PATHOLOGICAL EFFECTS Cerebral vessels The bacteria invade the adventitia directly in the early stage and initiate the process of acute vasculitis Progressive destruction of adventitia disruption of elastic fibers, and finally intimal destruction(endarteritis). lead to the obliterative vasculitis, which may facilitate the ischemia, encephalomalacia and necrosis of parenchyma8 PATHOLOGICAL EFFECTS Cerebral Vessels ◆The bacteria invade the adventitia directly in the early stage and initiate the process of acute vasculitis. ◆Progressive destruction of adventitia, disruption of elastic fibers, and finally intimal destruction (endoarteritis), lead to the obliterative vasculitis, which may facilitate the ischemia, encephalomalacia and necrosis of parenchyma