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Extradural hematoma EDH , also known as an epidural hematoma , is a collection of blood that forms between the inner surface of the skull and outer layer of the dura , which is called the endosteal layer. They are usually associated with a history of head trauma and frequently associated skull fracture. The source of bleeding is usually arterial, most commonly from a torn middle meningeal artery.
EDHs are typically biconvex in shape and can cause a mass effect with herniation. They are usually limited by cranial sutures, but not by venous sinuses. When the blood clot is evacuated promptly or treated conservatively when small , the prognosis of EDHs is generally good. Intracranial venous extradural hemorrhages and spinal epidural hemorrhages are discussed separately.
Typically extradural hematomas are seen in young patients who have sustained head trauma, usually with an associated skull fracture. Unlike subdural hemorrhages , in which a history of head trauma is often difficult to clearly identify, extradural hemorrhages usually are precipitated by clearly defined head trauma.
A typical presentation is of a young patient involved in a head strike either during sport or a result of a motor vehicle accident who may or may not lose consciousness transiently. Following the injury, they regain a normal level of consciousness lucid interval , but usually, have an ongoing and often severe headache. Over the next few hours, they gradually lose consciousness. Pain often severe headache is caused by the stripping of dura from the bone by the expanding hemorrhage.
The posterior fossa is a rare location for traumatic injury, in general, including EDH Occasionally, an EDH can form due to venous blood, typically a torn sinus with an associated fracture: see venous extradural hemorrhage.
Young patients being affected is not only a result of the prevalent demographics of patients with a head injury but also relates to the changes that occur in the dura in older patients, as the dura is much more adherent to the inner surface of the skull. It is important to realize that in the setting of sutural diastasis , extradural hematomas can cross sutures, as the continuation of the parietal periosteal component of the dura through the suture - which usually limits spread - is likely also to be disrupted.
Special locations to consider, particularly those related to venous extradural bleeding , include:. The morphology of extradural hematomas is best understood by reviewing their relationship to the bone and dura. An extradural hematoma is actually a subperiosteal hematoma located on the inside of the skull, between the inner table of the skull and parietal layer of the dura mater which is the periosteum.
As a result, EDHs are usually limited in their extent by the cranial sutures, as the periosteum crosses through the suture continuous with the outer periosteal layer. This is therefore helpful in distinguishing EDHs from subdural hematomas , which are not limited by sutures. Extradural hemorrhages can, however, cross and elevate venous sinuses as long as there is no suture there; after all a venous sinus is located between the parietal and visceral layer of the dura.
Unfortunately, these rules are not foolproof and not infrequently extradural hematomas do cross sutures. This occurs in many scenarios:. In almost all cases, extradural hematomas are seen on CT scans of the brain. They are typically bi-convex or lentiform in shape, and most frequently beneath the squamous part of the temporal bone. EDHs are hyperdense, somewhat heterogeneous, and sharply demarcated. Depending on their size, secondary features of mass effect e.
Postcontrast extravasation may be seen rarely in case of acute EDH and peripheral enhancement due to granulation and neovascularization can be seen in chronic EDH. MRI can clearly demonstrate the displaced dura that appears as a hypointense line on T1 and T2 sequences which is helpful in distinguishing it from a subdural hematoma.
Acute EDH appears isointense on T1 and shows variable intensities from hypo- to hyperintense on a T2 sequence. Intravenous contrast may demonstrate displaced or occluded venous sinus in case of the venous origin of EDH.
It can be used to evaluate nontraumatic cause i. Rarely angiography can demonstrate middle meningeal artery laceration and contrast extravasation from the middle meningeal artery into paired middle meningeal veins known as "tram track sign".
Prognosis, even with a relatively large hematoma, is in general quite good, as long as the clot is evacuated promptly. A smaller hematoma without mass effect or swirl sign can be treated conservatively 2 , sometimes resulting in calcification of the dura.
Occasionally late complications are encountered, usually relating to the injured meningeal vessel. They include:. With large hematomas, there is rarely significant confusion as to the correct diagnosis. In smaller lesions, especially when there is associated parenchymal injury e.
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Please use another browser until we can get it fixed. On this page:. Article: Epidemiology Clinical presentation Pathology Radiographic features Treatment and prognosis Differential diagnosis Related articles References Images: Cases and figures Imaging differential diagnosis.
Quiz questions. Al-Nakshabandi NA. The swirl sign. Radiology full text - Pubmed citation. Edit article Share article View revision history Report problem with Article. URL of Article. Article information. Systems: Central Nervous System , Trauma. Tags: hemorrhage , trauma. Support Radiopaedia and see fewer ads. Cases and figures. Figure 1: extradural hemorrhage Figure 1: extradural hemorrhage. Figure 2: layers of the scalp and meninges Figure 2: layers of the scalp and meninges.
Figure 3: gross pathology Figure 3: gross pathology. Case 1: typical bi-convex shape Case 1: typical bi-convex shape. Case 3 Case 3.
Case 4: in posterior fossa displacing sinus Case 4: in posterior fossa displacing sinus. Case 5: three months later - calcified dura Case 5: three months later - calcified dura. Case 7 Case 7. Case 10 Case Case associated with subgaleal hematoma Case associated with subgaleal hematoma. Case 12 Case Case 13 Case Case 14 Case Case 15 Case Case 16 Case Case 17 Case Case 18 Case Case anterior temporal type Case anterior temporal type.
Case bilateral frontal Case bilateral frontal. Case Left occipital late subacute epidural hematoma Case Left occipital late subacute epidural hematoma. Case with cephalohematoma and caput succedaneum Case with cephalohematoma and caput succedaneum. Imaging differential diagnosis. Subdural hemorrhage Subdural hemorrhage. Meningioma Meningioma. Loading more images Close Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys.
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Hématome extra dural
"hématome extra-dural" in English