Is migraine explained by Leao's spreading depression?

Spreading depression (SD) is a severe but transient disruption of neural activity in the brain, which spreads like waves in a pond in which a stone has been cast. It propagates to normal tissues and is accompanied by flux of Na+, Ca++, and Cl- ions into the cells, resulting in a brief burst of action potentials followed by electrical silence. Its rate of spread correlates almost exactly with the observed spread of the aura of classical migraine. It is accompanied in animal experiments by changes in regional cerebral blood flow which closely simulate changes observed in man during the migraine aura. There are serious difficulties in extrapolating from SD in animals to migraine in man, but the possibility of SD as the initiating event accords with the notion of migraine as a cerebral (neural) disorder and encourages further investigation in man.