Epidural hematoma 1017713 219790409 2008-06-16T21:54:50Z Delldot 476500 trivia sections discouraged. we don't want to be misleading readers into thinking that this info from star trek is relevant to treatment {{DiseaseDisorder infobox | Name = Extradural haemorrhage | Image = Epidural hematoma.png | Caption = Nontraumatic epidural hematoma in a young woman. The grey area in the top left is organizing hematoma, causing midline shift and compression of the ventricle. | ICD10 = {{ICD10|I|62|1|i|60}}, {{ICD10|S|06|4|s|00}} | ICD9 = {{ICD9|432.0}} | ICDO = | OMIM = | DiseasesDB = 4353 | MedlinePlus = 001412 | eMedicineSubj = emerg | eMedicineTopic = 167 | eMedicine_mult = {{eMedicine2|med|2898}} {{eMedicine2|neuro|574}} | MeshID = D006407 | }} '''Epidural''' or '''extradural hematoma''' is a buildup of blood occurring between the [[dura mater]] (the [[brain|brain's]] tough outer membrane) and the [[skull]]. Often due to [[physical trauma|trauma]], the condition is potentially deadly because the buildup of blood may increase [[intracranial pressure|pressure]] in the [[intracranial space]] and compress delicate brain tissue. The condition is present in one to three percent of [[head injury|head injuries]].<ref name="Mishra">{{cite journal|author=Mishra A, Mohanty S |title=Contre-coup extradural haematoma : A short report|journal=Neurology India|date=2001|volume=49|issue=94|url=http://www.neurologyindia.com/article.asp?issn=0028-3886;year=2001;volume=49;issue=1;spage=94;epage=5;aulast=Mishra | accessdate=2008-01-24}}</ref> Between 15 and 20% of patients with epidural hematomas die of the [[injury]].<ref>Sanders MJ and McKenna K. 2001. ''Mosby’s Paramedic Textbook'', 2nd revised Ed. Chapter 22, "Head and Facial Trauma." Mosby.</ref> ==Causes== [[Image:Skull interior anatomy.svg|thumb|left|150px|The interior of the skull has sharp ridges by which a moving brain can be injured.]] The cause of epidural hematoma is usually [[brain trauma|traumatic]], although spontaneous hemorrhage is known to occur. Hemorrhages commonly result from [[acceleration-deceleration trauma]] and transverse forces.<ref name="uv">University of Vermont College of Medicine. [http://web.archive.org/web/20050309165318/http://cats.med.uvm.edu/cats_teachingmod/pathology/path302/np/home/neuroindex.html "Neuropathology: Trauma to the CNS."] Accessed through web archive. Retrieved on [[February 6]], [[2007]].</ref><ref name="McCaffrey">McCaffrey P. 2001. [http://www.csuchico.edu/~pmccaff/syllabi/SPPA336/336unit11.html "The Neuroscience on the Web Series: CMSD 336 Neuropathologies of Language and Cognition."] California State University, Chico. Retrieved on [[February 6]], [[2007]].</ref> 10% of epidural bleeds may be [[vein|venous]].<ref name="Shepherd"/> Venous epidural bleeds are usually due to [[shearing injury]] from [[angular momentum|rotational]] or linear forces, caused when tissues of different densities slide over one another. Epidural hematoma commonly results from a blow to the side of the head. The [[pterion]] region which overlies the middle meningeal artery is exceptionally weak and prone to injury. <ref name="Shepherd">Shepherd S. 2004. [http://www.emedicine.com/med/topic2820.htm "Head Trauma."] Emedicine.com. Retrieved on [[February 6]], [[2007]].</ref> Thus only 20 to 30% of epidural hematomas occur outside the region of the temporal bone.<ref>Graham DI and Gennareli TA. Chapter 5, "Pathology of Brain Damage After Head Injury" Cooper P and Golfinos G. 2000. Head Injury, 4th Ed. Morgan Hill, New York.</ref> The brain may be injured by prominences on the inside of the skull as it scrapes past them. EDH is usually found on the same side of the brain that was impacted by the blow, but on very rare occasions it can be due to a [[coup-contrecoup injury|contrecoup injury]].<ref name="Mishra"/> ==Features== [[Image:Epidural hematoma.jpg|thumb|right|180px|Epidural hematomas usually look convex on CT scans.]] Epidural bleeds, like [[subdural hematoma|subdural]] and [[subarachnoid hemorrhage]]s, are [[extra-axial hemorrhage|extra-axial bleeds]], occurring outside of the brain tissue, while [[intra-axial hemorrhage]]s, including [[intraparenchymal hemorrhage|intraparenchymal]] and [[intraventricular hemorrhage]]s, occur within it.<ref>Wagner AL. 2006. [http://www.emedicine.com/radio/topic664.htm "Subdural Hematoma."] Emedicine.com. Retrieved on [[February 6]], [[2007]].