Simultaneous retinal and cortical visually evoked electrophysiological responses in between migraine attacks.
OBJECTIVE
People with migraine often report aversion to flickering lights and show abnormal results on behavioural tasks that require the processing of temporal visual information. Studies have reported that the cortically evoked electrophysiological response to a flickering visual stimulus is abnormal; however, none have considered whether there is an underlying pre-cortical abnormality. In this cross-sectional study, we consider whether people with migraine have retinal and cortical electrophysiological abnormalities to flickering stimuli.


METHODS
Monocular transient (1 Hz) and steady-state (8.3 Hz) pattern reversal electroretinograms (PERGs) and pattern visual evoked responses (PVERs) were measured simultaneously in 45 people with migraine (26 without aura, 19 with aura) and 30 non-headache controls at a time between migraine attacks.


RESULTS
PERG amplitude and timing did not differ significantly between groups. Transient PVER amplitude was significantly reduced (28%) in the migraine with aura group compared to the controls F(2,72) = 3.6, p = 0.03). Both migraine groups showed significant reductions (32%, 39%) in steady-state PVER amplitude relative to controls (F(2,70) = 4.3, p = 0.02).


CONCLUSIONS
This study finds normal retinal processing of flickering stimuli in the presence of abnormal cortical function between migraine attacks.
Department of Optometry and Vision Sciences, The University of Melbourne, Australia.
Bao N
BN
Nguyen
Allison M
AM
McKendrick
Algis J
AJ
Vingrys
D000328:Adult; D003430:Cross-Sectional Studies; D004596:Electroretinography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D006801:Humans; D008881:Migraine Disorders / Q000503:physiopathology*; D012160:Retina / Q000503:physiopathology*; D014793:Visual Cortex / Q000503:physiopathology*; D055815:Young Adult