paralysis
American Heritage Dictionary:
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pa·ral·y·sis
(pə-răl'ĭ-sĭs) 
n., pl., -ses (-sēz').
n., pl., -ses (-sēz').
- Loss or impairment of the ability to move a body part, usually as a result of damage to its nerve supply.
- Loss of sensation over a region of the body.
- Inability to move or function; total stoppage or severe impairment of activity: fear that led to national paralysis.
[Latin, from Greek paralusis, from paralūein, to disable, loosen : para-, on one side; see para-1 + lūein, to release.]
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paralysis
Britannica Concise Encyclopedia:
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paralysis
Loss or impairment of voluntary use of one or more muscles. It may be flaccid (with loss of muscle tone) or spastic (stiff). Hemiplegia (one-sided paralysis) is usually caused by stroke or brain tumour on the opposite side. Diplegia (two-sided paralysis, as in cerebral palsy) results from generalized brain disease. Spinal-cord damage (from bone or joint disease, fracture, or tumour affecting the vertebrae; inflammatory and degenerative diseases; or pernicious anemia) paralyzes the body at and below the level of the damage (paraplegia if the legs and lower body only; quadriplegia if arms and legs). Poliomyelitis and polyneuritis (neuritis of multiple nerves) result in paralysis with muscle wasting. Bell palsy (a type of neuritis) paralyzes the muscles of one side of the face. Muscular dystrophy causes paralysis by attacking muscle. Metabolic causes include myasthenia gravis. Paralysis may also have psychiatric causes ( hysteria).
For more information on paralysis, visit Britannica.com.
Oxford Companion to the Body:
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paralysis
Paralysis implies motor weakness, and can be partial or complete. It can result from dysfunction at any point in the motor system, and the level at which this occurs determines the characteristics of the paralysis.
Movement is initiated by specialized motor nerve cells, the upper motor neurons (sometimes called pyramidal cells, because of their shape). These cells are situated in a special part of the cerebral hemispheres, the motor cortex, and are arranged in a ‘somatotopic’ manner — which means that motor neurons subserving a particular part of the body are clustered together, and are always found in that same place. Upper motor- neurones destined to serve movements of the leg, for example, are located nearer the midline than those destined for the arms. On each side of the brain, the axons from these motor neurons converge as they leave the cerebral cortex, and pass down the brain stem as separate tracts. Just before they reach the spinal cord, most of the fibres from one side cross to the opposite side. This means that upper motor neurons on one side of the cerebral cortex control movements principally on the other side of the body. In the spinal cord they descend as a tract in the outer side part of the cord, and fibres leave the tract progressively to reach and to act on lower motor neurons (anterior horn cells), either directly or via intermediary neurons. Those destined to activate arm muscles, for example, synapse with lower motor neurons in the cervical part of the cord. From there, axons of the lower motor neurons form the motor component of the peripheral nerves, finally reaching the muscle for which they are destined. In the muscle, each nerve fibre divides into a large number of branches. A single branch innervates an individual muscle fibre at a specialized structure, the neuromuscular junction. The signal is finally passed from the nerve to the muscle by the release of a chemical substance, acetylcholine, which diffuses across the narrow gap between nerve and muscle and reacts with specialized acetylcholine receptors on the muscle fibres. This reaction leads to a local electrical potential that triggers muscle contraction.
Upper motor neuron paralysis
is characterized by stiffness of the affected muscles (spasticity) ; weakness of the muscles that extend the arm and of the muscles that flex the leg; drooping of the lower part of the face; increased tendon reflexes (the response that muscles make when their tendons are briefly tapped) ; and a positive Babinski (extensor plantar) reflex response, in which the toes move upwards when the side or sole of the foot is stroked. A common cause of an upper motor neuron paralysis is a ‘stroke’, in which either infarction (loss of blood supply) or haemorrhage in one cerebral hemisphere disrupts the motor neurons destined for the opposite half of the body. Hemiplegia is the term for such one-sided paralysis. Other causes include head injury, cerebral tumours, cerebral abscess, and also cerebral palsy in which damage occurs around the time of birth. The extent of the weakness can range from a slight interference with walking, to a paralysis so profound that the patient is chair-bound.
