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J-F Meder

Publications and source records attributed to J-F Meder.

10 recordsLinked to original sources
PubMed2007

Uncinate fasciculus fiber tracking in mesial temporal lobe epilepsy. Initial findings.

In temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS), ictal discharge spread to the frontal and insulo-perisylvian cortex is commonly observed. The implication of white matter pathways in this propagation has not been investigated. We compared diffusion tensor imaging (DTI) measurements along the uncinate fasciculus (UF), a major tract connecting the frontal and temporal lobes, in patients and controls. Ten right-handed patients referred for intractable TLE due to a right HS were investigated on a 1.5-T MR scanner including a DTI sequence. All patients had interictal fluorodeoxyglucose PET showing an ipsilateral temporal hypometabolism associated with insular and frontal or perisylvian hypometabolism. The controls consisted of ten right-handed healthy subjects. UF fiber tracking was performed, and its fractional anisotropy (FA) values were compared between patients and controls, separately for the right and left UF. The left-minus-right FA UF asymmetry index was computed to test for intergroup differences. Asymmetries were found in the control group with right-greater-than-left FA. This asymmetrical pattern was lost in the patient group. Right FA values were lower in patients with right HS versus controls. Although preliminary, these findings may be related to the preferential pathway of seizure spread from the mesial temporal lobe to frontal and insulo-perisylvian areas.

Adolescent↗
PubMed2006

[Inflammatory presentation of a cavernous dural fistula: diagnosis with color and pulse Doppler imaging].

We report a case of a cavernous dural fistula in a 54-year-old man the source of inflammatory ocular symptoms. Poorly adapted treatment with corticosteroids led to iatrogenic complications. We will attempt to show the advantage of color Doppler imaging for the diagnosis of this infrequent lesion. The only indication of digitalized angiography is for endovascular treatment.

Cavernous Sinus↗
PubMed2005

Suprasellar paraganglioma: a case report and review of the literature.

Paragangliomas arising in the suprasellar region are extremely rare. We report a case of suprasellar paraganglioma in a 47-year-old man who presented with amnesia and impaired visual acuity without any endocrine dysfunction. Magnetic resonance imaging (MRI) showed a large enhancing tumour in the suprasellar area. Following subtotal surgical excision, the diagnosis of paraganglioma was confirmed by pathology. In this case report we describe the MRI pattern of suprasellar paraganglioma and review the literature of this uncommon lesion.

Cerebral Angiography↗
PubMed2005

[MRI for oligodendrogliomas].

MRI has dramatically improved the management of cerebral tumors and consequently oligodendrogliomas. T1 and T2-weighted images and gadolinium enhancement are very useful for tumor detection and characterization. Tumor enhancement is of a great prognostic value because it is highly predictive of high-grade oligodendroglioma. Three-dimensional MR images provide, with high precision, the anatomical location and the relationships with functional structures (motor and language areas). The recent technical progress in MRI and the use of diffusion images in the screening of tumors lead to a better definition of the lesion. Comparative analysis of MRI images is helpful to detect eventual relapse and adverse effects of treatment.

Brain Neoplasms↗
PubMed2005

[Neuroimaging characteristics of cerebral infarcts].

Over the last years, technical advances in neuroimaging have allowed drastic improvements in the assessment of acute ischemic cerebral events. Beyond conventional morphological analysis, diffusion-weighted and perfusion-weighted MRI now enable routine functional assessment of brain tissue; spectroscopy and diffusion tensor imaging still remains in the domain of clinical research. During acute ischemia events, diffusion-weighted MRI can detect the movements of water molecules and cytotoxic edema related to cell injury enabling rapid diagnosis and early assessment of cerebral ischemia. In conjunction with perfusion imaging, which detects hypoperfusion areas, diffusion-weighted MRI provides a means to identify areas of penumbra ischemia. More recent multislice computed tomographic (CT) scans with multimodal analysis are also very competitive for assessment of cerebral ischemia (non-enhanced CT, CT angiography and perfusion CT). The purpose of this paper is to describe the CT and MRI patterns during the different stages of cerebral infarcts.

