[Two surgically treated cases with dural arteriovenous malformation in the anterior cranial fossa]

Dural arteriovenous fistulae(dAVF) in the anterior cranial fossa comprise about 6% of all dAVFs, and is usually detected after intracranial hemorrhage. However, non-hemorrhagic symptoms are uncommon. We encountered two patients with hemorrhagic and non-hemorrhagic dAVF in the anterior cranial fossa. Both cases were successfully treated using craniotomy and histopathological examination was performed. A 71-year-old male experienced sudden onset of nausea and headache, followed by progression of left hemiparesis and disturbance of consciousness due to intracerebral and subdural hematoma in 2005. Intracerebral venous aneurysm adjacent to the intracerebral hematoma originated from the draining cortical red vein was identified and successfully treated by operation. Histopathological examination revealed disappearance of the internal elastic lamina and scant muscle tissue in the venous aneurysmal wall originating from draining cortical vein. A 69-year-old male suffered sudden onset of mild headache, followed by progression of bruits in 2005. MRI suggested dAVF in the left anterior cranial fossa. 123I-IMP SPECT revealed an area of low perfusion in the left frontotemporal region. Histopathological examination after surgical treatment revealed thickening of the intima and an indistinct lamina elastica interna, indicating progressive degenerative changes of the arterialized vein likely to result in hemorrhage. Surgical obliteration of fistulae is reasonable even in the dAVF of the anterior cranial fossa with ischemic onset.