Chirp stimulation: H-response short and dynamic.

BACKGROUND: Migraine patients have an increased photic-driving response. This 'H-response' (HR) has potential diagnostic value but it is time consuming. AIM: The aim of the study was to establish a fast and standardized test for the study of migraine biology and treatment.
METHODS: We studied 11 migraine patients and 11 matched control participants. We used stroboscope flashes with a 'chirp'-like linear frequency-increase from 10 to 40 Hz. EEG was recorded from occipital electrodes. Power spectral density was calculated for the stimulus response and corrected for baseline. An HR-estimator was calculated as the average power between 18 and 26 Hz in the stimulation-frequency window.
RESULTS: There was a significant difference for single (p < 0.05) and for 10 averaged recordings (p < 0.01) between migraineurs and controls, and a high inter-test reliability (Cronbach's alpha = 0.94).
CONCLUSION: Chirp-like stimulation to study the H-response is reliable and efficient and might therefore have a potential for acute interventional studies in migraine research. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.