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Este artículo contiene 12 páginas, 2 tablas, 2 figuras., Background: Active surveillance aimed at the early detection of invasive mosquito species is usually focused on seaports and airports as points of entry, and along road networks as dispersion paths. In a number of cases, however, the frst detections of colonizing populations are made by citizens, either because the species has already moved beyond the implemented active surveillance sites or because there is no surveillance in place. This was the case of the frst detection in 2018 of the Asian bush mosquito, Aedes japonicus, in Asturias (northern Spain) by the citizen science platform Mosquito Alert. Methods: The collaboration between Mosquito Alert, the Ministry of Health, local authorities and academic research‑ ers resulted in a multi-source surveillance combining active feld sampling with broader temporal and spatial citizensourced data, resulting in a more fexible and efcient surveillance strategy. Results: Between 2018 and 2020, the joint eforts of administrative bodies, academic teams and citizen-sourced data led to the discovery of this species in northern regions of Spain such as Cantabria and the Basque Country. This raised the estimated area of occurrence of Ae. japonicus from < 900 km2 in 2018 to > 7000 km2 in 2020. Conclusions: This population cluster is geographically isolated from any other population in Europe, which raises questions about its origin, path of introduction and dispersal means, while also highlighting the need to enhance sur‑ veillance systems by closely combining crowd-sourced surveillance with public health and mosquito control agencies’ eforts, from local to continental scales. This multi-actor approach for surveillance (either passive and active) shows high potential efciency in the surveillance of other invasive mosquito species, and specifcally the major vector Aedes aegypti which is already present in some parts of Europe., RE and FB from Mosquito Alert received funding from “la Caixa” Foundation (ID 100010434), under agreement HR18-00336 (Community-Driven Big Data Intel‑ ligence to Fight Mosquito-Borne Disease). This project has also been funded by the European Union’s Horizon 2020 research and innovation program, under the grant agreement 874735 (VEO). Samplings in the Basque Country were funded by the Department of Public Health and the Department of Economic Development and Infrastructures of the Basque Government, and co-funded by the project EU-LIFE 18 IPC/ES/000001 (Urban Klima 2050).

12 páginas, 1 tabla, 3 figuras, Human mobility is becoming an accessible field of study, thanks to the progress and availability of tracking technologies as a common feature of smart phones. We describe an example of a scalable experiment exploiting these circumstances at a public, outdoor fair in Barcelona (Spain). Participants were tracked while wandering through an open space with activity stands attracting their attention. We develop a general modelling framework based on Langevin dynamics, which allows us to test the influence of two distinct types of ingredients on mobility: reactive or context-dependent factors, modelled by means of a force field generated by attraction points in a given spatial configuration and active or inherent factors, modelled from intrinsic movement patterns of the subjects. The additive and constructive framework model accounts for some observed features. Starting with the simplest model (purely random walkers) as a reference, we progressively introduce different ingredients such as persistence, memory and perceptual landscape, aiming to untangle active and reactive contributions and quantify their respective relevance. The proposed approach may help in anticipating the spatial distribution of citizens in alternative scenarios and in improving the design of public events based on a facts-based approach., The research leading to these results has received funding by Barcelona City Council (Spain), RecerCaixa (Spain) through grant Citizen Science: Research and Education (F.B., J.R.P., A.O., M.G.R. and J.P.), by Strep-EU LASAGNE Project under contract no. 318132 (A.D.G. and O.S.), by MINECO (Spain) through grant nos. FIS2013-47532-C3-2-P (J.P. and M.G.R.) and FIS2012-38266-C2-2 (A.D.G. and O.S.), by Generalitat de Catalunya (Spain) through grant no. 2014- SGR-608 (M.G.R., O.S., J.P. and O.S.) and 2012-ACDC-00066 (M.G.R., O.S., J.P. and O.S.), and by Fundación Espaola para la Ciencia y la Tecnología (FECYT, Spain) through the Barcelona Citizen Science Office project of the Barcelona Lab programme (J.P.). O.S. also acknowledges financial support from Generalitat de Catalunya (FI-programme) and the Spanish MINECO (FPU-programme).

