Quantitative electroencephalographic analysis of children and adolescents with attention deficit/hyperactivity disorder compared with non-clinical controls : diagnostic implications

The use of quantitative electroencephalography, or qEEG, in the diagnosis of psychiatric and neurological conditions is a growing field with important potential for the future. The recognition of Attention Deficit (Hyperactivity) Disorder, or ADD/HD, as a common, biologically based disability is also increasing, with such a diagnosis becoming increasingly common. The use of qEEG as to aid in the identification of ADD/HD in individuals would therefore be of great practical utility. It has already been demonstrated that qEEG can be used effectively to differentiate those with ADD/HD from non-clinical controls. However, most previous studies have used only single electrode recordings in their analysis. Thus further investigation is warranted to determine the potential for increasing the utility of qEEG based assessment through the use of multielectrode recordings. To investigate the potential usefulness of multielectrode qEEG in identifying ADD/HD, archival data on 125 children and adolescents with a diagnosis of ADD/HD were compared to a widely accepted normative database to determine if specific differences from the database typified the group. All EEG recordings had been taken on children between the ages of seven and eighteen, using the 19 electrode international 1020 montage with the Lexicor Neurosearch 24. Phase, coherence, asymmetry, and relative power were computed using Hudspeth\u27s Neurorep program and compared to Thatcher\u27s Lifespan Normative Database. This produced brain maps for each of the participants, which were visually sorted based on patterns of relative power distribution. Additionally, mathematically averaged maps were produced for each of five age-group categories. No consistent patterns were observed in the phase or coherence maps, and averaging these resulted in normal-looking maps as the individual differences washed out. Lateral asymmetry abnormalities were found to persist in the averaged brain maps, and to increase with age, particularly in the delta band. Many participants (about one third) were observed to have above average alpha over most of the head, and this was apparent in the averaged maps, but was not sufficiently high to classify as abnormal. However, power ratios of specific band passes were more robust, and it was found that α/β was very often high, especially in the younger ages, and that θ/β has a similar tendency to be high for children age ten or below. Also, α/β was most notably higher than the norm in the parietal regions, while θ/β was typically highest along the midline, especially at Cz and Fz. It was concluded that θ/β and α/β are the most useful qEEG measures for assessing ADD/HD. Further α/β was found to differentiate primarily in the parietal regions and for those age fifteen and younger, while θ/β was best at Cz and for children age ten and younger