Accidente cerebrovascular recurrente y adenocarcinoma mucinoso de páncreas / Mucin-secretine adenocarcinomas of pancreatobiliary origin, hypercoagulable states and stroke

El adenocarcinoma mucinoso de páncreas se caraacteriza por su rápido crecimiento, su alta mortalidad y su frecuente asociación a los síndromes de hipercoagulabilidad. Sin embargo, el accidente cerebrovascular recurrente (ACV) como manifestación inicial, es excepcional. Se prestenta un paciente masculino de 57 años con diagnóstico de adenocarcinoma mucinoso de probable origen pancreático con diseminación hepática, que presentó ACV múltiples. En la resonancia magnética nuclear (RMN) de encéfalo inicial se constató una lesión isquémica aguda temporoparietal izquierda, y desarrolló lesiones isquémicas agudas en diversos territorios vasculares. Ante la sospecha de síndrome de Trousseau, un síndrome paraneoplásico de hipercoagulabilidad y fenómenos trombóticos, se solicitó un ecocardiograma transesofágico que descartó focos embolígenos cardíacos (endocarditis trombótica no bacteriana o ETNB) pero visualizó pequeñas placas fibrocálcicas en el cayado aórtico. Este caso ilustra la asociación sinérgica de síndrome de Trousseau y embolias del cayado aórtico en un paciente con ACV recurrente multifocal y adenocarcinoma mucinoso.

Plaque rupture in the carotid artery is localized at the high shear stress region: a case report.

BACKGROUND AND PURPOSE: Cerebrovascular events are related to atherosclerotic disease in the carotid arteries and are frequently caused by rupture of a vulnerable plaque. These ruptures are often observed at the upstream region of the plaque, where the wall shear stress (WSS) is considered to be highest. High WSS is known for its influence on many processes affecting tissue regression. Until now, there have been no serial studies showing the relationship between plaque rupture and WSS. Summary of Case- We investigated a serial MRI data set of a 67-year-old woman with a plaque in the carotid artery at baseline and an ulcer at 10-month follow up. The lumen, plaque components (lipid/necrotic core, intraplaque hemorrhage), and ulcer were segmented and the lumen contours at baseline were used for WSS calculation. Correlation of the change in plaque composition with the WSS at baseline showed that the ulcer was generated exclusively at the high WSS location. CONCLUSIONS: In this serial MRI study, we found plaque ulceration at the high WSS location of a protruding plaque in the carotid artery. Our data suggest that high WSS influences plaque vulnerability and therefore may become a potential parameter for predicting future events.

Risk of acute brain injury related to cerebral microembolism during cardiac catheterization performed by right upper limb arterial access.

BACKGROUND AND PURPOSE: The primary objective of this study was to assess the incidence of new cerebral infarcts related to cardiac catheterization in patients explored through the right transradial approach. METHODS: This prospective study involved 41 consecutive patients with severe aortic valve stenosis. To assess the incidence of cerebral infarction, all patients underwent cerebral diffusion-weighted MRI before and after cardiac catheterization through the right transradial approach. RESULTS: We detected only two patients (4.9%) with new, small, isolated acute cerebral diffusion abnormalities postcatheterization. All patients remained asymptomatic. CONCLUSIONS: New cerebral lesions on diffusion-weighted MRI are infrequent in patients explored through the right transradial approach. Randomized studies are warranted to confirm for potential advantages of transradial approach versus the femoral approach in cardiac catheterization.

Angiogenesis and improved cerebral blood flow in the ischemic boundary area detected by MRI after administration of sildenafil to rats with embolic stroke.

