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INTRODUCTION: To date, little attention has been paid to the study of the venous system by means of transcranial Doppler ultrasound. The objective of our study was to learn how to localize cerebral blood flow and find the normal values of different ultrasonographic parameters. PATIENTS AND METHODS: We studied 20 healthy persons in whom the arterial system of the circle of Willis had previously been shown to be normal. Transcranial Doppler scan was done with the person lying face upwards, using a transtemporal 2 MHz catheter. In the study we included persons in whom at least one of the two veins could be studied unilaterally. RESULTS: We studied twelve men and eight women aged between 25 and 78 years. The basal vein of Rosenthal, localized bilaterally in 70% of the cases, was identified as a wave of low pulsation between segments P1 and P2 of the posterior cerebral artery, going away from the catheter at a speed of about 11 cm/second. The middle cerebral vein was found bilaterally in only 35% of the cases as a wave near to the middle cerebral artery but in the opposite direction, at an average velocity of approximately 11.7 cm/second and of low pulsation. CONCLUSIONS: In spite of the technical problems, which can be solved using contrast agents, it is possible to study the cerebral venous system by means of transcranial Doppler. Our Unit is the first in Spain to show this. We therefore wish to promote the use of transcranial Doppler in cerebral venous disorders.
We reported an autopsy case of thrombotic occlusion of the superior cerebral vein with hemorrhagic laminar necrosis of the right parietal cortex. A 68-year-old woman was admitted to our hospital because of a severe headache and left hemiplegia of acute onset. There was a past history of hypertension, fever of unknown origin, leukocytopenia and nasal dermatitis. Magnetic resonance images (MRI) disclosed thrombosis of the superior sagittal sinus and of the right parietal cortical vein as well as right parieto-occipital cerebral infarction. Although she improved with mild sequelae, the subsequent MRI showed a recurrent thrombosis of the superior sagittal sinus. Ten months after the onset she died suddenly, presumably due to acute myocardial infarction. Pathologically, thrombotic occlusion of the right parietal cortical vein, recurrent thrombosis of the superior sagittal sinus and old hemorrhagic cortical laminar necrosis of the right parietal region were revealed. Moreover, intracranial arteritis and phlebitis were observed, as well as arteriolitis in the peripheral nerves. In our case, MRI was useful for the diagnosis and following the course of cerebral venous thrombosis. Cerebral noninfective vasculitis may well have caused the venous thrombosis.
BACKGROUND AND PURPOSE: The natural history and long-term prognosis of cerebral vein and dural sinus thrombosis (CVT) have not been examined previously by adequately powered prospective studies. METHODS: We performed a multinational (21 countries), multicenter (89 centers), prospective observational study. Patients were followed up at 6 months and yearly thereafter. Primary outcome was death or dependence as assessed by modified Rankin Scale (mRS) score >2 at the end of follow-up. RESULTS: From May 1998 to May 2001, 624 adult patients with CVT were registered. At the end of follow-up (median 16 months), 356 patients (57.1%) had no symptom or signs (mRS=0), 137 (22%) had minor residual symptoms (mRS=1), and 47 (7.5%) had mild impairments (mRS=2). Eighteen (2.9%) were moderately impaired (mRS=3), 14 (2.2%) were severely handicapped (mRS=4 or 5), and 52 (8.3%) had died. Multivariate predictors of death or dependence were age >37 years (hazard ratio [HR]=2.0), male sex (HR=1.6), coma (HR=2.7), mental status disorder (HR=2.0), hemorrhage on admission CT scan (HR=1.9), thrombosis of the deep cerebral venous system (HR=2.9), central nervous system infection (HR=3.3), and cancer (HR=2.9). Fourteen patients (2.2%) had a recurrent sinus thrombosis, 27 (4.3%) had other thrombotic events, and 66 (10.6%) had seizures. CONCLUSIONS: The prognosis of CVT is better than reported previously. A subgroup (13%) of clinically identifiable CVT patients is at increased risk of bad outcome. These high-risk patients may benefit from more aggressive therapeutic interventions, to be studied in randomized clinical trials.
