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Biomedical subjects

R A Flom

Publications and source records attributed to R A Flom.

At least 19 recordsLinked to original sources
PubMed2000

Effects of gesture and target on 12- and 18-month-olds' joint visual attention to objects in front of or behind them.

Factors affecting joint visual attention in 12- and 18-month-olds were investigated. In Experiment 1 infants responded to 1 of 3 parental gestures: looking, looking and pointing, or looking, pointing, and verbalizing. Target objects were either identical to or distinctive from distractor objects. Targets were in front of or behind the infant to test G. E. Butterworth's (1991b) hypothesis that 12-month-olds do not follow gaze to objects behind them. Pointing elicited more episodes of joint visual attention than looking alone. Distinctive targets elicited more episodes of joint visual attention than identical targets. Although infants most reliably followed gestures to targets in front of them, even 12-month-olds followed gestures to targets behind them. In Experiment 2 parents were rotated so that the magnitude of their head turns to fixate front and back targets was equivalent. Infants looked more at front than at back targets, but there was also an effect of magnitude of head turn. Infants' relative neglect of back targets is partly due to the "size" of adult's gesture.

Adult↗
PubMed1996

Preliminary results of intracranial angioplasty for vascular stenosis caused by atherosclerosis and vasculitis.

PURPOSE: To evaluate the results of balloon angioplasty of 17 stenoses resulting from intracranial atherosclerosis and vasculitis. METHODS: Seventeen skull-base and intracranial lesions were dilated with a microballoon angioplasty catheter. RESULTS: Initially, 16 of the 17 stenoses showed improvement at angiography. Moderate residual stenosis was found in 2 of 12 atherosclerotic lesions, both in the distal vertebral artery. Angioplasty in 1 of 12 atherosclerotic lesions caused worsening of the stenotic site, also in the distal V4 region of the vertebral artery. All but one of the patients improved clinically. However, all five lesions caused by acute vasculitis progressed to occlusion after initial improvement. CONCLUSION: Intracranial percutaneous transluminal angioplasty is a viable nonsurgical option for the treatment of atherosclerotic vascular insufficiency, but it may not be as successful in treating lesions caused by vasculitis in the acute phase.

Aged↗
PubMed1996

Trigeminal-cavernous fistula: Saltzman anatomy revisited.

We report a case of a carotid-cavernous fistula through a persistent trigeminal artery with endovascular treatment, and discuss the Saltzman classification of persistent trigeminal artery anatomy and its importance in treatment of this lesion.

Adult↗
PubMed1995

The safety and effectiveness of brain arteriovenous malformation embolization using acrylic and particles: the experiences of a single institution.

The purpose of this article is to report on the safety and effectiveness of brain arteriovenous malformation (AVM) embolization for two series of patients, of which one was treated with particulate embolization and the other with acrylic embolization. Sixty-five consecutive patients from embolization logs and patient records from 1988 to 1993 were reviewed. AVMs were routinely treated with particulate embolization early in the review (1988-1991), and after a transition period, the technique was changed to acrylic embolization for the remainder of the study period (1992-1993). All patients were treated with the ultimate goal of complete AVM obliteration. AVMs were embolized and resected, if possible, and if unresectable, they were reduced in size with embolization and radiated. The course of treatment for each patient was reviewed. The effectiveness at the end of treatment was analyzed for the ability to resect the AVM and, if unresectable, the ability to reduce the AVM to radiation size. Additionally, the safety of each embolization technique was evaluated in the context of comprehensive care, in terms of the safety of the procedure itself, the surgical resection after embolization, and the outcome at the end of comprehensive treatment. This article outlines the safety and effectiveness of acrylic and particulate embolization at a single institution. The ability to surgically resect an AVM after embolization and to reduce nidus size with acrylic was at least comparable with that with particulate embolization. Comprehensive complication rates were lower after acrylic embolization and were heavily influenced by a decreased number of surgical complications in the acrylic series. These data support the need to conduct a randomized prospective clinical trial to compare the relative safety and effectiveness of the two methods of embolization.