Upper motor neuron fibres can be damaged in their course between the brain and their lower ends by spinal cord injury: a broken neck may cause paralysis of all four limbs as well as the muscles of the torso; or a broken back, paralysis of the legs. Paraplegia is the term for such paralysis on both sides.
Lower motor neuron paralysis
has a different set of characteristics, comprising muscle wasting and weakness, loss of muscle tone, and depressed tendon reflexes. The cause can be damage to the anterior horn cells themselves (as in poliomyelitis) ; spinal injury in the lower back, where the motor nerve roots run down inside the vertebral column after leaving the spinal cord; or damage to the motor fibres in the nerves running from the spine to the muscles. Weakness can be due also to a disorder at the neuromuscular junction. In this instance it has a characteristic ‘fatiguable’ quality, in which the more the muscle is used the weaker it becomes. The muscles are not wasted. The commonest disease causing a neuromuscular transmission disorder is myasthenia gravis, in which the immune system makes antibodies to the acetylcholine receptors on the muscle fibres. The toxins of certain snakes (e.g. the banded krait) and of bacteria (e.g. botulinum toxin) also block neuromuscular transmission and paralyse their victim. Curare and the contemporary drugs developed from it cause paralysis by acting at this site: originally an arrow poison, but now a feature used to good effect (and of course reversibly) in anaesthetic practice Paralysis can also be due to muscle disease (myopathy). The weakness here usually principally affects the shoulder girdle muscles (making it difficult for the patient to elevate their arms) and the muscles of the pelvis (thereby interfering with walking). Rising from a chair or climbing stairs can be particularly difficult. Muscular dystrophies are genetic disorders, usually progressive, which can lead to profound paralysis. Other causes include inflammatory disorders (e.g. polymyositis), metabolic conditions, and toxic substances.
— J. Newsom-Davis
See also motor neuron; muscle wasting; stroke.
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A loss or impairment of motor function due to a disorder in some part of the neuromuscular system. The extent of the paralysis will vary according to the location and extent of the disorder. The term is also applied to concomitant loss of sensory function. Paralysis is a symptom rather than a disease.
Columbia Encyclopedia:
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paralysis
paralysis or palsy (pôl'zē), complete loss or impairment of the ability to use voluntary muscles, usually as the result of a disorder of the nervous system. The nervous tissue that is injured may be in the brain, the spinal cord, or in the muscles themselves. Accordingly there may be general paralysis, involvement of only one side (hemiplegia), paralysis on both sides at one level (paraplegia or quadriplegia), or localized paralysis in a small group of nerves or muscles.
The cause of paralysis may be any injury that tears or compresses the nerves; it may be hemorrhage, tumor, infection, or substances toxic to nerve tissue. One of the most frequent causes of paralysis is stroke, in which hemorrhage, thrombosis, or obstruction of a cerebral vessel interferes with nerve function. Another disorder in which a resting tremor is one of the main symptoms, accompanied by slowness and poverty of movement, muscular rigidity, and postural instability is Parkinson's disease. Cerebral palsy is due to an injury to the brain motor tissue before or during birth. However, this disorder is nonprogressive. Partial or complete paralysis often accompanies multiple sclerosis.
Dictionary of Cultural Literacy: Health:
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paralysis
(puh-ral-uh-sis)
The loss of voluntary movement in a body part. Paralysis results from damage to the nerves that supply the affected part of the body.
Oxford Companion to the Mind:
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paralysis
Loss of motor function. Thought processes and perception may be subtly modified or impaired. It is an interesting question whether perception (which almost certainly depends primarily on active learning in infancy) and emotion (which may largely be sensations of bodily changes, for example to perceived danger) can remain normal with extensive paralysis. William James described the case of a woman paralysed almost from the neck down following a hunting accident, who yet experienced emotions when visited by her family. This has been used as evidence against the James–Lange theory of emotion, which is essentially that emotions are visceral sensations, and should therefore cease with sufficiently general paralysis. It was the observation, in classical times, that head wounds are associated with paralysis on the opposite side of the body that led to concepts of localization of brain function, with the left hemisphere controlling the right side of the body, and vice versa.
