Stent-Assisted Angioplasty of Intracranial Vertebrobasilar Atherosclerosis: The Best Therapeutic Option in Recurrent Transient Ischemic Events Unresponsive to Anticoagulant Treatments

Atherosclerotic stenosis of the posterior circulation refractory to medical treatment generally has a poor prognosis resulting in a high morbidity-mortality rate and the recurrence of ischemic events. Extracranial bypass in the vertebrobasilar system is possible but is also associated with high morbidity (3–21%) and mortality (13–55%)1,2, and has not been demonstrated to reduce the risk of stroke. Percutaneous angioplasty alone has also not shown favorable results, and further, has been associated with a remarkable number of complications. The improvement resulting from endovascular therapy has taken the treatment of this pathology to a new dimension. We describe eight patients with severe symptomatic basilar artery stenosis who, in addition to medical therapy, were treated by our service with angioplasty and stent placement. Three of them received urgent treatment. All patients suffering from severe stenosis of the basilar artery were treated by the insertion of balloon expandable stents. The degree of pre-stent stenosis was approximately 80% in all cases, and was reduced to 5–10% after the stent implant. There were no complications during treatment. There has not been a recurrence of symptoms or a new ischemic lesion during the one-year follow-up period. Endovascular therapy with a balloon expandable stent or angioplasty plus stent are presented as improved choices for treatment of patients with severe basilar artery stenosis refractory to medical treatment.

RADStation3G: a platform for cardiovascular image analysis integrating PACS, 3D+t visualization and grid computing

RADStation3G is a software platform for cardiovascular image analysis and surgery planning. It provides image visualization and management in 2D, 3D and 3D+t; data storage (images or operational results) in a PACS (using DICOM); and exploitation of patients' data such as images and pathologies. Further, it provides support for computationally expensive processes with grid technology. In this article we first introduce the platform and present a comparison with existing systems, according to the platform's modules (for cardiology, angiology, PACS archived enriched searching and grid computing), and then RADStation3G is described in detail.

Clinical and radiological features of posterior communicating artery aneurysms

SUMMARY

Treatment of unruptured intracranial aneurysms based on critical size and predictive risk factors is generally accepted, but several factors contribute to the clinical outcome in a patient with subarachnoid hemorrhage (SAH) secondary to a ruptured aneurysm. We decided to evaluate other parameters that might contribute to the clinical outcome of patients with a ruptured posterior communicating artery aneurysm. A retrospective review of the medical records of patients diagnosed and/or treated of cerebral aneurysms at our institution was carried out. We selected patients with Pcom aneurysms that presented with SAH and reviewed conventional and tridimensional angiographic images to determine its anatomical orientation and correlated the data with amount of SAH and clinical presentation and outcome. A total of 112 Pcom aneurysms presented with SAH and were included in this study. 92 patients were women and 20 were men, with a mean age of 57 years (range 25-81). According to anatomical orientation, 43 were inferolateral, 30 lateral, 13 superolateral, three inferomedial, two in medial location, two superomedial, 11 inferoposterior, five posterior and three superoposterior. Aneurysms in superolateral location are to be watched carefully, it is likely that this location joins several conditions for these aneurysms to grow faster or have a higher hemodynamic stress which makes them more at risk of rupture and contribute to a worse clinical outcome.

Temporary Balloon Occlusion Test of the Left Vertebral Artery Using Parenchymography as Tolerance Predictor

Temporary balloon occlusion is used as tolerance predictor in patients undergoing vascular occlusion with the aid of clinical assessment during a 30–40 minute temporary occlusion. Several other techniques have been used to help predict each patient's tolerance. Digital cerebral parenchymography (DCP) was originally described to improve our analysis of brain perfusion during ischemic events. We report a case using DCP as tolerance predictor in a patient undergoing sacrifice of the left vertebral artery.

