Timely event-related synchronization fading and phase de-locking and their defects in migraine.

Objective: To investigate the characteristics of event-related synchronization (ERS) fading and phase de-locking of alpha waves during passive auditory stimulation (PAS) in the migraine patients.

Methods: The subjects were 16 adult women with migraine and 16 normal controls. Electroencephalographic (EEG) data obtained during PAS with standard (SS) and deviant stimuli (DS) were used. Alpha ERS fading, the phase locking index (PLI) and de-locking index (DLI) were evaluated from the 10 Hz complex Morlet wavelet components at 100 ms (t100) and 300 ms (t300) after PAS.

Results: At t100, significant ERS was found with SS and DS in the migraineurs and controls (P=0.000). At t300 in the controls, ERS faded to zero for DS while in the migraineurs there was no fading for DS. In both groups the PLI for SS and DS was significantly reduced, i.e. de-locked, at t300 compared to t100 (P=0.000). In the migraineurs, the DLI for DS was significantly lower than in the controls (P=0.003).

Conclusion: The alpha ERS fading and phase de-locking are defective in migraineurs during passive auditory cognitive processing.

Significance: The defects in timely alpha ERS fading and in de-locking may play a role in the different attention processing in migraine patients.