[Electroencephalographic periodicity with asynchronous variations in period duration in both hemispheres following acute cerebral anoxia].

The periodicity of paroxysmal wave complexes in EEG after acute cerebral anoxia with special reference to the dynamics of period duration (alteration of Zeitmass) is described in case 20 hours before isoelectric tracing. The completely asynchronous feature of paroxysmal events within certain limits of period duration in both hemispheres is a rare condition. Late and pure cortical electrogenesis is suggested. Short and long EEG- periods in similar and different pathological processes and functional states are compared with respect to topography of lesions. Subcortical interactions and extraneuronal influences upon periodicty are discussed. The parameters "complex wave and periodicity" in EEG and the dynamics respectively are a matter of serial investigations for better understanding pathophysiology and prognostic value.