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Spinal-cord Stimulator
A spinal cord stimulator (SCS) or dorsal column stimulator (DCS) is a type of implantable neuromodulation device (sometimes called a "pain pacemaker") that is used to send electrical signals to select areas of the spinal cord (dorsal columns) for the treatment of certain pain conditions. SCS is a consideration for people who have a pain condition that has not responded to more conservative therapy. There are also spinal cord stimulators under research and development that could enable patients with spinal cord injury to walk again via epidural electrical stimulation (EES). Medical uses The most common use of SCS is failed back surgery syndrome (FBSS) in the United States and peripheral ischemic pain in Europe. As of 2014 the FDA had approved SCS as a treatment for FBSS, chronic pain, complex regional pain syndrome, intractable angina, as well as visceral abdominal and perineal pain and pain in the extremities from nerve damage. Once a person has had a psychological evaluation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuromodulation
Neuromodulation is the physiological process by which a given neuron uses one or more chemicals to regulate diverse populations of neurons. Neuromodulators typically bind to metabotropic, G-protein coupled receptors (GPCRs) to initiate a second messenger signaling cascade that induces a broad, long-lasting signal. This modulation can last for hundreds of milliseconds to several minutes. Some of the effects of neuromodulators include: alter intrinsic firing activity, increase or decrease voltage-dependent currents, alter synaptic efficacy, increase bursting activity and reconfiguration of synaptic connectivity. Major neuromodulators in the central nervous system include: dopamine, serotonin, acetylcholine, histamine, norepinephrine, nitric oxide, and several neuropeptides. Cannabinoids can also be powerful CNS neuromodulators. Neuromodulators can be packaged into vesicles and released by neurons, secreted as hormones and delivered through the circulatory system. A neuromodulator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system. Each axon, within the nerve, is an extension of an individual neuron, along with other supportive cells such as some Schwann cells that coat the axons in myelin. Within a nerve, each axon is surrounded by a layer of connective tissue called the endoneurium. The axons are bundled together into groups called fascicles, and each fascicle is wrapped in a layer of connective tissue called the perineurium. Finally, the entire nerve is wrapped in a layer of connective tissue called the epineurium. Nerve cells (often called neurons) are f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Horn Of Spinal Cord
The posterior grey column (posterior cornu, dorsal horn, spinal dorsal horn, posterior horn, sensory horn) of the spinal cord is one of the three grey columns of the spinal cord. It receives several types of sensory information from the body, including fine touch, proprioception, and vibration. This information is sent from receptors of the skin, bones, and joints through sensory neurons whose cell bodies lie in the dorsal root ganglion. Anatomy The posterior grey column is subdivided into six layers termed Rexed laminae I-VI *Marginal nucleus of spinal cord (lamina I) *Substantia gelatinosa of Rolando (lamina II) *Nucleus proprius (laminae III, IV) *Spinal lamina V, the neck of the posterior horn *Spinal lamina VI, the base of the posterior horn. The other four Rexed laminae are located in the other two grey columns in the spinal cord. Additional images File:Gray687.png, Section of the medulla oblongata through the lower part of the decussation of the pyramids See also * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gate Control Theory
The gate control theory of pain asserts that non-painful input closes the nerve "gates" to painful input, which prevents pain sensation from traveling to the central nervous system. The gate control theory of pain describes how non-painful sensations can override and reduce painful sensations. A painful, nociceptive stimulus stimulates primary afferent fibers and travels to the brain via transmission cells. Increasing activity of the transmission cells results in increased perceived pain. Conversely, decreasing activity of transmission cells reduces perceived pain. In the gate control theory, a closed "gate" describes when input to transmission cells is blocked, therefore reducing the sensation of pain. An open “gate” describes when input to transmission cells is permitted, therefore allowing the sensation of pain. First proposed in 1965 by Ronald Melzack and Patrick Wall, the theory offers a physiological explanation for the previously observed effect of psychology on pain perc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patrick David Wall
Patrick David Wall (25 April 1925 – 8 August 2001) was a British neuroscientist described as 'the world's leading expert on pain' and best known for the gate control theory of pain. Early life and education Wall was born in Nottingham on 25 April 1925 to Thomas Wall, the director of education for Middlesex, and his wife Ruth Cresswell. He was educated at St Paul's School, London and the University of Oxford, studying medicine at Christ Church, Oxford, where he became interested in pain. He published his first two papers, in the prominent science journals ''Brain'' and ''Nature'', at the age of 21. While at Oxford he had also helped found the British Medical Students' Journal, partially to help campaign for the introduction of the National Health Service (NHS). He graduated in 1948, by which time he had published three papers in prominent science journals. Career and research After graduating, he spent a short time treating holocaust survivors and refugees in mainland Europ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ronald Melzack
