Eight patients with dural arteriovenous malformations (AVM's) of the anterior cranial fossa are presented, and the pertinent literature is reviewed. Unlike cases of dural AVM's in other locations, sudden massive intracerebral hemorrhage was the most frequent reason for presentation. Other symptoms included tinnitus, retro-orbital headache, and a generalized seizure. The malformations were supplied consistently by the anterior ethmoidal artery, usually in combination with other less prominent feeding vessels. The lesion's venous drainage was through the superior sagittal sinus via a cortical vein; in addition, in two cases a subfrontal vein drained the AVM. A venous aneurysm was encountered near the site of anastomosis with the dural feeder in most cases, and was found in all patients who presented with hemorrhage. The AVM was obliterated surgically in six patients, with favorable results achieved in five. One patient died postoperatively from a pulmonary complication. Because of their anatomy and proclivity for hemorrhage, these vascular malformations represent a unique group of dural AVM's. Surgical management of anterior fossa dural AVM's carries low morbidity, and is indicated when the lesions have caused hemorrhage or when there is an associated venous aneurysm.

The anatomy of the carotid artery at the level of the anterior clinoid process was studied in autopsy specimens and at surgery. Marking clips placed at surgery were used to correlate anatomical and angiographic findings. Removal of the anterior clinoid process permits visualization of approximately 6 mm more of the proximal internal carotid artery without entering the cavernous sinus. The exposure reaches just to the hairpin bend of the carotid siphon, but the bend is not seen. The curve in the carotid artery which is observed after anterior clinoid removal is distal to the hairpin turn and corresponds to a bend seen on the anteroposterior projection of the angiogram. Temporary occlusion of the carotid artery proximal to a paraclinoid aneurysm is possible after clinoid removal. Complications of the removal include trauma to the third nerve and cerebrospinal fluid rhinorrhea.

A retrospective analysis of an unselected and sequential series of 433 patients with unilateral VSs was conducted. Tumor size was defined by the largest dimension of the tumor in the cerebellopontine angle, and the size was tested for a relationship with patient age and sex. In a subgroup of 231 patients in whom data were available, tumor size was also tested for a relationship with tumor cysts or the absence of an internal auditory canal (IAC) component. Some patients underwent a period of surveillance with serial imaging studies to monitor for tumor growth. Data from these patients, excluding those with cystic tumors, were analyzed to see if tumor growth was related to patient age, sex, or tumor size. CONCLUSIONS; Larger tumors were found in younger patients, in females, in the subgroup of cystic tumors, and in patients in whom there was no tumor component in the IAC. The probable explanations for these larger tumors are a faster growth rate and/or a delay in symptom onset. When untreated tumors are managed with observation, measurable growth is more often seen in larger tumors, although smaller tumors have a faster relative growth rate than larger ones.

A case of a large intraventricular meningioma of the trigone is described. The tumor was removed by the transcallosal route. The neuropsychological sequelae of this approach are discussed. The value of other surgical approaches for meningiomas of the trigone is reviewed. The transcallosal approach originally described by Kempe and Blaylock is highly recommended.

The angiographic and anatomical features of an anomalous communication between the intradural internal carotid artery and the anterior cerebral artery are described. Essential features of the anastomosis include an origin at, or close to, the origin of the ophthalmic artery, a course ventral to the ipsilateral optic nerve and anterior to the optic chiasm, and a termination near the anterior communicating artery. Although rare, the condition should be considered as an entity. The incidence of associated berry aneurysm and other congenital vascular anomalies is high.