A two-stage framework for neural processing of biological motion.

It remains to be understood how biological motion is hierarchically computed, from discrimination of local biological motion animacy to global dynamic body perception. Here, we addressed this functional separation of the correlates of the perception of local biological motion from perception of global motion of a body. We hypothesized that local biological motion processing can be isolated, by using a single dot motion perceptual decision paradigm featuring the biomechanical details of local realistic motion of a single joint. To ensure that we were indeed tackling processing of biological motion properties we used discrimination instead of detection task. We discovered using representational similarity analysis that two key early dorsal and two ventral stream regions (visual motion selective hMT+ and V3A, extrastriate body area EBA and a region within fusiform gyrus FFG) showed robust and separable signals related to encoding of local biological motion and global motion-mediated shape. These signals reflected two independent processing stages, as revealed by representational similarity analysis and deconvolution of fMRI responses to each motion pattern. This study showed that higher level pSTS encodes both classes of biological motion in a similar way, revealing a higher-level integrative stage, reflecting scale independent biological motion perception. Our results reveal a two-stage framework for neural computation of biological motion, with an independent contribution of dorsal and ventral regions for the initial stage.

Optimizing EEG Source Reconstruction with Concurrent fMRI-Derived Spatial Priors.

Reconstructing EEG sources involves a complex pipeline, with the inverse problem being the most challenging. Multiple inversion algorithms are being continuously developed, aiming to tackle the non-uniqueness of this problem, which has been shown to be partially circumvented by including prior information in the inverse models. Despite a few efforts, there are still current and persistent controversies regarding the inversion algorithm of choice and the optimal set of spatial priors to be included in the inversion models. The use of simultaneous EEG-fMRI data is one approach to tackle this problem. The spatial resolution of fMRI makes fMRI derived spatial priors very convenient for EEG reconstruction, however, only task activation maps and resting-state networks (RSNs) have been explored so far, overlooking the recent, but already accepted, notion that brain networks exhibit dynamic functional connectivity fluctuations. The lack of a systematic comparison between different source reconstruction algorithms, considering potentially more brain-informative priors such as fMRI, motivates the search for better reconstruction models. Using simultaneous EEG-fMRI data, here we compared four different inversion algorithms (minimum norm, MN; low resolution electromagnetic tomography, LORETA; empirical Bayes beamformer, EBB; and multiple sparse priors, MSP) under a Bayesian framework (as implemented in SPM), each with three different sets of priors consisting of: (1) those specific to the algorithm; (2) those specific to the algorithm plus fMRI task activation maps and RSNs; and (3) those specific to the algorithm plus fMRI task activation maps and RSNs and network modules of task-related dFC states estimated from the dFC fluctuations. The quality of the reconstructed EEG sources was quantified in terms of model-based metrics, namely the expectation of the posterior probability P(model|data) and variance explained of the inversion models, and the overlap/proportion of brain regions known to be involved in the visual perception tasks that the participants were submitted to, and RSN templates, with/within EEG source components. Model-based metrics suggested that model parsimony is preferred, with the combination MSP and priors specific to this algorithm exhibiting the best performance. However, optimal overlap/proportion values were found using EBB and priors specific to this algorithm and fMRI task activation maps and RSNs or MSP and considering all the priors (algorithm priors, fMRI task activation maps and RSNs and dFC state modules), respectively, indicating that fMRI spatial priors, including dFC state modules, might contain useful information to recover EEG source components reflecting neuronal activity of interest. Our main results show that providing fMRI spatial derived priors that reflect the dynamics of the brain might be useful to map neuronal activity more accurately from EEG-fMRI. Furthermore, this work paves the way towards a more informative selection of the optimal EEG source reconstruction approach, which may be critical in future studies.

Effects and response of the Cerrado ground-layer to frost along the canopy cover gradient.

Frost effects on savanna plant communities have been considered as analogous to those from fire, both changing community structure and filtering species composition. However, while frost impacts have been well-studied for the woody component of savannas, it is still poorly explored for the ground-layer community. Here, we investigated effects of frost in the Cerrado along a gradient of tree cover, focusing on ground-layer plant species, near the southern limit of the Cerrado in Brazil. We aimed to elucidate if the pattern already described for the tree layer also extends to the ground layer in terms of mimicking the effects of fire on vegetation structure and composition. We assessed how damage severity differs across species and across the tree-cover gradient, and we examined the recovery process after frost in terms of richness and community structure along the canopy cover gradient. Frost caused immediate and widespread dieback of the perennial ground-layer, with greatest impact on community structure where tree cover was lowest. However, frost did not reduce the number of species, indicating community resilience to this natural disturbance. Although frost mimicked the effects of fire in some ways, in other ways it differed substantially from fire. Unlike fire, frost increases litter cover and decreases the proportion of bare soil, likely hindering crucial processes for recovery of plant populations, such as seed dispersal, seed germination and plant resprouting. This finding calls attention to the risk of misguided conclusions when the ground layer is neglected in ecological studies of tropical savannas and grasslands.

