Trauma to the head can cause different medical and surgical problems, ranging from mild to severe. Each year, childhood head injuries result in tens of thousands of emergency room visits and hospitalizations in the United States. Although 90 percent of all childhood head injuries are minor, thousands of children die and many more develop permanent disabilities each year from head trauma.
The most common causes of childhood head injuries in the United States are motor vehicle accidents, falls, assaults, bicycle accidents and trauma related to sports. In infants younger than 1 year old, most serious head injuries are related to child abuse.
Children often bump their heads accidentally, resulting in minor bumps, bruises, or cuts in the scalp, but no damage to the brain inside. Sometimes, more serious injuries happen.
Injuries to the head can cause a concussion. Concussions are graded on a scale of I to III, depending on the severity of the symptoms.
A grade I concussion is the mildest type, with confusion lasting 15 minutes or less after the head injury.
With a grade II concussion, the confusion and other symptoms last longer than 15 minutes.
A grade III concussion involves any loss of consciousness (passing out) and is the most severe.
In most cases of concussion, X-rays or brain scans do not show any damage. Concussions do not usually cause long-term brain damage, but repeated concussions (for example, during high-risk activities such as boxing or football) can be very dangerous, putting the child at risk of serious brain damage.
Childhood head trauma is rarely more serious than a concussion. However, when it is severe, the injury usually is from a direct blow to the skull. Sometimes, the injury can be caused indirectly, such as when blood vessels stretch and tear, the brain "bounces" against the inside wall of the skull, or the brain swells as a result of chemical changes.
The most worrisome types of serious brain injury include:
Skull fracture – A skull fracture is a crack or break in one of the skull's bones. In most cases, a skull fracture causes only a bruise on the surface of the brain. If the skull is dented inward (a depressed skull fracture), pieces of the broken bone are pressing down against the surface of the brain. This may need more immediate attention and special surgery to fix.
Epidural hematoma – This is one of the most serious types of bleeding that can occur inside the head as a result of a skull fracture. It happens when a sharp fragment of bone cuts through one of the major blood vessels in the skull. As the injured vessel bleeds, a collection of blood called a hematoma forms in the space between the skull and the outermost membrane (dura) covering the brain. The blood vessel that ruptures is usually an artery, and the hematoma expands rapidly and presses on the brain. This can cause severe injury and even death. Epidural hematomas are especially common after significant injuries to the temple, such being hit by a baseball or baseball bat.
Subdural hematoma – This is a collection of blood between the coverings of the brain and its surface. It occurs when a head injury tears any of the large veins that carry blood away from the brain's surface. Subdural hematomas tend to get larger slowly, sometimes over days or weeks, with symptoms gradually worsening. This type of bleeding leads to serious brain injury and even death if not diagnosed and treated promptly.
Intraparenchymal hemorrhages and contusions (bleeding and bruising of the brain) – These injuries involve the brain itself. Both types of injury are caused by either a direct blow to the head or indirectly when the force of an injury to one side of the skull causes the brain to bounce against the other side. This causes an area of damage on the side of the brain opposite from the blow to the head.
After each of these serious head injuries, there can be swelling inside the brain, which increases the pressure inside the skull. Severe head injuries – especially those caused by motor vehicle accidents and falls from high places – also can be accompanied by damage to the neck bones or to important organs inside the body. These additional injuries often cause blood loss, breathing difficulties, very low blood pressure (hypotension), and other problems that can complicate the child's treatment and make recovery more difficult.