Epidural hematoma is an accumulation of blood that fills the space formed as a result of trauma between the bones of the skull and the dura mater. In typical cases, it is characterized by a violation of consciousness with the presence of a light period, signs of intracranial hypertension and compression of the brain, focal manifestations corresponding to the location of the hematoma. Diagnosis is carried out on the basis of the clinic using craniography, Echo-EG, cerebral angiography, CT and MRI. Treatment is mainly surgical — trepanation of the skull, removal of hematoma, search and elimination of the source of bleeding.
ICD 10
S06.4 I62.1
General information
Epidural hematoma is formed when blood accumulates over the dura mater, which is accompanied by the detachment of the latter from the inner surface of the skull bones. Since at the age of up to 2 years and after 60 years, the hard shell is tightly soldered to the bones of the skull, during these age periods, hematomas of epidural localization are extremely rare. On average, an epidural hematoma accounts for about 1-1.5% of all traumatic brain injuries, but in severe TBI it occurs in 9% of victims. In such cases, an epidural hematoma may be combined with a brain contusion and subdural hematoma.
The most common epidural hematoma occurs among young people aged 16-25 years. In this age category, 75% of cases are male. Among young children and the elderly, epidural hemorrhage in boys and men is noted 2 times more often than in girls and women. Patients with post-traumatic hematomas are jointly supervised by specialists in the field of traumatology and neurology.
Causes
Epidural hematoma has a traumatic genesis. Two mechanisms of injury are most typical. In the first case, an object of a small area (a hammer, a stick, a stone, a bottle, etc.) strikes a sedentary head, in the second case, a head hits a stationary object (falling from a bicycle, hitting a corner of a shelf or a step, etc.). In this case, the area of direct application of the traumatic factor is most often the temporal or the inferior parietal region of the skull.
The source of bleeding may be the middle meningeal artery and its branches, meningeal veins, venous sinuses and diploic veins — venous channels located in the thickness of the skull bones. Vascular damage is often caused by a depressed fracture of the skull.
Pathogenesis
There is still no clear opinion about the mechanism of hematoma formation in epidural bleeding. Some authors claim that at first, as a result of trauma, there is a detachment of the dura mater, and then blood accumulates in the resulting cavity. Other experts believe that the detachment of the shell occurs as blood is poured out and accumulated.
Usually an epidural hematoma does not exceed 8 cm in diameter, and its volume ranges from 80 to 120 ml, although it can vary in the range of 30-250 ml. A distinctive feature of an epidural hematoma is a decrease in its thickness from the center to the periphery. Due to the limited volume of the cranial cavity, the accumulation of blood above the dura leads to intracranial hypertension and compression of the underlying brain tissues.
Symptoms
The most common is the classic clinical picture of epidural hemorrhage, characterized by a pronounced light gap. A short loss of consciousness with its subsequent restoration or preservation of some deafness is typical. The victim complains of dizziness, weakness, moderate headache. Retro- and congrade amnesia, unexpressed anisoreflexia, some asymmetry of nasolabial folds, mild meningeal signs, spontaneous nystagmus are observed. The condition is initially regarded as mild or moderate TBI. The duration of the light interval varies from 30-40 minutes to several hours.
After a bright period, the condition of the victim deteriorates sharply. Headache increases, nausea and vomiting appear, psychomotor agitation is replaced by a rapidly progressive disorder of consciousness: from deafness to sopor and coma. Sometimes there is a rapid extinction of consciousness with the transition immediately into a coma. Bradycardia, arterial hypertension are noted; in the neurological status — increasing brachiocephalic paresis (paresis of the facial nerve and muscle weakness in the upper limb) on the opposite side of the hematoma. On the side of the hematoma, the pupil dilates, and then there is no reaction to light. In some cases of epidural hematoma, focal symptoms (paresis, anisocoria) come to the fore, outpacing the development of symptoms of compression of the brain.
