Epidural hematoma is when

bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...

occurs between the tough outer membrane covering the brain (dura mater) and the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

. Often there is

loss of consciousness Loss may refer to: Arts, entertainment, and media Music * ''Loss'' (Bass Communion album) (2006) * ''Loss'' (Mull Historical Society album) (2001) *"Loss", a song by God Is an Astronaut from their self-titled album (2008) * Losses "(Lil Tjay son ...

following a head injury, a brief regaining of consciousness, and then loss of consciousness again. Other symptoms may include

headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...

, confusion, vomiting, and an inability to move parts of the body. Complications may include

seizures An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with lo ...

. The cause is typically

head injury A head injury is any injury that results in trauma to the skull or brain. The terms ''traumatic brain injury'' and ''head injury'' are often used interchangeably in the medical literature. Because head injuries cover such a broad scope of inju ...

that results in a break of the

temporal bone The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears. ...

and bleeding from the

middle meningeal artery The middle meningeal artery ('' la, arteria meningea media'') is typically the third branch of the first portion of the maxillary artery. After branching off the maxillary artery in the infratemporal fossa, it runs through the foramen spinosum t ...

. Occasionally it can occur as a result of a

bleeding disorder Coagulopathy (also called a bleeding disorder) is a condition in which the blood's ability to coagulate (form clots) is impaired. This condition can cause a tendency toward prolonged or excessive bleeding (bleeding diathesis), which may occur spo ...

or blood vessel malformation. Diagnosis is typically by a CT scan or MRI. When this condition occurs in the spine it is known as a

spinal epidural hematoma Spinal extradural haematoma or spinal epidural hematoma (SEH) is bleeding into the epidural space in the spine. These may arise spontaneously (e.g. during childbirth), or as a rare complication of epidural anaesthesia or of surgery (such as lamin ...

. Treatment is generally by urgent surgery in the form of a

craniotomy A craniotomy is a surgical operation in which a bone flap is temporarily removed from the skull to access the brain. Craniotomies are often critical operations, performed on patients who are suffering from brain lesions, such as tumors, blood clot ...

or burr hole. Without treatment, death typically results. The condition occurs in one to four percent of

head injuries A head injury is any injury that results in trauma to the skull or brain. The terms ''traumatic brain injury'' and ''head injury'' are often used interchangeably in the medical literature. Because head injuries cover such a broad scope of inju ...

. Typically it occurs in young adults. Males are more often affected than females.

Signs and symptoms

Many people with epidural hematomas experience a

lucid period In emergency medicine, a lucid interval is a temporary improvement in a patient's condition after a traumatic brain injury, after which the condition deteriorates. A lucid interval is especially indicative of an epidural hematoma. An estimated 20 ...

immediately following the injury, with a delay before symptoms become evident. Because of this initial period of lucidity, it has been called "Talk and Die" syndrome. As blood accumulates, it starts to compress intracranial structures, which may impinge on the third cranial nerve, causing a fixed and dilated

pupil The pupil is a black hole located in the center of the Iris (anatomy), iris of the Human eye, eye that allows light to strike the retina.Cassin, B. and Solomon, S. (1990) ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing ...

on the side of the injury.Epidural Hematoma in Emergency Medicine
at Medscape. Author: Daniel D Price. Updated: Nov 3, 2010 The eye will be positioned down and out due to unopposed innervation of the fourth and sixth cranial nerves. Other symptoms include severe

; weakness of the extremities on the opposite side from the lesion due to compression of the crossed pyramid pathways; and vision loss, also on the opposite side, due to compression of the posterior cerebral artery. In rare cases, small hematomas may be

asymptomatic In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered a ...

. If not treated promptly, epidural hematomas can cause tonsillar herniation, resulting in

respiratory arrest Respiratory arrest is a sickness caused by apnea (cessation of breathing) or respiratory dysfunction severe enough it will not sustain the body (such as agonal breathing). Prolonged apnea refers to a patient who has stopped breathing for a long pe ...

. The

trigeminal nerve In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and che ...

may be involved late in the process as the

pons The pons (from Latin , "bridge") is part of the brainstem that in humans and other bipeds lies inferior to the midbrain, superior to the medulla oblongata and anterior to the cerebellum. The pons is also called the pons Varolii ("bridge of Va ...

is compressed, but this is not an important presentation, because the person may already be dead by the time it occurs. In the case of epidural hematoma in the

posterior cranial fossa The posterior cranial fossa is part of the cranial cavity, located between the foramen magnum and tentorium cerebelli. It contains the brainstem and cerebellum. This is the most inferior of the fossae. It houses the cerebellum, medulla and pons. ...

, tonsillar herniation causes

Cushing's triad Cushing reflex (also referred to as the vasopressor response, the Cushing effect, the Cushing reaction, the Cushing phenomenon, the Cushing response, or Cushing's Law) is a physiological nervous system response to increased intracranial pressure (IC ...

hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high b ...

bradycardia Bradycardia (also sinus bradycardia) is a slow resting heart rate, commonly under 60 beats per minute (BPM) as determined by an electrocardiogram. It is considered to be a normal heart rate during sleep, in young and healthy or elderly adults, ...

