An epidural hematoma is a bruise located in the epidural space. This is located between the outermost meninges, the dura mater, and the cranial bone. Normally, the said space in the head does not exist and arises only through pathological changes, such as bleeding.
The situation is different in the spine: here the epidural space exists in every human being and is filled with blood vessels and fatty tissue. Instead of the skull, vertebral bodies form the outer boundary. Hematomas occur more often intracranially, so in the head. Although epidural bleeding in the spine is possible, it is less common in everyday clinical practice. An epidural hematoma is caused by a previous bleeding. This can be caused in various ways, but is usually traumatic (caused by mechanical effects, such as an act of violence or an accident). A hematoma in the head or spine calls for urgent medical intervention and can result in the most serious damage to the patient and death.
Because traumatic bleeding is at the forefront of epidural hematoma, bleeding of this nature is highly correlated with the occurrence of craniocerebral trauma. The trauma is caused in most cases by an accident, especially by car accidents, in which the head is injured.
Extreme forces acting on the skull during an impact can damage vessels causing bleeding and, as a result, hematomas. A distinction can be made between arterial and venous hematomas. Due to the higher pressure in the arterial system of our circulation, a corresponding bleeding is more dramatic than one of the venous type. Mostly the artery is affected by the injury which supplies the meninges with blood - the meningeal artery. If venous bleeding is the cause of the epidural hematoma, it is a bleeding haemorrhage, which develops more slowly due to the lower pressure in the system and also occurs less frequently.
Since the epidural space in the spine physiologically (naturally) exists, other causes are represented here. A spinal epidural hematoma can be triggered in addition to traumatic effects by vascular malformations, errors in the coagulation system or tumors. The vessels in the epidural space of the spine can be triggered not only by uncontrolled mechanical influence but also by medical actions (iatrogen), such as the administration of syringes. The use of blood thinners in the treatment of a disease may promote the development of an epidural hematoma.
Peridural anesthesia (PDA) is a procedure in which the anesthetic is injected directly into the peridural space (also epidural space). In this case, for a single administration of the drug, a needle is passed between the vertebral bodies and the narcotic injected directly. If the duration of the drug treatment lasts longer time, a peridural catheter (PDK) can be placed in addition to a stiff needle. This thin plastic tube can stay in the epidural space for a long time and allows repeated anesthesia of the patient.
There may be various complications with intraspinal drug administration, including epidural bruising. If a vein injured in the epidural space is injured during the puncture, it usually comes to a standstill of the bleeding without corresponding symptoms. If the bleeding does not stop by itself, a spinal hematoma is formed, which can cause neurological symptoms and in the worst case permanent damage to the spinal cord. However, with a probability of 1 in 150, 000, such a complication is extremely rare and can be remedied with the help of emergency surgery. As bleeding disorders generally increase the risk of bleeding, bleeding during a PDA is also more likely (probability 1 to 3, 000).
The symptomatology of an epidural hematoma is very characteristic. After the patient has been injured, the majority of cases are fainted. After the patient clears up and regains consciousness, it may happen that no symptoms are noticeable. A phase of complete freedom from symptoms is not uncommon. A mild headache often accompanies this resting phase and is often perceived as a triviality.
Over the next 2 hours, the symptom construct slowly builds up. The headache worsens and nausea (possibly with vomiting) sets in. This deterioration of the condition should be alarming for the patient as well as for the treating persons and should result in hospitalization, if not yet done. Consciousness diminishes after a while and increased drowsiness dominates the patient's appearance.
The expansion of the hematoma causes progressive compression of the brain tissue. Nerves can also be affected if they are near the bleeding area. For example, in unilateral pressure, the pupil can enlarge (homolateral mydriasis), which is caused by an involvement of the nervus occulomotorius, which is responsible for their control. On the opposite side of the body may cause disturbances of the motor system or complete paralysis, since the movement control in the brain is reversed regulated.
The symptoms of an epidural hematoma must be differentiated in infants. Due to the low bone hardness vessels can be easily damaged by falls. The extensibility of the soft bones and the incompletely closed fontanelles leave the hematoma a certain amount of leeway. The first symptoms usually appear only 6 to 12 hours after the accident due to the compensation of the expansion. The clinical picture is similar to that of an adult. Among neurological symptoms, blood loss in the circulation becomes more relevant in small children. The size of the head allows a relatively high amount of blood to be taken, which can lead to a lack of blood (anemia).
For more information, also read: Cerebral Hemorrhage Symptoms
The clinical picture of a spinal epidural hematoma is, of course, different. The patient's consciousness remains unaffected as long as there is no additional injury to the head (combination of both injuries in severe car accidents, however, not unlikely). Due to the increasing pressure on the spinal cord, local pain first occurs before failures manifest below the hematoma. Cross-sectional syndrome may be the result of spinal cord involvement, with the patient initially losing his motor skills and developing sensory disorders. An operation can often restore the previous state.
The characteristic clinical picture of epidural hematoma often abbreviates the diagnosis. The knowledge and interpretation of the physician can be supported or confirmed by imaging techniques. The clinical picture is characterized by the temporally staggered symptoms and the uneven pupil size. In addition, the one-sided failure of various body functions and the progressive deterioration of the condition can be interpreted as an indication of bleeding. In physical examination, in many cases, a striking reflex status. An existing paralysis strengthens the patient's reflexes, while an arbitrary movement is not possible.