Acrylic Resins↗
PubMed1994

Efficacy of endovascular treatment of meningiomas: evaluation with matched samples.

PURPOSE: To evaluate the clinical efficacy, cost-effectiveness, and safety of presurgical devascularization of meningiomas. METHODS: Matched samples of embolized and nonembolized groups of meningiomas were compared. The study variables for clinical efficacy were estimated blood loss, number of transfusions, surgical resection time, and length of hospitalization. The cost-effectiveness was evaluated by adjusting all hospital costs to 1991 dollar amounts, and adding additional embolization costs and fees to the hospital cost totals for the embolized group. A qualitative comparison of complications was made. RESULTS: All dependent variables evaluating the clinical efficacy of the procedure (estimate blood loss, 533 cc versus 836 cc; number of transfusions, 0.39 units versus 1.56 units; surgical resection time, 305.8 minutes versus 337.5 minutes; and length of hospitalization, 10.6 days versus 15.0 days) displayed trends of higher means in the nonembolized group; however, only the estimated blood loss and number of transfusions variables were significant. The cost-effectiveness of the procedure was not statistically significant. The mean cost was $29,605 for the embolized group and $38,449 for the nonembolized group. There were three major and nine minor complications in the nonembolized group and zero major and six minor complications in the embolized group. There were four additional minor complications caused by the embolization procedure. CONCLUSION: Endovascular devascularization of meningiomas is beneficial for large meningiomas because it diminishes the necessity of intraoperative transfusions and decreases blood loss. The additional day of hospitalization, emolization costs, and costs of complications do not conversely increase treatment costs. There were no major complications or adverse long-term effects caused by the embolization procedure.

Blood Loss, Surgical↗
PubMed1994

Neurologic complications of cerebral angiography.

PURPOSE: To examine the incidence of neurologic complications associated with modern cerebral angiography and to assess patient characteristics associated with an increased risk of complications. METHODS: One thousand consecutive cerebral angiographic procedures were evaluated prospectively. Examinations were performed using transfemoral catheterization and film-screen methods. For purposes of this trial, a neurologic complication was defined as any new focal neurologic deficit or change in mental status occurring during the angiogram or within the following 24 hours. Patients were evaluated during and at the completion of angiography. Follow-up evaluations were performed on the day of and the day after angiography. RESULTS: There were a total of 10 neurologic complications within 24 hours of angiography, 5 of which were persistent. Onset of 5 of the deficits occurred during angiography, the other 5 (3 persistent) were delayed. All complications occurred in patients being evaluated for stroke/transient ischemic attack or (in one case) asymptomatic bruit. A higher average age, longer average procedure time, and greater volume of radiographic contrast was noted in these patients than in the study population. CONCLUSION: Cerebral angiography was associated with a 1% overall incidence of neurologic deficit and a 0.5% incidence of persistent deficit. All complications occurred in patients presenting with a history of stroke/transient ischemic accident or carotid bruit, which may reflect the difficulty of performing angiography in this population at risk for atherosclerotic changes.

Adolescent↗
PubMed1992

Carotid artery stenosis: clinical efficacy of two-dimensional time-of-flight MR angiography.

To assess the clinical efficacy of two-dimensional time-of-flight magnetic resonance (MR) angiography in the evaluation of carotid artery stenosis, a group of patients was evaluated in which 73 vessels were studied with both MR and conventional angiography. Four experienced neuroradiologists each scored both the MR and conventional angiograms in a blinded manner by using a standardized scoring scheme. Comparison of the scores revealed a high degree of correlation. In particular, MR angiography served to discriminate reliably between mildly narrowed and severely narrowed or occluded vessels. Furthermore, severe stenoses were accurately discriminated from occlusions in all cases. MR angiography is a robust and accurate modality for the characterization of carotid artery stenosis. It is useful in conjunction with routine MR imaging of the brain in the evaluation of the patient with suspected carotid arterial disease.

Carotid Arteries↗
PubMed1992

Relationship of perfusion pressure and size to risk of hemorrhage from arteriovenous malformations.

