What kind of habituation is impaired in migraine patients?

The acoustically evoked cortical potentials of 20 migraine patients were investigated using a combined conditioning-testing and oddball paradigm. The short- and long-term habituation results of the P50 and P300 waves were compared with 16 healthy subjects. Migraineurs were characterized by a sensory gating deficit of the P50 wave (reduced short-term habituation) in the non-target condition and a reduced long-term habituation of the P300 wave in the target condition. The study describes disturbances of information processing on the automatic and cognitive levels in migraine patients and emphasizes the role of sensory gating and orienting response in migraine pathogenesis.