Paralysis

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, cerebral palsy, peripheral neuropathy, Parkinson's disease, ALS, botulism, spina bifida, multiple sclerosis and Guillain–Barré syndrome. Incidents that can cause such damage include slip and fall accidents, motor vehicle accidents, assaults, gunshot wounds, industrial accidents and sports injuries.{{Cite web |last= |first= |date=2024-04-23 |title=Causes of Catastrophic Paralysis Injuries |url=https://thetexaslawdog.com/blog/causes-of-catastrophic-paralysis-injuries/ |access-date=2025-05-27 |website=Aulsbrook |language=en}} 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.

Pseudoparalysis (pseudo- meaning "false, not genuine", from Greek ψεῦδος{{harvnb|Liddell|Scott|1940|loc=[https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Dyeu%3Ddos ψεῦδος]}}) is voluntary restriction or inhibition of motion because of pain, incoordination, orgasm, or other cause, and is not due to actual muscular paralysis.[http://medical-dictionary.thefreedictionary.com/pseudoparalysis TheFreeDictionary > pseudoparalysis], in turn citing The American Heritage Medical Dictionary 2007, 2004 In an infant, it may be a symptom of congenital syphilis.{{Cite journal |vauthors=Workowski KA, Berman SM |date=August 2006 |title=Sexually transmitted diseases treatment guidelines, 2006 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5511a1.htm |journal=MMWR Recomm Rep |volume=55 |issue=RR–11 |pages=1–94 |pmid=16888612 |quote=... evidence of congenital syphilis (e.g., nonimmune hydrops, jaundice, hepatosplenomegaly, rhinitis, skin rash, and/or pseudoparalysis of an extremity).}} Pseudoparalysis can be caused by extreme mental stress and is a common feature of mental disorders such as panic anxiety disorder.{{Cite web |title=anxiety-panic.com |url=http://anxiety-panic.com/dictionary/en-dictp.htm |url-status=dead |archive-url=https://web.archive.org/web/20180730202939/http://anxiety-panic.com/dictionary/en-dictp.htm |archive-date=2018-07-30 |access-date=2017-06-06 |website=anxiety-panic.com}}

Paralysis can occur in localized or generalized forms, or it may follow a certain pattern. Most paralyses caused by nervous-system damage (e.g., spinal cord injuries) are constant in nature; however, some forms of periodic paralysis, including sleep paralysis, are caused by other factors.{{Cite journal |last=Hutchinson |first=Jonathan |date=1877 |title=Clinical Lecture On Cases Of Spina Bifida, With Paralysis Of Sphincters |journal=The British Medical Journal |volume=1 |issue=830 |pages=767–768 |doi=10.1136/bmj.1.860.767 |jstor=25244879 |pmc=2220916 |pmid=20748563}}

{{Cite book |last=Saladin |first=Kenneth |title=Anatomy and Physiology: Form and Function |date=2012 |publisher=McGraw Hill |isbn=978-0-07-337825-1}}

Paralysis can occur in newborns due to a congenital defect known as spina bifida. Spina bifida causes one or more of the vertebrae to fail to form vertebral arches within the infant, which allows the spinal cord to protrude from the rest of the spine. In extreme cases, this can cause spinal cord function inferior to the missing vertebral arches to cease. This cessation of spinal cord function can result in paralysis of lower extremities. Documented cases of paralysis of the anal sphincter in newborns have been observed when spina bifida has gone untreated. While life-threatening, many cases of spina bifida can be corrected surgically if operated on within 72 hours of birth.

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{{MedlinePlusEncyclopedia|001359|Tick paralysis}}

Ascending paralysis contrasts with descending paralysis, which occurs in conditions such as botulism.