Paralysis is usually organic, due to brain damage or loss of peripheral nerve function, but it can occur as a functional symptom of hysteria. See nothingness.
(Published 1987)
Paralysis is usually organic, due to brain damage or loss of peripheral nerve function, but it can occur as a functional symptom of hysteria. See nothingness.
(Published 1987)
The Dream Encyclopedia:
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Paralysis
Being unable to move may mean the dreamer feels helpless to control the situation at hand. Alternatively, perhaps the dreamer needs to "freeze" and do nothing about some issue for awhile.
Saunders Veterinary Dictionary:
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paralysis
Loss or impairment of motor function in a part due to a lesion of the neural or muscular mechanism; also, by analogy, impairment of sensory function (sensory paralysis). Called also palsy. Motor paralysis may be expressed as flaccid, in the case of lower motor neuron lesion, or spastic, in the case of an upper motor neuron lesion. See also paraplegia, quadriplegia, hemiplegia and paralyses of individual cranial and peripheral nerves.
- p. of accommodation — paralysis of the ciliary muscles of the eye so as to prevent accommodation.
- anal p. — manifested by flaccidity and lack of tone of the anal sphincter, and loss of house training restraint in companion animals.
- antepartum p. — pressure on sciatic nerves by a large fetus in late pregnancy in a cow can cause posterior paralysis that is cured by a cesarean section.
- ascending p. — spinal paralysis that progresses forwards involving first the hindlimbs then the forelimbs, then the intercostal muscles, then the diaphragm, and finally the muscles of the neck.
- birth p. — that due to injury received by the neonate at birth.
- bladder p. — manifested by fullness of the bladder and response to manual pressure. See also motor paralytic urinary bladder.
- cage p. — see thiamin nutritional deficiency.
- central p. — any paralysis due to a lesion of the brain or spinal cord.
- cerebral p. — paralysis caused by some intracranial lesion.
- Chastek p. — see thiamin nutritional deficiency.
- compression p. — that caused by pressure on a nerve.
- congenital p. — paralysis of the newborn. Many cases are due to birth trauma especially when lay persons exert excessive traction. Other causes are enzootic ataxia, inherited congenital paraplegias in calves and pigs, spina bifida and spinal dysraphism and occipito-alanto-axial malformations in foals and puppies.
- conjugate p. — loss of ability to perform some parallel ocular movements.
- coonhound p. — see idiopathic polyradiculoneuritis.
- crossed p. — paralysis affecting one side of the head and the other side of the body.
- curled toe p. — a disease of poultry caused by a nutritional deficiency of riboflavin. See also curled toe paralysis.
- decubitus p. — paralysis due to pressure on a nerve from lying for a long time in one position.
- esophageal p. — manifested by inability to swallow, and regurgitation.
- facial p. — weakening or paralysis of the facial nerve. See also facial paralysis.
- flaccid p. — paralysis characterized by loss of voluntary movement, decreased tone of limb muscles, absence of tendon reflexes and neurogenic atrophy.
- immunological p. — the absence of immune response to a specific antigen. See also tolerance.
- infectious bulbar p. — see aujeszky's disease.
- ischemic p. — local paralysis due to stoppage of circulation.
- lambing p. — maternal obstetric paralysis in the ewe.
- laryngeal p. — see laryngeal hemiplegia.
- mixed p. — combined motor and sensory paralysis.
- motor p. — paralysis of the voluntary muscles.
- nerve p. — paralysis caused by damage to the local motor nerve supply. See also peripheral nerve paralysis (below).
- obstetric p. — see maternal obstetric paralysis.
- partial p. — see paresis.
- peripheral nerve p. — the part deprived of its peripheral nerve supply shows flaccid paralysis, absence of spinal reflexes, muscle atrophy and a subnormal temperature.
- postcalving p. — see maternal obstetric paralysis.
