When a person sustains a brain injury, the initial trauma causes primary injury. The brain and spinal cord are surrounded by three layers of membranes for protection:
- The dura mater, which is tough, thick and attached to the skull
- The arachnoid membrane, which is the delicate middle membrane with a web-like appearance, attached to the dura mater
- The pia mater, which is also delicate and adheres to the brain’s surface. Between the pia mater and the arachnoid there is a narrow space filled with cerebrospinal fluid.
These three layers together are known as the meninges.
When the brain is hurt in an accident or trauma, primary injury can take several forms:
- Brain tissue bruising from the impact
- Bleeding (hemorrhage) within the skull. The layers of the meninges have veins penetrating them which branch off into smaller capillaries. Any of these blood vessels can break and bleed between the meninges layers.
- Nerve damage, where the fibers that carry electrical impulses are stretched or torn
These primary injuries give rise to secondary injuries. Secondary brain injury is the indirect result of the initial trauma or impact and does not necessarily happen at once. There may be hours or days, even weeks before they surface. Many TBI deaths occur because of these secondary injuries, rather than immediately from the primary injury.
Examples of secondary injuries are:
- Inadequate oxygen to the brain because of blood vessel damage
- Inadequate blood flow to the brain (ischemia)
- Swelling (edema) of the brain from fluid build-up
- Low blood pressure from bleeding
- Increased intracranial pressure (inside the head), from swelling and bleeding
- Meningitis — infection of the meninges
- High levels of carbon dioxide in the blood
Not much can be done medically about the primary injury, since it happens quickly and is a fait accompli by the time the injured person receives any medical care. It is regarded as irreversible. However, much can and should be done to prevent or care for all secondary injuries.
Therefore, if you or a loved one have sustained a head injury, you should seek medical care immediately. Even if there appears to be no major harm done, you should still go for an examination. There may be damage to blood vessels or nerves which you cannot see and may not feel at once. By the time you feel a severe headache or start to lose your balance, memory, or speech, it may be too late and you may suffer secondary injuries which immediate care could have prevented.
Once you have medical care, please consider your legal situation. If the injury was caused by another person’s negligence you may have a valid legal claim. Our brain injury attorneys are highly experienced and stand ready to give you a free case evaluation. Please call or email our personal injury law firm today.