Editing Plantar reflex

{{Short description|Reflex elicited when the sole of the foot is stimulated with a blunt instrument}}
{{Infobox diagnostic |
  Name        = Plantar reflex <br> Babinski response/Babinski sign (pathological) |
  Image       = File:Lawrence 1960 20.4-en.svg|
  Caption     = The reflex occurs upon stroking of the sole of the foot with a blunt object such as a pen. If the reflex occurs in adults as illustrated at bottom it may be due to nerve damage or disease. |
  Width       = 300px |
  ICD10       = |
  ICD9        = {{ICD9proc|796.1}} |
  MeshID      = |
  MedlinePlus = 003294 |
  OtherCodes  = |}}

The '''plantar reflex''' is a [[reflex]] elicited when the sole of the foot is stimulated with a blunt instrument. The reflex can take one of two forms.  In healthy adults, the plantar reflex causes a downward response of the [[hallux]] ([[flexion]]). 

An upward response ([[Extension (kinesiology)|extension]]) of the hallux is known as the '''Babinski response''' or '''Babinski sign''', named after the neurologist [[Joseph Babinski]]. The presence of the Babinski sign can identify [[disease]] of the [[spinal cord]] and [[Human brain|brain]] in adults, and also exists as a [[Primitive reflexes|primitive reflex]] in [[infant]]s.<ref>{{WhoNamedIt|synd|366}}</ref>

While first described in the medical literature by Babinski in 1896,<ref>''Comptes rendus de la Société de Biologie'', Vol. 48, 1896, p. 207, http://gallica.bnf.fr/ark:/12148/bpt6k6459605g/f225.image</ref> the reflex has been identified in art at least as early as [[Botticelli]]'s ''[[Virgin and Child with an Angel (Botticelli, Florence)|Virgin and Child with an Angel]]'', painted in the mid-[[15th century]].<ref>{{cite journal|last1=Massey|first1=E. W.|last2=Sanders|first2=L.|title=Babinski's Sign in Medieval, Renaissance, and Baroque Art|journal=Archives of Neurology|date=1 January 1989|volume=46|issue=1|pages=85–88|doi=10.1001/archneur.1989.00520370087025|pmid=2642699 }}</ref>

==Methods==
[[File:BabinskiSign.jpg|thumb|240px|Pathological Babinski's sign in adult]]

The [[Human anatomical terms#Near or away from the vertical longitudinal center of the body|lateral]] side of the [[sole (foot)|sole of the foot]] is rubbed with a blunt instrument or device, so as not to cause pain, discomfort, or injury to the skin; the instrument is run from the heel along a curve to the [[toe]]s<ref>{{DorlandsDict|seven/000091594|plantar reflex}}</ref> ([[metatarsus|metatarsal]] pads). Many [[reflex hammer]]s taper at the end of the handle to a point which was used for testing the plantar response in the past; due to the tightening of [[infection control]] regulation this is no longer recommended. Either a single use device or the thumbnail should be used.{{citation needed|date=May 2017}}

There are three responses possible:
*Flexor: the toes curve down and inwards, and the foot [[inversion (kinesiology)|inverts]]; this is the response seen in healthy adults.
*Indifferent: there is no response. This is called the neutral response, and has no clinical significance, as it does not rule out pathology.<ref>{{Citation |last=Acharya |first=Aninda B. |title=Babinski Reflex |date=2023 |url=http://www.ncbi.nlm.nih.gov/books/NBK519009/ |work=StatPearls |access-date=2023-12-04 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=30085551 |quote="If there is no movement, then this is considered a neutral response and has no clinical significance." "Sometimes there is no response to stimulation. This is called a neutral response. This response does not rule out pathology." |last2=Jamil |first2=Radia T. |last3=Dewey |first3=Jeffrey J.}}</ref>
*Extensor: the [[hallux]] [[dorsiflexion|dorsiflexes]], and the other toes fan out. If elicited in an adult, it indicates damage to the [[central nervous system]], but it is a normal reflex in infants (see below). It is also known as the Babinski Sign.

As the [[lesion]] responsible for the sign expands, so does the area from which the [[Afferent nerve|afferent]] Babinski response may be elicited. The Babinski response is also normal while asleep and after a long period of walking.

