Biomedical subjects

P Courthéoux

Publications and source records attributed to P Courthéoux.

At least 19 recordsLinked to original sources

PubMed2005

[Quantitative relationships between ADC and perfusion changes in acute ischemic stroke using combined diffusion-weighted imaging and perfusion MR (DWI/PMR)].

UNLABELLED: MR-based diffusion- and perfusion-weighted imaging (DWI/PWI) has become the standard imaging technique to assess the individual brain pathophysiological status in acute ischemic stroke. The finding of a "mismatch" with larger PWI than DWI abnormality is thought to reflect the presence of tissue at-risk of infarction, i.e., penumbra. However, there has been no detailed study of the quantitative relationships between perfusion and diffusion changes in stroke patients. According to the experimental concept of penumbra, the ADC would be expected to remain unchanged despite decreasing perfusion until a critical threshold is reached. We have tested this hypothesis directly in man. METHODS: DWI/PWI was performed in 7 patients with MCA territory stroke within 4-10 hrs from onset. Mismatch was defined on diffusion and rMTT maps, and circular ROIs were positioned within the ADC lesion (D), the mismatch area (M), and the normal appearing cortex (N); mirror ROIs were also obtained, and affected/unaffected ratios for ADC and rCBF were computed for each ROI. RESULTS: The mean (+/-1 SD) ADC ratios were 0.60 +/- 0.09, 0.95 +/- 0.10 and 1.02 +/- 0.04 in L, M and N, respectively; the corresponding rCBF ratios were 0.32 +/- 0.12, 0.75 +/- 0.14 and 0.97 +/- 0.09, respectively. The relationship was non-linear, with the rCBF but not the ADC ratio for M being significantly lower (p < 0.01) than that for N. A threshold for decline in ADC was apparent around 0.50 rCBF ratio. COMMENT: These results directly document in man that the ADC declines only after hypoperfusion has reached a certain degree (about 50%), consistent with the concept of the ischaemic penumbra.

Acute Disease↗

PubMed2005

[Diffusion MR imaging of the central nervous system: clinical applications].

Diffusion-weighted MR imaging is a technique in which image contrast is determined by the motion of water molecules within tissues. This motion is characterized by the apparent diffusion coefficient (ADC). This technique is particularly useful for the early detection of cerebral infarction but many other diseases of the central nervous system are associated with a change in water diffusion and may be assessed by diffusion-weighted MR imaging. This is an easy and fast pulse sequence providing useful data for early diagnosis and prognosis as well as information about underlying pathophysiology. After an overview of the basic concepts of diffusion imaging and the knowledge required for image interpretation, we will assess the potential value of this technique for the diagnosis of the main diseases of the central nervous system.

Brain Diseases↗

PubMed2003

[Serious cerebral venous thrombosis: can we use fibrinolytic?].

We report a case of thrombosis of superior sagittal and cavernous sinuses treated by direct instillation of fibrinolytic agents via selective catheterization. Despite risk of bleeding related to the pathology and treatment, no adverse side-effect occurred. This report is unusual regarding the poor initial clinical patient's condition with dilated and unreactive pupil. The good neurologic outcome warrants aggressive treatment in the most severe forms of cerebral venous thrombosis.

Adult↗

PubMed2001

[Pseudotumoral presentation of cat scratch disease].

BACKGROUND: A frequent cause of chronic benign lymphadenopathy, cat-scratch disease (CSD) occurs mainly in children and young adults. Bartonella henselae is the agent responsible for CSD. The most common symptoms of the disease are regional lymphadenopathy and fever. Atypical forms occur in about 10% of patients; among them, CSD may initially present as a tumor. CASE REPORT: A 4-year-old child developed a 'tumor' of the arm with fever. The values of white blood cell count and CRP were normal. Ultrasonography, MRI and arteriography did not contribute to the diagnosis, which was established on histologic examination and serologic test for infection with B. henselae. The outcome was favorable with antibiotic treatment. CONCLUSION: In case of tumor of the limbs, cat-scratch disease should be searched for.