Management of spinal dural arteriovenous fistulae with emphasis on an endovascular approach

Spinal arteriovenous shunts are rare and present at a rate of approximately 1:10 with cerebral arteriovenous shunts. Spinal dural arteriovenous fistulas (SDAVF) are the most common type of spinal vascular malformation in the adult and account for about 60% of all, with a marked male predominance (5:1). Endovascular treatment has gained force as the treatment of choice in recent years. We reviewed the patients sent to our service at Clinica del Rosario in Madrid and Hospital General de Cataluña in Barcelona between January 1991 and December 2005 with a diagnosis of SDAVF made clinically or by imaging for possible endovascular treatment. Location, presenting symptoms, and clinical outcome according to treatment were analyzed. A total of 104 patients were diagnosed and treated for a SDAVF, 85 were men and 19 women aged between 23 and 79 years (average 58). Seventy-six were treated with embolization alone (73%), 21 with a combination of endovascular therapy and surgery (20.1%) and seven patients had surgery alone (6.7%). Of the embolization group, 62 patients were cured (81.5%), 11 improved (14.4%) and three (3.9%) worsened. Of the group with combined therapy, 13 (61.9%) were cured, five (23.8%) improved and three (14.2%) worsened. Among the surgery group, four (57.2%) were cured and three (42.8%) worsened. Endovascular approach with liquid adhesive is gaining more acceptance as the treatment of choice for SDAVF if the conditions allow a super selective catheterization of the shunt. These patients benefit most when diagnosis is made early in the course of the pathology and have a better chance of a complete remission of symptoms.

Giant and large peripheral cerebral aneurysms: etiopathologic considerations, endovascular treatment, and long-term follow-up

BACKGROUND AND PURPOSE

Giant/large peripheral cerebral aneurysms beyond the circle of Willis and middle cerebral artery (MCA) bifurcation are rare lesions, their etiopathogenesis is not completely elucidated, and their treatment is often difficult. We reviewed the etiopathologic findings available in the literature and report the results and long-term follow-up in 10 patients with a giant/large peripheral aneurysm treated by parent artery occlusion.

METHODS

Four aneurysms were on the MCA, 2 on the anterior cerebral artery, and 4 on the posterior cerebral artery (PCA). Two patients presented with bleeding. An occlusion test was performed in 7 patients. Occlusion of the parent artery was performed by using coils in 8 patients; and liquid coils and glue, in 2. Imaging follow-up was available from 1.5 to 4.5 years; and clinical outcome, from 1.5 to 7 years.

RESULTS

All aneurysms were excluded. One patient developed a partial homonymous hemianopsia after PCA occlusion. A transient deficit was observed in 2 other patients. In the partially thrombosed aneurysms, follow-up imaging showed shrinkage of the thrombosed compartment of the aneurysm and disappearance of the mass effect. No patient experienced progression of symptoms and/or bleeding during the follow-up period. At long-term follow-up, 6 patients presented with a modified Rankin Scale score of 0; 3, with score of 1; and 1, with score of 2.

CONCLUSION

The endovascular occlusion of the parent artery appears a relatively safe and efficacious technique in the treatment of these lesions. Long-term follow-up studies confirm persistent exclusion of the aneurysm and good clinical tolerance to the vessel occlusion.

Salmonella enterica strains lacking the frataxin homolog CyaY show defects in Fe-S cluster metabolism in vivo

In Salmonella enterica, the isc operon contains genes necessary for the synthesis of Fe-S clusters and strains lacking this operon have severe defects in a variety of cellular processes. Other cellular loci that impact Fe-S cluster synthesis to a lesser extent have been described. The cyaY locus encodes a frataxin homolog, and it is shown here that lesions in this locus affect Fe-S cluster metabolism. When present in combination with other lesions, mutations in cyaY can result in a strain with more severe defects than those lacking the isc locus.

In vivo drug resistance of falciparum malaria in mining areas of Venezuela

The Lot Quality Assurance Double-Sampling Plan (LQADSP) technique was used in three areas, Maripa, Kilómetro 88 and Ikabaru, to assess the efficacy of antimalarials used routinely by the Venezuelan Malaria Programme. The use of chloroquine (25 mg/kg), chloroquine (40 mg/kg) and the combination of sulfadoxine (500 mg) and pyrimethamine (25 mg) registered treatment failures above the threshold level of 25% in Maripa and Kilómertro 88. In Ikabaru the use of chloroquine (40 mg/kg) did not surpass that quality level and could possibly be less than 10%. Quinine (30 mg/kg) was totally effective in curing patients in all three areas. The use of this technique seems adequate for rapid field evaluations and in this case for providing appropriate information to assist this health programme. However, whilst being an ideal technique for surveying areas in which considerable variation may exist among lots and particularly for Plasmodium falciparum infections in these areas, repeated surveys should be carried out in the same areas over time to monitor changes in the susceptibility of this parasite to first-, second- and third-line drugs. In that way, national drug policies can be modified adequately.

