Reliability of short interval cortical inhibition in children with attention deficit hyperactivity disorder

Donald L Gilbert1, David A Huddleston2, Karlee Y Migneault2

  • 1Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States.

Insights

Short Interval Cortical Inhibition (SICI) shows good test-retest reliability in children with Attention Deficit Hyperactivity Disorder (ADHD). This supports SICI

Area of Science:

  • Clinical Neurophysiology
  • Neuroscience
  • Pediatric Neurology

Background:

  • Biomarker utility relies on consistent test-retest reliability.
  • Reduced Short Interval Cortical Inhibition (SICI) is a consistent finding in children with Attention Deficit Hyperactivity Disorder (ADHD).
  • Test-retest reliability of SICI and Intracortical Facilitation (ICF) using Transcranial Magnetic Stimulation (TMS) has not been established in pediatric populations, particularly those with ADHD, despite high variability in motor evoked potential (MEP) measures.

Purpose of the Study:

  • To estimate the test-retest reliability of paired-pulse SICI.
  • To estimate the test-retest reliability of ICF.
  • To assess these measures in both children with ADHD and typically developing (TD) controls.

Main Methods:

  • Recruited 64 children aged 8-12 years (35 with ADHD, 29 TD) across two sites.
  • Measured SICI and ICF across two visits separated by 21 days.
  • Calculated Intraclass correlations (ICCs) after accounting for test-pulse MEP amplitudes and outliers.

Main Results:

  • Demonstrated good reliability for SICI in children with ADHD (ICC > 0.75).
  • Showed moderate reliability for ICF in children with ADHD (ICC > 0.50).
  • Reliability was assessed after controlling for MEP amplitudes (>0.25 mV) and removing outliers.

Conclusions:

  • Findings support the potential of SICI as a reliable biomarker for ADHD in school-aged children.
  • This research addresses a critical gap in clinical neurophysiology.
  • Establishing SICI reliability is essential for its use in interventional and longitudinal ADHD studies.
Abstract