The trans-cerebral veins: normal and non-pathologic angiographic aspects

Summary The trans-cerebral v. have long been described, but there is little or no knowledge of their function and dysfunction. They are the site of fundamental interchange across the blood-brain barrier, a unique process within the organism. Two systems can be structurally distinguished: the venous system draining the white matter and the trans-cerebral anastomotic system. The former seems to be associated with the nutrition and drainage of the parenchyma, and is rendered visible at angiography by anatomic variations based on developmental venous anomalies. The anastamotic trans-cerebral ventriculo-cortical system seems concerned with the regulation of reabsorption of the cerebrospinal fluid. It is visualized only in exceptional situations where an increased flow (arteriovenous shunt) is combined with obstruction of the normal routes of venous drainage and collateral circulation. It usually functions in the ventriculo-cortical direction. No specific dysfunction of this system is currently recognized.

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Les Veines trans-cérébrales: aspect angiographique normal et anormal

Résumés Les v. trans-cérébrales sont décrites depuis longtemps, mais leur fonctionnement et leur dysfonctionnement sont peu ou pas connus. Elles sont le siège d'échanges fondamentaux sur un mode unique dans l'organisme: la barrière hémato-encéphalique. Architecturalement on distingue 2 systèmes: le système veineux drainant la substance blanche et le système anastomotique trans-cérébral. Le premier semble lié à des fonctions de nutrition et de drainage du parenchyme; les anomalies veineuses de développement constituent des variations anatomiques qui le rendent angiographiquement visible. Le système anastomotique trans-cérébral ventriculo-cortical semble prédisposé à la régulation de la résorption du liquide céphalo-rachidien; il n'est visible que dans des situations exceptionnelles associant une augmentation de débit (shunt artério-veineux) à des obstacles veineux des voies habituelles de drainage et de circulation collatérale. Il est mis à contribution, le plus souvent dans le sens ventriculo-cortical. Aucun dysfonctionnement spécifique de ce système n'est actuellement connu.

     

Oculocerebrocutaneous syndrome

A female infant was found at birth to have an oculocerebrocutaneous syndrome in which the main clinical features include orbital cyst, cerebral malformations, accessory skin tags, and focal hypoplasia or "punched-out" skin lesions. This case, like the four previously reported, was sporadic.     

Prospective study of computed tomography in acute bacterial meningitis

We performed serial CT scans at the time of admission and discharge, and again after 6 to 18 months, in children older than 2 months of age with bacterial meningitis. During the 2-year study period, 60 patients with bacterial meningitis were admitted to British Columbia's Children's Hospital. Forty-one were included in the study, two of whom died soon after admission. The infecting organism was Haemophilus influenzae in 29, Neisseria meningitidis in six, and Streptococcus pneumoniae in six. Abnormalities on the first two CT scans included subdural effusion in eight patients, focal infarction in five, and pus in the basal cisterns in one. All patients with focal infarction or cisternal pus had hemiparesis. Marked cerebral edema was seen in the two patients who died. Transient mild dilation of the subarachnoid space was a common finding; the size of the ventricles or subarachnoid space was increased on the second scan in 29 of 36 patients, and decreased to normal on the third scan in 30 of 33 patients. Clinical management was not influenced by the CT findings, which failed to reveal any clinically significant abnormalities that were not suspected on neurologic examination.     

Synergistic Effect of Combinations of Sulfamethoxazole, Trimethoprim, and Colistin Against Pseudomonas maltophilia and Pseudomonas cepacia

Eighteen strains of Pseudomonas maltophilia and eight strains of P. cepacia were tested for susceptibility to sulfamethoxazole, trimethoprim, and colistin in different combinations. A synergistic effect was found against most of the strains.     

Point of care coagulation tests in critically ill patients

Point of care assays for various analytes have been established in critical care, including blood gas analysis, glucose, electrolytes, and markers for cardiac ischemia. Coagulation assays can also be adapted to the critical care environment by using whole blood as sample material and instruments optimized for point of care analysis. Available assays include the conventional coagulation assays, such as prothrombin time and activated partial thromboplastin time, fibrinogen, assays for monitoring of anticoagulant drugs, global coagulation assays based on thrombelastography and viscosimetry, platelet function assays, and D-dimer assays. The main problem in point of care coagulation diagnostics is quality control. Point of care coagulation assays help in rapidly establishing a diagnosis, clarifying causes of bleeding, and monitoring therapy. Thrombelastography and similar assays extend the scope of coagulation diagnostics by visualizing the process of clot formation and extending the observation period to provide an estimate of clot stability versus mechanical and proteolytic attack.     

