Serge Timsit

Value of spontaneous hyperdensity of cerebral venous thrombosis on helical CT.

Background Excluding a cerebral venous thrombosis (CVT) through imaging is a frequent request in the emergency setting. This assessment often starts by an unenhanced brain computed tomography (CT). Purpose Re-evaluate the value of spontaneous hyperdensity of CVT on helical unenhanced brain CT. Methods Multicentric retrospective study on CVT probability based on visual assessment of spontaneous hyperdensity of cerebral venous system, performed by four blinded radiologists, individually then collectively, on a population including 14 helical unenhanced brain CTs with CVT and 102 unenhanced brain CTs without CVT (all confirmed by CT or magnetic resonance [MR] venography). Exclusion criteria: no DICOM image, symptoms >15 days, CVT indirect signs on unenhanced CT. A fifth radiologist set 768 regions of interest to measure and to compare the density within the normal venous sinuses and the CVTs. Results After consensus reading, sensitivity of this sign for CVT diagnosis was 100%, specificity 95.1%, and negative predictive value (NPV) 100%, with high individual NPV (99–100%). Area under the receiver-operating characteristic curve was 0.992 after consensus (0.976–0.986 individually). The spontaneous density was significantly different (P <0.05) between normal sinuses and CVTs, with a density >70 HU reported only within the CVTs, except for the horizontal part of the superior sagittal sinus (hSSS). Conclusion The dense triangle sign on helical unenhanced brain CT has an excellent NPV to exclude a sinus thrombosis during the first 2 weeks. However, we believe that visual assessment of spontaneous hyperdensity is not sufficient for the diagnosis of CVT, with possible false-positive of the hSSS on unenhanced CT.

Teaching NeuroImages: Ornithine transcarbamylase deficiency revealed by a coma in a pregnant woman.

A 32-year-old pregnant (20 weeks of amenorrhea) woman, after change in dietary intake (due to a trip to Korea), developed over 3 weeks progressive neuropsychological disorders associated with behavior disorders. The patient rapidly worsened, and had impaired consciousness and a coma. Biological tests showed hyperammonemia (173 µmol/L), glutamine chromatographic peak, and increased urinary orotic acid concentration. Brain MRI (figure 1) and spectroscopy (figure 2) findings were consistent with urea cycle disorders.1,2 A novel heterozygous mutation p.Ala209Glu (c.626C>A) in OTC gene was identified. She was treated with sodium benzoate, sodium phenylacetate, citrulline, hemofiltration, and reduced protein intake. Consciousness improved, and pregnancy was carried to completion, but mild cognitive impairment persisted 3 months later. The baby girl also carried the mutation but had no sequelae at 11 months.

Accidents artériels ischémiques cérébraux du sujet jeune

En France, un quart des accidents vasculaires cerebraux (AVC) survient chez des personnes de moins de 65 ans. Bien que le risque d’accidents ischemiques cerebraux (AIC) augmente avec l’âge, une hausse de 10 % a ete enregistree chez les moins de 65 ans entre 2002 et 2008. La plupart des facteurs de risque des sujets plus âges : hypertension arterielle, hypercholesterolemie, diabete, sont aussi des facteurs de risque chez le sujet jeune. Mais, bien qu’il y ait des facteurs de risque identiques entre les populations jeunes et plus âgees, certains facteurs de risque vasculaires sont plus specifiques au sujet jeune : la contraception orale, la migraine, la prise de drogue, la grossesse. En plus de l’examen neurologique classique, l’examen extra-neurologique a une importance cruciale pour orienter vers une cause rare d’AIC. Les examens dermatologique et ophtalmologique sont particulierement interessants ainsi que la discussion multidisciplinaire avec les specialistes de ces memes organes. Jusqu’a 40 % des AIC restent de cause inconnue. Nous detaillerons les causes frequentes d’AIC du sujet jeune : les causes inconnues associees a un foramen ovale permeable (FOP), la dissection arterielle, et des causes plus rares mais non exceptionnelles : le syndrome des antiphospholipides, la maladie de Fabry, les AIC en rapport avec la prise de cannabis.