WASHINGTON — Children who suffer traumatic brain injuries can experience lasting or late-appearing neuropsychological problems, highlighting the need for careful watching over time, according to two studies published by the American Psychological Association.
In one study, a team of psychologists used a longitudinal approach to gain a better idea of what to expect after traumatic brain injury (TBI). The researchers found that severe TBI can cause many lasting problems with day-to-day functioning. Some children may recover academically but then start acting up; other children do surprisingly well for unknown reasons.
In the second study, the first systematic meta-analysis summarizing the collective results of many single studies, the researchers found that problems lasted over time and, in some cases, worsened with more serious injury. Some children with severe TBI started to fall even further behind their peers than one would normally expect, in a snowball effect that requires further study.
The results of both studies were reported in the May issue of Neuropsychology, published by the American Psychological Association.
The Centers for Disease Control in 2000 cited traumatic brain injury as the single most common cause of death and disability in children and adolescents.
Long-Term Study Digs Out Individual Differences
In the first study, researchers at The Ohio State University, Case Western Reserve University, and hospitals in Columbus and Cleveland followed 37 children after severe TBI, 40 children after moderate TBI, and 44 children after musculoskeletal injury (a common way to control for trauma and the hospital experience). All of the children were injured between the ages of 6 and 12, and assessed six months, 12 months, and three to five years following their injuries.
As expected, the children with severe brain injuries showed greater problems than children with other injuries in the areas of mental processing, learning and memory, behavior, adaptation and academics. Children whose comas were longer and more severe had more, and more serious, problems.
Some children seemed at first to be doing all right on cognitive tests and in the classroom, but then developed significant behavioral problems. Parents and doctors should watch children who’ve had traumatic brain injury closely because something may come up later – perhaps, the authors suggested, as a secondary reaction to the disruption caused by the injury, or because the family has not functioned very well, especially in response to the injury.
Generally, one year after injury, nearly 60 percent of the severe TBI group had problems in at least one area, compared with 25 percent of the controls. Four years after injury, 40 percent of children suffering severe TBI and 20 percent of the controls showed deficits. At both intervals, the share of brain-injured children with cognitive problems was at least twice that of the control group members with problems.
Even so, the researchers were intrigued that many children with moderate to severe TBI showed no significant weaknesses from six months to four years after the injury, in one or more of the areas measured.
Perhaps, they speculated, that was because in previous long-term studies, group averages may have hidden the fact that some individual children can do well over time. This team, by tracking individuals, revealed that some children are more mentally resilient. If researchers can learn why, they may be able to help more children to recover more fully from this type of injury.
“It’s probably a complex interplay of child, family and broader environmental/cultural factors. The care and treatment children receive may make a difference, such as whether they have access to rehabilitation and special-education services,” said co-author Keith Yeates, PhD, who also mentioned genetic differences in the brain’s ability to heal itself.
Meta-Analysis Shows Problems Grow Over Time
In the second study, conducted by Talin Babikian, PhD, and Robert Asarnow, PhD, at the University of California-Los Angeles, the authors analyzed 28 carefully selected articles published between 1988 and 2007. The children were sorted by TBI severity and time since injury. Severity levels were mild, moderate or severe TBI, and follow-ups were on average 0-5 months, 6-23 months, or 24+ months, for 14 key aspects of neurocognition.
According to their analysis:
- The worse the injury, the worse the neurocognitive outcome, especially on measures of general intellectual functioning and processing speed.
- Time didn’t heal all. The moderate and severe groups were even more similar by the third time band, especially on general intellectual functioning and attention/executive skills.
- Most problems stick. Despite modest recovery in intellectual functioning and attention, weaknesses in many children with moderate TBI persist even two years after the injury, compared to the children in control groups.
- Memory and visual-spatial skills seemed more or less normal by two-plus years, with even the moderately injured performing in the same range as controls.
- Children with severe TBI needed more help, showing robust and significant problems within months on IQ, executive functioning (processing speed, attention), and verbal memory (both immediate and delayed). After two or more years, all areas studied were impaired.
“It appears that there are significant, persistent neurocognitive impairments in a subset of children with severe TBI,” the authors concluded. Despite some recovery during the first two years, children in this group not only failed to catch up to peers, but appeared to fall further behind over time. Thus, severe traumatic brain injury may throw off children’s normal developmental timetable. The authors noted that well-controlled longitudinal studies evaluating the same children over time are necessary to confirm these findings.
That makes severe brain injuries at younger ages a “double hazard,” the authors noted. Because younger children have more development ahead of them, the same injury can affect a 4-year-old and a 12-year-old very differently. This finding highlights the importance of targeted treatment developed specifically for children with severe TBI.