Este artículo contiene 12 páginas, 8 figuras, 2 tablas., Global monitoring of disease vectors is undoubtedly becoming an urgent need as the human population rises and becomes increasingly mobile, international commercial exchanges increase, and climate change expands the habitats of many vector species. Traditional surveillance of mosquitoes, vectors of many diseases, relies on catches, which requires regular manual inspection and reporting, and dedicated personnel, making large-scale monitoring difcult and expensive. New approaches are solving the problem of scalability by relying on smartphones and the Internet to enable novel community-based and digital observatories, where people can upload pictures of mosquitoes whenever they encounter them. An example is the Mosquito Alert citizen science system, which includes a dedicated mobile phone app through which geotagged images are collected. This system provides a viable option for monitoring the spread of various mosquito species across the globe, although it is partly limited by the quality of the citizen scientists’ photos. To make the system useful for public health agencies, and to give feedback to the volunteering citizens, the submitted images are inspected and labeled by entomology experts. Although citizen-based data collection can greatly broaden disease-vector monitoring scales, manual inspection of each image is not an easily scalable option in the long run, and the system could be improved through automation. Based on Mosquito Alert’s curated database of expert-validated mosquito photos, we trained a deep learning model to fnd tiger mosquitoes (Aedes albopictus), a species that is responsible for spreading chikungunya, dengue, and Zika among other diseases. The highly accurate 0.96 area under the receiver operating characteristic curve score promises not only a helpful pre-selector for the expert validation process but also an automated classifer giving quick feedback to the app participants, which may help to keep them motivated. In the paper, we also explored the possibilities of using the model to improve future data collection quality as a feedback loop., Tis work was in part fnanced by EU Horizon 2020 program Grant agreement “VEO” No. 874735. Te research was supported by the Ministry of Innovation and Technology NRDI Ofce within the framework of the Artifcial Intelligence National Laboratory Program.

There is a widespread belief in ecology that the capacity of animals to orchestrate systematic and planned paths should represent a significant benefit for efficient search and exploration. Within this view, stochasticity observed in real animal trajectories is mostly understood as undesirable noise caused by internal or external effects. Far less is known, however, about the case when cognitive errors and limitations inherent to living systems are explicitly put into play. Here we compare within this context the search efficiency of (i) walkers driven by Bayesian rules generating deterministic paths, (ii) standard random walkers, and (iii) human trajectories obtained from search experiments in a soccer field and on the computer screen. Our results clearly challenge the view that deterministic paths are generally better for exploration than random strategies, as the latter are more resilient to cognitive errors. Instead, we provide numerical and experimental evidence that stochasticity would provide living organisms with a sufficient and cognitively simple exploration solution to the problem of uncertainty.

Este artículo consta de 5 páginas.

Este artículo contiene 13 páginas, 6 figuras, 1 tabla., Background: On February 1st 2016 the WHO declared the Zika Virus (ZIKV) infection a worldwide public health emergency because of its rapid expansion and severe complications, such as Guillain-Barré Syndrome or microcephaly in newborn. The huge amount of people traveling to endemic areas and the presence of Aedes albopictus in Barcelona increase the risk of autochtonous transmission. The objective of this study was to describe the first ZIKV cases diagnosed in our city and to analyze the surveillance, prevention, and control measures implemented to avoid autochthonous transmission. Methods: An observational cross-sectional population-based study in Barcelona, Spain was performed.An analysis of the socio-demographic, epidemiological, clinical characteristics, and mosquito control activities of the ZIKV cases detected between January 1st and December 2016 was carried out using a specific ZIKV epidemiological survey of the Barcelona Public Health Agency. Results: A total of 118 notifications of possible ZIKV infections were received, and 44 corresponded to confirmed cases in Barcelona residents.Amongst these, the median age was 35 years and 57% were women. All cases were imported, 48% were Spanish-born and 52% foreign-born. Dominican Republic was the most visited country amongst foreign-born patients and Nicaragua amongst Spanish-born. The most frequent symptoms were exanthema, fever, and arthralgia. Among the 24 diagnosed women, 6 (25%) were pregnant. There was one case of microcephaly outside Barcelona city. Entomological inspections were done at the homes of 19 cases (43.2% of the total) and in 34 (77.3%) public spaces. Vector activity was found in one case of the 44 confirmed cases, and 134 surveillance and vector control were carried out associated to imported ZIKV cases. In all cases prevention measures were recommended to avoid mosquito bites on infected cases.Conclusion: Epidemiological and entomological surveillance are essential for the prevention of autochthonous transmission of arbovirosis that may have a great impact on Public Health.The good coordination between epidemiologists, entomologists, microbiologists, and clinicians is a priority in a touristic city with an intense relationship with endemic countries to minimize the risk of local transmission by competent vectors., MJ, JG, NR, and JM receives funds from 2014 SGR 26 grant from the Department d’Universitats, Recerca i Societat de la Informacio de la Generalitat de Catalunya (AGAUR) and from RD12/0018/0010 grant, ISCIII RETIC (MICINN, Spain). PROSICS authors are supported by the 6th National Plan (PN) of Research + Development + Innovation (I + D + I) 2008–2011, ISCIII-General Division Networks and Cooperative Research Centres + FEDER funds + Collaborative Research Network on Tropical Diseases (RICET): RD12/0018/0020.