With the help of computed tomography (CT), 90% of epidural hematomas can be diagnosed or confirmed. The hematoma is represented in the CT image as a brightened (high density, hyperdens), sharply demarcated surface, which biconvex (lenticular) rests on the skull bone from the inside. Due to the one-sided pressure created by the bleeding, the midline of the brain is probably shifted to the healthy half of the head.
Magnetic resonance imaging (MRI) can also be used for diagnostics. If a spinal epidural hematoma is suspected, MRI is increasingly being selected as an imaging procedure. From a laboratory point of view, the search for causes can be accelerated by controlling the coagulation values and checking the platelet count, if a traumatic origin of the bruise can be ruled out.
An epidural hematoma complication may result in an entrapment syndrome as a result of the ongoing pressure situation in the skull. It differentiates between two different localizations. The upper entrapment results from the displacement of the temporal lobe, which slides under the tentorium cerebelli (cerebellum tent). This skeleton, which consists of meninges, sits on the cerebellum (cerebellum) and separates it from the cerebrum (telencephalon).
Due to its stabilizing and protective function, the cerebellum tent is relatively sturdy and not very slidable. This shifts the temporal lobe to the center when displaced and exerts pressure on the midbrain (mesencephalon), which contains important control centers of the human body. If the pressure is excessive, an epidural hematoma can lead to death of the patient.
The nerve tracts, which mediate the movement of the body (pyramidal tracts), run in close proximity to the diencephalon and are also compressed. If there are sudden signs of paralysis, this can be a sign of an incipient entrapment.
In addition to the upper, it can also lead to a lower entrapment. This equally life-threatening process is mediated by the cerebellum, which is pushed down. It may happen that the cerebellum is squeezed into the foramen ovale (oval hole). The foramen oval is located at the base of the skull and represents the portal of entry of the spinal cord in the head. Likewise, the hole contains part of the brainstem - especially the medulla oblongata. This is responsible among other things for the respiratory control. If the cerebellum now presses on the brainstem, it can lead to the loss of essential functions, for example to respiratory arrest, through which the patient dies.
The sequelae may be different if the pressure of the brain is prolonged or severe due to the epidural hematoma. In most cases occurring paralysis symptoms are reversible, but can also be permanent, the brain is not relieved fast enough. Furthermore, neurological deficits associated with the location of the bleeding may occur. For example, the language center may remain compromised even after a successful operation. About 20% of patients sustain a permanent disability from such injury.
In the case of a spinal epidural hematoma, possible long-term consequences are also dependent on the speed of medical assistance. All symptoms arising in the course can be completely reversible. In the case of long-term impairment of the spinal cord due to bruising, permanent damage may occur. As a rule, cross-sectional syndromes develop in which the patient loses motor abilities as well as the sensation of touch, temperature and pain from the level of bleeding.
In the spine, of course, not much space is available. Most of the space fills the spinal cord with the surrounding cerebrospinal fluid. If there is a hematoma due to bleeding in the epidural space, it can quickly affect the spinal cord. While initial pressure can be very painful, but rather does not cause any damage, the spread of the bruise begins to provoke neurological symptoms. Depending on the level of bleeding, the segments are affected by motor and sensory deficits. At the level of the thoracic vertebrae, the arm and leg regions, below only the legs are noticeable. In addition to movement and sensation, other body functions may also be restricted whose control center is located in the spinal cord. Thus, micturition (micturition = urinary control) is a typical conspicuousness in severe spinal cord failures. The vertebral bodies themselves, if otherwise healthy, normally do not suffer any damage from the resulting pressure. The condition of osteoporotically weakened or otherwise already injured vertebral bodies may worsen due to an extensive hematoma.
An epidural hematoma is a medical emergency. Both intracranial and spinal localization require immediate action and hospitalization. The standard therapy hereby represents a neurosurgical operation. A medicamentous treatment can be used concomitantly, but does not solve the problem per se.
During surgery, the skull bone is first gently opened, which is called trepanation. On the one hand this allows access to the place of bleeding, on the other hand pressure is reduced - which is important for the prevention of long-term consequences. After the tissue has been saved from further pressure-related decline, the hematoma can be cleared. In the process, coagulated blood is scraped off and liquid blood is sucked off. The vessel from which the bleeding comes is desolate and then the wound closed again. In an operation on the spine, attention must be paid to the surrounding nerves, which leave the spinal cord and the spinal canal laterally.
Due to the serious complications, the mortality rate for epidural hematomas is relatively high. Even with performed relief surgery and clearing of the bruise it comes in 30 to 40% of cases to death of the patient. If the patient survives the injury, there is the question of subsequent or late damage. One-fifth of all survivors have a permanent disability from the disease. Exercise therapy and other supportive measures can increase self-employment in the event of disability. Half of the patients who are admitted with an epidural hematoma survive without any sequelae and regain all their abilities, even with existing neurological symptoms. The prognosis of spinal hematomas is rather positive, because with competent treatment a complete remission (reduction) of the cross-sectional symptoms can be achieved.