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, urethr ...

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

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

. When this condition occurs in the spinal canal, 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 lami ...

. There may be

loss of consciousness 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 re ...

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

headache A headache, also known as cephalalgia, 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 (mood), depression in those with severe ...

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

seizure A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...

s. The cause is typically a

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 bone is a paired bone situated at the sides and base of the skull, lateral to the temporal lobe of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples where four of the cranial bone ...

and bleeding from the

middle meningeal artery The middle meningeal artery (') is typically the third branch of the maxillary artery#First portion, 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 sp ...

or blood vessel malformation. Diagnosis is typically by a

CT scan A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

MRI scan Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ra ...

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

craniotomy A craniotomy is a surgery, surgical operation in which a bone flap is temporarily removed from the Human skull, skull to access the Human brain, brain. Craniotomies are often critical operations, performed on patients who are suffering from brain ...

or burr hole, or (in the case of a spinal epidural hematoma)

laminotomy A laminotomy is an orthopaedic neurosurgery, neurosurgical procedure that removes part of the lamina of the vertebral arch, lamina of a vertebral arch in order to relieve pressure in the vertebral canal. A laminotomy is less invasive than conve ...

with

spinal decompression Spinal decompression is the relief of pressure on the spinal cord or on one or more compressed nerve roots passing through or exiting the spinal column. Decompression of the spinal neural elements is a key component in treating spinal radiculopat ...

. 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 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 The oculomotor nerve, also known as the third cranial nerve, cranial nerve III, or simply CN III, is a cranial nerve that enters the orbit through the superior orbital fissure and innervates extraocular muscles that enable most movements of ...

, causing a fixed and dilated

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

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 The posterior cerebral artery (PCA) is one of a pair of cerebral arteries that supply oxygenated blood to the occipital lobe, as well as the medial and inferior aspects of the temporal lobe of the human brain. The two arteries originate from the d ...

. In rare cases, small hematomas may be

asymptomatic Asymptomatic (or clinically silent) is an adjective categorising the medical conditions (i.e., injuries or diseases) that patients carry but without experiencing their symptoms, despite an explicit diagnosis (e.g., a positive medical test). P ...

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

respiratory arrest Respiratory arrest is a serious medical condition caused by apnea or respiratory dysfunction severe enough that it will not sustain the body (such as agonal breathing). Prolonged apnea refers to a patient who has stopped breathing for a long period ...

. The

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

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 mammals, 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 ...

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 the part of the cranial cavity located between the foramen magnum, and tentorium cerebelli. It is formed by the sphenoid bones, temporal bones, and occipital bone. It lodges the cerebellum, and parts of the brai ...

, 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 (I ...

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

bradycardia Bradycardia, also called bradyarrhythmia, is a resting heart rate under 60 beats per minute (BPM). While bradycardia can result from various pathological processes, it is commonly a physiological response to cardiovascular conditioning or due ...

, 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. It is also considered to be the weakest part of the skull, which makes it clinically si ...

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

thermal burn A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...

, 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 (also referred to as 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 deat ...

as brick red, or as radiolucent on

, 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 () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ...

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

vein Veins () are blood vessels in the circulatory system of 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 those of the pulmonary and feta ...

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 The occipital bone () is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone lies over the occipital lobes of the cere ...

, frontal, 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 adu ...

, 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 conti ...

, 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 caus ...

, 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

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and rad ...

. 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, intracranial mass, or

brain abscess The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head ( cephalization), usually near organs for special sense ...

. 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 surrou ...

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, 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 Surgical emergency is a medical emergency for which immediate surgical intervention is the only way to solve the problem successfully. The following conditions are surgical emergencies: * Acute trauma Cardiothoracic * Cardiac tamponade * Acut ...

. 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 human brain, brain is squeezed across structures within the human skull, skull. The brain can shift across such structures ...

. As with other types of intracranial hematomas, 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 -4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, t ...

(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 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