[Concentration of thyrotropic hormone and free thyroxin in children with Down's syndrome]

The incidence of hypothyroidism is higher among children with Down syndrome than among children in the general population. The frequency of hypothyroidism is higher in the areas of endemic goiter than in other areas. The aim of this paper was to study the concentrations of TSH and FT4 in children with Down syndrome residents of Mérida, a region of Venezuelan Andes. At the Centro de Estudio y Prevención del Retardo Mental y Alteraciones en el Desarrollo (CEPREMAD), the thyroid function was studied in 48 children (1 month to 6 years old), who had Down syndrome, and in 123 healthy children of similar ages. All the children were referred to the Center for thyroid function evaluation. Two (4.2%) of the 48 children with Down syndrome had congenital hypothyroidism and 22 (45.8%) had subclinical hypothyroidism (high concentration of thyrotropin-TSH). Among the control children, only 14% had elevated levels of TSH. There were no differences in relation to the gender. In conclusion in children with Down syndrome, the frequency of high concentrations of TSH was three times higher than the frequency among the healthy children. The frequency of hypothyroidism was similar to that found in areas without endemic goiter.

[Eating disorders and personal behavioral control]

OBJECTIVE

To explore the three components of personal behavioral control: Objective control, subjective control and control beliefs among normal women, women at risk of anorexia or bulimia and women with sub-clinical eating disorders.

MATERIAL AND METHODS

In 1997, a cross-sectional study was conducted in Caracas, Venezuela. The study population consisted of 87 women: 21 with sub-clinical eating disorders, 33 at risk of having an eating disorder, and 33 normal women. Measurement instruments used were: Eating Attitude Test, Composite International Diagnostic Interview, Self-control Inventory, Inventory for Perceived Self-efficacy for Self-control, and the Locus of Control Inventory. Data analysis consisted of analysis of variance, and post hoc comparisons were done with the Student-Neuman-Keuls test.

RESULTS

Women with sub-clinical eating disorders were found to have difficulty for behavior self-control, lower self-efficacy to regulate their behavior, and beliefs of control by powerful others over their behavior and its consequences.

CONCLUSIONS

The results from this study are a first attempt to understand the role of the psychological variable "personal control of behavior", as a protective or risk factor for developing sub-clinical anorexia or bulimia.

Cerebral aneurysms treated by Guglielmi detachable coils: evaluation with diffusion-weighted MR imaging

BACKGROUND AND PURPOSE

The most frequent and serious complications of endovascular treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs) are ischemic lesions caused by thromboembolic events. Diffusion-weighted MR imaging appears to be the most sensitive technique for detecting early ischemic phenomena. We evaluated this technique for the detection of brain changes in patients who underwent GDC treatment of aneurysms.

METHODS

Twenty patients with a cerebral aneurysm were studied with diffusion-weighted imaging before and after endovascular treatment with GDCs. Aneurysms were located in the anterior (n = 16) or posterior (n = 4) circulation. Bleeding had occurred in 11 patients. MR studies, including fast fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted sequences, were scheduled before, 2 to 4 hours after, and 48 hours after treatment. MR images, including apparent diffusion coefficient (ADC) maps, were assessed for the presence of acute ischemic stroke lesions.

RESULTS

In all patients, the aneurysm was excluded without neurologic worsening. In 18 patients, diffusion-weighted and FLAIR images showed no evidence of recent ischemic lesions after treatment. In one patient, an asymptomatic frontobasal hyperintense signal on diffusion-weighted images with a drop of ADC values corresponding to an acute ischemic lesion was observed. In another patient, multiple silent lesions were seen on diffusion-weighted images after embolization. These silent lesions were not all located in the vascular territory of the aneurysm's parent artery.

CONCLUSION

This preliminary study suggests that diffusion-weighted MR imaging is a potentially useful tool for monitoring patients after endovascular treatment of a cerebral aneurysm. While small asymptomatic lesions can be observed on these images after embolization, their exact prevalence should be evaluated in a larger series.