The relationship between EEG and fMRI connectomes is reproducible across simultaneous EEG-fMRI studies from 1.5T to 7T.

Both electroencephalography (EEG) and functional Magnetic Resonance Imaging (fMRI) are non-invasive methods that show complementary aspects of human brain activity. Despite measuring different proxies of brain activity, both the measured blood-oxygenation (fMRI) and neurophysiological recordings (EEG) are indirectly coupled. The electrophysiological and BOLD signal can map the underlying functional connectivity structure at the whole brain scale at different timescales. Previous work demonstrated a moderate but significant correlation between resting-state functional connectivity of both modalities, however there is a wide range of technical setups to measure simultaneous EEG-fMRI and the reliability of those measures between different setups remains unknown. This is true notably with respect to different magnetic field strengths (low and high field) and different spatial sampling of EEG (medium to high-density electrode coverage). Here, we investigated the reproducibility of the bimodal EEG-fMRI functional connectome in the most comprehensive resting-state simultaneous EEG-fMRI dataset compiled to date including a total of 72 subjects from four different imaging centers. Data was acquired from 1.5T, 3T and 7T scanners with simultaneously recorded EEG using 64 or 256 electrodes. We demonstrate that the whole-brain monomodal connectivity reproducibly correlates across different datasets and that a moderate crossmodal correlation between EEG and fMRI connectivity of r ≈ 0.3 can be reproducibly extracted in low- and high-field scanners. The crossmodal correlation was strongest in the EEG-ß frequency band but exists across all frequency bands. Both homotopic and within intrinsic connectivity network (ICN) connections contributed the most to the crossmodal relationship. This study confirms, using a considerably diverse range of recording setups, that simultaneous EEG-fMRI offers a consistent estimate of multimodal functional connectomes in healthy subjects that are dominantly linked through a functional core of ICNs across spanning across the different timescales measured by EEG and fMRI. This opens new avenues for estimating the dynamics of brain function and provides a better understanding of interactions between EEG and fMRI measures. This observed level of reproducibility also defines a baseline for the study of alterations of this coupling in pathological conditions and their role as potential clinical markers.

EEG Microstates Predict Concurrent fMRI Dynamic Functional Connectivity States.

Brain functional connectivity measured by resting-state fMRI varies over multiple time scales, and recurrent dynamic functional connectivity (dFC) states have been identified. These have been found to be associated with different cognitive and pathological states, with potential as disease biomarkers, but their neuronal underpinnings remain a matter of debate. A number of recurrent microstates have also been identified in resting-state EEG studies, which are thought to represent the quasi-simultaneous activity of large-scale functional networks reflecting time-varying brain states. Here, we hypothesized that fMRI-derived dFC states may be associated with these EEG microstates. To test this hypothesis, we quantitatively assessed the ability of EEG microstates to predict concurrent fMRI dFC states in simultaneous EEG-fMRI data collected from healthy subjects at rest. By training a random forests classifier, we found that the four canonical EEG microstates predicted fMRI dFC states with an accuracy of 90%, clearly outperforming alternative EEG features such as spectral power. Our results indicate that EEG microstates analysis yields robust signatures of fMRI dFC states, providing evidence of the electrophysiological underpinnings of dFC while also further supporting that EEG microstates reflect the dynamics of large-scale brain networks.

Flammability thresholds or flammability gradients? Determinants of fire across savanna-forest transitions.

Vegetation-fire feedbacks are important for determining the distribution of forest and savanna. To understand how vegetation structure controls these feedbacks, we quantified flammability across gradients of tree density from grassland to forest in the Brazilian Cerrado. We experimentally burned 102 plots, for which we measured vegetation structure, fuels, microclimate, ignition success and fire behavior. Tree density had strong negative effects on ignition success, rate of spread, fire-line intensity and flame height. Declining grass biomass was the principal cause of this decline in flammability as tree density increased, but increasing fuel moisture contributed. Although the response of flammability to tree cover often is portrayed as an abrupt, largely invariant threshold, we found the response to be gradual, with considerable variability driven largely by temporal changes in atmospheric humidity. Even when accounting for humidity, flammability at intermediate tree densities cannot be predicted reliably. Fire spread in savanna-forest mosaics is not as deterministic as often assumed, but may appear so where vegetation boundaries are already sharp. Where transitions are diffuse, fire spread is difficult to predict, but should become increasingly predictable over multiple fire cycles, as boundaries are progressively sharpened until flammability appears to respond in a threshold-like manner.

Physiological noise correction using ECG-derived respiratory signals for enhanced mapping of spontaneous neuronal activity with simultaneous EEG-fMRI.

