Cocaine- and methamphetamine-induced acute cerebral vasospasm: an angiographic study in rabbits.

Stroke is a frequently reported, though uncommon, complication of drug abuse, primarily cocaine. The pathogenesis is uncertain, although such cerebrovascular events may result from sympathetically mediated vasoconstriction of cerebral vessels. Amphetamine, another sympathomimetic amine that is commonly abused, may also cause strokes by producing cerebral vasospasm and/or vasculitis. Amphetamine and its derivatives are frequent adulterants of illegally obtained cocaine and may also be used concurrently; the effect(s) of this combination of drugs upon the cerebral vasculature is not known. Our aim was to develop an animal model that would enable us to study the ability of these drugs to produce acute cerebral vasospasm and to observe the response to IV administration of amphetamine and cocaine, either alone or together. Magnified basilar artery arteriograms were obtained in 12 New Zealand white rabbits before and after IV administration of cocaine, methamphetamine, or both, at various dosages. Low doses produced mild vasodilatation. At higher doses, the animals who received cocaine and methamphetamine alone showed little or no basilar artery spasm, but coadministration produced definite basilar artery vasospasm, reflecting a synergistic vasoconstrictive effect. If a similar response exists in the human cerebral vasculature, then this could help explain the cause of strokes associated with drug abuse.

Osteogenesis imperfecta associated with basilar impression and cerebral atrophy: a case report.

Osteogenesis imperfecta is a disease of bone formation subdivided into two types, congenita and tarda. It is associated with bony fragility, blue sclerae and abnormality of tooth dentin. Rarely the tarda form is associated with basilar invagination or infolding of the foramen magnum and upper cervical segments into the posterior fossa. This results in hydrocephalus and a spectrum of neurologic dysfunction known as the foramen magnum compression syndrome. Many radiologic methods have been used to evaluate basilar invagination including plain film and CT. We describe a patient with osteogenesis imperfecta tarda examined with CT, with a unique finding of diffuse cerebral atrophy associated with basilar invagination.

CT guided lateral C1-C2 puncture.

A technique for CT guided intrathecal contrast material administration via lateral C1-C2 puncture is described as an efficient strategy for evaluation of patients with recent cervical spine injury and quadriplegia.

What is expected of CT in the evaluation of stroke?

This study was based on 5042 cranial CT examinations in a 2-year period. 19.8% of all cranial CT scans were performed for confirmation or evaluation of clinically suspected stroke. 87% of the clinical diagnoses of stroke were confirmed by CT scan. Intracranial hemorrhage made up a small percentage in this study. The establishment of this diagnosis was a valuable service in the patients' management. Brain tumor may rarely present clinical symptoms mimicking stroke and may have a normal CT initially.

Cerebral infarction: shortcomings of angiography in the evaluation of intracranial cerebrovascular disease in 25 cases.

We studied the utility and limitations of conventional cerebral angiography in 25 patients with cerebral infarction unassociated with extracranial cerebrovascular disease during a 7-year period. In only one-third of cases was the angiogram diagnostic, and in a single case it altered the pre-angiogram diagnosis by revealing a previously unsuspected embolus. Among the cases clinically diagnosed as cerebral emboli, the 2 confirmatory angiograms were performed early (within 48 hours), and demonstrated medium-large or large vessel filling defects. Two-thirds of the negative angiograms in the embolic clinical category were delayed, but there was no statistically relevant predilection for specific vessel size involvement. The category, primary cerebral vasculopathy, comprised the largest group, 10 in all, and one-half had angiographic confirmation despite time delays. Angiographic recognition was dependent on a characteristic picture of vascular involvement, and not on timing or vessel size predilection. Mitral valve prolapse figured prominently in the clinical cases of vasculopathy of uncertain etiology, which contained a total of 4 cases. The 3 cases with nondiagnostic angiograms were all delayed and demonstrated nonspecific radiographic changes. Clinically, these cases demonstrated signs or symptoms of autoimmune dysfunction, raising the specter of primary cerebral vasculopathy as a cause of cerebral infarction, in contrast to recurrent cerebral emboli.

Thallium-201 brain tumor imaging: a comparative study with pathologic correlation.