Este artículo contiene 12 páginas, 4 figuras, 2 tablas., How animals explore and acquire knowledge from the environment is a key question in movement ecology. For pollinators that feed on multiple small replenishing nectar resources, the challenge is to learn efficient foraging routes while dynamically acquiring spatial information about new resource locations. Here, we use the behavioural mapping t-Stochastic Neighbouring Embedding algorithm and Shannon entropy to statistically analyse previously published sampling patterns of bumblebees feeding on artificial flowers in the field. We showthat bumblebeesmodulate foraging excursions into distinctive behavioural strategies, characterizing the trade-off dynamics between (i) visiting and exploiting flowers close to the nest, (ii) searching for new routes and resources, and (iii) exploiting learned flower visitation sequences. Experienced bees combine these behavioural strategies even after they find an optimal route minimizing travel distances between flowers. This behavioural variability may help balancing energycosts–benefits and facilitate rapidadaptationto changing environments and the integration of more profitable resources in their routes., This work was financially supported by grant no. CGL2016-78156-C2-1-R, MINECO, Programa Estatal IþDþi, Retos de la Sociedad, in Spain. J.M.K. is a career member of CONICET. M.L. was funded by the Centre National de la Recherche Scientifique (CNRS) and the Agence Nationale de la Recherche (ANR-16-CE02-0002-01). E.P.R. thanks the support from FACEPE and CNPq.

9 páginas, 5 figuras, 1 tabla, Recently, Lévy walks have been put forward as a new paradigm for animal search and many cases have been made for its presence in nature. However, it remains debated whether Le´vy walks are an inherent behavioural strategy or emerge from the animal reacting to its habitat. Here, we demonstrate signatures of Le´vy behaviour in the search movement of mud snails (Hydrobia ulvae) based on a novel, direct assessment of movement properties in an experimental set-up using different food distributions. Our experimental data uncovered clusters of small movement steps alternating with long moves independent of food encounter and landscape complexity. Moreover, size distributions of these clusters followed truncated power laws. These two findings are characteristic signatures of mechanisms underlying inherent Le´vy-like movement. Thus, our study provides clear experimental evidence that such multi-scale movement is an inherent behaviour rather than resulting from the animal interacting with its environment., A.K. and G.M.H. were supported by the Strategic Fund of the KNAW, granted to J.v.d.K., M.N. and B.A.N. A.A. was funded by the top programme Evolutionary Biology scholarship of the University of Groningen. F.B. acknowledges MINECO (ref. BFU2010–22337) and the Human Frontier Science Program (HFSP, ref. RGY0084/2011). M.d.J. was supported by a grant from The Netherlands Organisation for Scientific Research—Earth and Life Sciences (NWO-ALW). This is publication 5833 of The Netherlands Institute of Ecology (NIOO-KNAW).