The study of spontaneous brain activity based on BOLD-fMRI may be seriously compromised by the presence of signal fluctuations of non-neuronal origin, most prominently due to cardiac and respiratory mechanisms. Methods used for modeling and correction of the so-called physiological noise usually rely on the concurrent measurement of cardiac and respiratory signals. In simultaneous EEG-fMRI recordings, which are primarily aimed at the study of spontaneous brain activity, the electrocardiogram (ECG) is typically measured as part of the EEG setup but respiratory data are not generally available. Here, we propose to use the ECG-derived respiratory (EDR) signal estimated by Empirical Mode Decomposition (EMD) as a surrogate of the respiratory signal, for retrospective physiological noise correction of typical simultaneous EEG-fMRI data. A physiological noise model based on these physiological signals (P-PNM) complemented with fMRI-derived noise regressors was generated, and evaluated, for 17 simultaneous EEG-fMRI datasets acquired from a group of seven epilepsy patients imaged at 3T. The respiratory components of P-PNM were found to explain BOLD variance significantly in addition to the cardiac components, suggesting that the EDR signal was successfully extracted from the ECG, and P-PNM outperformed an image-based model (I-PNM) in terms of total BOLD variance explained. Further, the impact of the correction using P-PNM on fMRI mapping of patient-specific epileptic networks and the resting-state default mode network (DMN) was assessed in terms of sensitivity and specificity and, when compared with an ICA-based procedure and a standard pre-processing pipeline, P-PNM achieved the best performance. Overall, our results support the feasibility and utility of extracting physiological noise models of the BOLD signal resorting to ECG data exclusively, with substantial impact on the simultaneous EEG-fMRI mapping of resting-state networks, and, most importantly, epileptic networks where sensitivity and specificity are still limited.

Influence of interhospital transfer on outcomes of symptomatic and ruptured abdominal aortic aneurysms.

Objetive: Evaluate the influence of the geographic location of patients with symptomatic abdominal aortic aneurysms (AAA) or ruptured AAA (rAAA), on mortality. METHODS: Retrospective review of all cases of symptomatic AAA and rAAA submitted to surgery in a tertiary institution, between January 2011 and August 2017. The main outcome was in-hospital mortality. Secondary outcomes were admission to intensive care unit (ICU), length of ICU and hospital stay, type of repair and anesthesia and weekend presentation. Data was submitted to univariable analysis and logistic regression. Statistical significance was considered if the p value was <0.05. RESULTS: 135 patients were admitted with the diagnosis of symptomatic or rAAA and submitted to surgery, 83 (61.5%) by endovascular repair and 52 (38.5%) by open repair, 30.4% with local anesthesia and sedation. 92 patients (68.1%) were transferred from other hospitals, with a mean distance of 113±88 km. Subgroup analysis revealed that there were no significant differences between transferred and not transferred patients' groups concerning main outcome (31.5% vs 34.9%, p=0.35), baseline characteristics (age and gender), type of surgery and anesthesia, weekend presentation, ICU admission, length of ICU and hospital stay. Logistic regression analysis revealed that the variables associated with mortality were female gender (odds ratio [OR] 2.28; 95% confidence interval [CI] 1.40-3.70; p<0.01), open repair (OR 2.79; 95% CI 1.68-4.63; p<0.01) and general anesthesia (OR 9.16; 95% CI 2.33-36.06; p<0.01). CONCLUSION: Our study revealed that interhospital transfer of patients for urgent repair of AAA was not associated with an increased mortality.

Objetivo: Avaliar a influência da localização geográfica dos doentes com aneurismas da aorta abdominal (AAA) sintomáticos ou rotos (rAAA), na mortalidade. Métodos: Revisão retrospetiva de todos os casos de AAA sintomáticos ou rAAA submetidos a cirurgia numa instituição terciária, entre Janeiro 2011 e Agosto 2017. O outcome primário foi a mortalidade intrahospitalar. Os outcomes secundários foram a admissão em unidade de cuidados intensivos (UCI), duração do internamento na UCI e hospitalar, tipo de cirurgia e anestesia e a apresentação ao fim-de-semana. Os dados foram submetidos a análise univariável e regressão logística. Foi considerado um valor estatisticamente significativo quando o valor de p <0.05. Resultados: 135 doentes foram admitidos com o diagnóstico de AAA sintomático ou rAAA e submetidos a cirurgia, 83 (61.5%) por via endovascular e 52 (38.5%) por via convencional, 30.4% com anestesia local e sedação. 92 doentes (68.1%) foram transferidos de outros hospitais, com uma distância média de 113±88 km. A análise de subgrupos revelou que não existia diferença significativa entre os grupos de doentes transferidos e não transferidos relativamente ao outcome primário (31.5% vs 34.9%, p=0.35), características de base (idade e género), tipo de cirurgia e anestesia, apresentação ao fim-de-semana, admissão na UCI, duração do internamento na UCI e hospitalar. A análise de regressão logística revelou que as variáveis associadas com a mortalidade foram o género feminino (odds ratio [OR] 2.28; 95% intervalo de confiança [IC] 1.40- 3.70; p<0.01), cirurgia convencional (OR 2.79; 95% IC 1.68-4.63; p<0.01) e anestesia geral (OR 9.16; 95% IC 2.33- 36.06; p<0.01). Conclusão: Este estudo revelou que a transferência interhospitalar de doentes para a reparação cirúrgica urgente de AAA não está associada a aumento da mortalidade.

