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What is SBS?

How is it caused?

by Staff   7.10.2007

Babies are vulnerable to injury during a shaking episode for three main reasons:

1) They have relatively large heads compared to their bodies at this age;
2) They have very weak neck muscles that cannot control or lessen the movement of their head during shaking; and
3) The person doing the shaking is so much bigger and stronger than the infant.

Shaken baby syndrome occurs when an infant or young child is shaken violently and repetitively with or without impact. The forces on the brain during shaking are much different than the forces that occur during a fall. The baby's head whips back and forth creating an acceleration/deceleration force inside the baby's head. These forces are thought to increase in strength with each shake.

The infant's brain is not fully developed and has a very soft consistency like unset gelatin. It mainly consists of a watery substance that can easily be distorted. The brain is covered by a skull that is thin and hard. There are blood vessels that supply the brain with oxygen and other materials called bridging veins. It is usually these veins that stretch and tear during a shaking episode. This causes bleeding and/or swelling of the brain and may lead to serious damage.

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