Despite considerable sparing of function following
some forms of early brain disease, neural plasticity is
far from complete. Many children with early brain insults,
including those who sustain traumatic brain injury (TBI),
are susceptible to both immediate and long-term neurobehavioral
impairments. To introduce this symposium, the present article
reviews existing research on the effects of 3 age-related
factors on outcomes: age at injury, time since injury,
and age at testing. Research findings support the hypothesis
that development is more adversely affected the younger
the child at the time of brain insult. Although we know
less about how outcomes are related to the other developmental
factors, there is little evidence that sequelae resolve
with age. Potential brain mechanisms responsible for age-related
differences are explored and methodological problems are
considered. Emphasis is placed on the importance of prospective
designs, measurement of developmental change, comprehensive
assessments of outcome, and evaluation of factors contributing
to variability in outcomes, such as premorbid status, type
of brain injury, and environmental influences. Papers in
this series demonstrate the utility of these methods and
shed new light on developmental processes associated with
childhood brain insults. (JINS, 1997, 3,
555–567.)
