Spinal cord stimulation

Alpha-2 receptors have also been identified on interneurons in the spinal cord. Stimulation of these receptors causes interneuron inhibition, and a subsequent decrease in excitability of motor neurons supplied by the interneurons.6,8 Alpha-2 agonists have therefore been used to normalize neuronal activity in conditions such as spasticity the use of these drugs as antispasticity agents is discussed in more detail in Chapter 13. 

Ferrante FM, Rana MV, Ferrante MA (2004) Conversion disorder mimicking Dejerine-Roussy syndrome (thalamic stroke) after spinal cord stimulation. Reg Anesth Pain Med 29 164-167... 

Paraplegia has been reported 2 months after morphine infusion by intrathecal catheter (17). Another case of paraplegia was reported in a 73-year-old man with an intrathecal catheter and a spinal cord stimulator (18). 

Methylphenidate is similar to amphetamine and, like amphetamine, stimulates the central nervous system (CNS), which consists of the brain and spinal cord. Stimulant drugs affect mood and alertness, and depress food appetite by increasing levels of several neurotransmitters in the brain. Although the exact therapeutic mode of action of methylphenidate is not known, the drug has been shown to elevate levels of some of these neurotransmitters, primarily dopamine and norepinephrine (noradrenaline). 

Non-pharmacologic treatment like acupuncture, transcutaneous electric nerve stimulation, electrical spinal cord stimulation, physical approaches and psychological support is not addressed in this chapter. 

Premarket Approval applies to life-supporting or life-sustaining devices. Class III devices are those that support or sustain human life, are of substantial importance in preventing impairment of human health, or which present a potential, unreasonable risk of illness or injury. Those devices that if used improperly may cause unreasonable risk or illness or injury to a person. These devices must meet the standards set forth in Class I and Class II in addition to premarket approval of Class III. Examples include heart pacemakers, replacement heart valves, implanted spinal cord stimulators, silicone gel-filled breast implants. 

Rigidity may also be seen with a number of toxins and may be caused by CNS effects or spinal cord stimulation. Neuroleptic malignant syndrome and serotonin syndrome (see p 22) are characterized by rigidity, hyperthermia, metabolic acidosis, and an tered mental status. Rigidity seen with malignant hyperthermia (see p 22) is caused by a defect at the muscle cell level and may not reverse with neuromuscular blockade. 

High levels of calcium-dependent cytosolic phospholipase A2 (CPLA2) activity have been reported to occur in rat and monkey spinal cords. At the cellular level, dense immunoreactivity is present in motor neurons from cervical, thoracic, lumbar, and sacral regions (Ong et al., 1999). Traumatic injury to spinal cord stimulates activities of lipases and phospholipases (Taylor et al., 1988). SCI significantly stimulates CPLA2 activity and its expression in injured spinal cord. This increase in CPLA2 activity can be blocked by the PLA2 inhibitor, mepacrine (Liu et al., 2006). 

Cameron, T. Safety and efficacy of spinal cord stimulation for the treatment of chronic pain a 20-year literature review. /. Neurosurg. 2004 100 254 267. 

Holsheimer, J., Struijk, J.J., and Tas, N.R. Effects of electrode geometry and combination on nerve fibre selectivity in spinal cord stimulation. Med. Biol. Eng. Comput. 1995 33 676-682. 

Three channels for bilateral sacral root stimulation (S2-4) for bladder control (bowel control and erection, if possible) were provided. Sacral root stimulation was achieved by three pairs of LPR electrodes (10-mm long, solid platinum tubing of 1.0-mm diameter) inserted into the external sacral foramina in a lateral direction to follow and to stimulate the nerve roots epidurally. One further channel was connected to an epidural spinal cord stimulating electrode (Pisces Quad Medtronic Inc., Minneapolis, MN) for conus medullaris modulation of spastic bladder and bowel reflexes. 

Neurostimulators are much like cardiac pacemakers, except they apply small electrical signals to nerve tissue. Devices are available for spinal cord stimulation to manage chronic pain, vagal nerve stimulation to control epilepsy and deep depression, and deep brain stimulation to help relieve symptoms of Parkinson s disease and other neurological disorders. 

Monahan K, Casavant D, Rasmussen C, Hallet N. Combined use of a true-bipolar sensing implantable cardioverter defibrillator in a patient having a prior implantable spinal cord stimulator for intractable pain. Pacing Clin Electrophysiol 1998 12 2669-2672. 

