Investigators at the Research Institute Brainclinics, Nijmegen, Netherlands, conducted a meta-analysis on the Theta/Beta ratio (TBR) during Eyes Open from location Cz (the electrode halfway between the inion and the nasion) in the EEG of children/adolescents 6-18 years of age with and without ADHD. In nine studies identified with a total of 1253 subjects with and 517 without ADHD, the grand-mean effect size (ES) of the TBR decreased from 0.75 to 0.62 with increasing age, explained by an increase in TBR for the non-ADHD groups. A substantial sub-group of ADHD patients do deviate on the TBR measure, but excessive TBR is not a reliable diagnostic measure of ADHD. It may have prognostic value. [1]

COMMENTARY. The FDA approved the Neuropsychiatric EEG-Based ADHD Assessment Aid (NEBA) medical device in 2013 to be used as confirmatory support or to pursue further testing after an evaluation for ADHD, in a child aged 6-17. The device was not to be used as a stand alone method of diagnosis of ADHD.

The AAN, in an Evidence-Based Practice Advisory, concludes that it is highly likely that EEG theta-beta power ratio and EEG frontal beta power correctly identify patients with ADHD (accuracy 89% to 94%) as compared to a clinical evaluation. The AAN recommends that the EEG test should not be used in place of a standard clinical evaluation, because of the risks of misdiagnosis of 6-15% when using the theta/beta ratio. There is neither evidence for, nor against the use of theta/beta EEG power ratio either to confirm a diagnosis of ADHD, nor to support further testing. Whether comorbid disorders such as ODD have similar changes in the theta/beta ratios that mimic the reported finding in ADHD is not known [2].

A recent report of spectral analysis of EEGs on 28 normal and 58 ADHD children, aged 6 to 14 years, found TBR was higher in ADHD subjects, with lower beta but no difference in theta power over Broca's area. Beta-1 power over Broca's area was the best diagnostic test, with sensitivity 0.86 and specificity 0.57. The EEG beta-1 power and TBR assist in confirming the diagnosis of ADHD in a sample with moderate pretest probability of ADHD [3].

The present symptomatic method of diagnosis, based on parent and teacher evaluations, is relatively accurate in children with the hyperactive-impulsive subtype of ADHD but less so with the inattentive type. A more objective test such as EEG if validated could be a valuable aid in the diagnosis and management of ADHD. The significance of seizure discharges in approximately 25% of sleep-deprived EEGs in ADHD children is further evidence of the utility of the EEG in ADHD management [4].