Abnormal effective connectivity in migraine with aura under photic stimulation

Migraine patients with aura show a peculiar pattern of visual reactivity compared with those of migraine patients without aura and healthy subjects: an increased effective connectivity, connected to a reduced synchronization among EEG channels, for frequencies in the beta band. The effective connectivity is evaluated in terms of the Granger causality. This anomalous response to visual stimuli may play a crucial role in the progression of spreading depression and clinical evidences of aura symptoms.