The relationship between suboptimal effort and post-concussion symptoms in children and adolescents with mild traumatic brain injury.

This retrospective chart review study explored the relationship between suboptimal effort and post-concussion symptoms in pediatric mild traumatic brain injury (mTBI). Participants were 382 clinically referred children and adolescents between 8 and 16 years of age who sustained an mTBI. Suboptimal effort was identified using reliable digit span and age-corrected scaled scores from the Numbers subtest of the Children's Memory Scale (CMS); 20% of the sample were classified as non-credible performers. Chi-square analyses and t-tests were used to examine differences in post-concussion symptoms and neuropsychological test performance between credible and non-credible performers. Linear regression was used to examine whether CMS Numbers performance predicted post-concussion symptoms after controlling for baseline symptoms and other relevant demographic- and injury-related factors. We found that non-credible performers presented with a greater number of post-concussion symptoms as compared with credible performers. Additionally, non-credible performers demonstrated comparatively poorer performance on neuropsychological tests of focused attention and processing speed. These results suggest that children and adolescents with mTBI who fail effort testing might have a greater tendency to exaggerate post-concussion symptoms and cognitive impairment. The clinical implications of these findings are discussed.