- posterior p. — paralysis of the hindlimbs, tail and perineum. See also paraplegia.
- range p. — see marek's disease.
- sensory p. — loss of sensation resulting from a morbid process.
- spastic p. — paralysis with rigidity of the muscles and heightened deep muscle reflexes.
- tongue p. — see hypoglossal nerve paralysis.
Mosby's Dental Dictionary:
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paralysis
(pər-al′i-sis)
n
n
1. cessation of cell function. n 2. loss or impairment of the motor control or function of a part or region.
Random House Word Menu:
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categories related to 'paralysis'
- Defects and Disabilities - paralysis: muscle weakness of varying severity due to injury or disease, total paralysis resulting in motor inability
See crossword solutions for the clue Wikipedia on Answers.com:
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Paralysis
"Paralysed" redirects here. For other uses, see Paralysed (disambiguation).
"Paralyse" redirects here. For the 2008 pop song, see Paralyse (song).
For other uses, see Paralysis (disambiguation).
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This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (January 2010) |
| MeSH | D010243 |
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Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed with paralysis. [1] The word comes from the Greek παράλυσις, "disabling of the nerves",[2] itself from παρά (para), "beside, by"[3] + λύσις (lusis), "losing"[4] and that from λύω (luō), "to lose".[5]
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Contents
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Causes
Paralysis is most often caused by damage in the nervous system, especially the spinal cord. Other major causes are stroke, trauma with nerve injury, poliomyelitis, amyotrophic lateral sclerosis (ALS), botulism, spina bifida, multiple sclerosis, and Guillain-Barré syndrome. Temporary paralysis occurs during REM sleep, and dysregulation of this system can lead to episodes of waking paralysis. Drugs that interfere with nerve function, such as curare, can also cause paralysis. There are many known causes for paralysis, and perhaps more yet to be discovered.
Pseudoparalysis (pseudo- meaning "false, not genuine", from Greek ψεῦδος[6]) is voluntary restriction or inhibition of motion because of pain, incoordination, orgasm, or other cause, and is not due to actual muscular paralysis.[7] In an infant, it may be a symptom of congenital syphilis.[8]
Variations
Paralysis can occur in localised or generalised forms, or it may follow a certain pattern. Most paralyses caused by nervous-system damage (i.e. spinal-cord injuries) are constant in nature; however, some forms of periodic paralysis, including sleep paralysis, are caused by other factors.
Ascending paralysis presents in the lower limbs before the upper limbs. It can be associated with:
- Guillain–Barré syndrome (another name for this condition is Landry's ascending paralysis)
- Tick paralysis[9]
Ascending paralysis contrasts with descending paralysis, which occurs in conditions such as botulism.
Paralysis in the animal world
Many animal species use paralysing toxins to capture prey, evade predation, or both.
In invertebrates
A well-known example is the tetrodotoxin of fish species such as Takifugu rubripes, the famously lethal pufferfish of Japanese fugu. This toxin works by binding to sodium channels in nerve cells, preventing the cells' proper function. A non-lethal dose of this toxin results in temporary paralysis. This toxin is also present in many other species ranging from toads to nemerteans.
Some species of wasp, to complete the reproductive cycle, the female wasp paralyses a prey item such as a grasshopper and places it in her nest. She then lays eggs in the paralysed insect, which is devoured by the larvae when they hatch.
In vertebrates
Paralysis can be seen in breeds of dogs that are chondrodysplastic. These dogs have short legs, and may also have short muzzles. Their intervertebral disc material can calcify and become more brittle. In such cases, the disc may rupture, with disc material ending up in the spinal canal, or rupturing more laterally to press on spinal nerves. A minor rupture may only result in paresis, but a major rupture can cause enough damage to cut off circulation. If no signs of pain can be elicited, surgery should be performed within 24 hours of the incident, to remove the disc material and relieve pressure on the spinal cord. After 24 hours, the chance of recovery declines rapidly, since with continued pressure, the spinal cord tissue deteriorates and dies.