Median Arcuate Ligament Syndrome of Diaphragm - Literature Review and Case Report.

OBJECTIVES: To report a case of median arcuate ligament syndrome (MALS) and to review current literature. METHODS: Case report and literature review using PubMed with the terms "median arcuate ligament", "Dunbar syndrome" and "MALS treatment" as major topics. The bibliography of relevant articles has been checked to identify other significant papers. RESULTS: Median arcuate ligament syndrome (MALS) or Dunbar syndrome is a rare clinical entity characterized by celiac trunk compression by median arcuate ligament and variable gastrointestinal symptoms. However, some degree of radiographic compression is observed in 10%-24% of asymptomatic patients, so MALS is a diagnosis of exclusion. Treatment options include release of median arcuate ligament (open, laparoscopic or robot-assisted) and open vascular reconstruction. Endovascular treatment is currently used only as adjuvant procedure after surgical release of median arcuate ligament. A 34-year-old woman, previously healthy, presented with a epigastric pain, mainly postprandial, for 6 months, associated to anorexia and unprovoked weight loss of 8kg over 3 months. Physical examination was normal. Other gastrointestinal pathologies were ruled out. Abdomino-pelvic computed tomography angiography revealed a focal 80% stenosis of proximal celiac trunk. An open decompression of the celiac trunk was performed. The postoperative period was uneventful and the patient was discharged 5 days later, with normal gastrointestinal transit and without abdominal pain recurrence. CONCLUSION: MALS diagnostic and therapeutic approach must be patient focused, bearing in mind the multiple clinical presentation and treatment options. Open surgical decompression of median arcuate ligament is the base of treatment.

Objetivos: Descrever um caso clínico de síndrome do ligamento arqueado do diafragma (SLA) e realizar uma revisão da literatura. Métodos: Descrição de um caso clínico e revisão da literatura com recurso ao PubMed com os termos "median arcuate ligament", "Dunbar syndrome" e "MALS treatment". A bibliografia dos artigos relevantes foi verificada para identificar outros artigos pertinentes. Resultados: A síndrome do ligamento arqueado (SLA) ou síndrome de Dunbar é uma entidade clínica rara caracterizada pela compressão do tronco celíaco associada a sintomas gastrointestinais variáveis. No entanto, algum grau de compressão radiográfica é observado em 10-24% de doentes assintomáticos, o que torna o diagnóstico de SLA de exclusão. As opções terapêuticas incluem a secção do ligamento arcuato (via convencional, laparoscópica ou robótica) e a reconstrução vascular. A abordagem endovascular é atualmente utilizada apenas como procedimento adjuvante após a secção do ligamento arqueado. Doente do sexo feminino de 34 anos de idade, previamente saudável, recorre ao médico assistente por um quadro de dor epigástrica, especialmente pós-prandial, com 6 meses de evolução, associada a anorexia e perda ponderal não provocada superior a 8kg, num período de 3 meses. O exame objetivo não relevou alterações. Outras patologias gastrointestinais foram excluídas. A angiografia por tomografia computorizada revelou uma estenose focal de 80% na porção proximal do tronco celíaco. A doente foi submetida a uma descompressão cirúrgica por via convencional. O período pós-operatório decorreu sem intercorrências, tendo alta 5 dias após a intervenção com o trânsito gastrointestinal restabelecido e sem recorrência da dor abdominal. Conclusão: A abordagem diagnóstica e terapêutica do SLA deve ser individualizada e focada no doente, tendo em conta as múltiplas apresentações clínicas e possíveis opções terapêuticas. A descompressão cirúrgica convencional do ligamento arqueado continua a ser a base do tratamento.

In the Current Era of Endovascular Surgery, What is the Role of Axillofemoral Bypass?

