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Biomedical subjects

J M Provenzale

Publications and source records attributed to J M Provenzale.

At least 73 records · Page 4Linked to original sources
PubMed1998

Dural sinus thrombosis associated with activated protein C resistance: MR imaging findings and proband identification.

OBJECTIVE: The purpose of this study was to report the association of dural sinus thrombosis with a hypercoagulable state associated with activated protein C resistance. CONCLUSION: In our small study population, hemorrhagic venous infarction was common (three of four patients) among patients with dural sinus thrombosis and activated protein C resistance. Four of five patients with dural sinus thrombosis had positive tests for activated protein C resistance. This finding, in conjunction with data from other studies, suggests that patients with dural sinus thrombosis may need to be studied for the presence of activated protein C resistance. A positive finding for activated protein C resistance can be important not only in helping to explain the cause of thrombosis in affected individuals but also in identifying families at risk for thrombosis.

Adult↗
PubMed1998

Antiphospholipid antibodies: findings at arteriography.

PURPOSE: The purpose of this study was to determine the frequency and types of abnormalities at arteriography in patients with antiphospholipid antibodies (APA) and ischemic cerebrovascular events. METHODS: Twenty-three patients with APA and ischemic cerebrovascular events who underwent arteriography were identified. Patients over the age of 65 years were excluded. No patients met diagnostic criteria for systemic lupus erythematosus. All angiograms were reviewed by two neuroradiologists. RESULTS: Seventeen patients (74%) between the ages of 28 and 64 years (average age, 40 years) had abnormal angiograms. Sixteen patients had arterial abnormalities and one had dural sinus thrombosis. Ten had solely intracranial abnormalities (nine arterial and one venous), six had solely extracranial arterial abnormalities, and one had both intracranial and extracranial arterial abnormalities. Intracranial arterial abnormalities included stem or branch occlusions of the cerebral or basilar arteries, which were generally solitary (six patients), and findings suggestive of vasculitis (four patients). Four patients had stenoses of the origins of two or more great vessels. Two patients had extracranial internal carotid artery stenoses or occlusions that were not typical of atheromatous disease, considered to be embolic in one patient. In another patient, a stenosis of the origin of the internal carotid artery was present that appeared typical of atheromatous disease. Infarctions were seen on CT or MR studies in 13 of 17 patients with abnormal angiograms. CONCLUSION: In our group of patients, typical atheromatous lesions at the common carotid artery bifurcation were rare. Some lesions that are infrequent in the general stroke population (eg, vasculitis-like findings and stenoses at the origin of great vessels) were common. Patients with APA and cerebrovascular events appear to differ from the general stroke population with regard to types of arterial abnormalities seen at arteriography.

Adult↗
PubMed1997

Pictorial review: magnetic resonance angiography of arterial variants at the Circle of Willis.

As intracranial MR angiography becomes more widely used and spatial resolution improves, anomalies at the Circle of Willis which have been previously well described on angiographic studies and anatomic dissections will become more frequently appreciated by MR angiography. Recognition of these variants is important to avoid confusion of the anomalies with aneurysms, evaluate collateral pathways in the intracerebral circulation, and enhance pre-operative planning in patients undergoing surgery at the skull base. In this review, we illustrate several of the more common types of anomalies at the Circle of Willis and discuss the possible clinical significance of each.

Adolescent↗
PubMed1997

Typical and atypical MR imaging features of intracranial epidermoid tumors.