The relationship between the size of an arteriovenous malformation (AVM) and its propensity to hemorrhage is unclear. Although nidus volume increases geometrically with respect to AVM diameter, hemorrhages are at least as common, in small AVM's compared to large AVM's. The authors prospectively evaluated 92 AVM's for nidus size, hematoma size, and arterial feeding pressure to determine if these variables influence the tendency to hemorrhage. Small AVM's (diameter less than or equal to 3 cm) presented with hemorrhage significantly more often (p less than 0.001) than large AVM's (diameter greater than 6 cm), the incidence being 82% versus 21%. Intraoperative arterial pressures were recorded from the main feeding vessel(s) in 24 of the 92 patients in this series: 10 presented with hemorrhage and 14 presented with other neurological symptoms. In the AVM's that had hemorrhaged, the mean difference between mean arterial blood pressure and the feeding artery pressure was 6.5 mm Hg (range 2 to 15 mm Hg). In the AVM's that did not rupture, this difference was 40 mm Hg (range 17 to 63 mm Hg). Smaller AVM's had significantly higher feeding artery pressures (p less than 0.05) than did larger AVM's, and they were associated with large hemorrhages. It is suggested that differences in arterial feeding pressure may be responsible for the observed relationship between the size of AVM's and the frequency and severity of hemorrhage.

Adolescent↗
PubMed1991

Failure of transluminal angioplasty in the treatment of myointimal hyperplasia of the internal carotid artery: case report.

Recurrent stenosis of the carotid arteries after a carotid endarterectomy for atherosclerosis can occur as a result of myointimal hyperplasia. This condition was treated by percutaneous transluminal angioplasty. Excellent dilatation of the vessel lumen was documented after balloon dilatation. A 6-month follow-up angiographic study, however, demonstrated recurrent high-grade stenosis at the same level in both carotid arteries. Presumably, the failure of percutaneous transluminal angioplasty and the treatment of myointimal hyperplasia of the internal carotid artery results in the same condition after the original endarterectomy, that is, additional myointimal hyperplasia.

Angioplasty, Balloon↗
PubMed1990

Gliomas: classification with MR imaging.

The findings at magnetic resonance (MR) imaging in a group of 36 pathologically verified supratentorial gliomas were analyzed and compared with the biopsy diagnoses (a) to determine whether MR imaging could be used to classify astrocytic-series tumors into a three-tiered system of low-grade astrocytoma, anaplastic astrocytoma, and glioblastoma multiforme; and (b) to evaluate MR imaging features that may aid in this classification. The MR characteristics evaluated were crossing of the midline, edema, tumor signal heterogeneity, hemorrhage, border definition, cyst formation or necrosis, and mass effect. The statistically significant MR characteristics (positive predictors) were mass effect (P = .0000) and cyst formation or necrosis (P = .0512). The MR accuracy rate approached that of neuropathologic diagnosis, which is subject to sampling errors. MR imaging may serve as an adjunct in case management when the clinical course and MR findings appear to be at odds with the neuropathologic diagnosis.

Anaplasia↗
PubMed1989

Management of juvenile spinal AVM's by embolization and operative excision. Case report.

A small group of spinal arteriovenous malformations (AVM's) most commonly present in children or young adults, are characterized by a large size, high flow, the presence of multiple feeders, and frequent extension to paraspinous structures. Cardiac output requirements may be significantly increased by these so-called "juvenile" malformations, and a bruit is commonly noted. This report describes the obliteration of a juvenile spinal AVM. Staging of embolization and operative procedures was used to obliterate the AVM successfully without morbidity.

Adult↗
PubMed1988

Gd-DTPA-enhanced MR imaging in pediatric patients after brain tumor resection.