INTRODUCTION: Nowadays, axillofemoral bypass is viewed as an end-of-line solution for lower limb revascularization, owing to its classically described poor long-term patency, and recent advances in endovascular options for patients with complex aortoiliac anatomy not suitable for open reconstruction. There is a marked difference in patient profiles in published series of axillofemoral bypass, reflecting changing procedures indications due to technical innovations. The objective of this study is to determine the contemporary profile of patients treated with axillofemoral bypass and their outcome. METHODS: Patients who underwent axillofemoral bypass surgery in a tertiary hospital from April 2011 to September 2017 were identified. Surgical indication, patency, amputation and death rates were recorded. Patients were grouped in axillouni vs axillobifemoral, 1st revascularization procedure vs reintervention, and primary aortoiliac occlusive disease vs primary aneurysmal disease, and were compared using Kaplan-Meier survival analysis. RESULTS: 54 patients were included. 80% underwent an axillobifemoral bypass. Median age was 67 years; 96% were male. The most prevalent cardiovascular risk factors were HTA (81%) and history of smoking (76%). Primary vascular disease was aneurysmal in 24% of patients. The remaining group had peripheral occlusive arterial disease. In 53%, axillofemoral bypass was the first revascularization performed (naif group). On these, indications for this procedure were aorto-iliac occlusive disease (89%) and AA thrombosis (19%). In patients previously submitted to revascularization (47%), the most common first procedures were aortobifemoral bypass (56%), femoro-femoral bypass (44%) and EVAR (36%). Indications for axillofemoral bypass on this group were: prosthesis thrombosis (64%), secondary aorto-enteric fistulae (28%) and prosthesis infection (8%). Primary patency of axillofemoral bypass was 93% at 1 month and 80% at 5 years (Graphic 1). Differences were not significant regardless the vascular surgery status (naif vs reintervention), but axillobifemoral bypass and aneurysmal disease groups had a higher patency than axillounifemoral bypass and occlusive disease groups, respectively. No patient with aneurysmal disease required amputation over a 5-year follow-up. In primary occlusive disease group, 88% of patients were free-of-amputation at 1 month and 83% at 5 years. Patients who underwent this procedure had a survival rate of 78% at 1 month and 59% at 5 years (Graphic 2). No major difference was recorded between study groups. CONCLUSION: Axillofemoral bypass, although being an increasingly uncommon procedure, still allows acceptable rates of patency and limb salvage. As patients with aortoiliac disease usually have multiple comorbidities and a short life- -expectancy, axillofemoral bypass is attractive owing to its less invasive character.

Infrarenal Abdominal Penetrating Aortic Ulcer, an Atypical Location of a Rare Disease.

INTRODUCTION: Penetrating aortic ulcer (PAU) is classically included in acute aortic syndromes, together with aortic dissection and intramural hematoma. These three disorders are considered different stages of the same disease. PAU is the result of medial degeneration with disruption of the intima, mainly due to atherosclerotic risk factors. Most of them are located on descending thoracic aorta and only a few small series and case reports demonstrate location on infrarenal abdominal aorta. Clinical presentation varies in spectrum, from asymptomatic to fatal aortic rupture. Treatment options include medical therapy, particularly strict blood pressure control, and surgical approach. Nowadays endovascular exclusion is commonly performed, although open surgical reconstruction remains the gold standard. METHODS: Report a case of endovascular repair of an infrarenal abdominal PAU. RESULTS: A 72-year-old man, with hypertension, type 2 diabetes, hypercholesterolemia, lumbar osteoarthrosis, was referred to Vascular Surgery outpatient clinic with the diagnosis of infrarenal abdominal PAU on a Computed Tomography Angiography (CTA). This exam was performed due to chronic lumbar complaints from lumbar osteoarthrosis. The patient denied any other complaint. Physical examination was normal. A thoraco-abdomino-pelvic CTA revealed two sites of PAU in the infrarenal aorta with 10mm and 21mm of depth and associated aortic enlargement of 39mm maximum diameter. This exam revealed an enlargement of the depth of the PAU and the aorta diameter in 2 and 3mm, respectively, in the course of 2 months. An EVAR was performed, in a standard aorto-biiliac fashion. The post-operative period was uneventful and the patient discharged 3 days later. 1 month after the surgery, patient remained asymptomatic and the follow-up CTA demonstrated exclusion of both PAU, no endoleaks and stability of aortic diameter. A long term follow-up should be maintained, as for regular EVAR. CONCLUSION: PAU is a rare clinical entity, with infrarenal abdominal aorta location even scarcer. Asymptomatic patient must be regularly followed and threshold to treatment low, bearing in mind the possible catastrophic evolution of the disease. Endovascular approach should be considered as a first approach, considering the technical feasibility and the comorbidities associated with this elderly population.

Acute Iatrogenic Limb Ischaemia, a Report of 2 Late Presentation Cases.

INTRODUCTION: With increasing use of percutaneous vascular procedures, access complications that present to a vascular surgeon increase. The most limb-threatening condition is acute limb ischaemia. Acute limb ischaemia is the most common vascular surgical emergency. In spite of recent advances in vascular surgery, it continues to carry a poor prognosis, if not early diagnosed and managed. METHODS: This is a case-report of 2 patients referenced to a vascular surgery emergency department of a tertiary hospital with late acute limb ischaemia. RESULTS: Patient 1: Male, 42 years, alcoholic, autonomous, presented with pain with elbow active movements in a secondary hospital. Excluded acute orthopaedic injury, doctor recorded signs of acute limb ischaemia and referenced patient to a tertiary hospital, where vascular surgeon diagnosed an acute advanced upper limb ischaemia. Bed-side Eco-Doppler showed an echogenic linear material on a thrombosed umeral artery, surgically confirmed to be a guidewire (Fig.1. Surgical extraction of intra-umeral guidewire). Reviewing patient history, this guidewire should have been missed over 6 months, by the time the patient was hospitalized on an ICU for alcoholic coma. Patient underwent umeral, radial and ulnar thromboembolectomy and had a no-reflow status. However, poor persistent global status, with limited mobilization, pressure forces and prolonged vasotropic support, promoted progression of a cyanotic leg plaque to a necrotic evolving leg ulcer with septic response, despite persistent good perfusion of the foot (Fig.2. Necrotic evolving leg ulcer). Unfortunately, the two reported patients underwent urgent major limb amputation, patient 1 above the elbow, and patient 2 above the knee. CONCLUSION: Acute limb ischaemia continues to carry a poor limb and life prognosis if not early diagnosed. We should be alert for the increasingly prevalence of iatrogenic acute limb ischaemia, and regularly evaluate perfusion status of limbs after any percutaneous procedure.

