Editing Cushing reflex (section)

==History==
[[File:Harvey Cushing, Doris Ulmann 1920s.jpg|thumb|[[Harvey Cushing]], Doris Ulmann 1920s]]
Cushing's reflex is named after [[Harvey Williams Cushing]] (1869–1939), an [[United States|American]] [[neurosurgeon]]. Cushing began his research in [[Bern]], [[Switzerland]] studying abroad with [[Emil Theodor Kocher]]. A month into his trip, Cushing received a formal proposition from [[Kocher|Emil Theodor Kocher]] to begin testing how compression of the brain affected blood vessels. Cushing also enlisted the aid of [[Hugo Kronecker]], a known blood pressure researcher. Utilizing [[Hugo Kronecker|Kroenecker's]] assistance and resources, Cushing began his research. Cushing left [[Bern]] in 1901 to work in [[Turin]], [[Italy]] with [[Angelo Mosso]], a previous student of [[Hugo Kronecker|Kroenecker]]. He continued to work on the same research project, while also simultaneously improving his methods of recording coincidence of [[blood pressure]] and [[Intracranial pressure|ICP]]. In June 1901 Cushing published his first paper through Johns Hopkins Hospital Bulletin entitled "Concerning a definite regulatory mechanism of the vasomotor centre which controls blood pressure during cerebral compression".<ref name=Cushing /> Between 1901 and 1903, Cushing published five papers pertaining to his research on the vasopressor response. These papers were published in [[German language|German]] and [[English language|English]], and one was authored by [[Kocher|Emil Theodor Kocher]].<ref name=Fodstad>{{cite journal |vauthors=Fodstad H, Kelly PJ, Buchfelder M |title=History of the cushing reflex |journal=Neurosurgery |volume=59 |issue=5 |pages=1132–7; discussion 1137 |date=November 2006 |pmid=17143247 |doi=10.1227/01.NEU.0000245582.08532.7C }}</ref>

===Experimental setup and results===
Cushing began experimenting once he obtained approval from Kocher. His experimental setup was a modified version of  [[Leonard Erskine Hill|Leonard Hill's]] model to similarly test the effects of brain pressure on sinus pressure, cerebrospinal fluid pressure, [[arterial blood pressure|arterial]] and venous blood pressure.<ref name=Fodstad /><ref name=HillL>{{cite book |author=Leonard Hill |title= Physiology and Pathology of the Cerebral Circulation. |url=https://archive.org/details/cu31924024799110 |publisher= J & A Churchill |location=London |year=1896 }}</ref>  Like Hill, Cushing used dogs for his experiments. To begin, Cushing monitored the caliber and color of cortical vessels by fitting a glass window into the skull of the dog. Intracranial pressure was raised by filling an intracranial, soft, rubber bag with mercury. Cushing recorded the intracranial pressure along with [[blood pressure]], [[pulse rate]], and [[respiratory rate]] simultaneously. This three part effect is commonly referred to as [[Cushing's triad]]. In later experiments performed by [[Angelo Mosso|Mosso]], intracranial pressure was induced by injecting physiological saline into the [[subarachnoid space]] rather than increasing mercury content of an intracranial bag.<ref name=Fodstad />

This research clearly displayed the cause and effect relationship between intracranial pressure and cerebral compression.<ref name=FinkM>{{cite book |author1=Mitchell Fink |author2=Michelle Hayes |author3=Neil Soni |title= Classic Papers in Critical Care.  |publisher= Springer |location=London, England |year=2008 |pages= 89–90 }}</ref>  Cushing noted this relationship in his subsequent publications. He also noted that there must exist a specific regulatory mechanism that increased blood pressure to a high enough point such that it did not create anemic conditions.<ref name="Cushing"/> Cushing's publications contain his observations and no statistical analysis. The sample size of the experiment is also not known.<ref name="FinkM"/>

===Other researchers===
Several notable figures in the medical field, including [[Ernst von Bergmann]],<ref name=Hanigan>{{cite journal | last =Hanigan | first = WC|author2=W. Ragen |author3=M. Ludgera | title =Neurological surgery in the nineteenth century: the principles and techniques of Ernst von Bergmann.| journal =Neurosurgery | volume =30 | issue = 5| pages =750–7 | year =1992 | doi = 10.1227/00006123-199205000-00017| pmid =1584389}}</ref> [[Henri Duret]],<ref name=duret>{{cite book |author=Duret H |title=Anatomic Studies of the Cerebral Circulation |location=Paris, Bailliere|year=1878 |pages=642 }}</ref> [[Friedrich Jolly]],<ref name=JollyF>{{cite thesis |author=Friedrich Jolly |title= About Intracranial Pressure and Blood Circulation Inside the Cranium. Medical Thesis |location=Wurzburg, Germany |year=1871 }}</ref> and others experimented with intracranial pressure similarly to Cushing. Some of these researchers published similar findings concerning the relationship of intracranial pressure to arterial blood pressure before Cushing had begun experimenting. Cushing studied this relationship more carefully and offered an improved explanation of the relationship.<ref name=Fodstad />

Some controversy concerning plagiarism does surround some of Cushing's research. [[Bernhard Naunyn]], a German pathologist and contemporary of Cushing, made remarks claiming that Cushing neither cited him in Cushing's research nor expanded on any of the results that he had found in his original experiments.<ref name=FultonJF>{{cite book |author=JF Fulton |title= Harvey Cushing. A biography |url=https://archive.org/details/in.ernet.dli.2015.179766 |publisher= Charles C. Thomas |location=Springfield |year=1946 |pages=[https://archive.org/details/in.ernet.dli.2015.179766/page/n103 176]–193 }}</ref>