(a) Evidence in support of a link between blood-brain barrier failure and seizures in human subjects shows the rational for the use of serum S100β as a surrogate marker of BBBD. Extensive literature cited in this paper explains in further detail how this test is interpreted. The data presented herein refers to preliminary findings obtained in a cohort of subjects in the EEG monitoring unit. These subjects were continuously monitored for EEG changes suggestive of seizures. Serum samples were taken interictally, ictally, while another sample was taken postictally after approximately 3 hours. Note the increase of ictal S100β as indication of blood-brain barrier opening in these subjects. (b) Efficacy of glucocorticosteroids in a cohort of pediatric drug resistant epileptic subjects. The etiology of seizures that responded to steroids is shown in the pie chart in B1, while B2 shows the efficacy of anti-inflammatory treatment. (c) Note that discrete regions of the brain appear to have developed abnormal signal on contrast enhanced (Gd) or FLAIR sequences (see also [21]). Note that, in the MRI scans shown, the efficacy of steroids on seizures was paralleled by changes possibly associated with improved blood-brain barrier function ( patients).