==Interpretation==
[[File:Babinski-newborn.jpg|thumb|right|240px|Babinski's sign in a healthy newborn]]

The Babinski sign can indicate [[upper motor neuron lesion]] constituting damage to the [[corticospinal tract]]. Occasionally, a pathological plantar reflex  is the first and only indication of a serious disease process and a clearly abnormal plantar reflex often prompts detailed [[neurology|neurological]] investigations, including [[Computed tomography|CT scanning]] of the brain or [[Magnetic resonance imaging|MRI]] of the spine, as well as [[lumbar puncture]] for the study of [[cerebrospinal fluid]].

The phrase "negative Babinski sign" is sometimes used for the normal flexor plantar response.<ref name="Larner2006">{{cite book|last=Larner|first=A. J.|title=A Dictionary of Neurological Signs|url=https://books.google.com/books?id=lmk6vxPeE7sC&pg=PA50|year=2006|publisher=Springer|isbn=978-0-387-26214-7|pages=50–}}</ref>

===In infants===
{{main|Primitive reflexes}}
[[Infant]]s will usually show an extensor response. In one study of 256 healthy infants, the response to testing was extensor in 73.8%, flexor in 8.9%, and equivocal in 17.3%<ref>{{cite journal|last1=Gupta|first1=A|last2=Gupta|first2=Piyush|title=Neonatal plantar response revisited |journal=Journal of Paediatrics and Child Health|date=July 2003|volume=39|issue=5|pages=349–351|doi=10.1046/j.1440-1754.2003.00172.x|pmid=12887664|s2cid=19382928}}</ref> This extensor response occurs because the [[corticospinal tract|corticospinal pathways]] that run from the [[Human brain|brain]] down the [[spinal cord]] are not fully [[myelin]]ated at this age, so the reflex is not inhibited by the [[cerebral cortex]]. The extensor response usually disappears – giving way to the flexor response – by 12 months of age.<ref>{{cite web|title=Neonatal reflexes|url=http://www.healthofchildren.com/N-O/Neonatal-Reflexes.html|access-date=24 May 2017}}</ref> Its persistence beyond age 2–3 indicates a problem in the brain or spinal cord.<ref>{{cite web|title=Medline plus: Babinski reflex|url=https://medlineplus.gov/ency/article/003294.htm|access-date=24 May 2017}}</ref><ref>{{cite journal|last1=Neelon|first1=Francis A|last2=Harvey|first2=Elisabeth|title=The Babinski Sign|journal=N Engl J Med|volume=340|issue=3|pages=196|date=January 21, 1999|doi=10.1056/NEJM199901213400305|pmid=9895399}}</ref>

===Pathways===
* Afferent: [[Nociception]] detected in the S1 [[Dermatome (anatomy)|dermatome]] and travels up the [[tibial nerve]] to the [[sciatic nerve]] to roots of L5,S1 and synapse in the [[Anterior horn of lateral ventricle|anterior horn]] to elicit the motor response.
* Efferent: Motor response back through the L5,S1 roots to the sciatic nerve to its bifurcation.  Toe flexors are innervated by the tibial nerve. Toe extensors ([[Extensor hallucis longus muscle|extensor hallucis longus]], [[Extensor digitorum longus muscle|extensor digitorum longus)]] are innervated by the [[deep peroneal nerve]]. Loss of normal adult descending pyramidal control of the reflex arc to suppress extensor withdrawal results in the upgoing toes in the plantar reflex known as Babinski's sign.<ref>{{cite journal|last1=Futagi|first1=Y|last2=Suzuki|first2=Y|title=Neural mechanism and clinical significance of the plantar grasp reflex in infants.|journal=Pediatric Neurology|date=August 2010|volume=43|issue=2|pages=81–6|doi=10.1016/j.pediatrneurol.2010.04.002|pmid=20610116}}</ref>

==Relationship to Hoffmann's reflex==
{{main|Hoffmann's reflex}}
The [[Hoffmann's reflex]] is sometimes described as the [[upper limb]] equivalent of the Babinski sign<ref>{{cite journal |vauthors=Harrop JS, Hanna A, Silva MT, Sharan A |title=Neurological manifestations of cervical spondylosis: an overview of signs, symptoms, and pathophysiology |journal=Neurosurgery |volume=60 |issue=1 Supp1 1 |pages=S14–20 |year=2007 |pmid=17204875 |doi=10.1227/01.NEU.0000215380.71097.EC|s2cid=22166615 }}</ref> because both indicate [[upper motor neuron]] dysfunction. Mechanistically, they differ significantly; the finger flexor reflex is a simple [[Reflex arc|monosynaptic spinal reflex]] involving the [[flexor digitorum profundus muscle|flexor digitorum profundus]] that is normally fully inhibited by upper motor neurons. The pathway producing the plantar response is more complicated, and is not monosynaptic.