To dynamically investigate the long-term response of an ischemic lesion in rat brain to the administration of sildenafil, male Wistar rats subjected to embolic stroke were treated with sildenafil (n=11) or saline (n=10) at a dose of 10 mg/kg administered subcutaneously 24-h after stroke and daily for an additional 6 days. Magnetic resonance images were acquired and functional performance was measured in all animals at 1 day, 2 days and weekly for 6 weeks post-stroke. All rats were sacrificed 6 weeks after stroke and endothelial barrier antigen immunostaining was employed for morphological analysis and quantification of cerebral vessels. Map-ISODATA was computed from T(1), T(2) and T(1sat) maps. ISODATA derived tissue signatures characterize the degree of ischemic injury. Based on the map-ISODATA calculated at 6 weeks, the ischemic lesion for each animal was divided into two specific regions, the ischemic boundary and ischemic core. The temporal profiles of cerebral blood flow (CBF) and tissue signature were retrospectively tracked in these two regions and were compared with histological evaluation and functional outcome. After 1 week of sildenafil treatment, the ischemic lesion exhibited two significantly different regions, with higher CBF level and correspondingly, lower tissue signature value in the boundary region than in the core region. Sildenafil treatment did not significantly reduce the lesion size, but did enhance angiogenesis. Functional performance was significantly increased after sildenafil treatment compared with the control group. Administration of sildenafil to rats with embolic stroke enhances angiogenesis and selectively increases the CBF level in the ischemic boundary, and improves neurological functional recovery compared to saline-treated rats.

The use of intraoperative monitoring and treatment of symptomatic microemboli in carotid artery stenting: case report and discussion.

Carotid artery stenting is a recently introduced treatment in symptomatic atherosclerotic carotid artery disease with acceptable complication rates. The major risk is perioperative embolic stroke. Transcranial Doppler ultrasonography (TCD) can be used to identify embolic signals and guide therapy. We present a case of symptomatic embolization in a 72-year-old female following carotid stent deployment complicated by haemodynamic changes. Despite concurrent dual antiplatelet medication significant symptomatic embolization occurred even after restoration of the blood pressure, and modulation of the rate of embolization was achieved using dextran-40 guided by TCD monitoring. The patient recovered from an initially profound hemiparesis and dysphasia to minor sensory changes. Microemboli are common following carotid artery stenting and there appears to be a threshold phenomenon associated with prolonged embolization and progression to cerebral infarction. TCD can be used to detect particulate microemboli and therefore may be useful in guiding antithrombotic therapy in this setting. Dextran-40 has been shown to reduce the embolic load following carotid endarterectomy and was used to good effect in this patient in terms of both embolic load and clinical outcome. This is the first case of embolization following carotid stenting successfully treated with dextran-40, and offers a further option for therapeutic intervention in microembolism detected by TCD and stresses the importance of perioperative monitoring of embolic load for postoperative stroke risk.

Brain injury from cardiac bypass procedures.

Patients who undergo coronary artery bypass grafting (CABG) are at increased risk for brain injury. Surgical techniques have advanced so that the risk of neurological sequelae is decreased, but there remains significant morbidity and mortality related to the postoperative period as well as to the surgery itself. In addition, patients who undergo CABG have comorbidities or demographic factors that may increase their likelihood of developing neurological complications. Pathophysiological mechanisms of cerebral injury after CABG range from hemodynamic compromise to embolization, either intraoperatively or postoperatively. Biochemical markers such as S100 and neuron-specific enolase may play a role in the prediction of outcome after CABG, and because of this may help elucidate other potential risk factors. Specific neurological sequelae are discussed, such as stroke, with summaries of the apparent risk factors, as well as encephalopathy, seizure, and both short- and long-term cognitive deficits. Changes in surgical technique have led to some improvements, but there is no definitive information yet as to the role of some of these, such as the use of off-pump CABG. Other techniques such as the use of an arterial filter are discussed, as are their potential benefits in the prevention of neurological complications.

Incidence of new brain lesions after carotid stenting with and without cerebral protection.