Anti-Bacterial Agents↗

PubMed2000

Proton magnetic resonance spectroscopy of the medial prefrontal cortex in patients with deficit schizophrenia: preliminary report.

OBJECTIVE: Proton magnetic resonance spectroscopy (1H-MRS) was used to study medial prefrontal metabolic impairments in schizophrenic patients with the deficit syndrome. METHOD: The subjects were 22 schizophrenic patients categorized as deficit (N=5) or nondeficit (N=17) and 21 healthy subjects. (1)H-MRS was performed for the right and the left medial prefrontal cortex. RESULTS: The patients with the deficit syndrome had significantly lower ratios of N-acetylaspartate to creatine plus phosphocreatine than did the healthy subjects or nondeficit patients. CONCLUSIONS: As N-acetylaspartate levels could reflect neuronal density and/or viability, this finding suggests a neuronal loss in the medial prefrontal cortex of deficit patients.

Aspartic Acid↗

PubMed2000

Carotid-cavernous fistulas: diagnosis with spiral CT angiography.

Four cases in which the diagnosis of carotid-cavernous fistula was made by using CT angiography are illustrated. The diagnosis was confirmed by digital subtraction angiography in all four instances. To our knowledge, this is the first report of the CT angiographic appearance of carotid-cavernous fistulas.

Adult↗

PubMed1999

[Dysembryoplastic neuroepithelial tumors. Report of 8 cases including two with unusual localization].

OBJECTIVES: Dysembryoplastic neuroepithelial tumors (DNTs) are usually located within the supratentorial cortex. We present a series of eight cases of DNTs including two cases with an extracortical location, one in the caudate nucleus, the other one expanded in the lateral ventricule, septum and fornix. An origin from secondary germinal layers, as previously suggested, can explain these extracortical locations. MATERIAL AND METHODS: Of the eight patients, seven had partial epileptic seizures and one intracranial hypertension. All patients underwent clinical examination, a computed tomographic (CT) scan, a magnetic resonance imaging (MRI) and a surgical removal of the lesion with histological examination. RESULTS: Clinical examination was normal except in the case with intracranial hypertension where a bilateral papillary oedema was found. In seven cases the CT scan showed a hypodense lesion of pseudocystic appearance. All lesions were hypointense on T1-weighted and hyperintense on T2-weighted MRI. Contrast enhancement was observed in two cases. The lesion was intracortical in six cases and extracortical in the remaining two: one in the head of the caudate nucleus and one in the trigonoseptal region. Histological examination identified an appearance of DNT with a specific glioneuronal element in six cases. CONCLUSION: The diagnosis of DNT can be suspected before histological examination on radiological features, chiefly because the tumor is located in the supratentorial cortex. However, extracortical locations do exist, even if unusual. As DNTs are always benign, knowledge and accurate diagnosis of these atypical cases are mandatory in order to avoid useless and even deleterious additional treatments, such as radiotherapy.

Adolescent↗

PubMed1994

[Contribution of computerized cisternography using hydrosoluble contrast media or CT transit to the diagnosis of post-traumatic cerebrospinal rhinorrhea].

Based on a series of 100 cases, the authors present the value of CT transit in craniofacial traumatology. This examination, systematically performed in cases of fistulogenic fracture, is able to confirm or exclude the presence of an osteomeningeal breach, which is often difficult to detect during the immediate post-traumatic period. CT transit also allows precise localisation of the breach, which guides the operative procedure.

Adolescent↗

PubMed1994

[The role of magnetic resonance angiography in the follow-up of intracranial arteriovenous malformations treated by an intravascular approach].