Objective: Neurosurgery is one of the main therapies for pituitary tumors; optimising outcome is highly desirable for the patient and the health system. We have analysed predictors of outcome in surgically treated pituitary adenomas operated in this centre. Design and patients: A total of 289 patients underwent neurosurgery for a pituitary tumor, by the same two neurosurgeons, between 1982 and 2001. Their records were examined to find predictors of post-surgical outcome. Thirty-eight percent were males, with a median age of 40.8 (8–82.7) yr; 51.9% had been operated since 1992, 92.2% by the transsphenoidal route. Most tumors (70.2%) were macroadenomas; 28.4% were non-functioning, 27.3% secreted PRL, 26.3% GH of which 14 (4.8%) also secreted PRL, 17.3% ACTH, 0.3% FSH and 0.3% TSH. Results: A stepwise, forward logistic regression analysis revealed tumor size as the only significant predictor of radiological cure [odds ratio (OR) for macroadenoma 0.16 vs microadenoma, p=0.0005]. Hormonally, PRL-secretion by the tumor was a predictor of poor prognosis (OR 3.29 for cure of non-PRL-secreting tumors, p=0.005), as was tumor size (OR 0.45 for cure of macroadenomas, p=0.005). Considering simultaneous radiological and hormonal remission, tumor size (OR 0.35 for macroadenoma, p=0.0002), and operation date (OR 0.40 for up to 1991, p=0.0002) were the only significant predictors. Conclusions: PRL secretion, tumor size and operation date are the main predictors of neurosurgical outcome in pituitary tumors, the latter suggesting that neurosurgical experience plays an important role.

Resumen El granuloma de colesterol de punta de penasco (PP) se produce como consecuencia de una reaccion inflamatoria por la presencia de cristales de colesterol. Este proceso es silente durante anos. El diagnostico se establece mediante la combinacion de la TC y RM que permiten un adecuado diagnostico diferencial de las lesiones de PP. Presentamos dos casos de granulomas de colesterol de PP extirpados completamente mediante abordaje preauricular infratemporal. Se revisa la literatura y se discuten la etiopatogenia y las caracteristicas clinicas, histologicas, radiologicas y terapeuticas en estas lesiones. Nosotros pensamos que el abordaje preauricular infratemporal con exeresis completa de la tumoracion seguido de la obliteracion de la cavidad con grasa abdominal, es el procedimiento de eleccion para estas lesiones cuando la audicion esta conservada.

Recent studies have shown that MRS can substantially improve the non-invasive categorization of human brain tumours. However, in order for MRS to be used routinely by clinicians, it will be necessary to develop reliable automated classification methods that can be fully validated. This paper is in two parts: the first part reviews the progress that has been made towards this goal, together with the problems that are involved in the design of automated methods to process and classify the spectra. The second part describes the development of a simple prototype system for classifying H-1 single voxel spectra, obtained at an echo time (TE) of 135 ms, of the four most common types of brain tumour (meningioma (MM), astrocytic (AST), oligodendroglioma (OD) and metastasis (ME)) and cysts. This system was developed in two stages: firstly, an initial database of spectra was used to develop a prototype classifier, based on a linear discriminant analysis (LDA) of selected data points. Secondly, this classifier was tested on an independent test set of 15 newly acquired spectra, and the system was refined on the basis of these results. The system correctly classified all the non-astrocytic tumours. However, the results for the the astrocytic group were poorer (between 55 and 100%, depending on the binary comparison). Approximately 50% of high grade astrocytoma (glioblastoma) spectra in our data base showed very little lipid signal, which may account for the poorer results for this class. Consequently, far the refined system, the astrocytomas were subdivided into two subgroups for comparison against other tumour classes: those with high lipid content and those without

Resumen La infeccion postquirurgica comporta un aumento en el tiempo de estancia hospitalaria. Mediante un estudio observacional prospectivo se evaluo el coste economico atribuible a la infeccion postoperatoria en neurocirugia en base al aumento de estancia hospitalaria achacable a esta. Se identificaron 64 pacientes que sufrieron 73 episodios de infeccion postoperatoria sobre un total de 832 enfermos que se sometieron a 1.080 intervenciones durante un periodo de 28 meses. La comparacion de la estancia hospitalaria cuando la intervencion quirurgica no se afecto de una infeccion postoperatoria con respecto a cuando si la hubo, demostro que las permanencias hospitalarias en los casos con infeccion postoperatoria eran 21 dias mayores (de mediana) que en los casos sin infeccion (p ≤ 0,001), hecho que comporta un gasto extra minimo en base a la estancia hospitalaria de 549.000 pesetas/1996 por episodio infeccioso. De acuerdo con los resultados obtenidos, una infeccion de herida podria suponer un gasto adicional de hasta 579.000 ptas./1996; un paciente sometido a intervencion de columna e infectado podria comportar un coste extra de 1.098.000 ptas./1996. Sin olvidar las consecuencias en forma de morbimortalidad, la infeccion postquirurgica en neurocirugia se demuestra cara. Solo la aplicacion de las medidas preventivas conocidas, entre las que se incluye un programa de vigilancia y control de la infeccion postoperatoria en neurocirugia, permitiria una reduccion del gasto total atribuible a esta, que implicaria un ahorro considerable para nuestro sistema sanitario.

