Shaken baby syndrome is a severe form of head injury caused by violently shaking an infant or child.

Shaken baby syndrome can occur from as little as 5 seconds of shaking.

Such shaking usually takes place when the infant is crying inconsolably and the frustrated caregiver loses control. The violent shaking may result in severe injuries to the infant, permanent brain damage, or death.

Injuries are most likely to happen when there is both acceleration (from shaking) and deceleration (from the head hitting something). Even hitting a soft object, such as a mattress or pillow, may be enough to injure newborns and small infants. The result is a type of whiplash, similar to that seen in some auto accidents. A number of factors make infants highly vulnerable to such forces. For example, children's brains are softer, their neck muscles and ligaments are weak and not fully developed, and their heads are large and heavy in proportion to their bodies.

When an infant or toddler is shaken, the brain bounces back and forth against the skull. This can cause bruising of the brain (cerebral contusion), swelling, pressure, and bleeding in the brain.

The large veins along the outside of the brain may tear, leading to further bleeding, swelling, and increased pressure. This can easily cause permanent brain damage or death.

Shaking an infant or small child may cause other injuries, such as damage to the neck, spine, and eyes. Eye damage is very common and may result in loss of vision (retinal hemorrhage).

Shaken baby injuries usually occur in children younger than 2 years old but may be seen in children up to the age of 5.

In most cases, an angry parent or caregiver shakes the baby to punish or quiet the child. Many times the caregiver did not intend to harm the baby. Nevertheless, it is a form of child abuse.

Shaken baby syndrome does not result from gentle bouncing, playful swinging or tossing the child in the air, or jogging with the child. It also is very unlikely to occur from accidents like falling off chairs or down stairs, or accidentally being dropped from a caregiver's arms. Short falls may cause other types of head injuries, although these are often minor.

The symptoms can vary from mild to severe. They may include:

• Extreme irritability or other changes in behavior
• Lethargy, sleepiness, not smiling
• Poor feeding, lack of appetite
• Decreased alertness
• Loss of consciousness
• Pale or bluish skin
• Vomiting
• Convulsions (seizures)
• Not breathing

There are usually no physical signs of injury, such as bruising, bleeding, or swelling. In some cases, the condition can be difficult to diagnose and may not be identified during an office visit. However, rib fractures are common and can be seen on x-ray.

An ophthalmologist examining the infant's eyes may bleeding behind the eye or retinal detachment. There are, however, other causes of bleeding behind the eye and they should be ruled out before making a diagnosis of shaken baby syndrome. Other factors must be considered.

Call 911 or your local emergency number. Immediate emergency treatment is necessary.

If the child stops breathing before emergency help arrives, begin CPR. See: CPR in an infant under 1 year old

Steps to take if the child is vomiting:

• If you don't think there is a spinal injury, turn the child's head to one side to prevent choking and breathing in vomit to the lungs (aspiration).
• If you do think there is a spinal injury, CAREFULLY roll the child's whole body to one side at the same time (as if rolling a log) while protecting the neck to prevent choking and aspiration.

• DO NOT pick up or shake the child to attempt to wake him or her up.
• DO NOT attempt to give anything by mouth.

Call your health care provider if a child has any of the above signs or symptoms, regardless of their severity. Also call if you think a child has shaken baby syndrome.

• NEVER shake a baby or child, whether in play or in anger. Even gentle shaking can escalate to violent shaking when you are angry.
• Do not hold your baby during an argument.
• If you find yourself becoming annoyed or angry with your baby, put him in the crib and leave the room. Try to calm down. Call someone for support.
• Call a friend or relative to come and stay with the child if you feel out of control.
• Contact a local crisis hotline or child abuse hotline for help and guidance.
• Seek the help of a counselor and attend parenting classes.
• Do not ignore the signs if you suspect child abuse in your home or the home of someone you know.