%0 Journal Article
%T Correlation between habituation of visual-evoked potentials and magnetophosphene thresholds in migraine: A case-control study.
%A Ambrosini A
%A Iezzi E
%A Perrotta A
%A Kisialiou A
%A Nardella A
%A Berardelli A
%A Pierelli F
%A Schoenen J
%J Cephalalgia
%V 36
%N 3
%D Mar 2016
%M 26054364
%F 6.075
%R 10.1177/0333102415590241
%X <B>BACKGROUND: </B>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.<BR><B>METHODS: </B>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.<BR><B>RESULTS: </B>In MO patients VEP-hab was reduced compared to HV (p = 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.<BR><B>CONCLUSIONS: </B>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.