OBJECTIVE: We categorized the MR imaging characteristics of intracranial epidermoid tumors. MATERIALS AND METHODS: MR images from 23 cases of intracranial epidermoid tumors were reviewed retrospectively. Signal intensities of tumor relative to surrounding structures were noted, as were the internal architecture of the tumors and the presence and degree of hydrocephalus. RESULTS: Seventeen (74%) of 23 cases of intracranial epidermoid tumors were revealed as slightly hyperintense relative to CSF on T1-weighted MR images. Nineteen (95%) of 20 cases were hyperintense relative to CSF on proton density-weighted MR images. Fifteen (65%) of 23 cases were isointense to CSF on T2-weighted MR images, whereas the remaining eight cases (35%) were hyperintense to CSF on T2-weighted MR images. One (4%) of 23 cases showed signal intensity that was isointense to CSF on all pulse sequences. Fifteen (65%) of 23 cases showed heterogeneous signal characteristics on either T1-weighted or proton density-weighted MR images, or both. Eight (35%) of 23 cases showed a rim of hyperintensity on proton density-weighted MR images. Five (33%) of the 15 cases that received gadolinium showed rim enhancement. Five (22%) of 23 cases were multilocular, with different regions of tumors showing highly variable imaging characteristics. Two (9%) of 23 cases showed high signal intensity on T2-weighted MR images in the adjacent brain parenchyma. Two (9%) of 23 cases showed mild hydrocephalus. Six (43%) of 14 tumors that either originated in or secondarily involved the cerebellopontine angle also extended into the ipsilateral Meckel's cave. CONCLUSION: On T1-, proton density-, and T2-weighted MR images intracranial epidermoid tumors usually showed heterogeneous signal intensity that was hyperintense to CSF. On all spin-echo pulse sequences epidermoid tumors with signal characteristics isointense to CSF were unusual. Hydrocephalus, even in the setting of marked displacement and compression of the brainstem, was not usually seen on MR imaging. Meckel's cave was often involved secondarily with epidermoid tumors that involved the cerebellopontine angle.

Adult↗
PubMed1997

Brain infarction in young adults: etiology and imaging findings.

The causes of stroke in young adults differ substantially from those in older adults. In many instances, the diagnosis can be made by taking a clinical history and performing laboratory studies (e.g., in patients who have multiple thromboses associated with anti-phospholipid antibodies). In other circumstances, clues to the diagnosis can be found on routine CT and MR studies. However, in many circumstances, imaging tailored to a specific diagnosis is important (e.g., MR imaging of the neck in patients with suspected arterial dissection). In yet other cases, additional studies (e.g., echocardiography in suspected cardiogenic embolism) are important to establish the cause.

Adult↗
PubMed1997

Craniocerebral plasmacytoma: MR features.

We report the MR imaging findings in two patients with solitary craniocerebral plasmacytoma, a benign plasma cell tumor that can arise from the skull, the dura, or, rarely, the brain. In both patients, the lesion was extraaxial and nearly isointense with gray matter on T2-weighted MR images, and diffusely enhanced after administration of contrast material, bearing some similarities to meningioma. A diagnosis of solitary craniocerebral plasmacytoma should be considered when a mass with these imaging features is seen, because total excision may not be necessary for this radiosensitive tumor.

Adult↗
PubMed1997

Brain and spine imaging findings in AIDS patients.

Central nervous system complications in AIDS patients are common and often the cause of severe morbidity and mortality. Most symptomatic central nervous system complications in AIDS patients involve the brain, principally in the form of HIV encephalitis, various other forms of infection, or development of neoplasms. The imaging findings are important to recognize because in many instances the underlying brain lesions are responsive to medical therapy.

AIDS Dementia Complex↗
PubMed1996

Adult age differences in regional cerebral blood flow during visual world identification: evidence from H215O PET.

We used H215O PET to investigate adult age differences in regional cerebral blood flow (rCBF) during the performance of a visual word identification task. The study participants were 20 healthy, right-handed men: 10 young adults between 18 and 27 years of age, and 10 older adults between 63 and 75 years of age. The word identification task comprised six blocks of test trials representing four task conditions; subjects responded manually. The task conditions varied with regard to whether semantic retrieval was required (e.g., word/nonword discrimination vs simple response to each stimulus) and with regard to the difficulty of visual encoding (e.g., words presented normally vs words with asterisks inserted between adjacent letters). Each subject performed all six trial blocks, concurrently with each of six H215O PET scans. Analyses of quantitative CBF data obtained from the arterial time-activity curve demonstrated a significant age-related decline in global CBF rate. Analyses of the changes in rCBF between task conditions indicated that retrieval of semantic information sufficient to distinguish words from nonwords is mediated by a ventral occipitotemporal cortical pathway. Specific areas within this pathway were also associated with visual encoding processes. Several rCBF activations were significantly greater for young adults than for older adults, indicating an age-related decline in processing efficiency within this ventral occipitotemporal pathway. Although the performance data demonstrated a greater age-related slowing for visual encoding than for semantic retrieval, these age-related performance changes were not associated with corresponding changes in rCBF activation.

