Positron emission tomography in three children with pleomorphic xanthoastrocytoma.

The pleomorphic xanthoastrocytoma is generally considered a low-grade neoplasm with favorable prognosis. These tumors, however, can demonstrate primary anaplastic features, undergo malignant transformation, disseminate, or progress with poor outcome. Currently, there are no histologic or clinical features that reliably predict recurrent tumor or tumor progression.

Positron emission tomography using [18F] fluorodeoxyglucose and [11C] l-methionine to metabolically characterize dysembryoplastic neuroepithelial tumors.

Dysembryoplastic neuroepithelial tumors are unique and benign congenital tumors occurring frequently in children and adolescents. Differentiation from other low-grade tumors is important for management. Five patients with confirmed dysembryoplastic neuroepithelial tumors were studied with positron emission tomography using glucose and protein metabolic uptake in an attempt to categorize these tumors metabolically.

Positron emission tomography in children with neurofibromatosis-1.

Neurofibromatosis-1 is an autosomal dominant genetic disorder commonly associated with neuropsychological complications. Focal areas of high signal intensity on magnetic resonance imaging (MRI) scans occur commonly but have shown inconsistent correlation with neuropsychological problems. Positron emission tomography (PET) scans utilizing [18F]fluoro-2-deoxy-D-glucose and MRI studies were performed on 10 children with neurofibromatosis-1 and multiple focal areas of high signal intensity to evaluate the regional cerebral metabolic rate for glucose of these lesions and other central nervous system structures.

Chronic cerebral vasospasm: effect of calcium antagonists.

The efficacy of the calcium antagonists nifedipine and nimodipine was evaluated in a multiinjection canine model of severe chronic cerebral vasospasm. Each of 21 adult mongrel dogs (15 to 20 kg) was assigned to one of four experimental groups. All animals received a total of 15 ml of fresh, unheparinized arterial blood via three cisterna magna injections.

Chronic cerebral vasospasm: effect of volume and timing of hemorrhage in a canine model.

The effect of altering the volume and timing of hemorrhage on the severity of spasm was studied in a canine model. All animals received three cisterna magna injections of fresh unheparinized autologous arterial blood. Selective left vertebral arteriograms were obtained during the week before and exactly 7 days after the initial subarachnoid injection.

Magnetic resonance imaging of the orbit: a preliminary experience.

Eleven patients with various space-occupying lesions in the orbit were examined, using a 0.3-tesla superconducting magnet to assess the capabilities and limitations of magnetic resonance (MR) imaging in the investigation of orbital lesions. Although the images provided valuable anatomic data, the bright signal intensity of fat and the partial volume effects of large section thickness resulted in loss of resolution for small, low-signal-intensity structures.

Magnetic resonance imaging in the evaluation of the brainstem.

Magnetic resonance (MR) images of the brainstem region from 100 normal or asymptomatic individuals were reviewed in addition to those of 17 patients with intra-axial brainstem lesions and 15 patients with extra-axial masses around the brainstem. MR was able to demonstrate consistently the normal anatomy of the brainstem and adjacent cisterns, though the distinction between gray and white matter was seldom possible with the present technology. Masses in and around the brainstem were all accurately identified on MR and its sensitivity was superior to that of x-ray computed tomography (CT).

Head trauma evaluated by magnetic resonance and computed tomography: a comparison.

Magnetic resonance (MR) images and computed tomograms of 25 patients with head trauma were compared. MR proved to be superior in many ways for demonstrating extracerebral as well as intracerebral traumatic lesions. Isodense subdural hematomas, which present a diagnostic dilemma on CT images were clearly seen on MR, regardless of their varying CT densities.

NMR imaging of the spine.

The usefulness of nuclear magnetic resonance (NMR) images in the evaluation of spinal disorders below the craniocervical junction was studied. Six normal subjects and 41 patients with various spinal abnormalities were examined. NMR proved capable of demonstrating important normal and pathologic anatomic structures; it was useful in the evaluation of syringohydromyelia and cystic spinal cord tumors, and the bright signal intensity of lipoma was quite impressive.

