Neuromodulation : journal of the International Neuromodulation Society
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Objectives. The probability of success with spinal cord stimulation (SCS) depends largely on appropriate patient selection. Here, we have assessed the predictive value of pain etiology as it relates to pain relief with SCS as part of a prospective multicenter clinical trial. Methods. Sixty-five subjects with chronic and intractable pain tested an epidural SCS system. ⋯ No predictive value of pain etiology was observed. Conclusions. Spinal cord stimulation is an effective therapy for neuropathic pain arising from a variety of causes. Failed back surgery syndrome, complex regional pain syndrome, and pain of other etiologies responded equally well to SCS.
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Objective. In a randomized controlled trial comparing manual with automated computerized adjustment of spinal cord stimulators in patients with implanted power generators, automated adjustment conferred the following advantages: 1) more settings tested in a given time, 2) significantly greater pain/paresthesia overlap, 3) increased battery life, and 4) a $303,756 (95% confidence intervals = $116,503-491,009) reduction in lifetime per patient cost. The current study analyzes the sensitivity of this cost-savings to usage time/day, inflation, discount rate, and years of use. ⋯ This savings is attributable to increased battery life. Conclusion. Sensitivity analyzes reveal that the significant cost-savings achieved with computerized, patient-directed adjustment of spinal cord stimulation in selected patients with chronic pain is robust across a representative range of parameters.
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Long-term outcomes of 115 patients treated with continuous intrathecal baclofen infusion are reported. A prospective follow-up study was conducted in eight centers. Patients were followed up over a 12-month period. ⋯ Types of adverse events reported were wound complications (22%), catheter problems (36%), cerebrospinal fluid leakage (25%), and other complications (17%). Intrathecal baclofen reduces spasticity and severity of patient-reported problems but its effect on quality of life and functionality is less apparent. Improvements are desired in selection criteria, design of spinal catheters, and outcome scales.
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Objective. This study assessed 3-Tesla magnetic resonance imaging (MRI) issues for a programmable infusion pump and associated catheters. Methods. A programmable infusion pump and associated catheters (MedStream Programmable Infusion Pump, 40 mL; SureStream TI Coil-Reinforced Intraspinal Catheter; SureStream TI Connector; and SureStream Silicone Catheter; Codman and Shurtleff Inc., a Johnson & Johnson Company, Raynham, MA, USA) underwent evaluation for magnetic field interactions (deflection angle and torque), heating (transmit/receive body radiofrequency coil; whole-body averaged specific absorption rate, 3 W/kg for 15 min), functional changes (before and after MRI using eight different MRI conditions), and artifacts (T1-weighted spin-echo and gradient-echo pulse sequences) at 3-Tesla. Results. The programmable infusion pump and associated catheters exhibited minor magnetic field interactions. ⋯ Artifacts were relatively large for the pump and minor for the catheter. Conclusions. The programmable infusion pump and catheters will not pose increased risk to a patient examined using 3-Tesla MRI as long as specific safety guidelines are followed, which includes interrogation of the pump post-MRI to ensure proper settings. Artifacts for the programmable infusion pump may impact the diagnostic use of MRI if the area of interest is in the same area or near the device.
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Objectives. This paper describes an experimental investigation of variable frequency stimulation patterns as a means of increasing torque production and, hence, performance in cycling induced by functional electrical stimulation. Materials and Methods. Experiments were conducted on six able-bodied subjects stimulating both quadriceps during isokinetic trials. Constant-frequency trains (CFT) with 50-msec interpulse intervals and four catchlike-inducing trains (CIT) were tested. ⋯ Conclusions. The use of CITs improves the functional electrical stimulation cycling performance compared with CFT stimulation. This application might have a relevant clinical importance for individuals with stroke where the residual sensation is still present and thus the maximization of the performance without an excessive increase of the stimulation intensity is advisable. Therefore, exercise intensity can be increased yielding a better muscle strength and endurance that may be beneficially for later gait training in individuals with stroke.