Evaluation of the Effects of Optokinetic Stimuli and Dual-Task Performance on Vestibulo-Ocular Reflex Function in Children With Attention Deficit and Hyperactivity Disorder.

Objectives: This study investigated the effects of optokinetic stimuli and dual-task performance on vestibulo-ocular reflex (VOR) function. The study primarily focused on understanding the effects of attention deficit and hyperactivity disorder (ADHD) and its subtypes.

Study Design: A case-control study.

Setting: Tertiary medical centre.

Methods: Thirty-eight children diagnosed with ADHD and 40 typically developing (TD) children aged 8-18 were included in the study. According to their diagnostic reports, children diagnosed with ADHD were also examined in three subtypes: predominantly inattentive (ADHD-PI), predominantly hyperactive-impulsive (ADHD-HI) and the combined type. Functional head impulse test (fHIT) was applied to all participants in three conditions-with no additional stimulus, optokinetic stimulation and dual-task. Correct responses (CR) were determined for each group, and the conditions were compared. For the dual-task test performance, children were given a counting task.

Results: The findings of the study are significant. The CR values obtained from the fHIT tests applied under three different conditions were lower in the ADHD group compared to the control group. CR values for all fHIT conditions and all semicircular canals were lower in the ADHD-PI subtype and higher in the ADHD-HI subtype compared to other subgroups.

Conclusion: This study has significant practical implications underscoring its relevance. fHIT, when applied with different protocols, can provide valuable information about the vestibular and cognitive states of children with ADHD. These results are particularly significant as the diagnosis of ADHD often relies on subjective interpretations, and fHIT offers a more objective and reliable method of evaluation.