The impact of Toxocara-seropositivity on attention and motor skills in children with attention-deficit hyperactivity disorder

Early Hum Dev. 2024 Jun:193:106017. doi: 10.1016/j.earlhumdev.2024.106017. Epub 2024 Apr 22.

Abstract

Background: The study aims to compare neurological soft signs and executive functions between Toxocara-seropositive and seronegative groups in children with attention-deficit/hyperactivity disorder.

Methods: The study included 60 boys with ADHD, aged 7-12. After blood samples were taken, the Stroop Color Word Test and Judgment of Line Orientation test (JLOT) were implemented to measure executive functions. Neurological soft signs were evaluated with Physical and Neurological Examination for Subtle Signs (PANESS).

Results: Serological tests were positive for Toxocara antibodies in 20 cases. There was no significant difference between Toxocara seropositive and seronegative regarding age, socioeconomic status, developmental stages, and ADHD severity. However, Toxocara-seropositive children had higher Stroop time and Stroop interference scores and lower JLOT scores than Toxocara-seronegative children. Furthermore, Toxocara-seropositive children exhibited more neurological soft signs, such as gait and station abnormalities, dysrhythmia, and a longer total time in timed movements compared to Toxocara-seronegative children.

Conclusion: Our study indicates a link between Toxocara-seropositivity and impaired neurological soft signs and executive functions in ADHD. Further research is needed to understand ADHD mechanisms, develop practical treatments considering immunological factors, and thoroughly evaluate how Toxocara seropositivity affects executive functions and motor skills in children with ADHD.

Keywords: ADHD; Neurological soft signs; PANESS; Stroop; Toxocara; Visuospatial abilities.

MeSH terms

  • Animals
  • Attention
  • Attention Deficit Disorder with Hyperactivity* / blood
  • Child
  • Executive Function / physiology
  • Humans
  • Male
  • Motor Skills* / physiology
  • Toxocara*
  • Toxocariasis / blood