Adolescent↗
PubMed1996

MRI in hemiballismus due to subthalamic nucleus hemorrhage: an unusual complication of liver transplantation.

A 60-year-old man developed hemiballismus due to an intracranial hemorrhage involving the subthalamic nucleus 8 weeks after orthotopic liver transplantation. The hemorrhage was thought to be due to alterations in cerebral blood flow following a period of hypotensive shock due to sepsis, in the presence of anticoagulant therapy and thrombocytopenia. This represents a rare neurologic complication of liver transplantation.

Cerebral Hemorrhage↗
PubMed1996

Delayed development of sensorineural hearing loss after neonatal hyperbilirubinemia: a case report with brain magnetic resonance imaging.

Sensorineural hearing loss has long been known to be a clinical consequence of kernicterus. Brainstem auditory evoked potentials (BAEPs) that occur in hyperbilirubinemic infants, can be reversed in the neonatal period by exchange transfusion. The case was reported in an infant with neonatal hyperbilirubinemia from hemolysis due to glucose-6-phosphate dehydrogenase (G6PD) deficiency and napthalene exposure. BAEPs showed that the baby had normal hearing at 30 decibels at 13 days of age, after exchange transfusions, but had developed profound bilateral sensorineural hearing loss by 7 months of age. The brain magnetic resonance imaging (MRI) findings at 7 months are also presented.

Cochlea↗
PubMed1996

Cerebral infarction associated with Kearns-Sayre syndrome-related cardiomyopathy.

We present the clinical and neuroradiologic findings of a 31-year-old man with Kearns-Sayre syndrome- related dilated cardiomyopathy who experienced a left middle cerebral artery territory stroke, thought to be due to cardiogenic embolism. The rate of clinically apparent cardiomyopathy in Kearns-Sayre patients can be expected to increase as their survival is prolonged by the use of cardiac pacemaker devices. Under these circumstances, stroke caused by cardiogenic embolism, which is presently rare, may become more common.

Adult↗
PubMed1996

Orbital involvement by Wegener's granulomatosis: imaging findings.

OBJECTIVE: The purpose of this study was to define patterns of Wegener's granulomatosis (WG) orbital disease involvement. SUBJECTS AND METHODS: We evaluated the orbital examinations of 14 WG patients (CT for nine, MR imaging for three, and both CT and MR imaging for two) for the number of involved orbits, intraconal or extraconal location, involvement of the orbital apex, sinus involvement, bony erosion, and optic nerve compression. MR images were analyzed for signal characteristics and enhancement patterns. RESULTS: We found orbital disease to be unilateral in 12 patients (86%) and bilateral in two patients (14%) (total of 16 orbits). In 11 orbits (69%), coexistent orbital and sinus diseases with bony erosion were present. Orbital disease without sinus disease was seen in five orbits (31%). Intraorbital disease distribution was as follows: solely extraconal--seven orbits (44%) (four with involvement of muscle); intraconal with muscular involvement--one orbit (6%); combined intra- and extraconal--seven orbits (44%); and primarily orbital apex--one orbit (6%). Involvement of the apex was seen in six orbits. The WG mass was hypointense relative to orbital fat on three standard T2-weighted MR images. We saw homogeneous MR contrast enhancement in all four orbits studied on enhanced T1-weighted images. CONCLUSION: Intraorbital WG involvement is usually accompanied by paranasal sinus disease. A hypointense signal on T2-weighted MR images is helpful in suggesting the diagnosis.

Aged↗