S-100 PROTEIN - SERUM MARKER OF FOCAL BRAIN-DAMAGE AFTER ISCHEMIC TERRITORIAL MCA INFARCTION

Background and Purpose Elevations of protein S-100 (S-100) in cerebros pinal fluid and serum have been reported after cerebral infarctions. T he aim of our study was to evaluate the time course of serum S-100 con centrations after territorial middle cerebral artery (MCA) infarctions in correlation with clinical data and prognosis. Methods S-100 serum levels were serially determined in 26 patients with an acute infarctio n in the territory of the MCA at day 0 (within 12 hours after onset of symptoms), day 1 (24 hours after stroke onset), and days 2, 3, 4, 5, 7 or 8, and 10 after stroke and in 26 age- and sex-matched control sub jects. S-100 assays were performed using a two-site radioimmunoassay t echnique. The clinical status was documented using the Scandinavian St roke Scale. The functional deficit 4 weeks after stroke onset was scor ed by use of the modified Rankin scale. A cranial computed tomography (CCT) was performed initially and at day 4 or 5. Results Elevated conc entrations of S-100 (>0.2 mu g/L) were observed in 21 of 26 patients w ith MCA infarction but in none of the control subjects. S-100 levels p eaked at days 2 and 3 after stroke. The S-100 concentrations in serum were significantly higher in patients with severe neurological deficit s at admission, with extensive infarctions and a space-occupying effec t of ischemic edema as compared with the rest of the population. S-100 values were not significantly correlated with the functional prognosi s. Conclusions Presence of S-100 in serum after ischemic stroke may be due to combined leakage out of necrotic glial cells and passage throu gh an impaired brain-blood barrier, indicating severe ischemic cell in jury. Therefore, S-100 in serum can be used as a peripheral marker of ischemic focal brain damage and may be helpful for therapeutic decisio ns in acute ischemic stroke.