Another type of paralysis is caused by a fibrocartilaginous embolism. This is a microscopic piece of disc material that breaks off and becomes lodged in a spinal artery. Nerves served by the artery will die when deprived of blood.
The German Shepherd is especially prone to developing degenerative myelopathy. This is a deterioration of nerves in the spinal cord, starting in the posterior part of the cord. Dogs so affected will become gradually weaker in the hind legs as nerves die off. Eventually their hind legs become useless. They often also exhibit faecal and urinary incontinence. As the disease progresses, the paresis and paralysis gradually move forward. This disease also affects other large breeds of dogs. It is suspected to be an autoimmune problem.
Cats with a heart murmur may develop blood clots that travel through arteries. If a clot is large enough to block one or both femoral arteries, there may be hind leg paralysis because the major source of blood flow to the hind leg is blocked.
Many snakes exhibit powerful neurotoxins that can cause non-permanent paralysis or death.
See also
- Spinal cord injuries
- Paraplegia
- Quadriplegia
- Muscle relaxant
- Ptosis
- Sleep paralysis
- Hemiparesis
- Beriberi
- Neuroprosthetics
- Brain-computer interface
- Tonic immobility
- Cerebral palsy
- Cobra Toxin
- Obdormition
- Narcolepsy
- Cataplexy
References
- ^ http://www.christopherreeve.org/site/c.mtKZKgMWKwG/b.5184189/k.5587/Paralysis_Facts__Figures.htm
- ^ παράλυσις, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
- ^ παρά, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
- ^ λύσις, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
- ^ λύω, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
- ^ ψεῦδος, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
- ^ TheFreeDictionary > pseudoparalysis , in turn citing The American Heritage Medical Dictionary 2007, 2004
- ^ Sexually Transmitted Diseases Treatment Guidelines, 2006 National Centre for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
- ^ http://www.medscape.com/viewarticle/589591
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This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Translations:
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Paralysis
Français (French)
n. - paralysie
Deutsch (German)
n. - Lähmung, Paralyse
Ελληνική (Greek)
n. - (παθολ., μτφ.) παράλυση
Português (Portuguese)
n. - paralisia (f)
Español (Spanish)
n. - parálisis
Svenska (Swedish)
n. - förlamning, vanmakt
中文（简体）(Chinese (Simplified))
麻痹, 瘫痪, 停顿
中文（繁體）(Chinese (Traditional))
n. - 麻痹, 癱瘓, 停頓
한국어 (Korean)
n. - 마비, 활동불능, 무기력
日本語 (Japanese)
n. - 麻痺, 中風, 停滞, 無力
العربيه (Arabic)
(الاسم) شلل, عجز, ركود
עברית (Hebrew)
n. - שיתוק, אפיסות-כוחות
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American Heritage Dictionary
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
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Britannica Concise Encyclopedia. © 1994-2012 Encyclopædia Britannica, Inc. All rights reserved. Read more
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The Oxford Companion to the Body. Copyright © 2001, 2003 by Oxford University Press. All rights reserved.
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Oxford Dictionary of Sports Science & Medicine
The Oxford Dictionary of Sports Science & Medicine. Copyright © Michael Kent 1998, 2006, 2007. All rights reserved.
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Columbia Encyclopedia
The Columbia Electronic Encyclopedia, Sixth Edition Copyright © 2012, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/.
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Dictionary of Cultural Literacy: Health
The New Dictionary of Cultural Literacy, Third Edition Edited by E.D. Hirsch, Jr., Joseph F. Kett, and
James Trefil. Copyright © 2002 by Houghton Mifflin Company. Published by Houghton Mifflin. All rights reserved.
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Oxford Companion to the Mind
The Oxford Companion to the Mind. Second Edition. Copyright © Oxford University Press, 2004. All rights reserved.
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The Dream Encyclopedia
The Dreams Encyclopedia. 1995 ©Visible Ink Press (VisibleInkPress.com). All rights reserved.
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Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved.
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Mosby's Dental Dictionary. Copyright © 2004 by Elsevier, Inc. All rights reserved.
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Wikipedia on Answers.com
This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article Paralysis.
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