Intermittent spike-wave dynamics in a heterogeneous, spatially extended neural mass model

► Background and spike-wave oscillations are described in a cortical dynamic model. ► Transitions from background to spike-wave are described at three spatial scales. ► Spatially extended background oscillations are out-of-phase, spike wave are in-phase. ► A bistability exists between these two states. ► Spatial heterogeneity yields intermittent transitions into and out of seizure.