Purpose: In the United States, ADHD is estimated to affect 5.4 million children between 6-17 years old. It is the most prevalent pediatric neurodevelopmental disorder. The King-Devick (K-D) test is a vision-based assessment of rapid number naming that requires saccades and visual processing. In sideline testing of young athletes with concussions, the K-D test demonstrated higher score times after a concussive injury as compared to the baseline pre-season scores. ADHD, like concussion and mild TBI, has been linked with visual pathway dysfunction. Our investigation looked at whether children with ADHD scored worse or similar to age-matched controls.

Methods and Study Design: Our prospective study looked at children with ADHD and their age-matched controls in patients diagnosed with ADHD between ages 5-21. Analysis compared K-D scores of patients with ADHD to those scores of student-athlete controls matched for age and gender. Data analysis was done with logistic regression, ROC curves and t-test.

Results: Among 134 participants in this study, ADHD vs. control was significantly associated with higher K-D scores (p<0.001). K-D showed a greater capacity to distinguish ADHD in participants older than 11 years of age when compared to controls. Participants with a diagnosis of ADHD required an average of 14 seconds longer to complete the K-D test compared to controls. Stimulant medication use was not associated with differences in K-D scores within the ADHD group.

Conclusions: This study illustrates that visual pathways might be utilized differently in children and young adults with ADHD compared to controls.

Significance of Findings: Given the difference in baseline K-D scores of patients with ADHD, this study can have implications for assessing concussions. Different baseline norms may be needed in the management of concussions in athletes with ADHD.

Summary Points:

  • Visual pathways might be utilized differently in children and young adults with ADHD compared to controls.
  • Norms should not be used for sideline concussion screening as variables such as age and ADHD diagnosis can affect performance. Comparison against individual baseline should be used and is supported by the literature.
  • Caution should be used when considering used of baseline norms in the clinical management of concussion.