Intracranial pial arteriovenous fistula.

A 33-year-old woman presented with a rare intracranial pial arteriovenous fistula manifesting as monoparesis and hypesthesia of the right lower extremity. Computed tomography demonstrated an approximately 10-mm diameter subcortical hematoma in the left postcentral gyrus. Two months after suffering the ictus, angiography demonstrated a pial arteriovenous fistula in the late arterial phase fed by the left paracentral artery and drained into the left precentral vein. No nidus or dural arteriovenous fistula was detected. Left parietal craniotomy was performed and the pial arteriovenous fistula was extirpated by electrocoagulation. Intraoperative angiography demonstrated disappearance of the fistula. She experienced no postoperative neurological deterioration, but hypesthesia of the right leg persisted. Obliteration of the pial arteriovenous fistula was reconfirmed by postoperative angiography. She suffered no rebleeding episodes during the 36-month follow-up period. Pial arteriovenous fistula causing mild symptoms should be treated by flow disconnection because the direct arteriovenous shunt and attendant high blood flow usually results in huge venous varices. To determine whether direct surgery or endovascular treatment is appropriate, the position and shape of the lesion must be known.