Your brain controls your movements, behaviors, thoughts and sensations, so a traumatic brain injury can have wide-ranging physical and psychological effects. The immediate physical effects include bruising and swelling. When injured brain tissue swells up, it creates a second, delayed problem — pressure. As the injured tissue expands, it pushes against the skull with increasing force and causes additional damage.

Mild traumatic brain injuries
The signs and symptoms of a mild traumatic brain injury (concussion) may include:

• A brief period of unconsciousness
• Amnesia for events immediately before and after the injury
• Headache
• Confusion
• Dizziness or loss of balance
• Sensory problems, such as blurred vision, ringing in the ears or a bad taste in the mouth
• Mood changes
• Memory or concentration problems

Moderate to severe traumatic brain injuries
If the injury is moderate to severe, the list of signs and symptoms grows to include:

• Persistent headache
• Repeated vomiting or nausea
• Convulsions or seizures
• Inability to awaken from sleep
• Dilation of one or both pupils of the eyes
• Slurred speech
• Weakness or numbness in the extremities
• Loss of coordination
• Profound confusion
• Agitation, combativeness

Children's symptoms
Children with brain injuries may lack the communication skills to report headaches, sensory problems, confusion and similar symptoms. Instead, they may:

• Refuse to eat
• Appear listless and cranky
• Experience altered sleep patterns and school performance
• Lose interest in favorite toys or activities

When to see a doctor
To stay on the safe side, you should always get checked by a doctor if you have suffered a blow to the head. You should seek emergency medical care if signs and symptoms include:

• Convulsions
• Weakness or numbness in the extremities
• Repeated vomiting
• Slurred speech

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Your brain has the consistency of gelatin. It's cushioned from everyday jolts and bumps by the cerebrospinal fluid in which it floats inside your skull. A violent blow to your head can cause your brain to slide forcefully against the inner wall of your skull. Even the sudden stop of a car crash can bounce your brain against your skull. This can result in bleeding in or around your brain and the tearing of nerve fibers.

Crashes, violence and falls
According to the National Institutes of Health, half of all traumatic brain injuries are caused by collisions involving cars, motorcycles and bicycles. About 20 percent are caused by violence, such as gunshot wounds or incidents of child abuse. Traumatic brain injury can occur in infants and small children who have been shaken violently. Among older people, falls are the leading cause of traumatic brain injuries.

Explosive blasts
Explosive blasts are a common cause of traumatic brain injury in military personnel serving in Iraq and Afghanistan. In most of these cases, the skull remains intact and the damage is believed to be caused by a pressure wave of the explosion's concussive force passing through the brain.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

The risk of traumatic brain injury is highest in young men ages 15 to 24.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Complications of traumatic brain injuries can be mild or severe. Some complications respond well to treatment or even resolve on their own, while others may never improve.

Seizures
Some people who have had a traumatic brain injury will experience at least one seizure during the first week after the injury. This doesn't appear to increase their chances of developing epilepsy. However, the chance of epilepsy does increase if there are major structural injuries to the brain.

Infections
Skull fractures or penetrating wounds can tear the membranes (meninges) that surround the brain, letting in bacteria. Infection of these membranes (meningitis) can be especially dangerous because of its potential to spread to the rest of the nervous system.

Nerve damage
Injuries to the base of the skull can damage facial nerves, which may result in:

• Paralysis of facial muscles
• Damage to the nerves responsible for eye movements, which can cause double vision
• Damage to the nerves that provide sense of smell

Cognitive disabilities
Most people who have had a significant brain injury will experience some problems in their cognitive skills, which may include:

• Thinking
• Reasoning
• Problem solving
• Information processing
• Memory
• Speed of mental processing
• Judgment
• Attention
• Multitasking

The most common of these impairments is short-term memory loss. That means the injured person recalls information from before the head trauma, but has to struggle to learn new information after the head trauma.

Language difficulties
Communication problems are common. Some people who have had brain injuries have trouble with spoken and written language, while others have problems deciphering nonverbal signals. In some cases, poor cognitive skills may disrupt your ability to succinctly organize thoughts and ideas.

Personality changes
Brain injuries typically interfere with impulse control, so inappropriate behavior is often present during recovery and rehabilitation. You may also be more irritable, anxious or depressed. These unstable emotions and impaired social skills may pose the greatest coping challenge for many families.

Sensory problems
Problems involving your senses may include:

• A persistent ringing in the ears
• Difficulty recognizing objects
• Impaired hand-eye coordination, which can make you appear clumsy
• Blind spots or double vision
• A bitter taste or a bad smell

Post-concussion syndrome
Post-concussion syndrome is a complex disorder in which concussion symptoms — such as headaches and dizziness — last for weeks and sometimes months after the impact that caused the concussion.

Alzheimer's or Parkinson's disease
A traumatic brain injury appears to increase the risk of eventually developing Alzheimer's disease and, to a lesser degree, Parkinson's disease. The higher the frequency and severity of the injuries, the greater the risk.

Coma
A person who is unconscious and unresponsive is in a coma. A gradual awakening may begin after a coma has lasted a few days or weeks, although a coma may also lead to a vegetative state or death.

People in a vegetative state often open their eyes and may move, groan or show reflex responses. Despite this, they're still unconscious and unaware of their surroundings. Anyone in a vegetative state for more than a year rarely recovers.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Because traumatic brain injuries are often emergencies and the consequences can worsen swiftly without treatment, doctors usually need to assess the situation rapidly.