In patients with gliomas who were stable or improving, we noted a disparity between clinical status and computed tomography (CT) brain scan results. To elucidate this finding, 29 patients were sequentially scanned with 2.0 mCi of 201Tl (5-30 min), 20 mCi [99mTc]gluceptate (GH) (3-4 hr) and 7-10 mCi 67Ga (48-72 hr). A total of 198 images were obtained. A set of three scans at a midpoint in follow up was selected for analysis. Seven patients who died had neuropathologic data available; brain sections were reconstructed to match radionuclide views without knowledge of image results. In the seven patients with autopsy data, 201Tl offered the most accurate correlation with viable tumor. Gallium-67 gave similar results in patients not receiving steroids. Technetium-99m GH scans could not allow differentiation between tumor, necrosis, and edema. Similarly, the CT scan could not routinely differentiate between fibrotic, nonfibrotic, necrotic, and neoplastic tissue. In the 22 patients without autopsy data, 201Tl scans commonly showed smaller and more focal abnormal uptake when compared with [99mTc]GH and 67Ga scans. Thallium-201 scans more accurately reflect viable tumor burden than other radionuclide studies of primary brain tumors, are minimally affected by concomitant steroid administration, can be performed immediately following tracer administration, and complement the anatomic data obtained from CT scans.

Balloon occlusion of a recurrent carotid-cavernous fistula previously treated by carotid ligations.

A carotid-cavernous fistula recurred 16 years after a Hamby procedure. The recurrence was manifested by subarachnoid hemorrhage originating from dilated draining pial veins. The fistula was closed with a balloon catheter introduced through a patent remnant of the cervical carotid artery. Patients who have previously undergone Hamby trapping and embolization should be reassessed for an occult fistula that could predispose them to intracranial bleeding.

Ependymoma of filum terminale: metrizamide-enhanced CT evaluation.

Two cases of surgically proven myxopapillary ependymomas of filum terminale are reported. In both, myelography and metrizamide-enhanced computed tomographic (CT) scans were performed. An intramedullary tumor in the lower thoracic spine, soft-tissue masses in the neural foramina and enlarged bony spinal canal in the lower thoracic and upper lumbar spine were noted in one case and, in the other, an intradural extramedullary tumor at T12-L1 level. Both patients had normal cranial CT scans, and both presented with similar symptoms--low back pain and weakness and paresthesia of leg or legs for up to 3 years' duration. Myelography and metrizamide-enhanced CT scans were performed in order to evaluate disc disease in one patient and spinal stenosis in the other. Ependymoma was an incidental finding, which was then removed by surgical resection. Pathology confirmed the diagnosis.

Thoracic spinal metastasis from unexpected cerebellar medulloblastoma: the value of MRI.

A 28-year-old male was found on CT metrizamide myelography to have an intradural extramedullary tumor at the T8-T9 level. This was seen to compress the spinal cord, and on surgery it was proven to be medulloblastoma. Cranial CT scans disclosed only mild hydrocephalus and minimal anterior displacement of the inferior fourth ventricle on the right. However, magnetic resonance imaging (MRI) which was performed after the spinal surgery demonstrated an inferior cerebellar vermian tumor.

Septation and focal dilatation of ventricles associated with cryptococcal meningoencephalitis.

A 35-year-old woman developed temporal lobe seizures. Isolated dilatation of the right temporal horn was demonstrated by computed tomography. She was asymptomatic for the next 10 months while on anticonvulsants before severe headaches, vomiting, and mental confusion prompted hospitalization. Both temporal horns were now dilated, there was marked periventricular edema, and cryptococci were cultured from the ventricular fluid. She succumbed after prolonged systemic and intrathecal antifungal therapy, having developed isolation and dilatation of both frontal horns and third and fourth ventricles. Cryptococcal or other fungal meningoencephalitis should be considered in the differential diagnosis of isolated dilatations of the ventricular chambers as noted in the present case.

Lateral ventricular meningioma.

A 47-year-old woman presented with a 6-month history of progressive dizzy spells and occasional impairment of vision. Cranial computerized tomographic (CT) scan showed a calcified mass in the atrium of the left lateral ventricle, densely enhanced after intravenous administration of contrast material. Left carotid and vertebral angiograms demonstrated that the feeders of the tumor were coming from the left anterior choroidal and left lateral posterior choroidal arteries, both of which showed dilatation and neovascularity. The CT and angiographic findings led to successful removal of the tumor without impairment of the patient's vision. The pathological diagnosis was meningioma.