Surgical Treatment Options of Subclavian Artery Pseudoaneurysms: A Case Report and Litterature Review.

INTRODUCTION: Subclavian artery pseudoaneurysms are rare and occur mostly as a consequence of an inadvertent arterial puncture during central venous catheterization, endovascular therapeutic procedures or after penetrating or blunt trauma. They usually have a late clinical presentation, with pain, swelling or other compressive symptoms. The optimal treatment in this situation is still a matter of debate. The authors describe a case of late presentation of subclavian artery pseudoaneurysm after transjugular hepatic biopsy and discuss the several options for treatment. METHODS: A 41-year-old woman was admitted in our hospital due to symptomatic subclavian artery pseudoaneurysm. She underwent a biopsy 20 years earlier for an undetermined febrile syndrome. The pseudoaneurysm was diagnosed during investigation of a right non-pulsatile cervical mass that was associated to cervical edema and Horner's syndrome. CTA revealed a pseudoaneurysm of right subclavian artery with 35 mm of diameter and an arteriovenous fistula to jugular vein which presented with significant enlargement. Additionally, the vertebral venous plexus was also ingurgitated. The pseudoaneurysm caused a left shift of the thyroid, common carotid artery and trachea. The vertebral artery arised 4 mm distal to pseudoaneurysm. RESULTS: After a multidisciplinary evaluation including vascular surgery, neuroradiology and cardiac surgery, she underwent surgical exclusion of false aneurysm and arteriovenous fistula via partial upper sternotomy with cervicotomy. Care was taken to preserve the vertebral artery. There was a complete resolution of compressive symptoms and there were no complications during the first year of follow up. CONCLUSION: Subclavian artery pseudoaneurysms impose a major surgical challenge, especially when originating from the proximal third. Large pseudoaneurysms may rupture or produce signs and symptoms of compression. If intervention is considered necessary, several options are available: open surgical resection and vascular reconstruction, endovascular exclusion, stentgraft implantation or ultrasound-guided thrombin injection have all been described. The choice of procedure should be tailored to the patient, based on comorbidities, clinical presentation and anatomic characteristics. When compressive symptoms exist, an open approach is advised. However, because of their location, surgical exposure of the pseudoaneurysm may be technically difficult, requiring a sternotomy or a clavicular resection for adequate exposure. An endovascular approach demands an adequate landing zone and absence of severe tortuosity. When arteriovenous fistulae and enlargement of vertebral veins are verified, with subsequent increase in venous pressure, there is a risk of cervical radiculopathy (2-4%). This case report describes an uncommon presentation of subclavian pseudoaneurysm and exemplifies the complexity of their treatment.

Median Arcuate Ligament Syndrome - Literature Review and Case Report.

INTRODUCTION: Median arcuate ligament syndrome (MALS) or Dunbar syndrome is a rare clinical entity characterized by celiac trunk compression by median arcuate ligament and variable gastrointestinal symptoms (postprandial epigastric pain, nausea, weight loss, anorexia and diarrhea). However, some degree of radiographic compression is observed in 10%-24% of asymptomatic patients. Besides the extrinsic vascular compression, MALS has a multifactorial etiology and it has been suggested as a neurogenic disease resulting in altered sensation and pain from the somatic nerves in the splanchnic plexus. MALS is a diagnosis of exclusion, so other causes must be excluded. Treatment options include release of median arcuate ligament (open, laparoscopic or robot-assisted) and open vascular reconstruction. Endovascular treatment is currently used only as adjuvant procedure after surgical approach, in refractory cases with residual stenosis of celiac trunk. OBJECTIVE: To report a case of MALS and to review current literature. METHODS: The authors report a clinical case and present a literature review using PubMed with the terms "median arcuate ligament", "Dunbar syndrome" and "MALS treatment" as major topics. The bibliography of relevant articles has been checked to identify other significant papers. RESULTS: A 34-year-old woman, previously healthy, recurred to a General Practitioner with a recurrent epigastric pain, exacerbated by ingestion, without relieving factors, in the previous 6 months. Patient also reported anorexia and unprovoked weight loss of 8Kg over 3 months. Physical examination was normal. Other gastrointestinal pathologies were ruled out. Computed Tomography Angiography (CTA) abdomen revealed a focal 80% stenosis of the celiac trunk, located 8mm from its origin in aorta and a post- -stenotic enlargement of 9mm. An open decompression of the celiac trunk was performed. Through an 8cm median supraumbilical laparotomy, supraceliac abdominal aorta was approached. The compressive band across the celiac trunk was identified and cut. Further dissection was performed until the celiac artery became completely exposed and its branches identified. The postoperative period was uneventful and the patient was discharged 5 days later, with normal gastrointestinal transit and without recurrence of the abdominal pain. 1 month later, the patient remained asymptomatic. A long-term follow-up with annual duplex scan and clinical evaluation must be done, in order to evaluate the need of a revascularization due to persistent stenosis or aneurysmal degeneration. CONCLUSION: MALS diagnostic and therapeutic approach must be patient focused, bearing in mind the multiple clinical presentation and treatment options. Open surgical decompression of median arcuate ligament is the base of therapy.

