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RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-642-B-10

We report a case of persistent anterograde amnesia secondary to an anterior thalamic infarct. A 49-year-old right-handed man is referred for acute anterograde amnesia. Diffusion-weighted imaging performed at 24 hours shows an acute punctiform infarct of the left anterior thalamus, while T2-weighted imaging reveals a contralateral and symmetrical ischemic sequelae in the right anterior thalamus. The two lesions are isolated and remarkably centered with the mamillothalamic tract. We suggest the symptoms are caused by the addition of the two lesions interrupting the mamillothalamic tracts. This is the second clinico-pathological observation of a persistent amnestic syndrome secondary to a bilateral lesion of the mamillothalamic tract.

Resume Les fistules arterioveineuses vertebrovertebrales (F.A.V.V.) sont une pathologie vasculaire rare, decouverte de facon fortuite ou lors de l’exploration d’acouphenes pulsatiles, d’un souffle cervical, d’une pathologie ischemique du territoire vertebrobasilaire. Elles peuvent etre spontanees ou, plus souvent, post traumatiques. Notre serie comprend 8 patients âges de 20 a 77 ans, 4 femmes et 4 hommes (4 FVV post-traumatiques, 4 FVV spontanees) pris en charge sur une periode de 15 ans. Le bilan pre-therapeutique a comporte les examens suivants : echo-doppler (n = 4), IRM (n = 3) et surtout arteriographie (n = 8). 7 patients sur 8 ont beneficie d’un traitement realise avec succes par voie endovasculaire (5 occlusions par ballon, 1 occlusion par spire et 1 par manœuvre mecanique), sans complication ni recidive, a l’exception d’un cas. Nous confrontons nos resultats a ceux rapportes dans la litterature et proposons une mise au point sur cette pathologie et sa prise en charge therapeutique, laquelle s’est uniformisee a travers le developpement des techniques d’embolisation endovasculaire.

Resume Introduction nous rapportons quatre observations d’accident vasculaire cerebral ischemique revelant un anevrysme sacciforme. Patients et methodes : un homme et trois femmes (âges de 38 ans a 65 ans) ont ete admis a l’hopital pour un accident vasculaire cerebral ischemique. Le bilan neuroradiologique a mis en evidence un anevrysme intracrânien thrombose, pour trois des quatre cas, de taille inferieure a vingt cinq millimetres. Dans un cas, une ponction lombaire a ete realisee montrant une hemorragie sous arachnoidienne. Discussion nous discutons les hypotheses de la thrombose anevrysmale. Deux theories sont developpees pour l’expliquer : les theories « hemodynamique » et « parietale ». Nous proposons une conduite a tenir pour la prise en charge de ces anevrysmes atypiques, compte tenu du risque hemorragique potentiel. Conclusion l’histoire naturelle des anevrysmes intracrâniens n’est pas encore parfaitement comprise, mais leur thrombose peut etre a l’origine d’accident vasculaire ischemique.

Resume Introduction les anevrysmes mycotiques cerebraux sont une complication rare et grave des endocardites infectieuses, qui engagent le pronostic vital et fonctionnel. Nous rapportons quatre observations de patients ayant presente une endocardite compliquee d’un anevrysme mycotique cerebral. Patients et methodes quatre hommes (âges de 24 ans a 63 ans) ont ete admis a l’hopital pour une endocardite compliquee d’un accident vasculaire cerebral (AVC) ischemique dans 2 cas et d’un AVC hemorragique dans les 2 autres, dont un avec hemorragie cerebromeningee associee. Le bilan neuroradiologique a mis en evidence un anevrysme mycotique cerebral. Discussion a la lumiere des donnees de la litterature, nous discutons de l’histoire naturelle et de la prise en charge des anevrysmes mycotiques cerebraux. Trois therapeutiques sont evoquees : l’antibiotherapie, la chirurgie et le traitement par voie endovasculaire. Conclusion les anevrysmes mycotiques cerebraux sont rares, leur mode de prise en charge est toujours controverse, ne faisant pas l’objet d’un consensus clair dans la litterature, et necessitant une approche therapeutique multidisciplinaire, au cas par cas, en privilegiant le traitement endovasculaire en premiere intention.

Magnetic resonance angiography (MRA) is a very valuable tool in the routine evaluation of patients with stroke syndrome. It provides powerful noninvasive imaging of the cervical and intracranial vessels allowing the detection and the diagnosis of vascular anomalies. MRA usefully supplements, during the same examination, the analysis by MRI of the cerebral parenchyma. We will describe the indications of the various techniques (MRA with and without injection of contrast media) and show the value, artifacts and limitations of MRA in atherosclerotic stenosis or occlusive disease and in arterial dissections. This noninvasive vascular assessment will depend on the initial therapeutic orientation. Within the framework of the hemorrhagic stroke, we will discuss the role and the interest of dynamic MR angiography in the tracking and control of intracranial aneurysms and also the contribution of this newer sequences with gadolinium injection in the detection of cerebral vascular malformations.

