Neuromodulation : journal of the International Neuromodulation Society
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We present data collected from a multicenter study using a new neurostimulation system. This new system uses a current-shifting programming technique for spinal cord stimulation. The system maintains a continuous, suprathreshold stimulation field while adjusting the distribution of anodic and cathodic current among contacts along a multi-contact array. ⋯ This multicenter study evaluated the performance of the CEFA technique. The results of the study showed that paresthesia coverage could be shifted in real-time to different regions on the patient's body in a comfortable fashion, with the patient always feeling paresthesia during the adjustment process. The results of the study also show that the process was time-efficient: intraoperatively, the median time to assess 71 combinations on a single 8-contact lead across 18 patients was 4.1 (3.6-5.0) minutes.
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The objective of this study was to develop and test the feasibility of a model that employs electromyographic (EMG) signals to predict the occurrence of gait events in the child with cerebral palsy (CP). This model could be the basis of a future functional electrical stimulation (FES) control system to assist gait. Two children were implanted with bifilar intramuscular electrodes into the quadriceps muscle bilaterally. ⋯ For nine of the 10 gait events evaluated, the model predicted gait events to within 82 ms on average, as referenced to the VICON motion analysis system. For eight of the 10 events, prediction errors were 0.3% or less. Results indicate that EMG from the proximal musculature could be used to predict the occurrence of gait events in these two children with CP.
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Phantom limb pain (PLP) is a type of neuropathic pain syndrome that has evoked much interest in scientific and clinical fields. The condition is often intractable and severely debilitating. Though there are anecdotal reports in the literature of successful management of individual cases with brain and spinal cord stimulation, it has not been possible to develop a system of management that is consistently successful, mainly due to the paucity of basic neurophysiological data about PLP and its pathways in the central nervous system (CNS). ⋯ We describe two cases of PLP that have been satisfactorily treated with CNS stimulation (motor cortex and then periventricular gray in one and spinal cord in the other) and have been subjected to single photon emission computed tomography (SPECT) studies when in pain and then during stimulation with recorded pain relief. We found that regardless of the site of stimulation in the CNS, pain relief is associated with blood flow changes in similar areas of the brain, mainly the parietal and cingulate cortex and also in the thalamic nuclei and the central gray matter. Further studies of this kind should reveal more about the complex mechanisms of PLP and other forms of neuropathic pain.
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Twenty patients with chronic intractable spinal spasticity were implanted with a totally implantable programmable pump for intrathecal administration of baclofen. The objective of this study was to evaluate the relationship between pump and the host. Clinical efficacy of the therapy was evaluated by the Ashworth Scale, the Spasms Frequency Scale, and the Functional Independence Measure (FIM) motor scores. ⋯ Fifty percent of the patients were afraid of pump failure and 30% were afraid of their alarm signals going off. The fact that most patients would undergo this therapy again and some would even pay for it directly in the absence of public insurance for the therapy were indices of patient satisfaction with the procedure. Because this was a small study, we believe that larger studies are necessary to corroborate our findings.
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Baseline and 12-month follow-up data from a prospective controlled study on patients treated with SCS for neuropathic limb pain (NLP) are analyzed critically. The outcome on pain, use of medication, and quality of life are reported and compared with the literature. Patients enrolled from April 1999 to December 2001 were part of a quality system study by the Dutch Working Group on Neuromodulation. ⋯ The difference between baseline and 12-m follow-up is statistically significant for all measures. We conclude that the outcome measures indicate that SCS significantly reduces pain and enhances quality of life in patients having NLP not responding to other adjuvant therapy. Recommendations are proposed to make studies more comparable.