Often, an epidural hematoma occurs with an erased light period. As a rule, in such cases, a deep disturbance of consciousness (coma) initially occurs, and TBI is regarded as severe. After a few hours, the coma is replaced by a sopor, some verbal contact with the patient becomes possible. By the behavior of the victim, it becomes clear that he has an intense headache. Usually mild or moderate hemiparesis is noted. Such a not pronounced light period can last from a few minutes to a day.
Following this, the condition worsens: arousal increases, which then turns into a coma, paresis worsens up to complete plegia of contralateral hematomas of the extremities. Possible gormetonia (tonic contractions of the muscles of the paretic limbs), severe vestibular and oculomotor disorders, other manifestations of brain stem damage. There are violations on the part of vital functions.
An epidural hematoma without a light period is relatively rare. It is usually observed in severe TBI with multiple brain damage. The comatose state develops immediately after the injury and remains unchanged.
Subacute epidural hematoma is characterized by a long duration of the light period (up to 10-12 days). During this period, the victim’s consciousness is mostly clear, there is a tendency to bradycardia, some mild focal symptoms. Subsequently, there is a gradual, sometimes undulating, aggravation of disorders of consciousness to deep deafening, which is preceded by severe headache and excitement. On the fundus during ophthalmoscopy, stagnant optic nerve discs may be detected, indicating cerebral compression.
Focal manifestations, which are accompanied by an epidural hematoma, depend on its location. With hemorrhage in the parasagittal region, pyramidal disorders dominate with the greatest severity of paresis in the foot. Epidural hematoma of the frontal lobe is accompanied by mental disorders with frontal coloration with low severity of other focal symptoms. Epidural hematoma of the occipital region is manifested by the loss of the eponymous fields of vision — homonymous hemianopia.
Diagnostics
An epidural hematoma is diagnosed by a neurologist or neurosurgeon with the participation of a traumatologist according to anamnesis and typical clinical manifestations: disorder of consciousness, unilateral mydriasis and contralateral hemiparesis, bradycardia, etc. Diagnostic minimum:
- Radiography. According to the skull X-ray, the presence of a fracture that crosses the furrows of the meningeal vessels is established. In 90% of cases, the epidural hematoma is localized according to the fracture site. An epidural hematoma can be confirmed by cerebral angiography, which reveals a non-vascular area in the form of a convex lens.
- Echoencephalography. It usually diagnoses a progressive displacement of the median echo. Echo-EG has retained its importance in the diagnosis of intracranial hematomas in the absence of such modern methods as MRI or CT.
- Tomography. CT scan of the brain can provide more accurate data on the volume and location of the hematoma, as well as on other intracranial injuries. An isodensive and small-sized epidural hematoma is visualized using an MRI of the brain. MRI is also used to differentiate epi- and subdural hematomas, to assess the condition of basal structures and the brain stem.
Treatment
Conservative treatment under constant dynamic control of hematoma volume is possible in cases when the epidural hematoma does not exceed 30-50 ml, does not cause severe and progressive symptoms, is not accompanied by signs of brain compression.
In most cases, surgical treatment is performed. A milling hole in the skull is made above the place of the alleged localization of the hematoma. With a rapid increase in cerebral compression, a part of the hematoma is aspirated through the hole, and then a full-fledged skull trepanation is performed with complete removal of the epidural hematoma, search and ligation of the damaged vessel. When bleeding from the veins, they are coagulated and tamponed with a hemostatic sponge. If the sinuses are damaged, they are plasticized and tamponade is performed. When bleeding from diploic veins, surgical wax is used.
The operation is performed against the background of decongestant, hemostatic and symptomatic therapy. In the recovery period, resorbing and neurometabolic drugs are used, massage and physical therapy are carried out to restore strength in the muscles of the paretic limbs as soon as possible.
Forecast
About a quarter of epidural hemorrhages end in death. The prognosis depends on the volume of the hematoma, the age of the victim, and the timing of surgical treatment. During the operation at the stage of moderate decompensation, mortality is minimal, mainly there is a good recovery of lost neurological functions. Conservative treatment of small-sized subacute hematomas carried out in accordance with strict indications also has a favorable outcome. Hematomas operated on at the decompensation stage have an alarming prognosis. In such cases, mortality reaches 40%, survivors often have a significant neurological deficit.