Abnormal posturing 2983982 221300432 2008-06-23T22:39:48Z DOI bot 6652755 Citation maintenance. You can [[WP:DOI|use this bot]] yourself! Please [[User:DOI_bot/bugs|report any bugs]]. {{Infobox_Disease | Name = {{PAGENAME}} | Image = | Caption = | DiseasesDB = | ICD10 = {{ICD10|R|29|3|r|25}} | ICD9 = {{ICD9|781.92}} | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = | eMedicineTopic = | MeshID = | }} '''Abnormal posturing''' is an involuntary [[flexion]] or [[Extension (kinesiology)|extension]] of the arms and legs, indicating severe [[brain injury]]. It occurs when one set of [[muscle]]s becomes incapacitated while the opposing set is not, and an external [[stimulus (physiology)|stimulus]] such as [[pain]] causes the working set of muscles to contract.<ref name="AllRefer.com">AllRefer.com. 2003 [http://health.allrefer.com/health/decorticate-posture-info.html “Decorticate Posture”]. Retrieved [[January 15]], [[2007]].</ref> The posturing may also occur without a stimulus.<ref name="wrong">WrongDiagnosis.com, [http://www.wrongdiagnosis.com/symptoms/posture_symptoms/book-causes-13b.htm Decorticate posture: Decorticate rigidity, abnormal flexor response] (Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series). Retrieved on [[September 15]], [[2007]].</ref> Since posturing is an important indicator of the amount of damage that has occurred to the brain, it is used by medical professionals to measure the severity of a [[coma]] with the [[Glasgow Coma Scale]] (for adults) and the [[Pediatric Glasgow Coma Scale]] (for infants). The presence of posturing indicates a severe [[medical emergency]] requiring immediate medical attention. Decerebrate and decorticate posturing are strongly associated with poor outcome in a variety of conditions. For example, near-[[drowning]] victims that display decerebrate or decorticate posturing have worse outcomes than those that do not.<ref name="Nagel ">{{cite journal | last =Nagel | first =FO | authorlink = | coauthors =Kibel SM, Beatty DW. | title =Childhood near-drowning—factors associated with poor outcome | journal =South African Medical Journal | volume =78 | issue =7 | pages =422–425 | publisher = | date =1990 | url = | doi = | pmid = 2218768 }} </ref> Changes in the condition of the patient may cause him or her to alternate between different types of posturing.<ref>ADAM. [http://www.nlm.nih.gov/medlineplus/ency/article/003189.htm Medical Encyclopedia: Abnormal posturing.] Retrieved on [[September 3]], [[2007]].</ref> ==Causes== Posturing can be caused by conditions that lead to large increases in [[intracranial pressure]].<ref name="Yamamoto">Yamamoto, Loren G. 1996. [http://www.hawaii.edu/medicine/pediatrics/pemxray/v5c06.html “Intracranial Hypertension and Brain Herniation Syndromes: Radiology Cases in Pediatric Emergency Medicine"]. '''5'''(6). Kapiolani Medical Center for Women and Children; University of Hawaii; John A. Burns School of Medicine. Retrieved [[January 24]], [[2007]].</ref> Such conditions include [[traumatic brain injury]], [[stroke]], [[intracranial hemorrhage]], [[brain tumor]]s, and [[encephalopathy]].<ref name="adam">ADAM. 2005. [http://adam.about.com/encyclopedia/003300.htm "Decorticate Posture"]. Retrieved [[January 15]], [[2007]].</ref> Posturing due to stroke usually only occurs on one side of the body and may also be referred to as [[spastic hemiplegia]].<ref name="wrong"/> Diseases such as [[Malaria]] are also known to cause the brain to swell and cause this posturing effect. Decerebrate and decorticate posturing can indicate that [[brain herniation]] is occurring<ref name="Ayling ">{{cite journal | last =Ayling | first = J| authorlink = | coauthors = | title =Managing head injuries | journal =Emergency Medical Services | volume =31 | issue = 8| pages =42 | publisher = | date =2002 | url = | doi = | pmid =12224233 }} </ref> or is about to occur.<ref name="Yamamoto"/> Brain herniation is an extremely dangerous condition in which parts of the brain are pushed past hard structures within the skull. In herniation syndrome, which is indicative of brain herniation, decorticate posturing occurs, and, if the condition is left untreated, develops into decerebrate posturing.<ref name="Ayling "/> Posturing has also been displayed by patients with [[Creutzfeldt-Jakob disease]],<ref name="Obi ">{{cite journal | last =Obi | first =T | authorlink = | coauthors =Takatsu M, Kitamoto T, Mizoguchi K, Nishimura Y | title =A case of Creutzfeldt-Jakob disease (CJD) started with monoparesis of the left arm | journal =Rinsho Shinkeigaku (Clinical Neurology) | volume =36 | issue =11 | pages =1245–1248 | publisher = | date =1996 | url = | doi = | pmid =9046857 }} </ref> diffuse [[cerebral hypoxia]],<ref name="pmid15094576">{{cite journal |author=De Rosa G, Delogu AB, Piastra M, Chiaretti A, Bloise R, Priori SG |title=Catecholaminergic polymorphic ventricular tachycardia: successful emergency treatment with intravenous propranolol |journal=Pediatric emergency care |volume=20 |issue=3 |pages=175–7 |year=2004 |pmid=15094576 |doi=}}</ref> and [[brain abscess]]es.<ref name="wrong"/> ===In children=== In children younger than age two, posturing is not a reliable finding because their nervous systems are not yet developed.