TABLE 2
SOURCE: Kristen Kucera.
ally, 775,000 of them requiring emergency care. Sev-
enty-five percent are boys. Similarly, youth who are
employed are exposed to a variety of hazards, with as
many as half experiencing injuries at work.
Developmental Delays as a Result of
Injury
Just as development affects whether a child is at
risk of experiencing an injury-producing event, so is
development affected by being injured. Injuries with
the greatest impact in the behavioral and emotional
development of the child are head injuries, specifical-
ly traumatic brain injuries, and severe burns. Little re-
search has been done on the outcome of other types
of injuries in children and adolescents.
Brain Injury
As reported in 1996, more than 100,000 children
and adolescents are hospitalized each year with trau-
matic brain injury (TBI), of which about 88 percent
are classified as mild, 7 percent moderate, and 5 per-
cent severe. Although children under five years of age
have the lowest rate of TBI, the severity of injury is
disproportionately high. Evaluations of neurological
and psychological outcomes following pediatric TBI,
however, have been focused almost exclusively on
school-age children and adolescents. The few studies
that have assessed the consequences of mild TBI for
infants and/or preschoolers identified lower IQ scores
in infants and young children than in older children
who suffered a mild TBI. Philip Wrightson, Valerie
McGinn, and Dorothy Gronwall (1995) studied pre-
schoolers who sustained mild head injuries and re-
ported that deficits in cognitive development,
identified at twelve months after injury, were signifi-
cantly associated with reading ability at age six and a
half. It is not clear if mild TBI and concussion result
in long-term problems in children given the difficulty
in differentiating effects that may be a direct conse-
quence of mild TBI or of learning disabilities or at-
tention deficits in the TBI group, which do not
manifest themselves until later in development.
Follow-up studies of severe TBI in school-age
children and adolescents identified physical, cogni-
tive (e.g., lower IQ scores), language, and psychologi-
cal deficits that may be temporary or permanent. The
most common language problems are word retrieval
difficulties and decreased speed of information pro-
cessing. Follow-up studies for as long as three years
after the TBI reveal persistent neurobehavioral defi-
cits. Acute behavioral problems include emotional
outbursts, restlessness, and low tolerance to stimula-
tion.
Cognitive delays have significant effects on social,
educational, and vocational prognosis of children fol-
lowing TBI. For example, in a study in which TBI
children were compared with age, gender, and grade-
matched peers, Kenneth Jaffe and his colleagues
found that more severe head injury was associated
with lowered neurobehavioral functioning. Develop-
mental deficits include lack of attention and long,
heightened distractibility, short-term memory im-
pairment, difficulty with logical thinking and reason-
ing, slowed reaction time, and impaired spatial or
visual motor skills. The duration of post-traumatic
amnesia was reported to be the best predictor of these
deficits. Severe TBI results in significant neurobe-
havioral deficits that are persistent after the first year
and that are related to the severity of the head injury.
The effects of age at injury on subsequent cogni-
tive development are unclear. In studies examining
cognitive, social, academic, and vocational outcomes
following severe TBI, some have reported that age at
injury was not predictive of long-term outcome. Oth-
ers identified more severe consequences in children
ages zero to six than in older children. Several studies
of outcomes following TBI failed to find associations
between age at injury and either severity of cognitive
consequences and the rate of recovery of neuropsy-
chological, or behavioral disturbance. Several otherINJURIES 213