Intracarotid chemotherapy of glioblastoma after induced blood-brain barrier disruption.

Intracarotid chemotherapy has been suggested as an additional mode of therapy in patients with brain tumors. Seven comatose patients received intracarotid 5-fluorouracil and adriamycin after intracarotid infusion of 25% mannitol to open the blood-brain barrier at the tumor site. Five of seven patients became fully functional for 3-12 months.

Acute fulminant toxoplasma meningoencephalitis in a homosexual man.

A homosexual man with a history of sexually transmitted infections including recent giardiasis and high cytomegalovirus (CMV) titer was admitted with generalized weakness, headache, and depression. He rapidly became comatose and developed signs of increased intracranial pressure. CT scan revealed a right cerebral lesion.

Cerebral revascularization during barbiturate coma in primates and humans.

Extracranial-intracranial arterial bypass was performed in five baboons to assess the effectiveness of the procedure in preventing acute cerebral ischemia following middle cerebral artery occlusion in our primate model. Thirty minutes following middle cerebral artery occlusion, the animals were placed in barbiturate coma while the extracranial-intracranial artery bypass was being completed. In the three animals with patent extracranial-intracranial arterial bypasses, infarction was prevented.

Megalocephaly and hypodense extracerebral fluid collections.

Computed tomographic (CT) scans were identified and reviewed for 25 pediatric patients with enlarged heads and extracerebral fluid collections that showed cerebrospinal fluid-like attenuation. Mild to moderate enlargement of the subarachnoid space over the convexity, interhemispheric fissure, and the lateral ventricles was observed in most of the cases. The CT findings are not specific, and it is not always possible to determine the nature of the extracerebral fluid, whether it lies in the subarachnoid space, the subdural space, or both.

The radiographic anatomy of surgical extracranial-intracranial anastomoses.

Microvascular surgical techniques have been developed that allow anastomosis between extracranial arteries and cortical branches of intracranial arteries distal to a stenotic, occluded, or diseased arterial segment. Indications for this procedure other than cerebrovascular occlusive disease are discussed. The radiographic anatomy of the various surgical bypasses is described.

Spontaneous opening of large occipital-vertebral artery anastomosis during embolization. Case report.

A patient undergoing external carotid artery therapeutic embolization for obliteration of a dural arteriovenous malformation suddenly developed a large occipital artery to vertebral artery shunt. A devastating stroke was averted because the appearance of the shunt was observed by fluoroscopy, the embolization was stopped, and the shunt verified on a subsequent angiogram. The risk of external carotid artery embolization without constant fluoroscopic control is emphasized.

Angiographic and computed tomographic correlation in cerebral venous angiomas.

Venous angioma of the brain is a rare congenital vascular anomaly. In the last few years there have been several reports on the angiographic appearance of this lesion, but very little has been written about the findings on computed tomography (CT). Angiographically, the arterial phase is normal, while the capillary phase might demonstrate a blush.

Temporal sequencing of verbal and nonverbal materials: the effect of laterality of lesion.

The effect of laterality of cerebral lesion on sequencing ability, which is an ability to process two or more stimulus events with respect to the order in which they occur, was examined. Patients with either left or right hemisphere lesions performed on verbal and nonverbal sequencing tasks. Left hemisphere lesioned patients were inferior to the right hemisphere lesioned patients on verbal sequencing tasks, while the right hemisphere lesioned patients were inferior to the left hemisphere lesioned patients on nonverbal sequencing tasks.

Congenital arteriovenous malformation of the head and neck.

A discussion of congenital arteriovenous malformation of the head and neck based on five patients followed from three to twenty years is presented. Definition of the lesion and its progression as followed by angiography is described. The poor response to surgery is ascribed to the ischemic nature of the area of involvement.

Proptosis secondary to pneumocele of the maxillary sinus.

The third known case of a pneumocele of the maxillary sinus is reported. Radiographic findings included hyperlucency of a maxillary sinus with generalized expansion of its borders. Bone dehiscence was also visible with tomography.