<ref name="wrong"/> However, [[Reye's syndrome]] and traumatic brain injury can both cause decorticate posturing in children.<ref name="wrong"/> For reasons that are poorly understood, but which may be related to high intracranial pressure, children with [[malaria]] frequently exhibit decorticate, decerebrate, and opisthotonic posturing.<ref name="Idro ">{{cite journal | last =Idro | first =R | authorlink = | coauthors =Otieno G, White S, Kahindi A, Fegan G, Ogutu B, Mithwani S, Maitland K, Neville BG, Newton CR | title = Decorticate, decerebrate and opisthotonic posturing and seizures in Kenyan children with cerebral malaria| journal =Malaria Journal | volume =4 | issue =57 | pages = | publisher = | date = | url =http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=16336645 | doi = | pmid =16336645 | accessdate =2007-01-21 }} </ref> ==Types== Three types of abnormal posturing are '''decorticate posturing''', with the arms flexed over the chest; '''decerebrate posturing''', with the arms extended at the sides; and [[opisthotonos]], in which the head and back are arched backward. ===Decorticate posturing=== [[Image:Decorticate.PNG|thumb|450px|right|Decorticate posturing, with elbows, wrists and fingers flexed, and legs extended and rotated inward]] Decorticate posturing is also called '''decorticate response''', '''decorticate rigidity''', or '''flexor posturing'''. Patients with decorticate posturing present with the arms flexed, or bent inward on the chest, the hands are clenched into fists, and the legs extended. A person displaying decorticate posturing in response to pain gets a score of three in the motor section of the [[Glasgow Coma Score]]. There are two parts to decorticate posturing. * The first is the disinhibition of the [[red nucleus]] with facilitation of the [[rubrospinal tract]]. The rubrospinal tract facilitates [[motor neuron]]s in the cervical spinal cord subserving flexor muscles of the upper extremities. * The second component of decorticate posturing is the disruption of the lateral [[corticospinal tract]] which facilitates motor neurons in the lower cord serving extensor muscles of the lower extremities. The effects on these two tracts by lesions above the red nucleus is what leads to the characteristic flexion posturing of the upper extremities and extensor posturing of the lower extremities. Decorticate posturing indicates that there may be damage to areas including the [[cerebral hemisphere]]s, the [[internal capsule]], and the [[thalamus]].<ref name="Cuccurullo04"/> It may also indicate damage to the [[mesencephalon|mesencephalic]] region, or the [[corticospinal tract]], along which impulses travel from the [[human brain|brain]] to the [[spinal cord]].<ref name="AllRefer.com"/> While decorticate posturing is still an ominous sign of severe [[brain damage]], decerebrate posturing is usually indicative of more severe damage. ===Decerebrate posturing=== Decerebrate posturing is also called '''decerebrate response''', '''decerebrate rigidity''', or '''extensor posturing'''. It describes the involuntary extension of the [[upper extremity|upper extremities]] in response to [[external]] [[stimulus (physiology)|stimuli]]. In decerebrate posturing, the head is arched back, the arms are extended by the sides, and the legs are extended.<ref name="adam"/> A hallmark of decerebrate posturing is extended elbows.<ref name="Cuccurullo04"/> A person displaying decerebrate posturing in response to pain gets a score of two in the motor section of the [[Glasgow Coma Scale]] (for adults) and the [[Pediatric Glasgow Coma Scale]] (for infants). Decerebrate posturing indicates [[brain stem]] damage, specifically damage below the level of the [[red nucleus]] (e.g. mid-collicular lesion). It is exhibited by people with lesions or compression in the [[midbrain]] and lesions in the [[cerebellum]].<ref name="Cuccurullo04"/> A patient with decorticate posturing may begin to show decerebrate posturing, or may go from one form of posturing to the other;<ref name="AllRefer.com"/> progression from decorticate posturing to decerebrate posturing is often indicative of uncal (transtentorial) or tonsilar [[brain herniation]]. Posturing may occur on one or the other side of the body, or it may occur on both sides.<ref name="AllRefer.com"/> Activation of [[gamma motor neuron]]s is thought to be important in decerebrate rigidity due to studies in animals showing that dorsal root transection eliminates decerebrate rigidity symptoms.<ref>Berne and Levy principles of physiology/[editors] Metthew N. Levy, Bruce M. Koeppen, Bruce A. Stanton.-4th ed.Philadelphia, PA: Elsevier Mosby, 2006.</ref> ==History== [[Sir Charles Sherrington]] was first to describe decerebrate posturing after transecting the [[brain stem]]s of cats and monkeys, causing them to exhibit the posturing.<ref name="Cuccurullo04"> {{ cite book |author=Elovic E, Edgardo B, Cuccurullo S |chapter= Traumatic brain injury |Editor= Cuccurullo SJ |title=Physical Medicine and Rehabilitation Board Review |publisher=Demos Medical Publishing |location= |year=2004 |pages=54–55 |isbn=1-888799-45-5 |oclc= |doi= }} </ref> ==References== {{reflist|2}} {{Nervous and musculoskeletal system symptoms and signs}} [[Category:Neurotrauma]] [[Category:Medical signs]]