Acute Disease↗
PubMed2005

[MRI of acute ischemic stroke].

The advent of new MR techniques such as perfusion and diffusion weighted imaging has revolutionized diagnostic imaging in stroke. In some institutions, MRI is used as the sole screening imaging technique for acute stroke patients. In this document, the authors will review the MR pattern of acute ischemic arterial stroke, highlight the usefulness of MRI for the identification of acute hematomas and stroke like episodes, present the potential use of MRI in the management of acute stroke patients, especially when thrombolysis is contemplated, and discuss the role of MRI for imaging transient ischemic attack.

Cerebral Hemorrhage↗
PubMed2004

[Imaging of dementia with magnetic resonance].

The diagnostic approach of dementia has clearly improved with the progress in medical imaging, notably magnetic resonance imaging. The conventional T1 and T2 sequences or morphological imaging have demonstrated their interest in the positive and differential diagnosis of dementia, together with the more precise description of normal ageing of the brain. The ANAES (French medicines agency) proposes systematic brain imaging, notably by magnetic resonance imaging (MRI) in their practical guidelines for the diagnosis of Alzheimer's disease (http://www.anaes.fr). THE INTEREST OF CERTAIN IMAGING TECHNIQUES: The therapeutic progress in treatment of dementia implies that the different affections be recognised as early as possible. With this in mind, the functional MRI is capable of describing the damage in cases when morphological imaging is not sufficiently specific. Recent studies have reported the interest of diffusion and perfusion imaging, activation MRI and proton spectroscopy. FROM A THERAPEUTIC POINT OF VIEW: The combination of morphological and functional approaches will provide a better definition of the groups at risk in order to target current treatments and those to come.

Aged↗
PubMed2004

[Headaches in the emergency context].

Headaches constitute one of the most frequent reason of consultation. Their causes are extremely varied. The first step consists in the analysis of the characteristics of the pain and the associated signs in order to distinguish primary and secondary headaches. Primary headaches, including migraines and tension-type headaches are the most frequent types and do not require imaging evaluation. Secondary headaches are related to an organic cause and require specific investigations. In case of suspected symptomatic or secondary headaches, brain imaging plays an important role in the etiologic work-up. The main purpose of imaging in an emergency setting is to diagnose a life-threatening disease.

Acute Disease↗
PubMed2003

Risk of stroke and recurrent dissection after a cervical artery dissection: a multicenter study.

OBJECTIVE: To assess the risk of stroke, TIA, or dissection recurrence after a first event of cervical artery dissection (CAD). METHODS: The authors undertook a historical cohort study of consecutive patients with a first event of CAD who were admitted in 24 departments of neurology within a period of at least 1 year. Patients were retrospectively selected from a stroke data bank or from the local administrative data bank using the 10th revision of the International Statistical Classification of Diseases. A neurologist and a radiologist reviewed all charts to validate diagnosis and collect data. In 2002, patients were interviewed by phone or during a visit by the local investigators. RESULTS: Four hundred fifty-nine patients (mean age 44.0 +/- 9.7 years) were included in the study. Among the 457 survivors, 25 (5.5%) could not be contacted in 2002 because they had moved. After a mean follow-up of 31 months, four (0.9%) patients presented a recurrent ischemic stroke attributable to either not yet completely recovered initial CAD (n = 2) or a recurrent CAD (n = 2). Eight (1.8%) patients had a TIA without CAD recurrence. Two TIA occurred at the acute stage of CAD. Of the six remaining TIA, only one was associated with chronic arterial stenosis. In addition, two patients had recurrent CAD without stroke, giving a total of four (0.9%) CAD recurrences. CONCLUSIONS: Patients with a first event of CAD have a very low risk of ischemic events or dissection recurrences. Ischemic events seem rarely to be in relation with chronic arterial lesions.

Adult↗