Brain
In adults, the human skull is no longer capable of adapting to changes in pressure. If the intracranial pressure increases due to volume changes of tissue, blood or cerebrospinal fluid, a dangerous situation can arise relatively quickly. Most pressure conditions are caused by an increase in volume of the tissue, although in mild cases it is possible to compensate by shifting cerebrospinal fluid into the spinal canal of the spine.
In epidural hemorrhage, the brain does not swell, but the volume of cerebrospinal fluid and the vascular system remain the same, which is why the symptoms refer to the cerebral parenchyma (brain tissue). Due to the increased intracranial pressure, the blood flow to the tissue decreases increasingly. This so-called underperfusion leads to a brain edema, a swelling of the brain tissue.In addition to the actual cause of the pressure increase, namely the epidural bleeding, there is also an increase in volume due to the development of edema.
If the nerve cells are not supplied with blood, they die after some time. Since nerve cells in the brain cannot be reproduced within this framework, irreversible damage to the brain occurs, which can manifest itself in various ways. Brain edema can also cause the entrapment syndrome, which has already been explained in the complications.
Spine and spinal cord
Because the space in the spinal column is already relatively limited, bleeding into it causes a mass to be created which exerts pressure on the spinal cord. The spinal cord is able to withstand this slight pressure without damage, even though the patient may describe a clear pain symptom. The spinal cord contains nerve tracts that are responsible for the control of various systems.
Depending on the level at which compression takes place, deficits may also develop in the individual systems. While in the area of the chest, at the level of the thoracic vertebrae, the arms are also affected in the case of motor deficits, paralysis in the case of bleeding at the level of the lumbar or sacral vertebrae in the lower back is usually limited to the legs. It is not only the motor function that can be affected by compression of the spinal cord.
Sensitive failures are also signs of excessive pressure. Other bodily functions, such as the ability to hold or pass urine, can also be affected. Damage to the spinal column itself is rather unlikely due to epidural bleeding, as not enough force can be applied to damage a healthy bone. If the bleeding occurs in the area of injured vertebrae (a traumatically triggered spinal epidural bleeding can be accompanied by a bony injury in the same area), further damage cannot be ruled out in the worst case.