This paper presents the range of normal blood flow velocity in different cerebral veins in early infancy measured by transfontanelle pulsed Doppler ultrasonography. The blood flow velocity of the internal jugular vein (38 infants), internal cerebral vein (28 infants), and straight sinus (18 infants) in a group of clinically stable neonates and young infants (body weight 1060-3750 g, age 1-86 d, gestational age 28-41 wk) is specified. The time mean of maximum velocity (Vma) of internal jugular vein was 8.4 +/- 4.7 cm/s, of internal cerebral vein 5.5 +/- 1.6 cm/s, and of straight sinus 12.6 +/- 7.8 cm/s. While the variability between infants was high, the reproducibility of the method was in the range of 4.4-10.2% for Vma. This compares well with studies on cerebral arteries and offers a noninvasive approach to the study of the venous cerebral hemodynamics in neonates undergoing intensive care.
The distribution of nerve fibers in the cerebral veins was studied by catecholamine fluorescence simultaneously with acetylcholinesterase (AChE) histochemistry. A comparison of nerve fibers in the cerebral arteries was made. The ultrastructure of terminal boutons in the veins fixed with potassium permanganate was also studied. In the adventitia of the cerebral artery, green fluorescent aminergic fibers and brownish AChE-reactive (probably cholinergic) fibers were observed. In contrast, the cerebral venous system showed no AChE-positive fibers. Catecholamine fluorescent varicose fibers were detected in the dural sinus, the internal cerebral vein, and the superficial vein of Labbé. The highest density of aminergic fibers was found in the dural sinus and the second highest in the internal cerebral vein. Most of the terminal boutons in the adventitia of the cerebral veins were found adjacent to a muscle-like cell and showed only cored vesicles under electron microscopy. Results of our study suggest that the cerebral venous system has a neurogenic innervation, mainly from aminergic fibers, which is different from the neurogenic supply to the cerebral arterial system.
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Formation of cerebral veins can be retraced through eight embryologic stages: before the 4 mm stage, neither arteries nor veins can be distinguished within the primitive network of the head; the 5 mm stage, when three dural plexuses can be identified; the 6 to 12 mm stage, marked by development of anterior dural plexus and lateralization of veins in relation to future cranial pairs; the 12 to 16 mm stage, with development of the anastomosis between anterior and middle dural plexus, and of the pial veins; the 16 to 21 mm stage, marked by regression of primitive sinus of the head and appearance of the anlage of straight sinus and of transverse and sigmoid sinuses; the 21 to 29 mm stage, with appearance of a temporary prosencephalic median vein, possibly implicated in the etiopathogenicity of so-called aneurysms of Galen's ampulla; the 40 mm stage with elaboration of the deep cerebral venous networks; the 60 to 80 mm stage during which the basal veins and Galen's ampulla are formed. After 3 months, the fetal encephalic venous system has attained its adult appearance.
BACKGROUND: Idiopathic cerebral vein thrombosis (iCVT) represents approximately 30% of the cases of cerebral vein thrombosis (CVT). New, inherited - factor V Leiden (FVL) and prothrombin gene mutation (PTHRA20210) - and inherited/acquired - hyperhomocysteinemia (HHcy) - prothrombotic conditions have been detected recently. METHODS: We assessed fasting plasma homocysteine (Hcy) levels and main Hcy determinants, FVL and PTHRA(20210) in 30 patients with documented iCVT and 40 age- and sex-matched healthy subjects. RESULTS: A strong and significant association of PTHRA(20210) [30% (9/30) vs. 2.5% (1/40) iCVT vs. controls, respectively, p = 0.001; OR = 16.174, p = 0.002] and HHcy [13/30 (43.3%) vs. 4/40 (10%) iCVT vs. controls, respectively; p = 0.002, OR = 6.88, p = 0.002] with iCVT was found. CONCLUSIONS: PTHRA(20210) and HHcy should be considered when screening for thrombophilia and should be assessed in patients with a family or personal history of CVT.
