The pattern--reversal visual evoked potentials in children with migraine with aura and without aura.

PURPOSE Studies of the visual evoked potentials (VEP) in migraine have yielded contradictory results. Several investigators suggested that VEP may be helpful test in diagnosis of a child with headache. The aim of our study was to compare interictal pattern-reversal visual evoked potentials (PR-VEP) in children and adolescents with migraine and tension-type headaches and to evaluate VEP parameters in migraine with and without aura. MATERIAL AND METHODS The study was carried out in 93 children and adolescents aged 7-18 years with attack headaches. RESULTS 51 children had diagnosed migraine. In this group 30 children (59%) had migraine without aura (MO), 12 children (23.5%) migraine with aura (MA) and 9 (17.5%) patients other variants of migraine (MV): hemiplegic, ophthalmoplegic, basilar. In control group 42 children were classified as tension-type headaches. All children had PR-VEP performed in headache-free period, without prophylactic treatment. The P100 mean latency was significantly longer in migraine than in tension-type headache. Amplitudes N1-P100 and P100-N2 were significantly larger in migraneurs compared with tension-type headache. The mean amplitudes of N1-P100 and P100-N2 were significantly lower in MA compared with group MO. There were no statistically significant differences of other PR-VEP parameters between MA, MO, MV. If we compare individual results of each patient with migraine with mean value +/- 2 standard deviations (SD) of tension-type headaches group, only 25% have VEP abnormalities of latency or amplitude above 2SD value in tension-type headache group. CONCLUSIONS The diagnosis of migraine in children actually remains predominantly based on medical history, due to low sensitivity and specificity of electrodiagnostic tests in headaches. However PR-VEP may support the diagnosis of migraine in some cases. VEP could be also helpful method in studying the pathogenesis of different forms of migraine. VEP abnormalities in migraine can be related to a cortical spreading depression and a central neurotransmitter alterations.