Shaken Infant Syndrome
Shaken Infant Syndrome (also known as Shaken Baby Syndrome, SBS) is a relatively new term in the medical world. Simply put, it is the collective name of the symptoms produced when an infant is shaken violently or has sustained some type of head trauma. Any type of trauma to the head or cranial region results in some negative response to the body’s homeostatic system, in an infant or child this is especially true. An infant or child’s skull is disproportionately larger than that of a fully developed adult. This usually results in a higher susceptibility to head and neck injury.
To understand how SBS effects the human body’s homeostatic system it must first be established what happens to be diagnosed with SBS. The majority of cases are a result from an infant or small child being shaken vigorously back and forth. Cases have been documented from falls or accidents ; however, it must be noted that this is a relatively small number. For the purposes of the scope of this paper, those results will be ignored. Shaken Baby Syndrome is a term used to describe the constellation of signs and symptoms resulting from violent shaking or shaking and impacting of the head of an infant or small child.
When a small child or infant is shaken the head will act as a pendulum perched on the neck. The neck muscles are not fully developed yet so the head can not be held in place. The child’s skull is not yet fully developed at this point. The dura mater has not yet firmly attached itself to the skull since the sutures in the skull have not fully fused together. The skull is designed like this to allow for the future growth of the body and brain. When the head is snapped back and forth the brain can “rattle” inside the skull causing extradural, subdural, and subarachnoid hemorrhages that are sometimes referred to as extra-axial hemorrhages . Extra-axial hemorrhages indicate that these injuries occur outside the substance of the brain itself. Other injuries that can occur are damage to the neck, spine, and possible retinal hemorrhages or detachment.
Extradural, subdural, and subarachnoid hemorrhages are best understood by reviewing the anatomy of the meninges. The meninges are divided into three layers: the dura mater, arachnoid layer, and pia mater. The dura mater lines the inner surfaces of the skull and forms partial divisions in the cortex of the brain. The dura mater is attached to the skull, particularly at the cranial sutures of the bones that make up the skull. In infants and small children this attachment has not yet taken place. The space between the skull and the dura mater is the extradural space. A hemorrhage into this space is referred to as an extradural hemorrhage. These hemorrhages are usually the result of a tear in a meningeal artery.
An extradural hemorrhage is more prevalent in small children because the dura mater lining has not yet firmly attached itself to the junctures in the skull. When...