Resumen En la actualidad el diagnostico de neurinoma del VIII par craneal en pacientes con tumores de pequeno tamano y audicion conservada ha hecho que la preservacion de la audicion, en estos casos, sea un objetivo especifico. Presentamos los resultados de nuestra serie que abarca 73 casos de neurinoma del VIII p.c, intervenidos en el periodo 84–94. En 16 pacientes se cumplian criterios de audicion util, segun la American Medical Association y en todos ellos, se intento la preservacion de la audicion, lo que se consiguio en el 50%, con criterios de audicion util en 3 casos (19%). En 5 casos (31%) quedo audicion remanente sin criterios de audicion util. La preservacion anatomica del VIII p.c. se consiguio en 12 casos (75%). Los resultados se correlacionaron de forma inversamente proporcional con el tamano del tumor (

Resumen La inestabilidad en los segmentos superiores de la columna cervical es un hecho comun en pacientes con artritis reumatoide (A.R) de larga evolucion. Presentamos 8 pacientes con historia de A.R grave e inestabilidad cervical que han sido tratados con artrodesis posterior. En el momento del tratamiento la duracion media de la A.R era de 16.6 anos y la de los sintomas 5.7 meses. En todos los pacientes se evidencio subluxacion atlantoaxial reducible, uno de ellos presentaba ademas impresion basilar. Las indicaciones quirurgicas fueron deterioro neurologico progresivo en seis pacientes y subluxacion atlantoaxial mayor de 8 mm sin signos de compresion medular en dos pacientes. En cinco casos se realizo artrodesis atlanto-axial; en uno fijacion atlanto-C3 y en dos la union fue occipitocervical. En un paciente se realizo ademas una odontoidectomia transoral. El seguimiento medio tras la cirugia fue de 21.1 meses (minimo 5 meses y maximo 43 meses). En todos los pacientes mejoraron las parestesias y el dolor cervical. De los seis pacientes que presentaban sintomas neurologicos en el preoperatorio, cinco (83.3%) mejoraron un grado despues de la cirugia segun la clasificacion de Ranawat et al. En siete casos (87.5%) se produjo asimilacion del injerto y en uno se constato la reabsorcion de este. Entre las complicaciones encontramos dos casos de infeccion de herida quirurgica; en un paciente se produjo la rotura de los alambres. La mortalidad quirurgica fue nula.

24 páginas,9 figuras, 1 tabla., This article explores new methods for gathering and analyzing spatially rich demographic data using mobile phones. It describes a pilot study (the Human Mobility Project) in which volunteers around the world were successfully recruited to share GPS and cellular tower information on their trajectories and respond to dynamic, location-based surveys using an open-source Android application. The pilot study illustrates the great potential of mobile phone methodology for moving spatial measures beyond residential census units and investigating a range of important social phenomena, including the heterogeneity of activity spaces, the dynamic nature of spatial segregation, and the contextual dependence of subjective well-being., The work was funded by a grant from the Center for Information Technology Policy at Princeton University. Institutional support was provided by National Institutes of Health Training Grant T32HD07163 and Infrastructure Grant R24HD047879.

Resumen Presentamos 104 pacientes con meningiomas intracraneales, estudiados en nuestro Servicio durante el periodo de 1981–1990, que fueron clasificados en dos grupos: Grupo A, adultos con edad entre 19 y 64 anos y Grupo B, tercera edad –65 y 78 anos–. Predomino el sexo femenino 1:2,15. Practicamos TAC craneal en todos los casos, angiografia cerebral en 53 pacientes y RMN en 20 pacientes. En cuatro casos se prescindio de la intervencion quirurgica por diferentes causas clinicas. Consideramos los resultados quirurgicos de 100 pacientes, 70 del Grupo A y 30 del Grupo B. En todos se realizo seguimiento minimo de 1 ano. En la valoracion del grado de reseccion tumoral utilizamos la escala de Simpson. Considerando la escala de pronostico de Glasgow modificada en los resultados post-operatorios el 85% de casos (Grupo A 85,71%, Grupo B 83,35%) hacen vida normal, o presentan crisis comiciales en la mayor parte de los casos controladas farmacologicamente, o deficit neurologico menor, que les permite llevar una vida autonoma y funcional. Nuestros resultados apoyan el tratamiento quirurgico activo de meningiomas intracraneales en pacientes de la tercera edad, excepto si existiera contraindicacion medica especifica.