== Babinski-like responses ==
The plantar reflex can be elicited in a number of ways, which were described in the late 19th and early 20th century. These have their own eponyms.<ref name="pmid11146592">{{cite journal|last=Kumar|first=SP|author2=Ramasubramanian, D |title=The Babinski sign--a reappraisal.|journal=Neurology India|date=December 2000|volume=48|issue=4|pages=314–8|pmid=11146592|url=http://www.neurologyindia.com/article.asp?issn=0028-3886;year=2000;volume=48;issue=4;spage=314;epage=8;aulast=Kumar}}</ref><ref>{{cite book|title=Clinical methods : the history, physical, and laboratory examinations|year=1990|publisher=Butterworths|location=Boston|isbn=978-0-409-90077-4|author=Walker, H. Kenneth|edition=3rd|author2=Hall, W. Dallas |author3=Schlossberg, J. Willis Hurst  |author4=illustrations by Leon |author5= Boyter, Charles H. |editor=Walker, H. Kenneth|chapter=Chapter 73 The Plantar Reflex|quote=Table 73.1 Variants of the Babinski Sign|chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK397/}}</ref><ref name=Silva>{{cite book|last1=Silva Rosas|first1=Carlos|title=Semiología y Fundamentos de la Neurología Clínica|date=2013|publisher=AMOLCA|isbn=978-958-8760-73-5|pages=66–67|edition=First|url=http://www.amolca.com/semiologia-y-fundamentos-de-la-neurologia-clinica/}}</ref>

*[[Bing's sign|Bing sign]] &ndash; multiple pinpricks on the [[Dorsum (biology)|dorsum]] of the foot
*[[Cornell's sign|Cornell sign]] &ndash; scratching along the inner side of the [[Extensor hallucis longus muscle|extensor hallucis longus]] tendon
*[[Chaddock reflex|Chaddock sign]] &ndash; stroking the [[lateral malleolus]]
* Doug's sign &ndash; electrically stimulating peripheral nerves during a [[nerve conduction study]]
*[[Gonda's sign|Gonda sign]] &ndash; [[Flexion|flexing]] and suddenly releasing the 4th toe
*[[Gordon's sign|Gordon sign]] &ndash; squeezing the calf muscle
*[[Moniz sign]] &ndash; forceful passive [[Plantarflexion|plantar flexion]] of the ankle
*[[Oppenheim's sign|Oppenheim sign]] &ndash; applying pressure to the medial side of the [[tibia]]
*[[Schaeffer's sign|Schaeffer sign]] &ndash; squeezing the [[Achilles tendon]]
* Silva sign &ndash; pinching the [[rectus femoris muscle]]<ref name=Silva />
*[[Stransky's sign|Stransky sign]] &ndash; vigorously [[Abduction (kinesiology)|abducting]] and suddenly releasing the [[Fifth toe|little toe]]
*[[Strümpell's sign|Strümpell sign]] &ndash; patient attempts to flex the knee against resistance
*[[Throckmorton's reflex|Throckmorton reflex]] &ndash; percussion over the [[Metatarsophalangeal articulations|metatarsophalangeal joint]] of the big toe

=== Abnormal reflexes seen as flexion of toes ===
*[[Bekhterev-Mendel reflex]] &ndash; flexion of the 2nd to 5th toes on percussion of the dorsum of the foot
*[[Rossolimo's sign|Rossolimo sign]] &ndash; exaggerated flexion of the toes induced by rapid percussion on the tips of the toes

==References==
{{reflist}}
{{Reflex}}
{{Eponymous medical signs for nervous system}}

{{DEFAULTSORT:Plantar Reflex}}
[[Category:Reflexes]]