The purpose of our work was to measure the accuracy and reliability of MR-Angiography in the study and follow-up of intracranial arteriovenous malformations, and in particular to evaluate the results of endovascular treatment. Over an 18-month period 4 patients with such malformations were examined by MR-Angiography. There was an angioma of the corpus callosum, a left parieto-rolandic angioma, a posterior thalamic angioma and a cerebellar angioma. All examinations were performed with a Magneton-Impact 1 Tesla machine (Siemens, Erlangen, Germany), using a head coil, MR-Angiography with time-of-flight sequences and differential arterial and venous saturations. Each patient was examined by MR-Angiography first at the beginning of treatment, then when ambulatory after embolization. The morphological study applied to the afferent vessels, the nidus and the efferent veins. MR-Angiography proved to be very good in identifying the arteries feeding the malformation, and this made it easier to evaluate the reduction of their input after treatment, without having recourse to any arteriography. Beside, analysis of the nidus was facilitated by the judicious arrangement of arterial and venous saturations. In fact, the systematic use of MR-Angiography in the follow-up of intracranial arteriovenous malformations makes it possible to measure, with full reliability, the efficacy of the endovascular treatment under conditions of comfort unequalled in these out-patients, and selective angiography sequences need to be performed only during therapeutic phases.

Adolescent↗

PubMed1992

[Impotence of vascular origin. Techniques of exploration and therapeutic orientations].

Vascular problems of arterial and/or venous origin are often found as the cause of erectile dysfunction. Clinical examination alone is insufficient and must followed up by a number of non or minimally invasive tests in order to confirm the etiology. Such testing should include: Doppler measurements or, better, duplex sonography, nocturnal penile plethysmography, psychological status, clinical biochemistry and intracavernous injection of vasoactive drugs. Occasionally, it may be necessary to complete these tests by more invasive examinations: pharmacoarteriography and/or pharmacocavernosography. Several novel therapeutic approaches have been developed in recent years and have given rise to encouraging improvements.

Adult↗

PubMed1991

[Ioversol 350: clinical experience in skull x-ray computed tomography].

A single, open trial was conducted in 40 patients to evaluate the diagnostic efficacy and safety, in cranial computed tomography, of ioversol (350 mgl/ml), a new nonionic, monomeric, low-osmolality contrast medium. Ioversol is characterized by a hydrophilicity which is not only the highest of all nonionic agents available to date, but also evenly distributed among the various sides of the benzene ring. Diagnosis was possible in 100% of cases with a mean degree of certainty of 90.8%. Six minor adverse reactions requiring no treatment were recorded, of which two were observed by the investigator and four reported by the patients. No pain sensation was found and heat sensations were of minor intensity. Ioversol 350, which showed good diagnostic efficacy and proved to be well tolerated, is therefore suitable for cranial computed tomography at a mean dose of 1 ml/kg.

Adult↗

PubMed1990

[Intravascular technics of cerebral revascularization].

Two techniques of cerebral revascularization have been developed: angioplasty of the brachiocephalic vessels (204 cases) and local intra-arterial fibrinolysis in the carotid region (26 cases). Angioplasty appears to be the treatment of choice for inflammatory and atherosclerotic stenoses of the main trunks arising from the aortic arch (82 cases). Stenoses of the origin of the vertebral artery are not often ulcerated and may also be treated by angioplasty (42 cases) as long as the stenosis has been recognized as the cause of vertebral insufficiency symptoms. Among the stenoses of the carotid bifurcation, recurrent postsurgical ones are rather easily treated by angioplasty, particularly when they are recognized early by Doppler examination. Postsurgical and inflammatory stenoses do not require cerebral protection during angioplasty. Conversely, cerebral protection is mandatory for treatment of atherosclerotic stenoses because of the risk of embolic detachment of particles in to brain circulation. A new triple coaxial catheter system has been designed which seems so far to be very efficient. Local intra-arterial fibrinolysis in the carotid region is selected on the basis of clinical signs, the delay after onset and results of CT and complete cerebral angiographic workup. A classification into three topographic groups is proposed. The group at highest risk of post-fibrinolysis hemorrhage is the one with occlusion of the lenticulostriate arteries. It would seem hazardous to undertake fibrinolysis in a patient of this group unless it can be started no later than 4 or 5 hours after clinical onset. Rapid transportation of stroke patients is recommended so that CT and complete arteriography may be performed before deciding whether to use fibrinolytics.

Angioplasty, Balloon↗

PubMed1988