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C Oppenheim

Publications and source records attributed to C Oppenheim.

At least 73 records · Page 4Linked to original sources
PubMed1999

Yield of fluid-attenuated inversion recovery in drug-resistant focal epilepsy with noninformative conventional magnetic resonance imaging.

PURPOSE: To determine the role in presurgical assessment and evaluate the yield of fast fluid-attenuated inversion recovery (FLAIR) sequences for patients with intractable partial epilepsy for whom conventional magnetic resonance imaging (MRI) was normal. MATERIAL AND METHODS: Forty patients were selected. Conventional MRI including spin echo T1-weighted sagittal images and fast spin echo T2-weighted axial images was normal in 33 patients and showed noninformative lesions in 7. Fast FLAIR and T2-weighted sequences were performed perpendicularly to the hippocampal long axis. RESULTS: Additional abnormalities were found in 40%. They were correlated with electroclinical data in 13 patients (32.5%) and not correlated or doubtful in 3 (7.5%). CONCLUSION: Fast FLAIR sequences brought congruent additional information in 32.5% cases and seemed useful in presurgical evaluation.

Adolescent↗
PubMed1999

Radiosurgery of cerebral arteriovenous malformations: is an early angiogram needed?

BACKGROUND AND PURPOSE: Radiosurgical treatment of arteriovenous malformations (AVMs) has slow and progressive vasoocclusive effects. We sought to determine if early posttherapeutic angiography provides relevant information for the management of radiosurgically treated AVMs. METHODS: Between 1990 and 1993, the progress of 138 of 197 cerebral AVMs treated by linear accelerator (Linac) was regularly followed by angiographic study. On each posttherapeutic angiogram ("early," 6-18-month follow-up; "intermediate," 19-29-month-follow-up; and "late," > 30-month follow-up), the degree of reduction across the greatest diameter of the nidus and hemodynamic modifications were analyzed. Each cerebral AVM was qualitatively classified into one of the following categories after early angiographic study: 0%-reduced, 25%-reduced, 50%-reduced, 75%-reduced, and 100%-reduced or "complete obliteration." Vasoocclusive progress for each category was then studied over time. RESULTS: Three (10%) of the 30 0-25%-reduced, eight (38%) of 21 50%-reduced, and 27 (84%) of 32 75%-reduced cerebral AVMs showed complete obliteration after further follow-up. The three 0-25%-reduced AVMS that went on to complete obliteration underwent very early angiography (6-7 months). Fifty-five cerebral AVMs showed complete obliteration on early angiograms (40%). In this group, more follow-up, when performed, confirmed complete obliteration in all cases (n = 17). CONCLUSION: An early angiogram is needed to predict the effectiveness of radiosurgery. Important AVM changes seen on early angiograms are highly correlated with treatment success. Moreover, no or minor changes seen on early angiograms are highly predictive of radiosurgical failure. For these patients, further treatment should be discussed promptly.

Adolescent↗
PubMed1999

[Diffusion MRI and cerebral ischemia. When to calculate the coefficient of diffusion?].

INTRODUCTION: There are two types of diffusion images: so-called "diffusion-weighted" images (DWI) and apparent diffusion coefficient (ADC) images. For certain authors, ADC mapping is crucial for interpreting diffusion images while for others the ADC map adds no further sensitivity or specificity compared with diffusion weighted images. The objective of this work was to determine those situations where ADC mapping modifies image interpretation. MATERIAL AND METHODS: T2-weighted and diffusion-weighted (DIF) MRI sequences were acquired in 197 patients with suspected cerebral ischemia (< or = 48 hr). For each lesion (239 lesions in the 197 patients), we analyzed MRI interpretation with and without ADC mapping and compared the interpretations with the final diagnosis established on clinical data and complementary explorations. RESULTS: We observed 3 groups. In group A (36% of the lesions), ADC mapping did not change image interpretation. This group was subdivided into 3 subgroups. A1: T2 and DIF weighted images are normal: no lesions and normal ACD map (n = 38 patients); A2: High intensity signal on T2 and low intensity signal on DIF: ischemic sequelae, ADC always increased (n = 32 lesions); A3: T2 normal and high intensity signal on DIF: hyper acute ischemia and ADC always decreased (n = 16 patients) In group B (high intensity signal on T2 and DIF, 54.5% of the lesions), ADC mapping changed the MRI interpretation: there was acute ischemia if the ADC was decreased (n = 113) and "pseudo-ischemic" lesions if the ADC was normal or increased (n = 17 patients). Group C was comprised of 23 lesions with a false negative ADC (9.5%). These lesions were always small recent ischemic lesions (< or = 5 mm) with a high intensity signal on DIF and a strictly normal ADC map. CONCLUSION: ADC mapping was found to be useful in 54.5% of the lesions and should not be considered as solely a research tool but also as a useful tool for routine clinical practice.