Ronald Melzack (July 19, 1929 – December 22, 2019) was a Canadian psychologist and professor of psychology at McGill University. In 1965, he and Patrick David Wall revolutionized pain research by introducing the gate control theory of pain. In 1968, Melzack published an extension of the gate control theory, in which he asserted that pain is subjective and multidimensional because several parts of the brain contribute to it at the same time. During the mid-1970s, he developed the McGill Pain Questionnaire and became a founding member of the International Association for the Study of Pain. He also became the founding editor of '' Wall & Melzack's Textbook of Pain'' Melzack has received numerous honors including Prix du Québec (1994), the Order of Canada (1995), and the National Order of Quebec (2000). In 2010, he won the Grawemeyer Award for his research on the science of pain. Early life Melzack was born in Montreal, the son of Joseph Melzack, who worked in a clothing fact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluoroscopy
Fluoroscopy () is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope () allows a physician to see the internal structure and function of a patient, so that the pumping action of the heart or the motion of swallowing, for example, can be watched. This is useful for both diagnosis and therapy and occurs in general radiology, interventional radiology, and image-guided surgery. In its simplest form, a fluoroscope consists of an X-ray source and a fluorescent screen, between which a patient is placed. However, since the 1950s most fluoroscopes have included X-ray image intensifiers and cameras as well, to improve the image's visibility and make it available on a remote display screen. For many decades, fluoroscopy tended to produce live pictures that were not recorded, but since the 1960s, as technology improved, recording and playback became the norm. Fluoroscopy is s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuohy Needle
A Tuohy (/tOO-ee/) needle is a hollow hypodermic needle, very slightly curved at the end, suitable for inserting epidural catheters. Epidural needle Literally, an epidural needle is simply a needle that is placed into the epidural space. To provide continuous epidural analgesia or anesthesia, a small hollow catheter may be threaded through the epidural needle into the epidural space, and left there while the needle is removed. There are multiple types of epidural needles as well as catheters, but in modern practice in developed nations, disposable materials are used to ensure sterility. Epidural needles are designed with a curved tip to help prevent puncture of the dural membrane. But following accidental dural puncture, headache occurs in up to 85% of patients causing significant perioperative morbidity. However, in case of inadvertent dural perforation, the incidence of headache can be lowered by identifying the epidural space with the needle bevel oriented parallel to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidural Space
In anatomy, the epidural space is the potential space between the dura mater and vertebrae ( spine). The anatomy term "epidural space" has its origin in the Ancient Greek language; , "on, upon" + dura mater also known as "epidural cavity", "extradural space" or "peridural space". In humans the epidural space contains lymphatics, spinal nerve roots, loose connective tissue, adipose tissue, small arteries, dural venous sinuses and a network of internal vertebral venous plexuses. Cranial epidural space In the skull, the periosteal layer of the dura mater adheres to the inner surface of the skull bones while the meningeal layer lays over the arachnoid mater. Between them is the epidural space. The two layers of the dura mater separate at several places, with the meningeal layer projecting deeper into the brain parenchyma forming fibrous septa that compartmentalize the brain tissue. At these sites, the epidural space is wide enough to house the epidural venous sinuses. There are fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasodilation
Vasodilation is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. The process is the opposite of vasoconstriction, which is the narrowing of blood vessels. When blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance and increase in cardiac output. Therefore, dilation of arterial blood vessels (mainly the arterioles) decreases blood pressure. The response may be intrinsic (due to local processes in the surrounding tissue) or extrinsic (due to hormones or the nervous system). In addition, the response may be localized to a specific organ (depending on the metabolic needs of a particular tissue, as during strenuous exercise), or it may be systemic (seen throughout the entire systemic circulation). Endogenous substances and drugs that cause vasodilation are termed vasodilators. Such vasoactivity is necessary for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympathetic System
The sympathetic nervous system (SNS) is one of the three divisions of the autonomic nervous system, the others being the parasympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of the autonomic nervous system, and sometimes considered an independent system. The autonomic nervous system functions to regulate the body's unconscious actions. The sympathetic nervous system's primary process is to stimulate the body's fight or flight response. It is, however, constantly active at a basic level to maintain homeostasis. The sympathetic nervous system is described as being antagonistic to the parasympathetic nervous system which stimulates the body to "feed and breed" and to (then) "rest-and-digest". Structure There are two kinds of neurons involved in the transmission of any signal through the sympathetic system: pre-ganglionic and post-ganglionic. The shorter preganglionic neurons originate in the thoracolumbar division of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
