Intensity dependence of auditory evoked cortical potentials in migraine families

Intensity dependence of auditory evoked cortical potentials is abnormal in migraine. This study investigated intensity dependence in migraine and heal thy families using group comparisons and analysis of individual differences . Migraineurs were characterized by a steeper amplitude/stimulus function s lope and more pronounced difference between the amplitudes of N1-P2 on the more and the less intensive tones than healthy age matched subjects. Apart from migraine, the age of the participants was an important predictive vari able of intensity dependence. Analysis of individual differences revealed l ow sensitivity and moderate specificity of intensity dependence for migrain e. Familial prevalence of intensity dependence among first-degree relatives in migraine families was equal to that in healthy families. These findings support the assumption that high-intensity dependence reflects a functiona l CNS trait which is more pronounced and prevalent in migraine, but may als o be found in healthy individuals and in other neuropsychiatric disorders. Increased intensity dependence is only one of several factors contributing to the risk for this form of headache. (C) 2000 International Association f or the Study of Pain. Published by Elsevier Science B.V. All rights reserve d.