Shaken baby syndrome is a severe form of head injury caused by the forcible shaking of a child. The force is sufficient to cause the brain to bounce against the baby's skull, causing injury or damage to the brain.
Description
Shaking an infant forcibly transfers a great deal of energy to the infant. When the shaking occurs as the infant is being held, much of the force is transferred to the neck and the head. The force can be so great that the brain can move within the skull, rebounding back and forth from one side of the skull to the other. The bashing can be very destructive to the brain, causing bruising, swelling, or bleeding. Bleeding of the brain is also called intracerebral hemorrhage. The force of shaking can also damage the neck.
As its name implies, shaken baby syndrome can often be a result of deliberate abuse. The brain damage can also be the result of an accident. The force and length of the force necessary to cause shaken baby syndrome is debatable. What is clear is that not much time is needed, since most shaking events likely tend to last only 20 seconds or less. It is the explosive violence of the shaking that exacts the damage.
Demographics
Reliable statistics on the prevalence of shaken baby syndrome do not exist. Estimates in the United States approach 50,000 cases each year. Nearly 25% of infants with shaken baby syndrome die from the brain injuries sustained. The victims of this syndrome range in age from just a few days to five years, with an average age of six to eight months. Statistics point to men as the usual perpetrators, typically young men (i.e., early 20s). Females who shake babies tend to be caregivers. As reliable statistics emerge, it would not be unexpected to find the actual number of cases greatly exceeds these crude estimates. Abuse of children is a hidden event, so many cases of abuse, including shaken baby syndrome, are not reported or are presented in some other form (such as a fall or an accident).
Causes and symptoms
The cause of the brain, neck, and spine damage that can result from shaken baby syndrome is brute force. The violent shaking of a baby by a much stronger adult conveys a tremendous amount of energy to the infant. Part of the reason for the damage is because an infant's head is much larger than the rest of the body, in relation to an older child or an adult. This, combined with neck muscles that are still developing and are incapable of adequately supporting the head, can make shaking an explosively destructive event. The amount of brain damage depends on how hard the shaking is and how long an infant is shaken. If accidental, the force and length of the head trauma similarly determines the extent of injury.
The normal tossing and light "horse play" that can occur between an adult and an infant is not sufficient to cause shaken baby syndrome.
The damage to the brain can have dire consequences that include permanent and severe brain damage or death. Other symptoms that can develop include behavioral changes, lack of energy or motivation, irritable behavior, loss of consciousness, paling of the skin color or development of a bluish tinge to the skin, vomiting, and convulsions. These symptoms are the result of the destruction of brain cells that occurs directly due to the trauma of the blow against the skull, and secondarily as a result of oxygen deprivation and swelling of the brain. The banging of the brain against the sides of the skull causes the inflammation and swelling as well as internal bleeding. Increased intracranial pressure can be damaging to the structure and function of the brain.
Additionally, because the neck and head can absorb a tremendous amount of energy due to the shaking force of the adult, bones in the neck and spine can be broken and muscles can be torn or pulled. The eyes can also be damaged by the explosive energy of shaking. Retinal damage occur in 50–80% of cases. The damage can be so severe as to permanently blind an infant.
Diagnosis depends on the detection of a blood clot below the inner layer of the dura (a membrane that surrounds the brain), but external to the brain. The clot is also known as a subdural hematoma. Two other critical features of shaken baby syndrome that are used in diagnosis are brain swelling and hemorrhaging in the eyes.
An infant may also have external bruising on parts of the body that were used to grip him or her during shaking. Bone or rib fractures can also be apparent. However, these external features may not always be present. Diagnosis can also involve the nondestructive imaging of the brain using the techniques of computed tomography (CT), skull x ray, or magnetic resonance imaging (MRI). Typically, these procedures are done after an infant has been stabilized and survival is assured.
Treatment team
Treatment in an emergency setting typically involves nurses and emergency room physicians. A neurosurgeon is usually consulted when shaken baby syndrome is suspected. Depending on the extent of injury, neurosurgeons can become involved if surgery for brain repair is needed.
Police officers and social workers also become involved in cases of shaken baby syndrome, who work to ensure that the child is placed in a safe environment.
Treatment
Initially, treatment is provided on an emergency basis. Life-saving measures can include stopping internal bleeding in the brain and relieving pressure that can build up in the brain because of bleeding and swelling of the brain.
Recovery and rehabilitation
If the infant survives the initial injury from shaken baby syndrome, rehabilitation focuses on recovering as much function as possible. Physical and occupational therapies can offer exercises for caregivers to provide the child, as well as any supportive or positional devices required. The full effects of the brain injury sustained in infants who survive shaken baby syndrome may not become apparent until delays in developmental milestones such as sitting alone, walking, or acquiring speech are noticed.
Clinical trials
As of May 2004, there are no clinical trials on shaken baby syndrome underway or recruiting participants in the United States. However, agencies such as the National Institute of Neurological Disorders and Stroke fund studies that seek to better understand the basis of the damage. Other agencies attempt to lessen the occurrence of the syndrome through counseling, anger management, and interventions in abusive situations.
Prognosis
The prognosis for children with shaken baby syndrome is usually poor. Twenty percent of cases result in death within the first few days. If an infant survives, he or she will most often be left with intellectual and developmental disabilities such as mental retardation or cerebral palsy. Damage to the eyes can cause partial or total loss of vision. A survivor will likely require specialized care for the remainder of his or her life.
BOOKS
Lazoritz, Stephen, and Vincent J. Palusci, eds. Shaken Baby Syndrome: A Multidisciplinary Approach. Binghamton, NY: Haworth Press, 2002.
PERIODICALS
Geddes, J. F., and J. Plunkett. "The Evidence Base for Shaken Baby Syndrome." British Medical Journal (March 2004): 719–720.
Harding, B., R. A. Risdon, and H. F. Krous. "Shaken Baby Syndrome." British Medical Journal (March 2004): 720–721.
National Institute for Neurological Diseases and Stroke. P.O. Box 5801, Bethesda, MD 20824. (301) 496-5751 or (800) 352-9424. <http://www.ninds/nih.gov>.
The National Center on Shaken Baby Syndrome. 2955 Harrison Blvd., #102, Ogden, UT 84403. (801) 627-3399 or (888) 273-0071; Fax: (801) 627-3321. dontshake@mindspring.com. <http://www.dontshake.com>.
National Institute of Child Health and Human Development. 31 Center Drive, Rm. 2A32 MSC 2425, Bethesda, MD 20892-2425. (301) 496-5133; Fax: (301) 496-7101. <http://www.nichd.nih.gov>.
The Arc of the United States. 1010 Wayne Avenue, Suite 650, Silver Spring, MD 20910. (301) 565-3842; Fax: (301) 565-3843. info@thearc.org. <http://www.thearc.org>.
Think First Foundation [National Injury Prevention Program]. 5550 Meadowbrook Drive, Suite 110, Rolling Meadows, IL 60008. (847) 290-8600 or (800) 844-6556; Fax: (847) 290-9005. thinkfirst@thinkfirst.org. <http://www.thinkfirst.org>.