, and irregular breathing.

Causes

The most common cause of intracranial epidural hematoma is

, although spontaneous hemorrhages have been known to occur. Epidural hematomas occur in about 10% of traumatic brain injuries, mostly due to car accidents, assaults, or falls. They are often caused by acceleration-deceleration trauma and transverse forces.University of Vermont College of Medicine
"Neuropathology: Trauma to the CNS."
March 2005, Retrieved on February 6, 2007.McCaffrey P. 2001

California State University, Chico. Retrieved on February 6, 2007. Epidural hematoma commonly results from a blow to the side (temporal bone) of the head. The

pterion The pterion is the region where the frontal, parietal, temporal, and sphenoid bones join. It is located on the side of the skull, just behind the temple. Structure The pterion is located in the temporal fossa, approximately 2.6 cm beh ...

region, which overlies the

, is relatively weak and prone to injury.Shepherd S. 2004
"Head Trauma."
Emedicine.com. Retrieved on February 6, 2007. Only 20 to 30% of epidural hematomas occur outside the region of the temporal bone. The brain may be injured by prominences on the inside of the skull as it scrapes past them. Epidural hematoma is usually found on the same side of the brain which was impacted by the blow, but on very rare occasions it can be due to a

contrecoup injury In head injury, a coup injury occurs under the site of impact with an object, and a contrecoup injury occurs on the side opposite the area that was hit. Coup and contrecoup injuries are associated with cerebral contusions, a type of traumatic br ...

. A "heat hematoma" is an epidural hematoma caused by severe

thermal burn A thermal burn is a type of burn resulting from making contact with heated objects, such as boiling water, steam, hot cooking oil, fire, and hot objects. Scalds are the most common type of thermal burn suffered by children, but for adults thermal ...

, causing contraction and exfoliation of the dura mater and exfoliate from the skull, in turn causing exudation of blood from the venous sinuses. The hematoma can be seen on

autopsy An autopsy (post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death or to evaluate any d ...

as brick red, or as

radiolucent Radiodensity (or radiopacity) is opacity to the radio wave and X-ray portion of the electromagnetic spectrum: that is, the relative inability of those kinds of electromagnetic radiation to pass through a particular material. Radiolucency or hypod ...

on CT scan, because of heat-induced coagulation of the hematoma.

Pathophysiology

The break of the

causes bleeding from the

, hence epidural bleeding is often rapid as

arteries An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...

are high-pressure flow. In 10% of cases, however, it comes from

vein Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated ...

s and can progress more slowly. A venous hematoma may be acute (occurring within a day of the injury and appearing as a swirling mass of blood without a clot), subacute (occurring in 2–4 days and appearing solid), or chronic (occurring in 7–20 days and appearing mixed or lucent). In adults, the temporal region accounts for 75% of cases. In children, however, they occur with similar frequency in the occipital,

frontal Front may refer to: Arts, entertainment, and media Films * ''The Front'' (1943 film), a 1943 Soviet drama film * ''The Front'', 1976 film Music *The Front (band), an American rock band signed to Columbia Records and active in the 1980s and ea ...

, and posterior fossa regions. Epidural bleeds from arteries can grow until they reach their peak size 6–8 hours post-injury, spilling 25–75 cubic centimeters of blood into the intracranial space. As the hematoma expands, it strips the dura from the inside of the

, causing an intense headache. It also increases

intracranial pressure Intracranial pressure (ICP) is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue. ICP is measured in millimeters of mercury ( mmHg) and at rest, is normally 7–15 mmHg for a supine adul ...

, causing the brain to shift, lose blood supply, be crushed against the skull, or herniate. Larger hematomas cause more damage. Epidural bleeds can quickly compress the

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is ...

, causing

unconsciousness Unconsciousness is a state in which a living individual exhibits a complete, or near-complete, inability to maintain an awareness of self and environment or to respond to any human or environmental stimulus. Unconsciousness may occur as the r ...

abnormal posturing Abnormal posturing is an involuntary flexion or extension of the arms and legs, indicating severe brain injury. It occurs when one set of muscles becomes incapacitated while the opposing set is not, and an external stimulus such as pain cause ...

, and abnormal pupil responses to light.Singh J and Stock A. 2006
"Head Trauma."
Emedicine.com. Retrieved on February 6, 2007.

Diagnosis

Diagnosis is typically by CT scan or MRI. MRIs have greater sensitivity and should be used if there is a high suspicion of epidural hematoma and a negative CT scan. Differential diagnoses include a

transient ischemic attack A transient ischemic attack (TIA), commonly known as a mini-stroke, is a minor stroke whose noticeable symptoms usually end in less than an hour. TIA causes the same symptoms associated with strokes, such as weakness or numbness on one side of ...