Resume Objectif decrire l’aspect IRM de la degenerescence olivaire hypertrophique (DOH) secondaire a une lesion du triangle de Guillain et Mollaret. Patients et methodes nous presentons 15 cas de degenerescence olivaire hypertrophique chez 12 patients (4 femmes et 8 hommes) secondaires a une lesion de la fosse posterieure. L’IRM initiale etait realisee dans un delai de 3 semaines a 8 1/2 ans, avec acquisitions axiales, en echo de spin ponderee en densite protonique, T2 et T1 sans et apres injection de Gadolinium. De plus chez 6 patients, l’evolution du signal dans le temps etait analysee. Resultats neuf patients avaient une DOH unilaterale tandis que 3 presentaient une atteinte bilaterale. La DOH etait liee 8 fois a une lesion controlaterale du noyau dentele, 5 fois a une lesion homo-laterale du faisceau central du tegmentum et dans 2 cas a une atteinte contro-laterale du pedoncule cerebelleux superieur. La DOH etait visible en hypersignal densite protonique et T2 des 3 semaines. Apres injection de Gadolinium, il n’existait pas de rehaussement. Un hypersignal courbe central (HCC) pouvait etre rencontre apres 7 mois d’evolution. Enfin une decroissance progressive du signal etait observee a partir de 3 1/2 ans et les anomalies de signal persistaient apres 13 ans. Sur le plan clinique des myoclonies palatales etaient notees a 5 mois d’evolution chez un patient. Conclusion La degenerescence olivaire hypertrophique est une forme rare de degenerescence transsynaptique, qui associe un hypersigal T2 et un hypertrophie du noyau inferieur de l’olive bulbaire. Elle est secondaire a une lesion de triangle de Guillain et Mollaret et peut entrainer des myoclonies palatales.

A 30-year-old woman, G3P3, was progressively affected by spastic paraparesis with loss of sensitivity and urinary incontinence due to medullar adhesive arachnoiditis occurring five months after an epidural analgesia for repeat cesarean section. Magnetic resonance imaging showed a voluminous subarachnoid cyst and a septated syringomyelic cavitation attributed to metabisulfite, the preservative of epinephrine and to multiple lidocaine injections through the catheter in the postoperative period. Despite two decompressive neurosurgical operations, the neurological state of the patient continues to worsen.

Over the last 25 years, advances in neuroimaging have significantly changed the evaluation and management of acute stroke syndromes. In the seventies, computed tomography (CT) could differentiate between ischemic and hemorrhagic stroke. Magnetic resonance imaging (MRI) is nowadays the imaging modality of choice in the initial assessment of acute stroke. MRI images can better discriminate acute, subacute and chronic infarcts, differentiate venous from arterial infarcts, detect arterial dissection, stenosis or occlusion. Diffusion-weighted images are highly sensitive and specific to acute infarction and the combination with perfusion technique is suitable to define potentially reversible ischemia (area of cerebral "mismatch" which is thought to represent the so-called ischemic penumbra). This penumbra is a potential therapeutic target of valuable interest for the treating physician.

Objective: To investigate the relationship between baseline hypertension and severity of white matter hyperintensities (WMH) at 4-year follow-up in a sample of subjects aged 59 to 71 years old at entry.Methods: Subjects were participants in the Epidemiology of Vascular Ageing study, a longitudinal study on vascular aging and cognitive decline. At 4-year follow-up, 845 subjects had a cerebral MRI. MRI examinations were read by a single rater to determine the severity of WMH, ranging from absent to severe. Hypertension at each wave of the study was defined as systolic blood pressure ≥160 mm Hg, diastolic blood pressure ≥95 mm Hg, or use of antihypertensive medication.Results: Hypertension at baseline was significantly associated with an increased risk of having severe WMH at 4-year follow-up. When taking into account both blood pressure levels and antihypertensive drug intake, analysis showed that the risk of having severe WMH was significantly reduced in subjects with normal blood pressure taking antihypertensive medication compared with those with high blood pressure taking antihypertensive agents. Cross-sectional relationships between hypertension and WMH at 4-year follow-up showed that the frequency of severe WMH was significantly higher in people who were hypertensive at both baseline and 4-year follow-up than those who were hypertensive only at 4-year follow-up.Conclusions: Hypertension is a major risk factor for severe WMH. Subjects taking antihypertensive drugs and who have controlled blood pressure had a reduced risk of severe WMH. Longitudinal studies are needed to investigate whether reduction of the development of WMH, by treatment and prevention of hypertension, might reduce the subsequent risk of cognitive deterioration or stroke.