BACKGROUND AND PURPOSE: Diffusion-weighted imaging (DWI) may be a useful tool to evaluate the efficacy of cerebral protection devices in preventing thromboembolic complications during carotid angioplasty and stenting (CAS). The goals of this study were (1) to compare the frequency, number, and size of new DWI lesions after unprotected and protected CAS; and (2) to determine the clinical significance of these lesions. METHODS: DWI was performed immediately before and within 48 hours after unprotected or protected CAS. Clinical outcome measures were stroke and death within 30 days. RESULTS: The proportion of patients with any new ipsilateral DWI lesion (49% versus 67%; P<0.05) as well as the number of new ipsilateral DWI lesions (median=0; interquartile range [IQR]=0 to 3 versus median=1; IQR=0 to 4; P<0.05) were significantly lower after protected (n=139) than unprotected (n=67) CAS. The great majority of these lesions were asymptomatic and less than 10 mm in diameter. Although there were no significant differences in clinical outcome between patients treated and not treated with protection devices (7.5% versus 4.3%, not significant), the number of new DWI lesions was significantly higher in patients who developed a stroke (median=7.5; IQR=1.5 to 17) than in patients who did not (median=0; IQR=1 to 3.25; P<0.01). CONCLUSIONS: The use of cerebral protection devices significantly reduces the incidence of new DWI lesions after CAS of which the majority are asymptomatic and less than 10 mm in diameter. The frequent occurrence of these lesions and their close correlation with the clinical outcome indicates that DWI could become a sensitive surrogate end point in future randomized trials of unprotected versus protected CAS.

Computer-assisted intraaneurysmal thrombus visualization.

OBJECTIVE: Improved visualization of intraaneurysmal thrombi can contribute to understanding their impact on clinical courses and treatments. Digital subtraction angiography (DSA) demonstrates the hemodynamic portion of aneurysm domes and vasculature structures and has been considered by many to be the principal technique used for aneurysm diagnosis. An intraaneurysmal thrombus may be visualized as a filling defect on DSA, but DSA does not reliably indicate the presence of an intraaneurysmal thrombus or its details. Computerized tomography (CT) and magnetic resonance (MR) imaging may have advantages over DSA, particularly because of their capacity to visualize soft tissue. Hence, we investigated the reconstruction of MR and CT images and compared it to DSA for assessment of intraaneurysmal thrombi. METHODS: Thirty-one patients with 34 aneurysms were enrolled. The entire group was examined with DSA. Sixteen cases were also examined with MR imaging; the remaining 15 were examined with CT imaging. Images of intraaneurysmal thrombi were rendered from corresponding MRI and soft tissue scans using CT. Intracranial vessels and aneurysms were defined from MR and CT angiography. Whole images were linked via imaging software for the reconstruction of vasculature structures. Images were superimposed to produce visualizations of thrombi situated in aneurysmal bodies. RESULTS: Reconstruction of the MR and CT images clearly demonstrated the presence and details of intraaneurysmal thrombi in 9 (26.4 %) of 34 aneurysms. DSA detected only 4 (11.7 %) of the cases as a filling defect. Significant differences in thrombus visualization were observed between DSA used alone or in conjunction with either MRA (P = .02) or CTA (P = .04) images. Mean volume of thrombosed aneurysms was 3.2 +/- 0.84 mL (mean +/- SEM) and thrombosis volume was 0.9 +/- 0.31 mL. Aneurysm and nested thrombus volumes were highly correlated (r = 0.987; P < .001). CONCLUSION: Intraaneurysmal thrombi were clearly visualized by computerized MR and CT image reconstruction. MR and CT were superior to DSA alone in demonstrating the presence of intra-aneurysmal thrombi. Computer-assisted 3-D visualization can be invaluable in understanding the shape and volume of intraaneurysmal thrombi, which may contribute to more accurate assessment and effective treatment of aneurysms cases.

[Two cases of top of the basilar syndrome with onset seizure].

