Dural sinus thrombosis: a mechanism-based classification and review of 42 cases.

Cranial venous outflow obstruction due to dural sinus thrombosis may result in venous hypertension, cerebral infarction, cerebral haemorrhage or impaired cerebrospinal fluid (CSF) absorption with consequent pseudotumour syndrome. We propose a mechanism based classification of dural sinus thrombosis from these four outcomes. Forty two cases of dural sinus thrombosis presenting to Royal Prince Alfred Hospital between 1986-1997 were retrospectively reviewed. These cases were classified according to mechanism of presentation and relevance of this to site of thrombosis, treatment and prognosis. This study shows that the superior sagittal sinus and transverse sinus are the commonest sites of thrombosis, and multiple sites of thrombosis (69%) are more frequent than a single site. Magnetic resonance imaging (MRI) with venous flow studies is the investigation of first choice for diagnosis but angiography remains the gold standard. A pseudotumour syndrome is the commonest presentation (43%) followed by cerebral haemorrhage (31%). The overall prognosis for sinus thrombosis is good, with 71% of cases recovering to normal function.