[Evolution of angiographic signs of venous hypertension and clinical signs of intracranial hypertension in intracranial dural arteriovenous fistulas]

Dural arteriovenous fistulas (dAVFs) can cause cerebral venous hypertension (VHT). The most common mechanism is due to the fact that some dAVFs can drain retrogradelly in cortical (better defined as leptomeningeal) veins (directly or after drainage in a dural sinus) causing venous engorgement and consequently an impairment of the cerebral venous drainage. However, more rarely, dAVFs without a cortical venous drainage can also be responsible for VHT probably due to dAVF shunts causing insufficient antegrade cerebral venous drainage. In addition, dAVFs are often associated with stenosis and/or thrombosis of dural sinus(es) which can worsen the VHT. Raised pressure within the superior sagittal sinus causes impeded cerebrospinal reabsorption in the arachnoid villi allowing increased intracranial pressure. The venous engorgement in the cortical veins can cause a venous congestive encephalopathy analogous to the venous congestive myelopathy of the spinal dural AVFs. Clinically VHT can cause not only symptoms related to increased intracranial pressure but also seizures, neurological deficits, impairment of the cognitive functions and dementia. An important aspect is the risk of hemorrhage in dAVFs with a leptomeningeal venous drainage leading to VHT. Although the term VHT sensu strictu should be used if venous pressure measurements are performed, angiographic criteria for VHT such as delayed circulation time, venous engorgement and abnormal visualization of the cerebral veins are well established. The purpose of our study was to evaluate the angiographic signs of VHT in patients with dAVF and to study the course of the VHT and of the clinical signs of increased intracranial pressure before and after dAVF endovascular treatment. A retrospective chart analysis of 22 patients (13 males, 9 females) ranging in age from 20 to 87 years (mean: 53 ys.) with a dAVF associated with angiographic signs of VHT was performed. Ten dAVFs were located on the transverse/sigmoid sinus(es), 6 on the superior sagittal sinus, 3 on the petro-tentorial incisura, 1 on the inferior petrosal sinus, 1 on the anterior ethmoidal region and 1 on the Galen vein region. All dAVFs had a retrograde leptomeningeal venous drainage. Stenosis or thrombosis of the dural AVF sinus was observed in 17 cases and stenosis or thrombosis of another sinus(es) and/or of the jugular vein in 8 cases. In 11 patients, the angiographic signs of VHT were global affecting the entire cerebral venous drainage and, in the other 11 patients, the VHT was focal. The VHT caused clinical symptoms of increased intracranial pressure in 18 patients. Other clinical findings included: bruit (11 cases), seizures (3 cases), vertigo (3 cases), visual deficits (2 cases) and impairment of cognitive functions (4 cases). Three patients presented hemorrhage (one parenchymal hematoma, one hemorrhagic infarction and one subarachnoid hemorrhage). The 4 patients without clinical symptoms of increased intracranial pressure presented only bruit in 2 cases, bruit and vertigo in 1 case, bruit and hemorrhagic infarction in another one. The dAVFs were treated by endovascular therapy (arterial approach: 3 cases, venous approach: 6 cases and both arterial and venous approach: 13 cases). Endovascular sessions ranged from 1 to 7 (mean: 2.8) for each patient. After the endovascular treatment, in 12 patients with complete occlusion of the dAVF, the disappearance of angiographic signs of VHT and clinical cure were observed. In 8 patients with partial occlusion of the dAVF, the disappearance of angiographic signs of VHT and clinical cure were observed in 4 cases (almost complete dAVF occlusion in 2 cases); in the other 4 cases, only reduction the angiographic signs of VHT and clinical improvement were obtained. In all 16 patients who were clinically cured angiographic signs of VHT disappeared despite the persistence of dAVF shunts as observed in 4 cases. (ABSTRACT TRUNCATED)

Heart rate variability and inappropriate sinus tachycardia after catheter ablation of supraventricular tachycardia