, intracranial mass, or

brain abscess Brain abscess (or cerebral abscess) is an abscess caused by inflammation and collection of infected material, coming from local (ear infection, dental abscess, infection of paranasal sinuses, infection of the mastoid air cells of the temporal bone ...

. Epidural hematomas usually appear convex in shape because their expansion stops at the skull's 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 A subdural hematoma (SDH) is a type of bleeding in which a collection of blood—usually but not always associated with a traumatic brain injury—gathers between the inner layer of the dura mater and the arachnoid mater of the meninges surround ...

s. Most people also have a skull fracture. Epidural hematomas may occur in combination with subdural hematomas, or either may occur alone. CT scans reveal subdural or epidural hematomas in 20% of unconscious people.Downie A. 2001
"Tutorial: CT in Head Trauma"
. Retrieved on February 6, 2007. In the hallmark of epidural hematoma, people may regain consciousness and appear completely normal during what is called a

lucid interval In emergency medicine, a lucid interval is a temporary improvement in a patient's condition after a traumatic brain injury, after which the condition deteriorates. A lucid interval is especially indicative of an epidural hematoma. An estimated 20 ...

, only to descend suddenly and rapidly into unconsciousness later. This lucid interval, which depends on the extent of the injury, is a key to diagnosing an epidural hematoma. File:Epidural hematoma.png, Nontraumatic epidural hematoma in a young woman. The grey area in the top right is organizing hematoma, causing

midline shift Midline shift is a shift of the brain past its center line. The sign may be evident on neuroimaging such as CT scanning. The sign is considered ominous because it is commonly associated with a distortion of the brain stem that can cause serious d ...

and compression of the ventricle. File:Traumatic acute epidual hematoma.jpg, Non-contrast CT scan of a traumatic acute hematoma in the right fronto-temporal area. File:Hematoma.png, A diagram showing an epidural hematoma.

Treatment

Epidural hematoma is a surgical emergency. Delayed surgery can result in permanent brain damage or death. Without surgery, death usually follows, due to enlargement of the hematoma, causing a

brain herniation Brain herniation is a potentially deadly side effect of very high pressure within the skull that occurs when a part of the brain is squeezed across structures within the skull. The brain can shift across such structures as the falx cerebri, the t ...

. As with other types of

intracranial hematoma Intracranial hemorrhage (ICH), also known as intracranial bleed, is bleeding within the skull. Subtypes are intracerebral bleeds ( intraventricular bleeds and intraparenchymal bleeds), subarachnoid bleeds, epidural bleeds, and subdural blee ...

s, the blood almost always must be removed surgically to reduce the pressure on the brain. The hematoma is evacuated through a burr hole or

. If transfer to a facility with neurosurgery is unavailable, prolonged

trephination Trepanning, also known as trepanation, trephination, trephining or making a burr hole (the verb ''trepan'' derives from Old French from Medieval Latin from Greek , literally "borer, auger"), is a surgical intervention in which a hole is drill ...

(drilling a hole into the skull) may be performed in the emergency department. Large hematomas and blood clots may require an open craniotomy. Medications may be given after surgery. They may include antiseizure medications and hyperosmotic agents to reduce brain swelling and intracranial pressure. It is extremely rare to not require surgery. If the volume of the epidural hematoma is less than 30 mL, the clot diameter less than 15 mm, a

Glasgow Coma Score The Glasgow Coma Scale (GCS) is a clinical scale used to reliably measure a person's level of consciousness after a brain injury. The GCS assesses a person based on their ability to perform eye movements, speak, and move their body. These thre ...

above 8, and no visible neurological symptoms, then it may be possible to treat it conservatively. A CT scan should be performed, and watchful waiting should be done, as the hematoma may suddenly expand.

Prognosis

The prognosis is better if there was a lucid interval than if the person was comatose from the time of injury. Arterial epidural hematomas usually progress rapidly. However, venous epidural hematomas, caused by a dural sinus tear, are slower. Outcomes are worse if there is more than 50 mL of blood in the hematoma before surgery. Age, pupil abnormalities, and Glasgow Coma Scale score on arrival to the emergency department also influence the prognosis. In contrast to most forms of traumatic brain injury, people with epidural hematoma and a Glasgow Coma Score of 15 (the highest score, indicating the best prognosis) usually have a good outcome if they receive surgery quickly.

Epidemiology

About 2 percent of head injuries and 15 percent of fatal head injuries involve an epidural hematoma. The condition is more common in teenagers and young adults than in older people, because the dura mater sticks more to the skull as a person ages, reducing the probability of a hematoma forming. Males are affected more than females.

References

External links

MedPix: Epidural hematoma

Epidural hematoma , Radiology Case , Radiopaedia.org
{{DEFAULTSORT:Epidural Hematoma Cerebrovascular diseases Neurotrauma Wikipedia medicine articles ready to translate de:Hirnblutung#Epiduralblutung