Medscape- Effects of Early TBI May Linger 10 Years Later

Effects of Early TBI May Linger 10 Years Later
Megan Brook
January 30, 2012 — Young children who suffer severe traumatic brain injury (TBI) from a fall, car accident, or other mishap may have intellectual deficits and behavior problems that persist 10 years later, new research indicates.

Until now, few studies have documented long-term outcomes of childhood TBI. The new data, reported in 2 papers published online January 23 in Pediatrics, are from researchers at Murdoch Children’s Research Institute and Royal Children’s Hospital, Melbourne, Australia.

In the first article, the researchers plotted recovery of cognitive and functional skills out to 10 years after the injury and assessed factors influencing recovery in 40 children who suffered TBI between the ages of 2 and 7 years. TBI was characterized as mild in 7, moderate in 20, and severe in 13 children.

Compared with 16 healthy control children, children with severe TBI had depressed intellectual abilities at 10 years, “with medium to large effect sizes for adaptive, executive, and social abilities,” report first author Vicki Anderson, PhD, from the Department of Child Neuropsychology, Murdoch Childrens Research Institute; Department of Psychology, Royal Children’s Hospital; and Department of Psychological Sciences, University of Melbourne, all in Melbourne, Australia, and colleagues.

Dr. Vicki Anderson
Children with severe TBI had the lowest IQ scores, at 18 to 26 points below the control group, indicating that serious TBI in early childhood results in “global and persisting intellectual deficits,” the researchers say.

A “Positive Message”

In comments to Medscape Medical News, Dr. Anderson said it is important to note that only children with serious TBI have significant cognitive consequences; children with less severe TBI appear to recover normal functions.

Regardless of TBI severity, recovery seemed to plateau 5 to 10 years after the injury. This observation counters the theory that children with severe brain insults “grow into deficits” with time since injury, the researchers say. Rather, it appears that after a protracted recovery period, these children gradually stabilize and begin to make some developmental gains, suggesting that even many years after the insult, intervention may be necessary and helpful.

“Stabilization after 2 to 3 years is a new and positive message,” Dr. Anderson said. However, although children with severe TBI “begin to do better, [they] never catch up to their healthy peers,” she noted.

The researchers say they found “surprisingly few” predictors of functional outcomes. In particular, preinjury adaptive function was predictive of 10-year adaptive abilities, and family function/intimacy was linked to social and behavioral outcomes.

“Young children with severe injuries with social disadvantage have the worst outcomes,” Dr. Anderson noted. “The strong impact of environment is also new,” she added. “The impact of environment we found suggests that, after injury, we can improve outcomes by optimizing the child’s environment.”

Intellectual and Social Outcomes

In the second article, first author Louise M. Crowe, PhD, from the Psychology Department at the University of Melbourne and the Murdoch Childrens Research Institute, Dr. Anderson, and colleagues describe intellectual, behavioral, and social outcomes of 53 children who sustained TBI (20 mild, 33 moderate to severe) before age 3 years. The children were assessed when they were 4 to 6 years old, and an average of 40 months after the injury. The study also included 27 healthy control children for comparison.

There were no demographic differences between the 2 groups. The results in this cohort provide more evidence that moderate to severe TBI at an early age is associated with lowered intellectual function, and possibly behavior problems, the researchers say.

For various intellectual outcomes, the group with moderate to severe TBI scored below the control and mild TBI groups, although still in the average range. The difference between the groups was significant overall (P = .030), as well as for verbal, performance, and full-scale IQ.

Although there were no marked differences in parent-reported behavior ratings, effect sizes between groups were “medium to large.” A link between social disadvantage and poor outcomes after TBI in early childhood was also noted in this cohort.

In a linked commentary, Harvey S. Levin, PhD, from Baylor College of Medicine in Houston, Texas, notes that trauma is the most common cause of acquired brain injury in young children. He says these 2 reports provide much-needed, long-term outcome data on TBI in young children.

“Taken together, writes Dr. Levin, the 2 studies “challenge views long held by clinicians and researchers” that young children are more resilient to the effect of TBI on cognitive development than older children because of their greater capacity for neuroplasticity.

It appears, Dr. Anderson told Medscape Medical News, that although the brain “might be ‘plastic’ in normal development, when it’s injured in young children, usual development processes are derailed, resulting in significant cognitive and psychosocial consequences.”

The research was supported by the Foundation for Children, the Victorian Government’s Operational Infrastructure Support Program, and the Australian National Health and Medical Research Council. The authors have disclosed no relevant financial relationships. Dr. Levin was supported by an award from the National Institute of Neurologic Disorders and Stroke.

Pediatrics. Published online January 23, 2012. Anderson abstract, Crowe abstract, Commentary full text

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