Sinus tachycardia has been reported after radiofrequency catheter ablation of supraventricular tachycardia. Frequently, these patients require beta-blocking agents for symptomatic control. The purpose of this study was to evaluate prospectively the incidence of inappropriate sinus tachycardia and heart rate variability after ablation of atrioventricular nodal reentrant tachycardia and accessory pathways. Patients undergoing ablation had 24-h ambulatory monitoring ECG (Holter) performed before the procedure, on the day of the ablation, and 3 months afterwards. There were 170 patients, mean age 48 +/- 23 years; 93 were female. A complete study of the 24-h Holter with analysis of heart rate variability: SD, rMSSD, pNN50, high and low frequency was obtained. There was a low prevalence of inappropriate sinus tachycardia after the ablation procedure (10 of 170 patients: five with four atrioventricular nodal reentry, with posteroseptal accessory pathways and one of the latter following ablation of the left accessory pathway). There was no modification of time and frequency domain parameters of heart rate variability in the remaining patients who underwent radiofrequency ablation. Holter monitoring 3 months after ablation showed that parameters of heart rate and heart rate variability had normalized in patients who had developed inappropriate sinus tachycardia. Inappropriate sinus tachycardia may be initiated by both radiofrequency ablation of atrioventricular nodal reentrant tachycardia and radiofrequency ablation of posteroseptal accessory pathways. Specific damage to the posteroseptal region is responsible for these changes, which usually recover spontaneously after 3 months.

Posttranslational modifications in microcin B17 define an additional class of DNA gyrase inhibitor

Drugs that inhibit the activity of DNA gyrase fall almost exclusively into two structural classes, the quinolones and the coumarins. A third class of DNA gyrase inhibitor is defined by the ribosomally synthesized peptide antibiotic microcin B17 (MccB17). MccB17 contains 43 amino acid residues, but 14 of these are posttranslationally modified. Here we describe the characterization of the structure of these modifications. We propose that four cysteine and four serine side chains undergo condensation with the carbonyl group of the preceding residue, followed by alpha/beta dehydrogenation to yield four thiazole and four oxazole rings, respectively. The three proteins implicated in catalyzing these modifications (McbBCD) would constitute the only thiazole/oxazole biosynthetic enzymes identified. These results open up possibilities for the design of DNA gyrase inhibitors and add to the repertoire of posttranslational modifications with potential for protein engineering. Escherichia coli sbmA mutants, which lack the inner membrane protein (SbmA) involved in MccB17 uptake, were found to be resistant to bleomycin. Bleomycin is structurally unrelated to MccB17 except for the fact that it contains two thiazole rings. This suggests that thiazole rings are part of the MccB17 structure recognized by SbmA. This observation and the finding that SbmA homologs are widely conserved and can play developmental roles [Glazebrook, J., Ichige, A. & Walker, G. C. (1993) Genes Dev. 7, 1485-1497] suggest that thiazole- and oxazole-containing compounds may serve as signaling molecules for a wide variety of bacteria in diverse environments, including pathogen interactions with plant and animal hosts.

Characteristics of Venezuelan school refusers. Toward the development of a high-risk profile

Parent, teacher, and child reports were used to identify situational and personal factors associated with school refusal in 114 3- to 13-year-old Venezuelan children. The sample consisted of 57 school refusers and 57 nonrefusers matched on age, school, and sex. As compared with nonrefusers, the refusers had changed schools more often, were rated as more dependent, had more school-related fears, and were perceived by their parents as more difficult to manage. Stepwise multiple regression analyses revealed that school refusal status could be predicted by both situational and personality variables including the child's fear level, dependency, depression, frequency of school changes, history of refusal in the family, and other variables. Refusal onset frequently coincided with situational stress (e.g., the beginning of the school year, a new school or teacher, or trouble with a teacher or peers). Categories of refusal resembled those of other studies and included adjustment reaction, school phobia, and emotional disturbance. In the future, these risk factors can be used to identify and treat potential school refusers.

Estimating the prevalence of school refusal and school-related fears. A Venezuelan sample

This study investigated the prevalence of school refusal and school-related fears in a sample of 1034 Venezuelan children from 3 to 14 years of age. Fear surveys were administered to children older than 9 years and to the younger children's parents. In addition, parents and teachers completed questionnaires regarding the children's other behavior problems, and teachers reported on the children's school achievement and attendance. Although a significant proportion (17.7 per cent) of the children expressed intense fears of school, only rarely were such fears combined with high absenteeism or with parents' or teachers' reports of school refusal problems. School refusal prevalence was calculated using six different fear and absenteeism criteria. When refusal was defined by agreement among all information sources, prevalence was .4 per cent, which is comparable to rates reported in other countries using similar criteria. However, the data indicate that there are various degrees of school aversion and refusal.