Adult↗
PubMed1999

[The value of MRI for the diagnosis of meningeal hemorrhage during vasospasm].

Retrospectively, subarachnoidal hemorrhage can be misdiagnosed when the acute event did not bring the patient to medical attention, when clinical history is unclear and the CT scan is normal. Moreover, days after subarachnoid hemorrhage, cerebral vasospasm can result in neurological deficits that are indistinguishable from that produced by other causes of stroke. We report our experience with two patients who presented with symptoms of ischemia due to an arterial vasospasm that followed unrecognized rupture of an intracranial aneurysm. In both cases, CT scan failed to detect subarachnoid hemorrhage while MR detected the presence of signal changes in the subarachnoidal spaces associated with an ischemic stroke in one case. Neurological symptoms resolved completely after aneurysm treatment. MR can be a critical for the diagnosis of stroke secondary to vasospasm in order to prescribe an adapted treatment, avoid anticoagulant or thrombolytic therapy, and rapidly exclude the recently ruptured aneurysm to protect the patient from the risk of rebleeding.

Adult↗
PubMed1998

Hippocampal developmental changes in patients with partial epilepsy: magnetic resonance imaging and clinical aspects.

Developmental disorders of the hippocampal formation (HF) have been described in epileptic syndromes associated with lissencephaly, but HF malformations can be found without widespread cortical changes. We report 19 patients with partial epilepsy and abnormal HF patterns on magnetic resonance imaging (MRI). The changes consisted of incomplete folding with abnormal medial location along the choroid fissure, globular shape and/or verticalization, and were observed in the following three contexts: (1) diffuse disorder of neuronal migration (n=1); (2) temporal lobe malformation (n=5), including heterotopia, abnormal gyration, and, in 2 cases, reduced HF volume; and (3) apparently isolated HF changes (n=13, bilateral in 3 cases). The clinical features were heterogeneous in terms of severity of epilepsy and, when the focus could be determined, in localization (temporal or extratemporal). In 4 patients with apparently isolated HF changes, MRI was suggestive of both abnormal development and hippocampal sclerosis. In these patients, presurgical investigation and postoperative results suggested multiple epileptogenic foci, involving the frontal lobes in 2 cases. One HF specimen was large enough for the observation of developmental abnormalities corresponding to the changes seen on MRI. HF changes in shape and/or position should be included among the structural abnormalities associated with partial epilepsies. They may represent the visible part of a more extensive or more distant disorder of brain development.

Adolescent↗
PubMed1998

Glossopharyngeal neuralgia associated with a vascular loop demonstrated by magnetic resonance imaging.

We report two cases of glossopharyngeal neuralgia associated with a vascular loop of the postero-inferior cerebellar artery, diagnosed by magnetic resonance imaging. Reviewing the literature, we found this to be the first report of a magnetic resonance-validated vascular abnormality related to such a condition. One patient was cured by surgical decompression, confirming the role of the abnormal vessel in the pain. As with trigeminal neuralgia, a possible vascular aetiology should be considered in glossopharyngeal neuralgia.

Cerebellum↗
PubMed1998

Diffusion-weighted magnetic resonance imaging in a case of cerebral venous thrombosis.

