Evaluation of cognitive function in migraine patients-a study using event-related potential

It is known that cognitive impairments can be observed in some patients with migraine. To clarify the neurophysiological mechanism of cognitive impairments in migraine patients, we evaluated the relationships between event-related potentials (ERPs) and various behavioral data such as performance, subtype, severity, duration, and usage of preventive medicine. Thirty one patients suffering from migraine without and with aura were enrolled in headache-free periods. Severity of the headache was assessed by headache impact test-6(HIT-6). Two tones counting auditory oddball paradigm was used for the ERPs. EEG was recorded from 20 channels on the scalp and recomputed global field power (GFP) from the all channel. We assessed counting performance and the P3 GFP peak amplitude and latency. Forty four percent of patients (n=15) were classified into the good performance group. There were no differences in age, usage of prophylactic drug, the presence or absence of aura, score of HIT-6, and P3 parameters between the good and poor performance groups. The group of long duration showed decreased P3 GFP peak amplitude and HIT-6 score. The group with preventive treatment significantly had more attacks of the month than the non-medication group. In addition, this group showed prolonged P3 GFP peak latency and decreased P3 GFP peak amplitude. These findings suggest that ERPs abnormalities may reflect abnormal information-processing for the attention preceding target recognition in migraine patients regarding with preventive treatment.