{Reference Type}: Journal Article {Title}: Correlation between habituation of visual-evoked potentials and magnetophosphene thresholds in migraine: A case-control study. {Author}: Ambrosini A;Iezzi E;Perrotta A;Kisialiou A;Nardella A;Berardelli A;Pierelli F;Schoenen J; {Journal}: Cephalalgia {Volume}: 36 {Issue}: 3 {Year}: Mar 2016 {Factor}: 6.075 {DOI}: 10.1177/0333102415590241 {Abstract}: BACKGROUND: In migraine most studies report an interictal deficit of habituation of visual-evoked potentials (VEP-hab) and reduced thresholds for phosphene induction (PT) by transcranial magnetic stimulation (TMS). We searched for a possible correlation between VEP-hab and PT in migraine patients and healthy controls to test whether they reflect the same pathophysiological abnormality.
METHODS: We assessed PT and VEP-hab measured as the percentage change of N1/P1 amplitude over six blocks of 100 responses in 15 healthy volunteers (HV) and in 13 episodic migraineurs without aura (MO) between attacks. Results were compared using Mann-Whitney U test. Interrelationships were examined using Spearman's correlation.
RESULTS: In MO patients VEP-hab was reduced compared to HV (pā€‰=ā€‰0.001), while PT were not significantly different between HV and MO. There was no correlation between PT and VEP-hab in either group of participants.
CONCLUSIONS: We confirm that in interictal migraine VEP habituation is deficient, but magnetophosphene threshold normal. VEP-hab and PT were not correlated with each other in healthy controls or in migraineurs. This finding suggests that they index different facets of cortical excitability in migraine, i.e. a punctual normal measure of the cortical activation threshold for PT and a dynamic response pattern to repeated stimuli for VEP habituation.