Edema in the lower limb of patients operated on for proximal femoral fractures

BACKGROUND: Patients with proximal femoral fracture (PFF) often develop postoperative edema in the operated limb. This may lead to reduced mobilization, increasing the length of hospitalization. It is therefore relevant to gain information about the extent and pathogenesis of this edema formation. METHODS: Forty-one patients with PFF (30 women and 11 men) were studied pre- and postoperatively. Patients were grouped into pertrochanteric fractures and femoral cervical fractures, according to the AO/ASIF classification of PFF. Thigh and calf volumes were calculated in both fractured and contralateral limbs preoperatively and on postoperative days 3, 5, 7, and 30. RESULTS: All patients with PFF developed edema in the operated limb. The greatest volume increase occurred on postoperative day 7 (p < 0.0005). The magnitude of edema in the thigh and the leg of patients with pertrochanteric fractures as compared with the nonoperative side was approximately twice as great as in those with femoral cervical fractures (p < 0.0001). There was a statistically significant daily increase in the volume of the operative limb as compared with the nonoperative side. Age and sex were not correlated with the extent of edema formation. Functionally significant deep venous thrombosis and local infection could be excluded as causative factors. CONCLUSIONS: Postoperative edema in the thigh and leg of the operated limb was considerable. The magnitude of edema formation was related to the severity of primary trauma and the type of osteosynthesis. Therefore, the operation performed for PFF should be minimally traumatic.     

Valproate-associated coagulopathies are frequent and variable in children

PURPOSE: Valproic acid (VPA) is an antiepileptic drug (AED) commonly used for generalized and focal epilepsies. The clinical relevance of coagulopathies, known as side effects of VPA therapy, especially thrombocytopenia, von Willebrand disease, and a decrease of factor XIII, is still unclear. METHODS: In our institute, we noticed a high incidence of clinically relevant coagulation problems related to VPA in eight patients within 1 year only and a further seven children with significant coagulopathy were identified in the context of planned surgery. RESULTS: We provide an overview of these patients and all six VPA-induced coagulopathies. CONCLUSIONS: At this time, it cannot be recommended to control all hemostatic parameters in every patient. Whenever an increased bleeding tendency is observed, or before surgical procedures, a platelet count, thrombelastography, prothrombin time, activated partial thromboplastin time, TT, fibrinogen, von Willebrand factor, and factor XIII should be examined. With 385 VPA-treated patients per year and 15 cases of coagulation disorders in this period, we estimate the incidence of coagulation disorders related to VPA in children to be nearly 4%.     

Effects of alimentary lipemia and inflammation on platelet CD40-ligand

INTRODUCTION: In patients with chronic hypercholesterolemia, the CD40-CD40L dyad is upregulated, contributing to the initiation and progression of atherosclerosis. Our aim was to describe the role of postprandial lipemia and inflammatory stimulation on platelet and monocyte activation and CD40-ligand (CD40L) levels. METHODS AND RESULTS: Before and 2 h after consumption of a defined fatty meal, whole blood samples of 31 healthy subjects were incubated with endotoxin (LPS). CD40-ligand and CD62P expression on platelets, tissue-factor expression on monocytes and platelet-monocyte aggregates were measured with flow cytometry. Soluble CD40-ligand plasma levels were measured with an ELISA. After the meal, serum triglyceride levels increased from 137.6+/-60.5 mg/dl to 201.5+/-75.0 mg/dl. Expression of CD40L and CD62P on platelets and plasma levels of soluble CD40L were significantly decreased. No significant changes after the meal were observed concerning tissue factor expression on monocytes and platelet-monocyte aggregates. Addition of LPS showed no significant effect concerning CD40L or CD62P expression on platelets, whereas the amount of platelet-monocyte aggregates significantly increased under LPS stimulation after the fatty meal. CONCLUSIONS: Acute alimenatry lipemia leads to a decreased expression of CD40L on platelets and a reduced plasma level of sCD40L, suggesting an increased turnover in the CD40L system. CONDENSED ABSTRACT: Before and after a fatty meal, blood samples of 31 healthy subjects were incubated with LPS. After the meal, expression of CD40L and CD62P on platelets and plasma levels of soluble CD40L were significantly decreased. Addition of LPS showed no effect concerning CD40L or CD62P expression, whereas the amount of platelet-monocyte aggregates significantly increased under LPS stimulation after the fatty meal.