Costs of Injury
The costs associated with pediatric TBI are significant. In a study of hospital resource utilization for pediatric TBI in the year 2000, Schneier et al. (3) reported that more than $1 billion in hospital charges was generated for TBI patients 24 cm/s in healthy newborns, 97 cm/s in children aged 6 to 9 years, and then decreasing to the adult value of approximately 50 cm/s (27).
Some studies have suggested that children with TBI have a lower middle cerebral artery flow rate and therefore hypoperfusion is common (27).Another phenomenon associated with cerebral swelling is called second impact syndrome, and is said to occur after repeated concussion in children and adolescents. Brain swelling can be severe, even fatal, and develops after seemingly minor head trauma in an athlete who is still symptomatic (though at times subclinically) from a previous concussion (29). Second impact syndrome is a theoretical condition with only a few case reports available. The theory describes an initial injury (the first concussion), which deranges the brain's autoregulatory and metabolic systems enough to produce vascular engorgement and poor brain compliance. This allows marked changes in intracranial pressure with small changes in intracranial volume (29). Second impact syndrome presumes that the brain cells are in a vulnerable state after the initial concussion. Minor changes in cerebral blood flow during the second concussion result in an increase in intracranial pressure and ultimately apnea due to herniation, cerebral ischemia, and brain death (30,31). Also, there have been reports of diffuse cerebral swelling after mild TBI in sports, usually occurring in male adolescents (32).