Summary: Since the brain is important, we are frequently concerned when a child suffers an injury to the head. The signs and symptoms of concussions and more severe brain injuries are discussed. A CAT scanner is a miraculous device that can painlessly visualize the brain, providing very useful information when signs or symptoms of serious brain injury are present.
Children get into accidents and hit their head frequently. The brain is very important which makes this is a common reason for concerned parents to seek medical attention. Small children frequently fall head first onto something hard such as a table or floor because their balance is poor and their bodies are "top heavy" (due to their large head).
It is common for parents to bring their child to an ER just because of the loud bonking sound that occurred when their child's head hit the floor or table. This sound can be quite alarming.
The skull protects the brain inside. In young children, the skull is softer and more flexible compared to the rigid hard skull of adults. An infant's skull is actually several bones connected together by growth cartilage and ligaments. In a newborn infant, the bones overlap. These overlapping areas, which can be felt as ridges, gradually close and smooth out. There is a noticeable soft spot on the top of the head just above the forehead. This gap in the developing skull is called the fontanelle. Some parents think this spot is weak and they are afraid to touch it. This spot is very tough and it can be touched and washed just like the rest of their head. The fontanelle should always be flat and soft. It can sometimes be noticeably pulsatile; you can see or feel the pulsation. It should not bulge out (a sign of too much pressure in the brain) and it should not be sunken in (a sign of dehydration).
The brain is delicately suspended by supportive structures and blood vessels. The surrounding fluid also protects the brain from sudden impacts. This is an excellent way of protecting the brain since it provides impact protection while gently holding it in place so that blood vessels, nerves and other important structures can stay reliably connected to the brain for a lifetime.
Head trauma is the term that is used when the head is struck. Hitting your head really hard can basically result in several possible things which can occur together: 1) Scalp injury, 2) Skull fracture, 3) Concussion, 4) Brain bleeding, 5) Tearing, bruising or swelling of parts of the brain.
Examples of scalp injuries include lacerations, bruises and hematomas (collections of blood under the scalp). Hematomas may seem worrisome because large ones can resemble an egg under the skin. Large hematomas take a long time to resolve, but they are usually not serious. Hematomas usually result from breaking a blood vessel under the skin. As the blood vessel bleeds, blood collects under the skin forming a swelling. Hematomas can also result from a crack in the skull since a skull fracture bleeds a lot (there are lots of blood forming elements within the skull bone).
A skull fracture is a crack in the skull bone. A skull fracture does not require a cast. Most skull fractures are small and linear (straight like a line). Some fractures might require some type of corrective procedure if the skull fracture is depressed (indented) and pushing onto the brain. Although depressed skull fractures require special care, most simple skull fractures do not require any care.
Although many parents are concerned about the possibility of a skull fracture, most of the time, skull fractures do not require special treatment. Unfortunately, it's not this simple because there are several special types of skull fractures which do require special treatment or special instructions. Additionally, as a parent, even if a simple skull fracture does not require special treatment, finding out whether a skull fracture is present, is useful information for a parent. As a parent, I would like to know if my child's skull is cracked even if there is no special medical treatment for this.
X-rays of the skull are able to find most skull fractures (but not all), so the identification of most skull fractures is most easily seen with plain x-rays of the skull. CAT scans (more commonly called CT scans nowadays, can also identify most skull fractures. Some skull fractures are more easily seen on plain x-ray, while others are more easily seen on a CT scan.
The major advantage of a CT scan is that it can see the brain itself. Plain x-rays can only see the skull, not the brain. The disadvantage of a CT scan is that it costs more and it is slow, requiring the patient to be very still for about five minutes. Some newer faster scanners can complete a scan in about one minute. However, it may be very difficult to complete a CT scan on young children who are awake and do not understand the need to be still. CT images are totally useless if the patient moves during the CT scan. Young children frequently need to be sedated with a sleeping medicine to complete a CT scan. This sedation medication adds risk to the procedure because occasionally, a small child can have a serious complication from sedation. Skull x-rays are taken just like camera snapshots so even if the child is moving, the x-ray pictures can still be taken. CT scans take a series of continuous x-rays in a circular pattern. A computer must then put together these individual pictures (actually numbers) to construct the actual image. If the patient is moving during these pictures, the computer's reconstruction of the image is a total blur because the patient's head is in a different position during different parts of the scan. The need to sedate young patients for a CT scan increases the risk of the procedure so it is not such a simple decision. A sedated child is also more difficult to observe later on because we generally use the child's arousability and alertness as a sign of getting worse or better. A sedated child will be persistently drowsy making it difficult for an observer to be confident that they are getting better.
