[A case of venous dural sinus thrombosis presenting dementia syndrome. An autopsy case].

We report clinical and pathological features of a case of dementia syndrome due to dural sinus thrombosis. In three years before admission, the patient, a 64-year old man, had had four convulsive attacks; scattered calcification shadows were disclosed by plain CT. Ten months before the admission, he complained of progressive memory disturbance and dyscalculia. General physical examination showed no remarkable abnormalities except for bruit at the left mastoid process. Although his time orientation was poor, he was otherwise fully awake. Neurologically, memory disturbance, finger agnosia, and dyscalculia were observed. Right Barré's sign, and exaggerated right patellar tendon reflex were observed. Plain X-ray CT revealed calcification-like, scattered high-density areas in the floor of the cerebral cortical sulci. Enhanced CT showed abnormal vessel high-density areas in both the cerebrum and brainstem. Cerebral angiography showed thrombosis of bilateral transverse sinuses, arterio-venous fistula in the left transverse sinus, and remarkably dilated cortical veins over both cerebral hemispheres. Positron emission tomography revealed misery perfusion areas in bilateral cerebral hemispheres. We presume that the mass effect of venous engorgement and chronic ischemia due to the arterio-venous fistula caused the dementia syndrome. These clinical manifestations were improved by amantadine and the patient was discharged. During follow-up, he died of subarachnoid hemorrhage, and an autopsy was performed. Pathological findings were as follows: 1) cortical and subcortical multiple-infarction in the cerebrum, 2) hematoma in the subarachnoid space, 3) venous dilatation of the cortical veins and pseudocalcification of their walls, and 4) thrombus in the transverse dural sinus.