BACKGROUND: Diffusion-weighted imaging (DWI) is the most sensitive MR sequence in acute arterial ischemic stroke but has not yet been evaluated in venous cerebral ischemia. We describe a patient with DWI performed at the acute phase of a venous ischemic stroke. CASE DESCRIPTION: A rapid cerebral MRI including DWI and fast fluid-attenuated inversion recovery (FLAIR) sequences was performed at the acute phase of a venous stroke confirmed by conventional angiography. DWI showed a slight decrease in apparent diffusion coefficient values 3 hours after onset (0.53+/-0.07x10(-3) mm2/s) and was normal 48 hours later (0.064+/-0.15x10(-3) mm2/s). Fast FLAIR sequences showed large left frontoparietal hyperintensities. The lack of a clear decrease in apparent diffusion coefficient values associated with marked FLAIR abnormalities may suggest prominent or early associated vasogenic edema. Physiopathological differences between arterial and venous ischemia may explain the different type of DWI FLAIR abnormalities during the acute phase as well as the better recovery of neurological deficit in venous stroke than in arterial ischemic stroke. CONCLUSIONS: In the context of an acute stroke, the contrast between marked FLAIR and subtle DWI abnormalities on MRI may reflect the venous mechanism of cerebral ischemia.

Brain↗
PubMed1998

Loss of digitations of the hippocampal head on high-resolution fast spin-echo MR: a sign of mesial temporal sclerosis.

PURPOSE: The purpose of our study was to determine the significance of the loss of visualization of digitations in the hippocampal head on high-resolution fast spin-echo MR images in the diagnosis of mesial temporal sclerosis (MTS). METHODS: MR examinations of 193 patients with intractable epilepsy were evaluated retrospectively for atrophy and/or T2 signal changes of the hippocampi. On the basis of these two criteria, MTS was diagnosed in 63 hippocampi. Twenty-four patients had surgery, and MTS was confirmed in all cases. A control group included 60 hippocampi in patients with frontal seizures but no MR-detectable abnormalities. In a second step, visibility of digitations in the hippocampal head was evaluated in the two groups of subjects. RESULTS: In the group of 63 hippocampi in which MTS was diagnosed, digitations were not visible in 51 cases, poorly visible in eight, and sharply visible in four. Twenty-two of 24 hippocampi in which MTS was confirmed histologically had no MR-visible digitations. In the control group, digitations were sharply visible in 55 cases and poorly visible in five. Statistical analysis showed a significant difference in the visualization of digitations between hippocampi with MTS and those in the control group. CONCLUSION: With a sensitivity of 92% and a specificity of 100%, the finding of complete loss of digitations in the hippocampal head may be used as a major diagnostic criterion to establish the MR diagnosis of MTS. This morphologic sign may also be useful in the diagnosis of bilateral MTS or to validate the MR diagnosis of MTS when there is no obvious atrophy or changes in signal intensity.

Adolescent↗
PubMed1997

Cerebral arteriovenous malformations: the value of radiologic parameters in predicting response to radiosurgery.

PURPOSE: To define the morphological patterns of cerebral arteriovenous malformations (AVMs) that influence their response to radiosurgery at 2 years. METHODS: We retrospectively reviewed the yearly MR and angiographic follow-up studies in 102 patients who had radiosurgical treatment for cerebral AVMs between 1990 and 1992. Parameters studied were maximum length and volume of the nidus, position relative to the midline, anatomic structures involved, sectional anatomic location (depth within the brain tissue), angioarchitecture, and Spetzler and Martin grading. Statistical analysis determined their influence on treatment results at 2 years. RESULTS: Parameters that correlated with obliteration at 2 years were maximum length less than 25 mm, small volume, sectional location deep within brain tissue, and plexiform angioarchitecture. Ventricular and paraventricular locations correlated with nonobliteration at 2 years. CONCLUSION: This study highlights the role of two new morphological parameters in predicting the efficiency of radiosurgery in the treatment of cerebral AVMs: depth within the parenchyma and angioarchitecture. It also emphasizes the usefulness of sectional imaging in the work-up before radiosurgery.

Adolescent↗
PubMed1997

[Stereotaxic radiotherapy of cerebral arteriovenous malformations: the role of neuroradiology].

The therapeutic approach to cerebral arteriovenous malformations has been modified with the availability of stereotactic radiosurgery, initially, the main indications of radiosurgery were limited, non surgical arteriovenous malformations. Indications are now much more diverse. Imaging plays an important role in the radiosurgical management of arteriovenous malformations and its evaluation. In this review, the different roles of neuroimaging are discussed; characterization of malformations, choice of the best indications, role of embolization, delimitation of the target, evaluation of results and complications of radiosurgery.

Cerebral Angiography↗
PubMed1996

[Is magnetic resonance the first indication in neurologic imaging?].

