Children diagnosed with attention deficit hyperactivity disorder (ADHD) are more likely to develop a disability following a minor head injury resulting in a mild traumatic brain injury (TBI).
Thus, experts say parents may wish to steer such children away from full-contact sports and hobbies carrying a greater risk of TBI.
For years, researchers and parents of children with ADHD had wondered whether the condition exacerbated the effects of brain injury, minor and major, following an accident. In research published Tuesday, investigators at the University of Pittsburgh and the University of Chicago report findings that children with ADHD have a greater chance of developing a moderate disability after sustaining a mild TBI, when compared to children without the condition.
Reviewing patient records between January 2003 and December 2010 at Children's Hospital of Pittsburg, the investigators analyzed data from cases in which children suffered mild "closed-head injury," which requires no neurosurgical treatment, resulting in mild TBI, as measured by an initial score of 13-15 on the Glasgow Coma Scale. Against this group of patients, 48 in total, the researchers compared outcomes from another 45 patients who suffered the same type of trauma, but were not diagnosed with ADHD.
After eliminating possible confounders relating to demographics and injury types, the researchers found that a quarter of the patients with ADHD had a moderate disability while 56 percent had made complete recoveries after a period of 25 or so weeks. By that time, only two percent of patients without ADHD had developed a disability as a result of their brain injury, while the vast majority — 84 percent — had recovered fully after only seven weeks or so.
Statistical analysis of this study showed that "patients with ADHD were statistically significantly more disabled after mild TBI than were control patients without ADHD, even when controlling for age, sex, initial [Glasgow Coma Scale] score, hospital length of stay, length of follow-up, mechanism of injury, and presence of other [extracranial] injury," the researchers wrote.
The evidence of a relationship between ADHD and exacerbated effects from brain injury came as no surprise to the investigators, leaving them to speculate about the possible reasons, including not only a greater vulnerability to such injury but an impaired healing process within the brain afterward, or perhaps a factor rendering rehabilitation programs less effective.
"Our study provides evidence that for children with ADHD who sustain a TBI, different treatment and patient and family education may be necessary to achieve optimal outcomes." Dr. Christopher M. Bonfield, a co-author of the study, told reporters.
Aside from recommending children with ADHD refrain from more dangerous sports and hobbies, Bonfield and his colleagues said doctors must monitor such patients more closely following brain injury, counseling parents and other family members about possible outcomes in the weeks following. More study is needed, Bonfield said, on the effect of ADHD on more severe brain injuries, as well as the underlying mechanisms of the relationship between the two conditions.
Source: Bonfield CM, Lam S, Lin Y, Greene S. The impact of attention deficit hyperactivity disorder on recovery from mild traumatic brain injury. Journal of Neurosurgery: Pediatrics. 2013.