Therapeutic approaches approved by the FDA include spinal cord stimulation for pain, DBS for Parkinson s disease and essential tremor, and vagus nerve stimulation in epilepsy and depression. Techniques stiU at the investigational stj e include DBS for depression, epilepsy, headache, Tourette s syndrome, and pain cortical stimulation in Parkinson s disease, tremor, pain, depression, and stroke rehabilitation and peripheral nerve stimulation for headache and tinnitus. 

Medtronic, Inc. [22] RestoreUItra (Implant brand name) Spinal cord stimulation and muscular pain management... 

QuaUion, LLC [24] QL0003I, QL0020B, QL0200I-A (Batteries) Medical implants, sensors cochlear implants, spinal cord stimulators, glucose sensors, and cardiac rhythm management devices... 

V2O5 = Ag2V40ii) [9,10]. The combination reaction produces a crystalline and phase pure SVO, which provides stable power capability in the second portion of the discharge curve over time [11]. Li/SVO has also been adopted to power implantable neurological devices such as deep brain, sacral nerve, and spinal cord stimulators. 

When systemic or topical pharmacotherapy and other non-invasive approaches provide inadequate relief in patients with NP, interventional approaches may be used, including sympathetic blockade with local anesthetics, intraspinal drug delivery, spinal cord stimulation, peripheral subcutaneous nerve stimulation, or stimulation of specific central nervous system structures, and various neuroablative procedures (e.g. dorsal rhizotomy, neurolytic nerve block, intracranial lesioning). Neuroablative procedures are not reversible and should be reserved for carefully and properly selected patients with intractable pain. 

Spinal cord stimulation (SCS) is a form of therapy used to treat certain types of chronic pain. An array of stimulating metal contacts is positioned in the dorsal epidural space. An electrical field is generated through connection of the contacts with an electrical generator. The leads can be implanted by laminectomy or percutaneously, and the source of power is supplied by an implanted battery or by an external radio-frequency transmitter. The resulting field presumably stimulates DRG axons and dorsal column fibers [41,42]. The goal is to create a field of (tolerable) paresthesias that overlap and cover the anatomic distribution of pain reported by the patient. A temporary trial of stimulation, most commonly performed with percutaneous lead placement, is required to identify patients who might benefit. 

A comprehensive set of practice parameters on the use of spinal cord stimulation in the treatment of chronic neuropathic pain has been developed [42]. Indications include failed back surgery syndrome, complex regional pain syndrome, peripheral neuropathic pain, phantom limb/post-amputation syndrome, recalcitrant PHN, root injury pain, and spinal cord injury or lesions. It also is being used in the management of pain associated with multiple sclerosis, pain due to ischemic peripheral vascular disease, and interstitial nephritis. 

Lazorthes Y, Verdie JC, Sol JC. Spinal cord stimulation for neuropathic pain. Handb Clin Neurol 2006 81 887-899. 

North R, Shipley JS. Practice parameters for the use of spinal cord stimulation in the treatment of chronic neuropathic pain. Pain Med 2007 8(Suppl 4) S200-S275. 

JA Turner, JD Loeser, KG Bell. Spinal cord stimulation for chronic low back pain a systematic literature synthesis. Neurosurgery 1995 37 1088-1095. 

P. Kreis and S. Fishman, Spinal Cord Stimulation Implantation Percutaneous Implantation Techniques, Oxford University Press, USA, 2009. 

Implantable neural prostheses have been widely used to improve or restore main functions of nervous systems for patients with neural damage. Some common neural prostheses include cochlear implants [1-2], spinal-cord stimulators [3-6], and deep-brain stimulators [7-10], Novel neural prostheses, such as retinal prostheses [11-12] and brain-machine interfaces [13-14], with higher resolution and site specificity are being actively investigated. These devices require larger numbers of microelectrodes patterned in a very small area, more sophisticated circuit designs, and longer lifespans. 

North RB (2(X)8) Neurtd interface devices Spinal cord stimulation technology. Proc IEEE 96 1108-1119... 

Cameron T (2(X)4) Safety and efficacy of spinal cord stimulation for the treatment of chronic pain A 20-year literature review. J Neurosurg 100 254-267 Rise MT (2(XX)) Instmmentation for neuromodulation. J Arc Med 31 237-247 Perlmutter JS, Mink JW (2006) Deep brain stimulation. Annu Rev Neuro. 29 229-257 Diamond A, Jankovic J (2005) The effect of deep brain stimulation on quality of life in movement disorders. J Neurol 76 1188-1193... 

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