Resumen Presentamos una paciente de sexo femenino, de 33 anos de edad, con ataques isquemicos transitorios (AIT) ocasionados por un aneurisma gigante parcialmente trombosado de la arteria cerebral media derecha. Se intervino quirurgicamente practicandose anastomosis termino-terminal de arterias temporal superficial y cerebral media derecha, y exeresis total de la lesion aneurismatica. El resultado postoperatorio fue satisfactorio, con una exploracion neurologica normal. La angiograna cerebral postoperatoria, demostro la desaparicion del aneurisma y permeabilidad de la anastomosis vascular extra-intracraneal.

Resumen Introduccion El estesioneuroblastoma (ENB) es un tumor maligno de origen neuroectodermico poco habitual que afecta principalmente a la fosa craneal anterior y cavidad nasal. Objetivos Revisar nuestra experiencia en el manejo de los ENB, evaluar la validez del diagnostico anatomopatologico, el tipo de tratamiento y factores pronosticos de la enfermedad comparando nuestros hallazgos con los descritos en la literatura. Material y metodos Estudio retrospectivo de 11 casos de ENB tratados en nuestro hospital en el periodo comprendido entre 2000 y 2008. Se realiza analisis estadistico sobre la existencia de factores pronosticos. Se revisa la bibliografia publicada sobre el ENB entre 1990 y 2009. Resultados Se trataron 3 mujeres y 8 hombres, cuya edad media fue 42 anos (rango 20–71 anos). El sintoma inicial fue la obstruccion nasal (81%), epistaxis (27%), disminucion de agudeza visual (18%), cefalea y otros. Segun la clasificacion de Kadish, 2 son estadio B y 9 estadio C; segun la clasificacion de Dulguerov, 2 son T2, 3 son T3 y 6 son T4. El resultado histologico segun la clasificacion de Hyams fue de 2 casos en grado I, 4 en grado II, 3 en grado III y 2 en grado IV. Dos de los casos inicialmente catalogados en grado IV cambiaron de diagnostico en la segunda biopsia a tumor indiferenciado. Se realizo un abordaje subcraneal en 73% (8 casos) con comprobacion de la exeresis completa mediante endoscopia endonasal. De ellos, tras radioterapia coadyuvante en todos y en uno quimioterapia, el 62% (5 pacientes) estan vivos sin enfermedad, 12,5% (1) vivo con enfermedad controlada, 25% (2) muerte por progresion de la enfermedad. En 1 paciente se realizo reseccion subtotal por endoscopia endonasal mas radioterapia y esta vivo sin enfermedad. En los otros 2 casos, que se consideraron irresecables, se realizo biopsia endonasal mas quimioterapia y radioterapia; uno esta vivo con enfermedad controlada y el otro fue exitus por progresion de la enfermedad. Se realizo RT coadyuvante en todos los casos y QT adyuvante en 5 de los pacientes. El grado histologico de Hyams se ha encontrado como factor pronostico estadisticamente significativo en la prediccion de menor periodo libre de enfermedad en nuestra serie. Conclusiones En el diagnostico histopatologico del ENB, la gradacion de Hyams puede ser valida considerando los grado IV como la variante mas avanzada siendo en ocasiones dificil de diferenciar de otros tumores indiferenciados. El abordaje subcraneal o reseccion craneofacial en estadios avanzados (Kadish C y algunos B) creemos que sigue siendo de eleccion como primer tratamiento. La radioterapia es coadyuvante en todos los casos y la quimioterapia en casos seleccionados. El unico factor pronostico que hemos podido extraer de nuestra serie es el grado histologico segun la clasificacion de Hyams.

Resumen Se analizan los datos clinicos y el tratamiento en cuatro casos de hematomas del tronco cerebral secundarios a malformacion vascular, angiograficamente oculta. Aparte de la existencia de paresia facial en un caso y la hipoestesia facial en otro, despues de la cirugia, los cuatro pacientes hacen vida normal en el momento actual. Recomendamos la extirpacion global de estas lesiones en los pacientes que sufren deterioro clinico, bien progresivo, o bien recurrente.

