Low interhemispheric and high intrahemispheric EEG coherence in migraine.

Twenty women with migraine were evaluated by EEG coherence analysis. In comparison with controls, the migrainous subjects showed lower interhemispheric coherence values at C3-C4 for the delta band (P=0.0030) and at F3-F4 (P=0.0055) and C3-C4 (P=0.0018) for the beta band frequency (Wilcoxon criterion). In contrast, 22 intrahemispheric coherence pairs were significantly higher in the migraine group than in the control group (P<0.01). The subjects with visual aura showed lower interhemispheric coherence at O1-O2 and T5-T6 for the alpha band than the subjects without the aura. Discriminant analysis revealed that 95% of the subjects with migraine and 85% of the controls were correctly classified into their proper groups. We suggest that EEG coherence analysis is a sensitive parameter in the detection of electrophysiological abnormalities in patients with migraine.