Cerebral laceration simply means tearing of brain tissue or blood vessels in the brain. It is similar to Diffuse Axonal Injury, but affects different parts of the brain.
Lacerations often happen when the brain forcefully accelerates and decelerates or rotates within the head. The strong force moves the brain so quickly that it can’t all move at the same time and the brain tissue stretches. If it stretches too far, the tissue tears and bleeds.
They can also occur when a foreign object or a bone fragment (usually from a skull fracture) penetrates the brain, severing the tissue or blood vessels. These types of trauma are considered open head injuries and put the injured person at great risk of infection.
Penetration need not occur for bone to cause lacerations though. As the brain rotates within the skull, it sometimes hits the skull’s bony ridges. You can feel the ridges and bumps on your head if you move your hair. The human skull is not as smooth and rounds as we imagine, making it nearly as dangerous as it is safe as a shell for the brain.
Lacerations can be diffuse or localized. Diffuse damage is far-reaching, across a large area of brain matter. Localized or focal lacerations are more concentrated in one particular area. In cases involving a direct impact causing acceleration and deceleration, the brain injury victim is likely to have severe localized lacerations at the point of impact and more, smaller lacerations across a widespread area of the brain due to the stretching of the brain tissue.
CT scans are the method of choice for emergency medical professionals to diagnose cerebral lacerations because they are best suited to show bleeding and swelling within the brain immediately after an accident.
Lacerations often result in brain swelling because they lead to a buildup of blood from the torn tissue and blood vessels. It works the same in the brain as it does anywhere else. Say, you get a paper cut and begin to bleed, what happens next? Your body wakes up it and sends extra blood to the area so the blood will clot and you don’t bleed to death. The area turns reddish and swells because of the increased blood flow to the wound.
The same thing happens in your brain, except it is much more dangerous. The blood vessels in the brain swell as they pump blood to the lacerations in an attempt to ultimately stop the bleeding. This can cause headaches, dizziness, nausea, loss of brain functions and death in severe cases.