Prognosis of cerebral vein and dural sinus thrombosis: results of the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT) - Ferro, J M; Canhão, P; Stam, J; Bousser, M G; Barinagarrementeria, F; ISCVT Investigators (Stroke, 2004)