We examined the efficacy of a bypass from an extracerebral artery to a cerebral vein (EA-CV) with retrograde verapamil infusion on acute focal cerebral ischemia in 35 rats. In 12 rats, within 1 hour after occlusion of the middle cerebral artery (MCAO), changes in blood-brain barrier permeability were examined by [14C]alpha-aminoisobutyric acid autoradiography after EA-CV bypass surgery; there were no significant changes during a period of 2 hours after EA-CV bypass. The other 18 rats having MCAO were divided into three groups of six each. Group A rats (control) underwent only cannulation of the cerebral vein. Group B rats had an EA-CV bypass. Group C rats received verapamil (0.1 mg/kg every 2 h) by transvenous perfusion of the brain (TVPOB) through the EA-CV bypass. In all rats in Groups A and C, local cerebral blood flow (LCBF) and quantitative measurement of early cerebral infarct volume were performed by autoradiography using [14C]iodoantipyrine and histochemical staining methods. Group B rats were examined only with the LCBF measurement. Group B (EA-CV bypass only) showed a nonsignificant improvement (18-40%) of LCBF in the ischemic cerebral cortical areas as compared with control Group A. Group C (EA-CV bypass with TVPOB with verapamil) showed an extensive and significant improvement in LCBF in the ischemic cortical areas (115-140%; P less than 0.05) and a slight increase in LCBF in the subcortical areas (17-29%), with a significant reduction (greater than 35%; P less than 0.05) in a total cerebral infarct volume in the ischemic cerebral hemisphere as compared with the control Group A.(ABSTRACT TRUNCATED AT 250 WORDS)
Cerebral venous angiomas are vascular malformations of the brain which, before the advent of modern imaging, and in particular MRI, were thought to be rare. They have a specific angiographic aspect called "caput Meduse" as it corresponds to the description of a large draining vein to which converge numerous radial veins located in the white matter. These true vascular malformations have characteristic histological features making it possible to differentiate them from other vascular malformations, notably cavernomas. These lesions are less scanty than classically believed, being the most frequent malformations encountered in post-mortem examination series. The circumstances in which cerebral venous angiomas are discovered vary considerably, and haemorrhage can be the revealing sign. Some authors regard these malformations as "abnormalities" of white matter veins and not as pathological entities, since they derive from a change in development during embryogenesis, but this theory is not supported by any anatomical evidence. The same authors attribute the bleeding to an associated cavernoma. Whereas CT enables venous angiomas and possible associated cavernomas to be detected, only repeated MRI explorations performed after the finding of venous angioma and hemorrhage can permit, by analysis of signal changes, to confirm or invalidate the non-pathological theory of the venous malformation and its tendency to bleed. Apart from hemorrhages, since gadolinium is used MRI is the most reliable and least invasive means to diagnose angiomas and to detect associated occult angiographic malformations. For this reason, nowadays only hemorrhages require an angiography in search of an arteriovenous malformation demanding prompt treatment. Moreover, MRI makes it possible to detect angiographically occult malformations.
Comparative histochemical study of the nervous apparatus of the large cerebral vein system (Galen's vein) and its influxes--the interior cerebral veins and the veins of the cerebral basis, was performed in cats, rats, guinea-pigs, and humans. Deep cerebral veins were found to be rather well supplied with cholin- and adrenergic nerves. Paravasal, surface and deep adventitious plexuses are a single nervous formation having unequal structure on different depth of the vessel wall. No difference was found between the concentration of cholin- and adrenergic nerves in the wall of the large cerebral vein and its influxes in rats, cats and guinea-pigs. The density of the nervous plexus on 1 mm2 of the total preparation of the large cerebral vein wall and its influxes increases in the row: rat--guinea-pig--cat--humans.