The movement ecology framework depicts animal movement as the result of the combined effects of internal and external constraints on animal navigation and motion capacities. Nevertheless, there are still fundamental problems to understand how these modulations take place and how they might be translated into observed statistical properties of animal trajectories. Of particular interest, here, is the general idea of intermittence in animal movement. Intermittent locomotion assumes that animal movement is, in essence, discrete. The existence of abrupt interruptions in an otherwise continuous flow of movement allows for the possibility of reorientations, that is, to break down previous directional memories of the trajectory. In this study, we explore the potential links between intermittent locomotion, reorientation behavior, and search efficiency. By means of simulations we show that the incorporation of Lévy intermittence in an otherwise nonintermittent search strongly modifies encounter rates. The result is robust to different types of landscapes (i.e., target density and spatial distribution), and spatial dimensions (i.e., 2D, 3D). We propose that Lévy intermittence may come from reorientation mechanisms capable of organizing directional persistence on time (i.e., fractal reorientation clocks), and we rationalize that the explicit distinction between scanning and reorientation mechanisms is essential to make accurate statistical inferences from animal search behavior. Finally, we provide a statistical tool to judge the existence of episodic and strong reorientation behaviors capable of modifying relevant properties of stochastic searches, ultimately controlling the chances of finding unknown located items.

Resumen Objetivos Establecer unos criterios terapeuticos en las malformaciones arteriovenosas (MAVs) grados III, IV y V de Spetzler y Martin y analisis de resultados en el subgrupo de tratamiento con embolizacion mas cirugia. Material y metodos Estudio retrospectivo de 31 pacientes con MAVs cerebrales tratados en nuestro servicio entre 1999 y 2004. Se trata de 19 mujeres y 12 hombres, con una edad media de 31,6 anos (rango de 1 a 62a). La forma de presentacion fue en un 77,4% hemorragia intracraneal, en un 12,9% crisis comicial y en un 3,2% cefalea, infarto isquemico y hallazgo casual en cada uno de ellos. En 29 casos se realizo arteriografia diagnostica y en 2 casos el diagnostico fue anatomopatologico. Segun la clasificacion de Spetzler y Martin, 10,3% fueron de Grado I, 24,1% de Grado II, 37,9% de Grado Ill, 24,1% de Grado IV y 3,4% de Grado V. Se clasificaron en 6 grupos segun el tratamiento realizado (cirugia, embolizacion, radiocirugia, embolizacion mas cirugia, embolizacion mas radiocirugia y tratamiento conservador). Resultados Las MAVs grado III, IV y V (19 pacientes) fueron tratadas en su mayoria por cirugia (6 casos) y embolizacion mas cirugia (5 casos) pero tambien se utilizaron otras modalidades de tratamiento (embolizacion, radiocirugia y conservador). Los resultados funcionales de estos 3 subgrupos muestra un 36,8% (7 casos) de asintomaticos o con minimos sintomas (Rankin m 0-1), un 52,6% (10 casos) de discapacidad leve pero independientes (Rankin m=2), un 5,3% (1 caso) de moderada discapacidad (Rankin m=3), y un 5,3% (1 caso) de mortalidad. En el manejo combinado embolizacion mas cirugia de malformaciones complejas, se observa un alto porcentaje de sangrado postembolizacion que motivo cirugia precoz con buen resultado funcional. Hubo un caso de mortalidad postquirurgica. Conclusiones En el tratamiento de las MAVs cerebrales se debe tener en cuenta factores como la historia natural, la forma de presentacion (hemorragia), las caracteristicas angioestructurales (presencia de aporte arterial profundo, aneurismas), la escala de Spetzler y Martin y el estado clinico del paciente. En el tratamiento con embolizacion mas cirugia es recomendable obtener una embolizacion prequirurgica subtotal > 50%, no ocluir mas del 50% por sesion, mantener un intervalo entre sesiones de embolizacion entre 4 y 6 semanas y un intervalo entre ultima embolizacion y cirugia entre 1 y 3 semanas.

