Luedtke K, et al. - Authors studied and compared 47 episodic (EM) and 39 chronic migraineurs (CM) (interictal) to 34 healthy controls (HC) to evaluate the changes of afterimage-duration in migraineurs and HC and also to represent changes in the excitatory/inhibitory equilibrium within the visual cortex throughout the migraine cycle. They observed shorter after-image duration interictally but a significantly longer in the ictal as compared to the interictal phase. They suggested an altered excitatory/inhibitory equilibrium in migraineurs which wavered over the migraine cycle.