We reported 2 patients with top of the basilar syndrome manifested by onset seizure. Patient 1 was a 76-year-old man. When he was sleeping, suddenly he gave a loud cry and went into convulsions. So he was brought to our hospital by ambulance. On admission, he had unconsciousness and left hemiplegia. Patient 2 was a 70-year-old man. When he was bathing, he lost his consciousness and brought to our hospital by ambulance. On admission, he had convulsion and tetraplegia. Both patients had convulsions and palsy when they had brain infarctions. Brain diffusion weighted MR image showed high intensity area in bilateral internal thalamus, brainstem and cerebellum and no high intensity area in cerebral cortex. We know well that Todd's palsy is palsy after convulsion, but vertebro-basilar occlusion also shows convulsion and palsy. Therefore attention should be paid in the case of the patients who had convulsion and palsy.

Absence of microemboli on transcranial Doppler identifies low-risk patients with asymptomatic carotid stenosis.

BACKGROUND AND PURPOSE: Carotid endarterectomy clearly benefits patients with symptomatic severe stenosis (SCS), but the risk of stroke is so low for asymptomatic patients (ACS) that the number needed to treat is very high. We studied transcranial Doppler (TCD) embolus detection as a method for identifying patients at higher risk who would have a lower number needed to treat. METHODS: Patients with carotid stenosis of > or =60% by Doppler ultrasound who had never been symptomatic (81%) or had been asymptomatic for at least 18 months (19%) were studied with TCD embolus detection for up to 1 hour on 2 occasions a week apart; patients were followed for 2 years. RESULTS: 319 patients were studied, age (standard deviation) 69.68 (9.12) years; 32 (10%) had microemboli at baseline (TCD+). Events were more likely to occur in the first year. Patients with microemboli were much more likely to have microemboli 1 year later (34.4 versus 1.4%; P<0.0001) and were more likely to have a stroke during the first year of follow-up (15.6%, 95% CI, 4.1 to 79; versus 1%, 95% CI, 1.01 to 1.36; P<0.0001). CONCLUSIONS: Our findings indicate that TCD- ACS will not benefit from endarterectomy or stenting unless it can be done with a risk <1%; TCD+ may benefit as much as SCS if their surgical risk is not higher. These findings suggest that ACS should be managed medically with delay of surgery or stenting until the occurrence of symptoms or emboli.

[Headache in patients with cerebral venous thrombosis]. / Céphalées au cours des thromboses veineuses cérébrales.

Headache is the most frequent symptom of cerebral venous thrombosis. They do not have particular characteristics and can mimic other numerous varieties of headache. Frequently associated with other neurological symptoms, such as intracranial hypertension, seizures, focal deficits or disorders of consciousness, they are sometimes isolated, which stresses the need for investigations in all recent and unusual headache.

Can transcranial Doppler discriminate between solid and gaseous microemboli? Assessment of a dual-frequency transducer system.

BACKGROUND AND PURPOSE: Transcranial Doppler ultrasound can reliably detect both gaseous and solid cerebral emboli. However, conventional equipment is unable to discriminate between gaseous and solid emboli. This is a major limitation in situations in which the 2 coexist, because they may have very different clinical relevance. Recently, a novel Embo-Dop system, using insonation at 2 ultrasound transducer frequencies, has been developed. An initial study with a small sample size suggested it provided excellent discrimination. We performed a validation study in subjects with embolic signals of known nature. METHODS: Gaseous embolic signals were obtained in 7 patients with known patient foramen ovale by intravenous injection of agitated saline injections. Solid embolic signals were obtained in patients with symptomatic carotid stenosis (N=23). Discrimination of the 2 using the Embo-Dop system dual-frequency system was assessed. It was compared with discrimination using embolic signal maximum intensity with an intensity threshold. RESULTS: One hundred forty-five solid embolic signals were recorded from carotid stenosis patients. Seventy-three were classified as solid and 72 as gaseous by the Embo-Dop system. Six hundred forty-eight gaseous embolic signals were recorded from 7 patients with patent foramen ovale. Six hundred twenty-five were classified as gaseous and 23 as solid. This gave a sensitivity of 50.3% and specificity of 96.5% for detecting solid embolic signals. Discrimination was better than using a simple intensity threshold. CONCLUSIONS: The Embo-Dop dual-frequency system allows better discrimination than a simple intensity threshold but it is not accurate enough for use in clinical or research studies. Further work is needed to develop reliable clinical systems for discrimination of emboli.