Many animal species use paralyzing toxins to capture prey, evade predation, or both. In stimulated muscles, the decrease in frequency of the miniature potentials runs parallel to the decrease in postsynaptic potential, and to the decrease in muscle contraction. In invertebrates, this clearly indicates that, e.g., Microbracon (wasp genus) venom causes paralysis of the neuromuscular system by acting at a presynaptic site. Philanthus venom inhibits both the fast and slow neuromuscular system at identical concentrations. It causes a decrease in the frequency of the miniature potentials without affecting their amplitude significantly.{{citation needed|date=July 2021}}

In some species of wasp, to complete the reproductive cycle, the female wasp paralyzes a prey item such as a grasshopper and places it in her nest. In the species Philanthus gibbosus, the paralyzed insect (most often a bee species) is coated in a thick layer of pollen. The adult P. gibbosus then lays eggs in the paralyzed insect, which is devoured by the larvae when they hatch.{{Cite journal |last1=Colman |first1=D. R. |last2=Toolson |first2=E. C. |last3=Takacs-Vesbach |first3=C. D. |date=2012-10-01 |title=Do diet and taxonomy influence insect gut bacterial communities? |journal=Molecular Ecology |volume=21 |issue=20 |pages=5124–5137 |doi=10.1111/j.1365-294X.2012.05752.x |issn=1365-294X |pmid=22978555 |bibcode=2012MolEc..21.5124C |s2cid=23740875}}

An example of a vertebrate-produced paralyzing toxin is the tetrodotoxin of fish species such as Takifugu rubripes, the famously lethal pufferfish of Japanese fugu, which works by binding to sodium channels in nerve cells, inhibiting the cells' proper function. A nonlethal dose of this toxin results in temporary paralysis. This toxin is also present in many other species ranging from toads to nemerteans.{{Cite journal |last1=Noguchi |first1=Tamao |last2=Arakawa |first2=Osamu |date=2008-05-28 |title=Tetrodotoxin--distribution and accumulation in aquatic organisms, and cases of human intoxication |journal=Marine Drugs |volume=6 |issue=2 |pages=220–242 |doi=10.3390/md20080011 |doi-access=free |issn=1660-3397 |pmc=2525488 |pmid=18728726}}

Paralysis can be seen in breeds of dogs that are chondrodysplastic.{{Cite web |last=Coile |first=Caroline |date=October 10, 2023 |title=Dog Paralysis: Everything You Need to Know About Causes & Treatments |url=https://www.akc.org/expert-advice/health/dog-paralysis-what-to-know/ |access-date=2025-05-27 |publisher=American Kennel Club |language=en}} 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.{{Cite web |title=Fibrocartilaginous Embolus/Emboli (FCE) in Dogs |url=https://vcahospitals.com/know-your-pet/fibrocartilaginous-embolusemboli-fce-in-dogs |access-date=2025-05-27 |website=Vca |language=en}}

The German Shepherd Dog 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. Affected dogs will become incontinent and gradually weaker in the hind legs as nerves die off. Eventually, their hind legs become useless. This disease also affects other large breeds of dogs.{{Cite web |title=German Shepherd - Degenerative Myelopathy |url=https://www.ufaw.org.uk/dogs/german-shepherd-degenerative-myelopathy |access-date=2025-05-27 |website=www.ufaw.org.uk |language=english}}

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.{{Cite web |title=Saddle Thrombus in Cats: Causes, Symptoms, and How To Help Your Cat |url=https://www.petmd.com/cat/conditions/cardiovascular/saddle-thrombus-cats-causes-symptoms-and-how-help-your-cat |access-date=2025-05-27 |website=www.petmd.com |language=en}}

Many snakes and trees exhibit powerful neurotoxins that can cause nonpermanent paralysis or death.{{Cite journal |last1=AlShammari |first1=Altaf K. |last2=Abd El-Aziz |first2=Tarek Mohamed |last3=Al-Sabi |first3=Ahmed |date=2023-12-25 |title=Snake Venom: A Promising Source of Neurotoxins Targeting Voltage-Gated Potassium Channels |journal=Toxins |volume=16 |issue=1 |pages=12 |doi=10.3390/toxins16010012 |doi-access=free |issn=2072-6651 |pmc=10820993 |pmid=38251229}}

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• Spinal cord injuries
• Paraplegia
• Quadriplegia
• Hemiparesis
• Monoplegia
• Muscle relaxant
• Beriberi
• Neuroprosthetics
• Brain–computer interface
• Tonic immobility
• Cerebral palsy
• Cobratoxin
• Obdormition
• Narcolepsy
• Cataplexy
• {{annotated link|Locked-in syndrome}}

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| ICD9 = {{ICD9|359.3}}

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Category:Nervous system

Category:Motor control

Category:Cerebral palsy and other paralytic syndromes

Category:Neurology