What does CEEG contribute to the recognition of neurological disorders, in addition to EEG? The aim of this study is to answer these questions. A sophisticated system, consisting of a computer, a printer and a screen (HZ1 system), connected to an 8 channel standard EEG equipment and giving the percentage, average voltage and topographic distribution of the recorded brain activity frequencies (delta, theta, alpha, beta) as a report .and as a dynamic brain map, was used. The following results were obtained after comparing more than 2000 EEG and CEEG findings: 1/ CEEG, which estimates wave frequencies, naturally did not record focal and generalized sharp waves, paroxysmal projected discharges and various wave patterns (spike-wave, triphasic wave, periodic anomalies, etc.), useful in the recognition of diseases; 2/ Correlation beween EEG and CEEG results was usually good if standart EEG was normal or focal or generalized wawes were present. Occasionally, some artefacts were recorded as pathological activity in CEEG; 3/ CEEG made it easy to see the activity type, distribution and percentage at one glance.