INTERHEMISPHERIC AND INTRAHEMISPHERIC PHASE-CHANGES OF DIFFUSE 3 HZ SPIKE-AND-WAVE COMPLEX

The inter- and intrahemispheric phase characteristics were investigate d on diffuse 3 Hz spike-and-wave complex (D3SW) in eight epileptic pat ients who were diagnosed with typical absence, The phase of D3SW was a nalyzed sequentially using cross-power spectral arrays dividing D3SW i nto two components (spike-and-wave complex, spike component), The phas e of spike-and-wave complex preceded most at the midline structure, an d delayed symmetrically toward the lateral side of each hemisphere in all cases, while not in all cases when spike component was investigate d, In spite of this symmetry, there was sparse correlation in phase ch ange between the homologous hemispheres, There was almost no linear co rrelation between the phase of spike-and-wave complex and the correspo nding spike component, The author concludes that the 'centrencephalic system' hypothesis still plays an important role for the generation of D3SW, and suggest a mechanism other than the cortical recurrent inhib ition for the generation of wave component.