[An unusual case of superior sagittal sinus thrombosis accompanied with dural AV fistula]

Benign intracranial hypertension or pseudotumor cerebri is an collective term for a number of diverse syndromes characterized by increased intracranial pressure. Neither intracranial mass nor ventricular dilatation is observed in this disorder. Moreover, the pathogenesis of this syndrome has yet to be determined. We report a case of 36-year-old female diagnosed as benign intracranial hypertension, who has developed superior sagittal sinus thrombosis and dural AV fistula during the follow up period. The patient was pointed out to have papilledema and elevated intracranial pressure six years ago. Although she was examined by both DSA and CT scan, no abnormal intracranial lesions were observed. Consequently, she was diagnosed as the benign intracranial hypertension and had been followed as an out patient. Three years later, lumboperitoneal shunting was performed because of severe headache and visual impairment. Postoperatively, the patient had been well for two years. Recently, occipital headache recurred and she was readmitted to our hospital. MRI studies demonstrated dilated vessels in the right occipital area. Additionally, angiograms revealed not only the superior sagittal sinus thrombosis but also the rich network of dural AV fistula adjacent to the occlusion. According to those results, the superior sagittal sinus was supposed to have the incomplete occlusion or delayed blood flow that were not observed by DSA, MRI and CT scan performed previously. Those occlusive change in the superior sagittal sinus impeded the CSF absorption and elevated the pressure of venous inflow, then the arterio-venous communication has been developed.(ABSTRACT TRUNCATED AT 250 WORDS)