Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2007
Review Case ReportsNeuroprosthetics of the upper extremity--clinical application in spinal cord injury and challenges for the future.
The complete restoration of movements lost due to a spinal cord injury (SCI) is the greatest hope of physicians, therapists and certainly of the patients themselves. Particularly, in patients with lesions of the cervical spinal cord every little improvement of missing or weak grasp function will result in a large gain in quality of life. Despite the fact that novel drugs for axonal regeneration in the spinal cord are in the phase of imminent human application, up to now, the only possibility of restoration of basic movements in SCI persons consists in the use of functional electrical stimulation (FES). ⋯ Particularly, with the use of implantable systems a long-term stable, user-friendly application is possible. Most recent work aims at the development of minimally invasive, subminiature systems for individual functional support. The possibility of direct brain control of FES systems will extend the application of grasp neuroprostheses to patients with injuries of the highest cervical spinal cord.
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Acta Neurochir. Suppl. · Jan 2007
Review Clinical TrialMotor cortex stimulation for neuropathic pain.
Since the initial publication of Tsubokawa in 1991, epidural motor cortex stimulation (MCS) is increasingly reported as an effective surgical option for the treatment of refractory neuropathic pain although its mechanism of action remains poorly understood. The authors review the extensive literature published over the last 15 years on central and neuropathic pain. Optimal patient selection remains difficult and the value of pharmacological tests or transcranial magnetic stimulation in predicting the efficacy of MCS has not been established. ⋯ In general, the efficacy of MCS depends on: a) the accurate placement of the stimulation electrode over the appropriate area of the motor cortex, and b) on sophisticated programming of the stimulation parameters. A better understanding of the MCS mechanism of action will probably make it possible to adjust better the stimulation parameters. The conclusions of multicentered randomised studies, now in progress, will be very useful and are likely to promote further research and clinical applications in this field.
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Acta Neurochir. Suppl. · Jan 2007
ReviewAn introduction to operative neuromodulation and functional neuroprosthetics, the new frontiers of clinical neuroscience and biotechnology.
Operative neuromodulation is the field of altering electrically or chemically the signal transmission in the nervous system by implanted devices in order to excite, inhibit or tune the activities of neurons or neural networks and produce therapeutic effects. It is a rapidly evolving biomedical and high-technology field on the cutting-edge of developments across a wide range of scientific disciplines. The authors review relevant literature on the neuromodulation procedures that are performed in the spinal cord or peripheral nerves in order to treat a considerable number of conditions such as (a) chronic pain (craniofacial, somatic, pelvic, limb, or due to failed back surgery), (b) spasticity (due to spinal trauma, multiple sclerosis, upper motor neuron disease, dystonia, cerebral palsy, cerebrovascular disease or head trauma), (c) respiratory disorders, (d) cardiovascular ischemia, (e) neuropathic bladder, and (f) bowel dysfunction of neural cause. ⋯ The authors highlight promising lines of research such as endoneural prostheses for peripheral nerve stimulation, closed-loop systems for responsive neurostimulation or implanted microwires for microstimulation of the spinal cord to enable movements of paralyzed limbs. The above growing scientific fields, in combination with biological regenerative methods, are certainly going to enhance the practice of neuromodulation. The range of neuromodulatory procedures in the spine and peripheral nerves and the dynamics of the biomedical and technological domains which are reviewed in this article indicate that new breakthroughs are likely to improve substantially the quality of life of patients who are severely disabled by neurological disorders.
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Functional neuroimaging has demonstrated that a relationship exists between the intensity of deafferentation pain and the degree of deafferentation-related reorganization of the primary somatosensory cortex. It has also revealed that this cortical reorganization can be reversed after the attenuation of pain. Deafferentation pain is also associated with hyperactivity of the somatosensory thalamus and cortex. ⋯ The first studies demonstrated a statistically significant pain suppression in all patients and a clinically significant pain suppression in 80% of them. This clinical experience suggests that somatosensory cortex stimulation may become a neurophysiology-based new approach for treating deafferentation pain in selected patients. In this chapter, we review the relevant recent reports and describe our studies in this field.
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Acta Neurochir. Suppl. · Jan 2007
ReviewSpinal cord stimulation in the treatment of chronic critical limb ischemia.
This paper reviews the clinical experience and proposed working mechanisms of spinal cord stimulation (SCS) in the treatment of chronic critical limb ischemia (CCLI). SCS appears to provide a significant long-term relief of ischemic pain and to improve healing of small ulcers, most likely due to effects on the nutritional skin blood flow. Despite these observations, randomized trials were not able to show limb salvage. Assessment of the microcirculatory skin blood flow, by means of transcutaneous oxygen pressure measurements and videocapillaromicroscopy, is necessary to evaluate the remaining microcirculatory reserve capacity likely to be exploited by SCS and to help identify patients that will benefit most from this treatment and in whom stimulation could lead to limb salvage.