Paralysis
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Paralysis | |
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Specialty | Neurology, neurosurgery, psychiatry |
Paralysis (pl.: paralyses; also known as plegia) is a loss of motor function in one or more muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, roughly 1 in 50 people have been diagnosed with some form of permanent or transient paralysis.[1] The word "paralysis" derives from the Greek παράλυσις, meaning "disabling of the nerves"[2] from παρά (para) meaning "beside, by"[3] and λύσις (lysis) meaning "making loose".[4] A paralysis accompanied by involuntary tremors is usually called "palsy".[5][6]
Causes
Paralysis is most often caused by damage in the
Pseudoparalysis (pseudo- meaning "false, not genuine", from Greek ψεῦδος
Variations
Paralysis can occur in localised or generalised forms, or it may follow a certain pattern. Most paralyses caused by nervous-system damage (e.g.,
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.[12] 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.[11] 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[13]
Ascending paralysis contrasts with descending paralysis, which occurs in conditions such as botulism.
Other animals
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.,
Invertebrates
In 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. In the species Philanthus gibbosus, the paralysed insect (most often a bee species) is coated in a thick layer of pollen. The adult P. gibbosus then lays eggs in the paralysed insect, which is devoured by the larvae when they hatch.[14]
Vertebrates
A well-known example of a vertebrate-produced paralyzing toxin is the
Paralysis can be seen in breeds of dogs that are
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
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
See also
- Spinal cord injuries
- Paraplegia
- Quadriplegia
- Hemiparesis
- Monoplegia
- Muscle relaxant
- Beriberi
- Neuroprosthetics
- Brain–computer interface
- Tonic immobility
- Cerebral palsy
- Cobratoxin
- Obdormition
- Narcolepsy
- Cataplexy
References
- ^ "Paralysis Facts & Figures - Spinal Cord Injury - Paralysis Research Center". Christopherreeve.org. Archived from the original on 2016-03-24. Retrieved 2013-02-19.
- ^ Liddell, Henry George; Scott, Robert (1940). "παράλυσις". A Greek-English Lexicon. Oxford: Clarendon Press. on Perseus
- ^ Liddell & Scott 1940, παρά
- ^ Liddell & Scott 1940, λύσις
- ^ "Palsy". Lexico. Archived from the original on July 24, 2012. Retrieved 27 May 2015.
- ^ "Palsy". Merriam-Webster. Retrieved 27 May 2015.
- ^ Liddell & Scott 1940, ψεῦδος
- ^ TheFreeDictionary > pseudoparalysis, in turn citing The American Heritage Medical Dictionary 2007, 2004
- PMID 16888612.
... evidence of congenital syphilis (e.g., nonimmune hydrops, jaundice, hepatosplenomegaly, rhinitis, skin rash, and/or pseudoparalysis of an extremity).
- ^ "anxiety-panic.com". anxiety-panic.com. Archived from the original on 2018-07-30. Retrieved 2017-06-06.
- ^ PMID 20748563.
- ^ ISBN 978-0-07-337825-1.
- ^ MedlinePlus Encyclopedia: Tick paralysis
- S2CID 23740875.