Glasgow Coma Scale
This 15-point test helps assess the severity of a brain injury by checking your ability to follow directions, to blink your eyes or to move extremities. The coherence of your speech also provides important clues. Your abilities are scored numerically. Higher scores mean milder injuries.

Imaging tests

• CT scans. CT scans employ an X-ray unit that rotates around your body and a powerful computer to create cross-sectional images, like slices, of the head. CT scans can quickly visualize fractures and uncover evidence of bleeding in the brain (hemorrhage), large blood clots (hematomas), bruised brain tissue (contusions) and brain tissue swelling.
• MRIs. Doctors rarely use MRIs during emergency assessments of traumatic brain injuries because the procedure takes much longer to complete than do CT scans. Once your condition has been stabilized, you might have an MRI, which utilizes a strong magnet and radio waves to record detailed images of your brain.

Intracranial pressure monitor
Injured brain tissue tends to swell. That can increase the pressure inside the skull and cause additional damage to the brain. Doctors may insert a probe through the skull to monitor this pressure, and sometimes to drain excess fluid.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Mild traumatic brain injuries usually require no treatment other than rest and perhaps over-the-counter pain relievers if you have a headache. More-severe brain injuries usually require hospitalization and often need intensive care.

Emergency care for traumatic brain injury focuses on preventing the brain damage from getting any worse. The main problem is that injured brain tissue tends to swell, and there's a finite amount of space inside the skull. If blood vessels were torn during the initial injury, pooled blood or clots take up even more of the confined space.

As the pressure increases inside the skull, brain tissue and the blood vessels that feed the brain get squeezed. The pressure alone can harm brain tissue, but damage can also occur if compressed blood vessels can't supply the brain's cells with food and oxygen. Serious brain injuries may also lead to very low blood pressure, which further reduces the amount of blood reaching brain tissue.

Medications

• Diuretics. These types of drugs reduce the amount of fluid in tissue and increase urine output. Unlike the "water pills" heart patients may take to reduce blood pressure, the diuretics used for traumatic brain injuries are administered intravenously. The most common diuretic used for brain swelling is mannitol, but some studies indicate that certain concentrations of saline solution may work just as well — particularly in children.
• Anti-seizure drugs. People who've had a moderate to severe traumatic brain injury are at higher risk of having seizures during the first week after their injury. Some doctors recommend taking an anti-seizure drug during that first week, to avoid any additional brain damage that might be caused by a seizure.
• Coma-inducing drugs. Doctors sometimes deliberately use drugs to put people into temporary comas because a comatose brain needs less oxygen to function. This is especially helpful if compressed blood vessels are unable to deliver the usual amount of food and oxygen to brain cells.

Therapy
Most people who have had a significant brain injury will require rehabilitation. They may need to relearn basic skills, such as walking or talking. The overall goal is to improve their abilities to function at home and in the community.

Therapy usually begins in the hospital. When you're well enough to leave the hospital, you may be transferred to a residential treatment facility to receive intensive training for weeks or months. Outpatient services also are available.

The type of rehabilitation needed varies by individual, depending on the severity of the brain injury and what part of the brain was injured. Therapy focuses on regaining lost skills and learning ways to compensate for abilities that have been permanently changed.

Surgery
A portion of the scalp is shaved prior to brain surgery, then a flap of skin is cut and folded back and a section of skull is removed so that the surgeon can access the brain.

• Removing clotted blood (hematomas). Many people who have traumatic brain injuries are taken straight from the emergency department to the operating room for removal of large deposits of clotted blood trapped between the skull and the brain. This reduces the pressure inside the skull and helps prevent additional brain damage.
• Repairing skull fractures. Many skull fractures heal on their own, but repairs are needed if any portion of the skull is pressing into the brain.
• Opening a window in the skull. If the pressure inside the skull cannot be controlled by any other means, one surgical option is to create an opening in the skull and leave it open until the swelling subsides — which usually happens within just a few days.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Follow these tips to reduce the risk of brain injury:

• Always wear a seat belt in a motor vehicle. Small children should be secured in child safety seats or booster seats. Depending on their size, older children may be adequately restrained with seat belts.
• Never drive under the influence of drugs or alcohol.
• Store firearms, unloaded, in a locked cabinet or safe. Store bullets in a separate location.
• Wear a helmet while riding a bicycle, skateboard, motorcycle, snowmobile or all-terrain vehicle. Also wear head protection when you bat or run bases, ski, skate, ride a horse, or play a contact sport.
• Avoid falls by installing safety features in your home — such as handrails on stairways, nonslip mats in the bathtub and grab bars in the bathroom. An exercise program can improve your strength, balance and coordination. Regular vision tests also can help lower the risk of falling.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

A brain injury often erases your memory of events that occurred just before your injury. It can also make it more difficult for you to remember new information and learn new tasks. While some memory problems may diminish over time, others may be permanent.

As they slowly recover and adjust, some people who have had brain injuries carry cue cards that list coping strategies, such as:

• Slow down.
• Stop and think.
• Break it down, step by step.
• Ask questions.
• Do not assume.
• Pay attention to details.
• Take a break.
• Think of other things to try to problem solve.

Many people also find it helpful to carry a calendar for planning and organizing daily activities, step by step. It can serve as a reminder of uncompleted tasks and as a storage site for information you might otherwise forget.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.