Influence of Interhospital Transfer on Outcomes of Symptomatic and Ruptured Abdominal Aortic Aneurysms.

INTRODUCTION: Symptomatic or ruptured abdominal aortic aneurysms (rAAA) maintains a high mortality index despite technical advances in its treatment. The influence of patients' geographic location on rAAA outcomes, when the rupture occurs or when the AAA becomes symptomatic, has not been a commonly studied issue. Due to the lack of research on this matter, the impact of interhospital transfer on mortality is ambiguous. OBJECTIVE: Evaluate the influence of the geographic location of patients with symptomatic AAA or rAAA on AAA mortality. METHODS: Retrospective review of all cases of symptomatic AAA and rAAA submitted to surgery in a tertiary institution, between January 2011 and August 2017. The main outcome was in-hospital mortality. Secondary outcomes were admission to intensive care unit (ICU), length of ICU and hospital stay, type of repair and anesthesia and weekend presentation. Data was submitted to univariable analysis and logistic regression. Statistical significance was considered if the p value was <0.05. RESULTS: During the defined period of 80 months, a total of 135 patients were admitted with the diagnosis of symptomatic or rAAA and submitted to surgery. Most patients had a ruptured AAA (90.4%, n=122), while symptomatic AAA represented a minority (9.6%, n=13). All patients (91.1% male gender, mean age 74±10 years) were submitted to surgery, 83 (61.5%) by endovascular repair and 52 (38.5%) by open repair, 30.4% with local anesthesia and sedation (n=41), all in the endovascular group. 92 patients (68.1%) were transferred from other hospitals, with a mean distance of 113±88 km. In this cohort, in-hospital mortality was 31.5% in transferred patients and 34.9% in not transferred patients. Subgroup analysis revealed that there were no significant differences between transferred and not transferred patients' groups concerning main outcome (p=0.35), baseline characteristics (age and gender), type of surgery and anesthesia, weekend presentation, ICU admission, length of ICU and hospital stay. Logistic regression analysis revealed that the variables associated with mortality were female gender (odds ratio [OR] 2.28; 95% confidence interval [CI] 1.40-3.70; p<0.01), open repair (OR 2.79; 95% CI 1.68-4.63; p<0.01) and general anesthesia (OR 9.16; 95% CI 2.33-36.06; p<0.01). CONCLUSION: Our study revealed that transfer of patients for urgent repair of AAA was not associated with an increased mortality. The hypothetical increased mortality due to transfer might have been compensated by endovascular treatment and local anesthesia in some cases. Further studies must be carried out, particularly comparing endovascular and open repair in emergency setting.

Ballistocardiogram artifact correction taking into account physiological signal preservation in simultaneous EEG-fMRI.

The ballistocardiogram (BCG) artifact is currently one of the most challenging in the EEG acquired concurrently with fMRI, with correction invariably yielding residual artifacts and/or deterioration of the physiological signals of interest. In this paper, we propose a family of methods whereby the EEG is decomposed using Independent Component Analysis (ICA) and a novel approach for the selection of BCG-related independent components (ICs) is used (PROJection onto Independent Components, PROJIC). Three ICA-based strategies for BCG artifact correction are then explored: 1) BCG-related ICs are removed from the back-reconstruction of the EEG (PROJIC); and 2-3) BCG-related ICs are corrected for the artifact occurrences using an Optimal Basis Set (OBS) or Average Artifact Subtraction (AAS) framework, before back-projecting all ICs onto EEG space (PROJIC-OBS and PROJIC-AAS, respectively). A novel evaluation pipeline is also proposed to assess the methods performance, which takes into account not only artifact but also physiological signal removal, allowing for a flexible weighting of the importance given to physiological signal preservation. This evaluation is used for the group-level parameter optimization of each algorithm on simultaneous EEG-fMRI data acquired using two different setups at 3T and 7T. Comparison with state-of-the-art BCG correction methods showed that PROJIC-OBS and PROJIC-AAS outperformed the others when priority was given to artifact removal or physiological signal preservation, respectively, while both PROJIC-AAS and AAS were in general the best choices for intermediate trade-offs. The impact of the BCG correction on the quality of event-related potentials (ERPs) of interest was assessed in terms of the relative reduction of the standard error (SE) across trials: 26/66%, 32/62% and 18/61% were achieved by, respectively, PROJIC, PROJIC-OBS and PROJIC-AAS, for data collected at 3T/7T. Although more significant improvements were achieved at 7T, the results were qualitatively comparable for both setups, which indicate the wide applicability of the proposed methodologies and recommendations.