A concussion is a type of brain injury which is generally microscopic. If a CT scan is done on a patient with a concussion, it is normal. A CT scan cannot identify a microscopic injury. Once a head injury concussion occurs, there is nothing that can be done to reverse the injury. There is no medicine or surgery that can fix it. Acetaminophen will help the headache. Ibuprofen, aspirin and naproxen should not be taken since these medications can cause bleeding. In other words, if bleeding in the brain is destined to occur, taking these drugs will make the bleeding worse. Children with a concussion should also rest, limiting their activity to indoor activity only, because jumping around will also bounce the brain around and this will make the concussion worse.
Brain bleeding can be identified on a CT scan, but not a skull x-ray. The presence of a skull fracture does not necessarily indicate the presence of bleeding in the brain. Bleeding in the brain can occur with or without a skull fracture. There are several different bleeding patterns that occur. Some of them are associated with significant brain injury, while in others, the brain can remain unharmed. Identifying the presence of bleeding in the brain early is important because surgical procedures to remove blood clots from the brain can reduce the likelihood and severity of damage to the brain. Continued bleeding in the brain causes increased pressure in the brain. Eventually, there is no more room in the skull, and the heart is unable to pump blood into the brain. Since the brain needs blood flow to survive, when the pressure within the skull becomes too high, the brain dies.
Removing this blood collection in the brain early, relieves the pressure build up so that blood flow to the brain is maintained. This can prevent additional damage to the brain, which is serious since the brain has only a slight ability to recover after serious injury. A small amount of brain bleeding does not cause enough pressure build up to require surgical removal, but the early identification of small brain bleeds allows physicians to identify those who may develop larger bleeds that will benefit from an early surgical procedure to remove the blood clot.
The brain is made up of many cells which do the thinking and many fine nerves which connect the brain cells together and the brain cells to the body parts. If these nerve connections are cut, or the brain cells are crushed, swollen, bruised or starved of oxygen, damage to the brain has occurred and there is only a limited ability for the brain to recover following serious damage to the brain.
Removing large blood clots from the brain may not be helpful if severe damage to the brain has already occurred. This is why, sometimes, in a case of severe brain injury, an operation is not performed because it will not improve the patient's chance of recovery.
The decision of whether to obtain a CT scan is based on symptoms. Examination of the pupils (in the eyes) is important, but changes in the pupils occur too late, long after other signs have indicated the presence of a potentially severe head injury. The set of instructions below is from a patient information sheet which I wrote for the emergency room. One general rule is that the presence of any of these signs requires a call to your doctor or an evaluation by a physician.
Your child has a mild head injury. The doctor has examined your child and everything seems to be satisfactory. However, changes can still occur up to 36 hours after injury to the head. Watch for the following signs and call your doctor or the emergency room right away if these signs appear:
1. Unusually sleepy, unable to awaken easily. But do not insist that your child remain awake. Allow your child to rest or even sleep. Wake him/her up periodically and ask how he/she feels or if he/she has any headache.
2. Headache that gets worse.
3. Any vomiting.
4. Unusually restless, irritable, jumpy, or jittery.
5. Clumsy, falling to one side, swaying.
6. Acting strange or different in any way.
7. Fits or convulsions (uncontrollable movements).
If any of these occur after a head injury, this is probably due to at least a concussion. It also may be due to a significant brain injury such as brain bleeding, tearing, bruising or swelling. A physician should be called for advice, or your child should be taken to a doctor's office or emergency room for evaluation. Some of these signs are more serious than others. Number 1 above, persistent drowsiness or being difficult to arouse is very serious. Children who are active, alert and playful are unlikely to have a serious brain injury. Number 2 above, headache is serious if the headache is bad or if it is worsening. Number 3 above, vomiting, is usually not serious unless the child is vomiting a lot. Number 7 above, convulsion, is very dramatic and frightening. Interestingly, a convulsion (also known as a seizure) which occurs on impact or within a minute after the head injury, is usually not serious. Convulsions which occur later after the head injury, are more serious. Regardless, all patients with a convulsion after a head injury should be taken to an emergency room for evaluation.
One of the myths about head injuries is the need to keep the patient awake. Some believe that if you fall asleep after hitting your head, you may never wake up. It is true that difficulty waking up (see sign number 1 above) is a sign of a serious brain injury, but sleeping does NOT make the brain injury worse. You may let your child rest or fall asleep after hitting their head, but you should wake them up periodically to see how they are. If they awaken easily and indicate to you by behavior or speech that they are OK (no nausea or headache), then they can go back to sleep until their next check.