The authors conclude that the hypsarrhythmic EEG shares less features with EEGs with generalized seizure activity than suggested by the often used adjective "chaotic" in the description of the visually inspected time series. Although the hypsarrhythmic EEG may occasionally contain some weak nonlinear structures, as in the control EEGs, the authors believe that, given the current state of knowledge, the adjective "chaotic" does not apply. Clearly, additional studies may elucidate more specific features of this brain disorder, of which the pathophysiology is still unresolved.