Prolactinomas. Clinical presentation, radiologic assessment, and therapeutic options.

Of the pituitary tumors, the prolactinoma is the most common, characteristically causing amenorrhea/galactorrhea in women and symptoms secondary to mass effect in men. Direct coronal CT scanning with rapid infusion contrast enhancement is now considered the most sensitive and specific method for evaluating the pituitary. Normally the gland is either homogeneous or heterogeneous in a repetitive fashion, and measures up to 9-10 mm in height. Adenomas typically are hypodense lesions in the anterior lobe associated with mass effect--superior surface convexity, gland enlargement, bony erosion, infundibulum displacement, or vascular "tuft" shift. High field superconductive MRI is thought to be superior to CT for evaluation of macroadenomas and may soon surpass CT in the evaluation of microadenomas. Treatment remains controversial. Perhaps surgery is the best alternative for women 15 to 30 years of age with microadenomas producing prolactin less than 100 ng/ml. Patients who are either beyond the child-bearing years, present with tumors greater than 10 mm in diameter, or have microadenomas producing prolactin greater than 100 ng/ml may be better served by medical therapy using bromocriptine or pergolide mesylate.

Direct sagittal computed tomography of the temporal bone.

A technique of obtaining direct sagittal (lateral) CT images of the temporal bone is described, and the normal sagittal CT landmarks are illustrated. Using this technique, structures seen to advantage by lateral polytomography may now be imaged by CT. The ability to scan the temporal bone in the sagittal plane should be a useful adjunct to coronal and axial images.

Computed tomography of aneurysmal bone cyst of the L1 vertebral body.

A 31-year-old woman with an aneurysmal bone cyst of the L1 vertebral body proved by biopsy and studied by plain lumbar spine roentgenography, radionuclide studies, myelography, and CT is presented. The unusual location of involvement of the vertebral body alone and the difficulty in differential diagnosis between aneurysmal bone cyst and benign giant cell tumor are discussed.

Posterior fossa ependymal cyst and atlantoaxial subluxation in a patient with Down syndrome: CT findings.

A 61-year-old woman with Down syndrome presented with progressive deterioration of gait over 9 months. Cranial CT without and with intravenous administration of contrast material demonstrated a posterior fossa cyst. The cyst did not communicate with the fourth ventricle or subarachnoid spaces as proven by CT following a metrizamide ventriculogram. Surgical fenestration of the cyst into the fourth ventricle was done. In addition, a moderate atlantoaxial subluxation with 2 mm movement from extension to flexion was present, which was thought not to be clinically significant, but which might require a spinal fusion at a future time. Ependymal cells were found as a result of a biopsy of the cyst wall.

Spinal cord or nerve root compression in patients with malignant disease: CT evaluation.

Fifty patients with malignant disease were seen on an emergency basis because they showed clinical signs of spinal cord or nerve root compression. All were studied with high resolution computed tomography (CT) of the spine; in addition, myelography was performed on 10 of the patients. We found that 48 cases (96%) could be accurately diagnosed by CT alone. In two cases (4%) CT was inconclusive, but myelography was diagnostic; one proved to be cerebrospinal fluid seeding with nerve root involvement, and the other showed conus medullaris involvement. In the remaining eight cases studied by both techniques, correlation between CT and myelography was very good.

Cervical chordoma presenting with intervertebral foramen enlargement mimicking neurofibroma: CT findings.

A cervical chordoma, confirmed at surgery, presented on plain spine films as a focal enlargement of the intervertebral foramen and mimicked the characteristic appearance of cervical neurofibroma. Computed tomography (CT) of the cervical spine was obtained immediately following metrizamide myelography; it demonstrated a soft-tissue mass in the enlarged intervertebral foramen that extended posteriorly to compress the spinal cord and anteriorly to compress the hypopharynx. The mass was sharply demarcated, inhomogeneous, and low in attenuation; CT density measured between those of cerebrospinal fluid and muscle. Although this CT appearance is not specific for cervical chordoma, it is unusual for neurofibroma. Cervical chordoma should be considered in the differential diagnosis of focal enlargement of cervical intervertebral foramina.