Various methods of neuroradiologie examination are described, with an emphasis on recent developments, in particular in CT scan (angioscan, spiral acquisition) and MRI. CT scan, which is the most accessible method, can answer most questions in intracerebral emergencies (trauma, vascular accidents, intracerebral hypertension ...). Outside the emergency setting, morphological study of the brain by MRI is much superior to that provided by CT scan and should be the first-line examination for investigation of suspected tumour, wite matter lesion.... This is even more evident in exploration of lesions of the posterior cranial fossa. In addition, introduction in the near future of functional MRI should lead to better knowledge of the relationship between cerebral lesions and functional zones. Ultrasonography remains a noninvasive and effective technique to seek lesions of the arteries supplying the brain. For spinal cord disorders, MRI is by far the examination of choice, except when contraindicated by the presence of cardiac pacemaker, metallic foreign bodies in the patient.

Brain Diseases↗
PubMed1995

The legal responsibilities of the health-care librarian.

This article discusses the legal responsibilities that information intermediaries have towards the users of their services. The areas of law that affect legal liability are contract law, tort and strict liability. The likelihood of health-care librarians being held liable for the service they provide is assessed, and methods of reducing this risk are discussed. The key issues are: whether the recipient is relying on the information you provide and whether this reliance is reasonable; whether money changed hands; and whether the institution is under a statutory obligation to provide the information. All-embracing exclusion clauses are often used as an attempt to exclude liability, but their validity in law is doubtful, and they should be replaced by more reasonable ones. Adhering to good professional practice, and avoiding interpreting information for laymen are ways of minimizing liability. If court proceedings do take place, professional indemnity insurance can reduce financial loss.

Insurance, Liability↗
PubMed1994

Bronchopulmonary dysplasia: value of CT in identifying pulmonary sequelae.

OBJECTIVE: Pulmonary dysfunction is common in children who survive bronchopulmonary dysplasia. Chest radiographs are not satisfactory for the identification of the sequelae of bronchopulmonary dysplasia because, although they often show abnormalities, the abnormalities are usually minor and sometimes absent. We therefore assessed the value of CT for identifying the sequelae of bronchopulmonary dysplasia. MATERIALS AND METHODS: Twenty-three children (mean age, 4 years) who had survived neonatal bronchopulmonary dysplasia and had signs of chronic pulmonary dysfunction (recurrent episodes of coughing, wheezing, dyspnea, pneumonia, respiratory insufficiency) were examined with chest radiographs and high-resolution CT scans of the chest. Two reviewers qualitatively analyzed the chest radiographic and CT findings by describing the most consistently found lesions and their frequencies. RESULTS: The chest radiographs showed hyperexpansion in 17, hyperlucent areas in 11, and linear opacities in 10 of the 23 children. Pleural thickening was not observed, and four children had normal findings on chest radiographs. All 23 CT scans showed abnormalities, including multifocal areas of hyperaeration, well-defined linear opacities, and triangular subpleural opacities with an external base and an internal apex. In 20 of 23 children, all three abnormalities were present. For the three other children, two of these three abnormalities were found. No bronchiectasis was observed in any of the cases. CONCLUSION: Lesions in survivors of bronchopulmonary dysplasia with chronic pulmonary dysfunction are visualized better on CT scans than on chest radiographs. Importantly, CT findings of multifocal areas of hyperaeration, numerous linear opacities facing triangular subpleural opacities visible on several consecutive sections, and no bronchiectasis should suggest the presence of sequelae of bronchopulmonary dysplasia.

Bronchopulmonary Dysplasia↗
PubMed1981

Patent coverage by abstracting services. 4. Coverage of microbiological patents.

The paper reports a study on the coverage by seven major abstracting services in the field of microbiology in regard to patents. Only three of the services--Chemical Abstracts, Microbiology Abstracts, Section A, and Food Science and Technology Abstracts--cover patents at all. We assessed the three services in terms of the information they provide about patents and then in terms of their performance in retrieving patents taken from a master list of patents on genetic engineering and Vitamin D, obtained by searches on World Patents Index. Timeliness of the three services was also assessed. We found that none of the standard abstracting services in the field cover patents satisfactorily and they are slow in picking up patents. The research demonstrates that by scanning just Japanese, Soviet, U.S., and British patents, both timely and comprehensive coverage of the microbiological patent literature can be obtained.

Abstracting and Indexing↗