A prospective study was conducted in 15 pediatric patients who had undergone resection of intracranial tumors. The object of the study was to determine the safety and efficacy of magnetic resonance (MR) imaging performed after the administration of gadolinium diethylenetriamine-pentaacetic acid (Gd-DTPA) in evaluating residual or recurrent tumor. Precontrast T1-weighted, intermediate, and T2-weighted images were obtained at a field strength of 1.5 T. Gd-DTPA was then injected intravenously in a dose of 0.1 mmol per kilogram of body weight. T1-weighted images were obtained within 5 minutes after the injection, intermediate and T2-weighted images were obtained 10 minutes after the injection, and T1-weighted images were obtained approximately 20 minutes after the injection. None of the patients experienced allergic reactions or other side effects. Physical examination findings and laboratory values were unchanged after the Gd-DTPA-enhanced examination. In six patients, contrast-enhanced images depicted tumor not suspected on nonenhanced images. In four other patients, enhanced images provided better definition of the tumor core. The images of one patient with a brain stem tumor showed no evidence of enhancement. Pre- and postcontrast images of three previously treated patients showed no evidence of tumor. Gd-DTPA appears to be a safe and effective contrast agent for MR imaging and provides a more accurate method of imaging in the follow-up of brain tumors in pediatric patients.

Brain↗
PubMed1988

Gradient echo (GRASS) MR imaging in cervical radiculopathy.

Limited flip angle (LFA), gradient echo imaging was performed in 130 patients for evaluation of cervical radicular complaints. The LFA study was compared with myelography, CT myelography, and surgical results. Image quality was considered good or excellent for 128 patients. The use of a 10 degrees flip angle with a TR of 75 msec and TE of 12.3 msec consistently provided good contrast and signal-to-noise ratio, giving a CT myelographic effect. The use of both axial and sagittal LFA images was important for optimal detection of extradural defects and for distinction of herniated disk versus osteophyte. There was excellent correlation between the MR and surgical findings. Our results suggest that MR imaging is the initial procedure of choice for the evaluation of suspected cervical radiculopathy.

Cervical Vertebrae↗
PubMed1987

Surgical management of large AVM's by staged embolization and operative excision.

A series of 20 patients with giant arteriovenous malformations (AVM's) managed with staged embolization and surgical resection is presented. Complete excision was accomplished in 18 of these patients. There were no deaths and only three complications, of which one was disabling. Further evidence for the presence of low perfusion surrounding the AVM, emphasizing the risk of normal perfusion pressure breakthrough, is provided by cortical perfusion pressure, cortical cerebral blood flow (CBF), and stable xenon computerized tomography CBF measurements. The staged approach to giant AVM management is a proposed method to render AVM's that were previously considered inoperable or marginally operable into totally excisable lesions, while maintaining an acceptable level of morbidity and mortality.

Adolescent↗
PubMed1985

Multiple intracranial aneurysms: determining the site of rupture.

A retrospective hospital chart and radiograph review was performed of all patients with multiple intracranial aneurysms seen over a 52-month period. Sixty-nine patients with a total of 205 aneurysms were studied. Among the patients with aneurysms, the incidence of multiple aneurysms was 33.5%. Multiple aneurysms were much more common in women, with a female to male ratio of 5:1 for all patients and 11:1 for patients with three or more aneurysms. Common locations for multiple aneurysms were the posterior communicating artery (22%), middle cerebral artery (21.5%), anterior communicating artery (12%), and ophthalmic artery (11%). However, locations with the highest probability of rupture were the anterior communicating artery (62%), posterior inferior cerebellar artery (50%), and basilar artery summit (50%). The middle cerebral artery was the least likely site for rupture. In contrast to previous studies, in this series irregularity of contour was more important than size in identifying the site of rupture. Using a simple algorithm outlined in the text, it was possible to identify the site of aneurysm rupture in 97.5% of cases.

Aged↗
PubMed1985

Computed tomography in cases of coccidioidal meningitis, with clinical correlation.

Cranial computed tomographic (CT) scans of 22 patients with coccidioidal meningitis were reviewed and their clinical course was analyzed. Abnormalities of the ventricular system or the basilar cisterns or both were present in 16 instances. Although it is not a definitive diagnostic tool, the CT scan is helpful in suggesting a diagnosis of coccidioidal meningitis and in predicting the prognosis of patients affected by the disease.

Adolescent↗