques. As a group, we have implanted over 1600 pumps and currently manage over 800 pump patients. ⋯ This compares favorably to reports of programmable pumps requiring 5.3 ± 3.5 adjustments over a period of 3-6 months to reach an effective dose. Conclusions A comparison of our protocols shows that after an initial stabilization period, dose adjustments can be made at subsequent refill, that it is not necessary to adjust the dose by prematurely emptying and filling constant flow pumps, and that it is not necessary to adjust the dose as often as has been done with programmable pumps.