[The unstable-frequency EEG--as a concept and its correlations to neuropsychiatric diseases in children].

: A total of 21,040 electroencephalograms obtained from 6,834 children constituting the routine patient stock of an electroencephalographic department of a pediatric clinic were checked for "frequency instability". It was possible to observe an age dependence of this characteristic and determine statistical correlations with certain clinical disease units showing different frequencies of this particular characteristic, especially neuropathies and neuroses.