Fate of left atrial thrombi in patients with atrial fibrillation determined by transesophageal echocardiography and cerebral magnetic resonance imaging.

Patients with atrial fibrillation (AF) and atrial thrombi have an increased risk for cerebral embolism. However, there is little knowledge about the long-term fate of atrial thrombi and the incidence of cerebral embolism in patients receiving continued oral anticoagulation. Forty-three consecutive patients with AF and atrial thrombi were enrolled in the study. Serial and prospective transesophageal echocardiographic studies, cranial magnetic resonance imaging (MRI), and clinical examinations were performed during a period of 12 months. Oral anticoagulation was continued or initiated in all patients. An international normalized ratio of 2.0 to 3.0 was regarded as effective. During follow-up, 56% of the thrombi disappeared (7 [16%] at 1 month, 18 [42%] at 3 months, 21 [49%] at 6 months, and 24 [56%] at 12 months). Patients with the disappearance of thrombi had significantly smaller thrombi compared with patients with persistent thrombi (1.5 +/- 0.8 cm in length and 0.8 +/- 0.5 cm in width vs 1.9 +/- 0.6 cm in length and 1.3 +/- 0.4 cm in width, p = 0.04), reduced echogenicity of thrombi (46% vs 89%, p <0.01), and smaller left atrial (LA) volume (83 +/- 27 vs 116 +/- 55 cm(3)). Seven patients (16%) had embolic lesions during follow-up MRI. Six of these patients (86%) had clinically apparent embolisms, and 1 died from stroke. The only independent predictors of cerebral embolism were an elevated peak emptying velocity of the LA appendage (p <0.01) and previous thromboembolic events (p = 0.02). Patients with AF and atrial thrombi have a large likelihood of cerebral embolism (16%) and/or death despite oral anticoagulation therapy. Thrombus size may predict thrombus resolution under continued anticoagulation.

Deconvolution of dynamic contrast-enhanced MRI data by linear inversion: choice of the regularization parameter.

Truncated singular value decomposition (TSVD) is an effective method for the deconvolution of dynamic contrast-enhanced MRI. Two robust methods for the selection of the truncation threshold on a pixel-by-pixel basis--generalized cross validation (GCV) and the L-curve criterion (LCC)--were optimized and compared to paradigms in the literature. The methods lead to improvements in the estimate of the residue function and of its maximum and converge properly with SNR. The oscillations typically observed in the solution vanish entirely and perfusion is more accurately estimated at small mean transit times. This results in improved image contrast and increased sensitivity to perfusion abnormalities, at the cost of 1-2 min in calculation time and isolated instabilities in the image. It is argued that the latter problem may be resolved by optimization. Simulated results for GCV and LCC are equivalent in terms of performance, but GCV is faster.

[Etiology, clinical variants, diagnosis and treatment tactic of cerebellar infarction]. / Etiologiia, klinicheskie varianty, diagnostika i lechebnaia taktika infarkte mozzhechka.

The article contains a review of revelant medical literature focusing on etiology, diagnosis and treatment of cerebellar infarction (CI). The above health problem occurs relatively seldom covering about 2% of all strokes. Common CI etiological factors include atherothrombotic lesions of the vertebrobasilar arteries, cardiac embolism. CI symptoms depend on localization and size of the infarction site. The infarct topography in accordance with the affected arterial region correlates with neurological disfunction. CI may bring about complications such as acute obstructive hydrocephalus and brain stem compression developing in the wake of the mass-effect. Computerized tomography and magnetoresonance topography permit making an early diagnosis and timely to make detect the development of complications. Cases of complicated CI need the neurosurgical treatment to be carried out.

Streptokinase in the treatment of venous sinus thrombosis: a case report.

We present a case of cerebral venous thrombosis diagnosed by magnetic resonance venography, magnetic resonance imaging, and angiography. Selective direct thrombolytic treatment with streptokinase via highly selective venography was successful.