Supplementary Material for: Measurement of GFAP in Nasal Exudate in the Differential Diagnosis between Ischemic Stroke and Intracerebral Hemorrhage

<b><i>Background:</i></b> Differential diagnosis between ischemic stroke (IS) and intracerebral hemorrhage (ICH) is a great challenge. Recently, the discovery of cerebral lymphatic drainage toward the nostrils suggested nasal exudate (NE) as a new source for measuring biomarkers from neural damage. <b><i>Objectives:</i></b> In this study, we sought to confirm whether glial fibrillary acidic protein (GFAP) levels in NE could identify ICH. <b><i>Methods:</i></b> GFAP in nasal exudate (nGFAP) was studied in 5 IS and 5 ICH patients. All patients underwent neurological examination, brain computed tomography, laboratory tests, and measurement of nGFAP and serum GFAP. <b><i>Results:</i></b> We found higher concentrations in ICH patients (<i>p</i> = 0.02). The area under the ROC curve for IS/ICH discrimination was 0.840, with a cut-off point of 0.06 pg/mg for 100% sensitivity and 80% specificity. <b><i>Conclusions:</i></b> These findings suggest that nGFAP could be a useful biomarker for differential diagnosis between IS and ICH and opens a potential field of study for other biomarkers in NE in neurological disorders.