26 patients with an acute infarction in the territory of the MCA at day 0 (within 12 h after onset of symptoms), day 1 (24 h after stroke onset), and days 2, 3, 4, 5, 7 or 8, and 10 after stroke.S100b correlates with the severity of post-traumatic neurological deficit as well as with the infarct volume after stroke. The gene discussed is S100B; the disease is stroke disorder.