</ref> Epidural bleeding is rapid because it is usually from arteries, which are high pressure. Epidural bleeds from arteries can grow until they reach their peak size at six to eight hours post injury, spilling from 25 to 75 [[cubic centimeter]]s of blood into the [[intracranial space]].<ref name="uv"/> As the hematoma expands, it strips the dura from the inside of the skull, causing an intense headache. Epidural bleeds can become large and raise [[intracranial pressure]], causing the brain to shift, lose blood supply, or be crushed against the skull. Larger hematomas cause more damage. Epidural bleeds can quickly expand and compress the brain stem, causing [[coma|unconsciousness]], [[abnormal posturing]], and abnormal [[pupil]] responses to light.<ref name="singh Stock">Singh J and Stock A. 2006. [http://www.emedicine.com/ped/topic929.htm "Head Trauma."] Emedicine.com. Retrieved on [[February 6]], [[2007]].</ref> On images produced by [[CT scan]]s and [[MRI]]s, epidural hematomas usually appear convex in shape because their expansion stops at skull's [[skull suture|sutures]], where the dura mater is tightly attached to the skull. Thus they expand inward toward the brain rather than along the inside of the skull, as occurs in [[subdural hematoma]]. The lens like shape of the hematoma leads the appearance of these bleeds to be called "lentiform". Epidural hematomas may occur in combination with subdural hematomas, or either may occur alone.<ref name="Shepherd"/> CT scans reveal subdural or epidural hematomas in 20% of unconscious patients.<ref name="Downie">Downie A. 2001. [http://www.radiology.co.uk/srs-x/tutors/cttrauma/tutor.htm "Tutorial: CT in Head Trauma"]. Retrieved on [[February 6]], [[2007]].</ref> In the hallmark of epidural hematoma, patients may regain consciousness during what is called a [[lucid interval]], only to descend suddenly and rapidly into unconsciousness later. The lucid interval, which depends on the extent of the injury, is a key to diagnosing epidural hemorrhage. If the patient is not treated with prompt surgical intervention, death is likely to follow.<ref name="Caroline">Caroline NL. 1991. ''Emergency Medical Treatment''. Little Brown & Company.</ref> ==Treatment== As with other types of [[intracranial hematoma]]s, the blood may be aspirated surgically to remove the mass and reduce the pressure it puts on the brain.<ref name="McCaffrey"/> The hematoma is [[neurosurgery|neurosurgically]] evacuated through a [[burr hole]] or [[craniotomy]]. The diagnosis of epidural hematoma requires a patient to be cared for in a facility with a neurosurgeon on call to decompress the hematoma if necessary and stop the bleed by ligating the injured vessel branches. ==Epidural hematoma in the spine== Bleeding into the epidural space in the spine may also cause epidural hematoma. These may arise spontaneously (e.g. during [[childbirth]]), or as a rare complication of anaesthesia (such as [[epidural]] anaesthesia) or surgery (such as laminectomy). The anatomy of the epidural space means that spinal epidural hematoma has a different profile from cranial epidural hematoma. In the spine, the epidural space contains loose fatty tissue, and the '''epidural venous plexus''', a network of large, thin-walled veins. This means that bleeding is likely to be venous. Anatomical abnormalities and [[coagulopathy| bleeding disorder]]s make these lesions more likely. They may cause pressure on the spinal cord or [[cauda equina]], which may present as pain, muscle weakness, or bladder and bowel dysfunction. The diagnosis may be made on clinical appearance and time course of symptoms. It usually requires [[MRI]] scanning to confirm. The treatment is surgical decompression. The incidence of epidural hematoma following epidural anaesthesia is extremely difficult to quantify; estimates vary from 1 per 10,000 to 1 per 100,000 epidural anaesthetics. This means that a typical anaesthetist or [[anesthesiologist]] is statistically unlikely to cause one in a whole career. ==References== {{reflist|2}} ==External links== * [http://rad.usuhs.mil/medpix/medpix.html?mode=single&recnum=810 MedPix: Epidural hematoma] {{Injuries, other than fractures, dislocations, sprains and strains}} {{Neurotrauma}} {{Vascular diseases}} [[Category:Neurotrauma]] [[Category:Neurology]] [[de:Hirnblutung]] [[fr:Hématome extra-dural]] [[nl:Epidurale bloeding]] [[ja:急性硬膜外血腫]] [[zh:硬脑膜下血肿]]