Three of 4 cases of dural arteriovenous fistulas (DAVFs) in the anterior cranial fossa were detected incidentally by magnetic resonance (MR) imaging, and one case manifested as intracerebral hemorrhage. Cerebral angiography revealed fistulas located in the anterior cranial fossa. Three patients underwent surgery, and the fistulas were successfully obliterated. One patient with nonruptured DAVF requested conservative medical management. Incidental detection of asymptomatic or nonruptured DAVFs in the anterior cranial fossa has increased with the wider use of MR imaging. Increase in the size of a venous varix is the indicator for aggressive therapeutic intervention in a patient receiving conservative medical management for asymptomatic or nonruptured DAVFs in the anterior cranial fossa.

A 66-year-old female with a 3-year history of left trigeminal neuralgia presented with an unusual left cerebellopontine angle meningioma associated with asymptomatic syringomyelia at the C2 to C4 levels diagnosed by magnetic resonance (MR) imaging. Two months after total tumor removal, the syrin gomyelia had diminished without shunting. MR images are useful as a basis for early diagnosis of syringomyelia.

Background and Purpose Pyramidal tract Wallerian degeneration has been detected on magnetic resonance imaging (MRI) as T 2 -weighted high-intensity areas. We analyzed the relation between the extent of brain stem Wallerian degeneration and activities of daily living (ADL) after supratentorial hemorrhagic stroke.Methods Twenty-six patients with supratentorial hemorrhage were examined on the coronal T 2 -weighted image of the pons 3 months or later after stroke, and the percentage of Wallerian degeneration in the pons was calculated. The patients were divided into three groups. In group A (n=6), MR films were taken 3 to 6 months from the onset, and the ADL assessment was done within 2 months from the MRI. In group B (n=ll), MR films were taken 3 to 6 months from the onset, and the ADL assessment was done within 10 months from the MRI (mean, 15.5 months from the onset). In group C (n=9), MR films were taken after 10 to 17 months (mean, 12.0 months) from the ictus, and the ADL assessment was done

A 60-year-old man presented with a left frontal mass lesion incidentally detected at a health check without apparent symptoms. Computed tomography revealed the lesion as homogeneous high density and magnetic resonance (MR) imaging showed the lesion as hyperintense on T 1 -weighted images, isointense on T 2 -weighted images, and hypointense on diffusion-weighted images. T 1 -weighted MR images with gadolinium showed no enhancement of the mass lesion. Cerebral angiography revealed an avascular area around the left frontal lesion. Total removal of the lesion was achieved through a craniotomy without complications. Histological, immunohistochemical, and electron microscopy examinations established the definite diagnosis of colloid cyst.

Failed coil embolization of cerebral aneurysms may be occasionally followed by direct surgical treatment. We had 5 patients who underwent coil retrieval and surgical clipping after coil embolization because of periprocedural complications. The patients, ranging in age from 40 to 71, had wide-neck aneurysms located at the anterior communicating artery (AcomA) in 3 patients, the middle cerebral artery (MCA) in 1, and the internal carotid-ophthalmic artery (IC-Ophthalmic) in 1. They were embolized with Guglielmi detachable coils (GDCs), which had to be retrieved within 8 days because of coil protrusion and migration in 3 patients, aneurysm rupture in 1, and increased mass effect due to coil compaction in 1. Coils were successfully removed with aneurysmotomy or arteriotomy under temporary trapping, aneurysms were then clipped or trapped. Three patients had a good outcome, but one suffered permanent visual disturbance and the other had a motor deficit. Our study revealed that a small AcomA aneurysm had a high risk of complication in a case of complex anatomy of the AcomA-A1-A2 complex with its difficult access. In addition, insufficient packing of the inflow zone in a large and symptomatic aneurysm may cause coil compaction and regrow with increasing mass effect. The indication and treatment strategy for these aneurysms should be carefully determined.

No abstract

Leukemic intracranial space occupying lesions are rare. A 69 year old man with acute myelogenous leukemia was found to have an intracranial leukemic mass at the time of his remission period. Computed tomography and magnetic resonance imaging study demonstrated a large irregular mass in the right temporal lobe. After total removal of the tumor, the patient was treated with whole brain irradiation and intrathecal chemotherapy. After surviving for 7 months, the patient expired of hematologic relapse.

Recurrent hemorrhaging from intrathrombotic vascular channels caused dissection between the thrombus and the aneurysm wall, which led to growth of the experimental aneurysms to giant aneurysms. With this model, we demonstrated the growth mechanism of giant fusiform aneurysms.