EEG as a potential ground truth for the assessment of cognitive state in software development activities: A multimodal imaging study.

Cognitive human error and recent cognitive taxonomy on human error causes of software defects support the intuitive idea that, for instance, mental overload, attention slips, and working memory overload are important human causes for software bugs. In this paper, we approach the EEG as a reliable surrogate to MRI-based reference of the programmer's cognitive state to be used in situations where heavy imaging techniques are infeasible. The idea is to use EEG biomarkers to validate other less intrusive physiological measures, that can be easily recorded by wearable devices and useful in the assessment of the developer's cognitive state during software development tasks. Herein, our EEG study, with the support of fMRI, presents an extensive and systematic analysis by inspecting metrics and extracting relevant information about the most robust features, best EEG channels and the best hemodynamic time delay in the context of software development tasks. From the EEG-fMRI similarity analysis performed, we found significant correlations between a subset of EEG features and the Insula region of the brain, which has been reported as a region highly related to high cognitive tasks, such as software development tasks. We concluded that despite a clear inter-subject variability of the best EEG features and hemodynamic time delay used, the most robust and predominant EEG features, across all the subjects, are related to the Hjorth parameter Activity and Total Power features, from the EEG channels F4, FC4 and C4, and considering in most of the cases a hemodynamic time delay of 4 seconds used on the hemodynamic response function. These findings should be taken into account in future EEG-fMRI studies in the context of software debugging.

Efficacy of a high concentration of nano silver fluoride in preventing caries: A randomized controlled trial.

Background: To investigate the effectiveness of a novel agent containing Nano Silver Fluoride 1500 (NSF 1500) and chitosan to inactivate carious lesions in children. Material and Methods: The study included eighty children. While both groups had fluoride dentifrice applied to their teeth, only the experimental group received treatment with the NSF 1500-ppm solution. The first and sixth-month interval examinations were conducted by two calibrated dentists (k = 0.85). Results: The NSF 1500 group had 69.2% of their teeth with arrested decay, while the control group had 24.1%. The difference was statistically significant (p 0.001), with a preventive fraction of 59.4%. The number needed to treat (NNT) was approximately two. The NSF 1500 formulation was more effective than toothbrushing alone with fluoridated dentifrice in preventing dental caries. Conclusions: The effectiveness of NSF 1500 is determined by the size and depth of the dental cavity. Its ability to arrest caries lesions was comparable to previously tested products, NSF 400 and NSF 600. Key words:Preventive dentistry, dental caries, nanoparticles.

[Reconstructive surgery of the large intrathoracic veins, four case reports]. / Cirurgia Reconstrutiva das Grandes Veias Intratorácicas, a Propósito de Quatro Casos Clínicos.

The resection and reconstruction of the large venous vessels of the chest is a procedure intended to treat the symptoms of venous hypertension caused by the Superior Vena Cava Syndrome and to allow resection of mediastinal tumors that invade the superior vena cava (SVC) and the left and right innominate veins. We report four clinical cases of mediastinal tumors involving the large intrathoracic venous vessels, submitted to surgery between 2010 and 2013. In all cases our purpose was to completely resect the tumor. We intended to evaluate the surgical results in terms of improvement of symptoms, complications of the procedures, permeability of the bypasses in the short and medium term and mortality rates. We used ringed ePTFE grafts to perform the following vascular reconstructions: - Y configuration bypass from the left subclavian vein and the left internal jugular vein to the left inominate vein; - two bypasses from the top of the left innominate vein to the right atrial appendage; - bypass from the left innominate vein to the right atrial appendage and a bypass from the right innominate vein to the SVC. All patients were discharged, and all the bypasses were patent at discharge and after 30 days . There were two cases of late thrombosis, but patients remained asymptomatic. Our series shows the feasibility of these technically complex surgeries, which are an excellent example of the benefits of multidisciplinary collaboration between vascular and thoracic surgeons.

Emergent Endovascular Repair For Primary Aortoenteric Fistula.

We report the case of a 64-year-old male with significant cardiac comorbidities who reported three episodes of gastrointestinal bleeding. In the third episode, he presented massive hematemesis, anaemia and hypotension. Despite a standard upper endoscopy, a computed tomography (CT) showed an infrarenal abdominal aortic aneurysm and densification of the aortic fat cover. A primary aortoenteric fistula, with acute bleeding and haemodynamic instability, was assumed, and an emergent endovascular repair was performed. Subsequent CT scans and endoscopies demonstrated control of the enteric lesion. After five months, there was no evidence of infection or rebleeding.