International audience; OBJECTIVE: To compare 3D time-of-flight MR angiography (TOF-MRA) at 3 Tesla (3T) with digital subtraction angiography (DSA) for the evaluation of intracranial aneurysm occlusion after endovascular coiling. METHODS: In a prospective study, 51 consecutive patients (25 females, 26 males; median age, 51 years) with 51 saccular aneurysms treated with endovascular coiling underwent simultaneous DSA and 3T TOF-MRA at follow-up. DSA and TOF-MRA images were analyzed independently by two senior neuroradiologists. Findings were assigned to 1 of 3 categories in the Raymond classification: complete obliteration, residual neck or residual aneurysm. Agreement between observers and techniques was evaluated using kappa statistics. RESULTS: DSA images were not interpretable for one patient. Interobserver agreement was determined as excellent for DSA (kappa=0.86) and TOF-MRA (kappa=0.80). After reaching a consensus, DSA follow-up showed 26 (51%) complete obliterations, 20 (39%) residual necks and 4 (8%) residual aneurysms. TOF-MRA showed 23 (45%) complete obliterations, 22 (43%) residual necks and 6 (12%) residual aneurysms. Comparison between TOF-MRA and DSA showed excellent agreement between the techniques (kappa=0.86). In the four cases that were misclassified, TOF-MRA findings were assigned to a higher class than for DSA. CONCLUSION: TOF-MRA at 3T is at least as efficient as DSA for the evaluation of intracranial aneurysm occlusion after endovascular treatment with detachable coils. We suggest that TOF-MRA at 3T might be used as the primary method for imaging follow-up of coiled intracranial aneurysms.

Vertebrovertebral Arteriovenous Fistula (V.V.A.V.F.) is a relatively rare entity. It may be an incidental finding or be detected in patients presenting with pulsatile tinnitus, cervical bruit, or vertebro-basilar insufficiency. It can be spontaneous but it most frequently is post-traumatic in etiology. The authors report 8 patients, 4 women and 4 men aged between 20 to 77 years, with 4 post-traumatic V.V.A.V.F. and 4 spontaneous V.V.A.V.F. that were seen over a 15 year period. Imaging work-up included Doppler US (n=4), MRI 9n=3) and angiography (n=8). Seven of 8 patients were treated successfully using an endovascular technique (5 with balloon occlusion, 1 with coil embolization and 1 using a mechanical maneuver), without complication or recurrence, except in one case. We compare our results with published reports from the literature and review the underlying pathology and management strategies of V.V.A.V.F.

To report four cases of patient with an acute ischemic event as a presenting symptom of a berry aneurysm.One male and three female (aged range 38 to 65 years) patients were admitted for acute stroke. The neuroradiologic finding disclosed aneurysm thrombosis, inferior to twenty five millimetres in three cases. Lumbar puncture was done in one case and showed subarachnoid haemorrage.We will discuss the hypothesis leading to the mechanism of aneurysm thrombosis. Two theories will be presented: "hemodynamic" and "parietal" modifications. We will propose a management protocol for these patients with atypical presentation of intracranial aneurysms given the potential risk of rupture.The natural history of intracranial aneurysms is still not fully understood. Nevertheless, aneurym thrombosis may occur and lead to ischemic stroke.

mycotic intracranial aneurysms are a rare complication of infectious endocarditis. We report four cases of patients with endocarditis, complicated by an acute stroke, revealing a mycotic intracranial aneurysm.four men (aged range 24 to 63 year old) were admitted for endocarditis, complicated by ischemic stroke in two cases and hemorrhagic stroke in the two other cases, including one with subarachnoid hemorrhage. Neuroimaging disclosed a mycotic cerebral aneurysm in all four cases.we will discuss the natural history and the management of mycotic intracranial aneurysm based on a review of the literature and our experience. Three therapeutic options are possible: medical treatment, surgery and endovascular embolisation.management of mycotic intracranial aneurysms is still controversial, frequently requiring a multidisciplinary strategy with priority given to endovascular interventions.

Magnetic resonance angiography (MRA) is a very valuable tool in the routine evaluation of patients with stroke syndrome. It provides powerful noninvasive imaging of the cervical and intracranial vessels allowing the detection and the diagnosis of vascular anomalies. MRA usefully supplements, during the same examination, the analysis by MRI of the cerebral parenchyma. We will describe the indications of the various techniques (MRA with and without injection of contrast media) and show the value, artifacts and limitations of MRA in atherosclerotic stenosis or occlusive disease and in arterial dissections. This noninvasive vascular assessment will depend on the initial therapeutic orientation. Within the framework of the hemorrhagic stroke, we will discuss the role and the interest of dynamic MR angiography in the tracking and control of intracranial aneurysms and also the contribution of this newer sequences with gadolinium injection in the detection of cerebral vascular malformations.