[A case with an isolated cortical vein thrombosis].

A 45-year-old man was admitted to our hospital because of generalized seizure. He had epilepsy and mental retardation since age of two. On admission temperature was 37.9 degrees C but, nuchal rigidity and Kernig's sign were not present. There were no other abnormal findings on physical examination. Neurological examination revealed consciousness disturbance, generalized seizure and mental retardation. Right hemiparesis gradually developed after generalized seizure. Laboratory data did not show any abnormalites to induce cerebral venous thrombosis. A brain MRI revealed hyperintensity on T2-weighted images and slightly enhanced on T1-weighted images in the left frontal lobe, using Gd-DTPA. An increased signal was also noted in the superior sagittal sinus on T1-weighted images. The superior sagittal sinus was patent but the cortical vein in the left frontal lobe was not demonstrated on cerebral angiography. A diagnosis of an isolated cortical vein thrombosis was made by exploratory craniotomy. Anticoagulation with heparin was started. Although the cortical vein thrombosis usually co-exsists with dural sinus thrombosis, an isolated cortical vein thrombosis like this case was rather rare. A case with cerebral venous thrombosis localized only in the left frontal cortical vein is reported, but definitive etiology is not known.