Concussions Do Not Lower Children’s IQ Scores Months After Recovery

Pediatric concussion is not associated with reduced cognitive ability, according to study findings published in the journal Pediatrics.

It is well known that traumatic brain injury (TBI) reduces intellectual ability (IQ) in children. However, it has been unclear whether concussion carries similar risk, in part due to small participant populations.

For the study, researchers analyzed data from children aged 8–16 living in the US and Canada. By drawing from 2 prospective, multisite cohorts — the Mild Injury Outcomes Study (MIOS) and the Advancing Concussion Assessment in Pediatrics (A-CAP) — the researchers recruited a relatively large group of 866 participants in the final analysis.

The researchers included children who had sustained a blunt head impact within 1 (US) or 2 (Canada) days before presenting to a participating emergency department, and who displayed signs and symptoms of concussion or mild TBI. These participants attended 3 follow-up visits over the next 6 months.

A comparison group was composed of children who had sustained a non-head orthopedic injury, in order to control for general effects of trauma, as well as demographic and injury risk factors. During one of the post-acute visits, each participant completed IQ testing and performance validity tests, via the Wechsler Abbreviated Scale of Intelligence and the Medical Symptom Validity Test.

The researchers used 3 complementary statistical models for this study: linear modeling to detect between-group differences; Bayesian analysis to compute probability of a true difference, and to eliminate potential sampling bias; and factor analysis to confirm whether the mental abilities being tested were commensurate across groups.

Linear regression analysis revealed a minor difference between concussion and (orthopedic) injury groups in full-scale IQ (concussion mean [SD] = 104.95 [14.10], injury mean [SD] = 106.08 [14.39]; Cohen’s d = 0.13, 95% CI, 0.00-0.26). A similarly small difference was evident for fluid reasoning, but not for vocabulary. The Bayesian analysis, however, indicated a “moderate to very strong” probability of no true difference across groups, for any IQ measure. Finally, factor analysis confirmed that intelligence was tested similarly across groups.

Patient clinical characteristics, such as mechanism of injury or symptom profile, did not affect these results.

The researchers acknowledged that all participants were recruited through presentation at an emergency department, which could limit generalizability. Another study limitation was that the IQ testing did not measure processing speed or working memory, which can be altered in concussion. 

Nevertheless, the research team concluded, their results provided robust evidence “that pediatric concussion does not negatively affect intellectual functioning early and up to 3 months postinjury, and hence suggest that using IQ tests to assess concussion outcomes is likely of limited utility.”

Disclosures: Several study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

This article originally appeared on Neurology Advisor