Resumen La introduccion del control neuroflsiologico intraoperatorio ha conseguido minimizar el riesgo funcional quirurgico en lesiones localizadas en areas cerebrales funcionales. En la actualidad realizamos control neuronsiologico intraoperatorio para localizar el area motora o sensitiva y el area del lenguaje mediante estimulacion cortical, asi como de los pares craneales en cirugia del angulo ponto cerebeloso. La monitorizacion neuronsiologica durante cirugia del tronco del encefalo y fosa romboidea esta menos instaurada. La cirugia del tronco del encefalo implica una cuidadosa seleccion de los pacientes, dado el alto riesgo de morbilidad y mortalidad asociadas. Por esta razon, los cavernomas de esta region suelen ser tratados de manera conservadora cuando se trata de un hallazgo casual o no son sintomaticos. Sin embargo, la presencia de un sangrado o afectacion neurologica inducen a tomar una decision quirurgica, dada la mala evolucion natural. Presentamos el caso de una mujer de 29 anos, diagnosticada de cavernomas multiples, que ingreso por cuadro de debilidad motora y deficit sensitivo en hemicuerpo izquierdo. Se realizo TC craneal y RM que mostraba hemorragia protuberancial y se practico una craniectomia infratentorial y reseccion de la lesion vascular por linea media, con control neurofisiologico intraoperatorio del VII, VIII, X y XII pares craneales con lectura electromiografica. El control neurofisiologico ayudo a decidir el punto de acceso a la lesion que no afloraba a la superficie, minimizar las secuelas postoperatorias y pronosticar precozmente los deficits asociados con el fin de iniciar una rehabilitacion precoz.

Resumen Presentamos el caso de una paciente de 48 anos de edad, con una lesion expansiva de caracter infiltrativo a nivel fronto-parietal izquierdo y clinica focal de 5 meses de evolucion. El estudio neurorradiologico evidenciaba una lesion expansiva con efecto de masa y captacion irregular de contraste sugestiva de metastasis o glioma cerebral a nivel rolandico izquierdo. Se intervino quirurgicamente consiguiendose la reseccion total de la lesion. El estudio anatomopatologico objetivo la existencia de zonas de necrosis caseosa y permitio visualizar formas de BK en varios cortes. Consideramos de interes el caso, dada la escasa incidencia de tuberculomas cerebrales y la atipica forma de presentacion.

Resumen Los meningiomas del cuarto ventriculo son raros. Se describe un meningioma meningotelial en esta localizacion. Se discuten algunos detalles de la tecnica quirurgica y se revisa la literatura.

Se presentan 2 casos de quistes de septum pellucidum sintomaticos en pacientes pediatricos, tratados mediante fenestracion neuroendoscopica con resolucion clinica. Se revisa la literatura sobre las posibles variantes de cavidades extras de linea media, asi como su fisiopatologia, epidemiologia, clinica tratamiento (tecnica quirurgica) y resultados.

Presentamos dos casos (38 y 45 anos) de abordaje anterolateral microscopico a la columna cervical llevandose a cabo foraminotomia y exeresis de la hernia discal foraminal mediante uncinatectomia. En ambos casos el dolor radicular desaparecio en el postoperatorio inmediato, y ambos pacientes se encuentran asintomaticos hasta la fecha. Precisaron de collarin cervical durante dos semanas. No se han registrado complicaciones. Las radiografias y TAC cervical de control demuestran la ausencia de hernia cervical y la preservacion de la movilidad cervical. Conclusion La foraminotomia cervical anterior microscopica mediante uncinatectomia resulta una tecnica eficaz en la exeresis de hernias cervicales sin que precise de otros procedimientos asociados para sustituir el disco.

Se presenta videoconferencia de 3 casos de quistes aracnoideos sintomaticos de linea media tratados mediante fenestracion quistica neuroendoscopica. Mediante apoyo de imagen dinamica se comentan material y metodos, y se discute sobre la tecnica quirurgica y resultados a corto y medio plazo.

Se presenta 1 caso de un paciente de 19 anos de edad con cuadro de panhipopituitarismo y macrocefalia de varios anos de evolucion y consulta por aparicion reciente de hipersomnia secundaria a hidrocefalia por obstruccion del acueducto de Silvio. Se realizan estudios de neuroimagen mediante TAC y RM que demuestran la presencia de un quiste de linea media en III ventriculo. La RM dinamica confirmo la sospecha de un quiste de velum interpositum. El paciente es tratado quirurgicamente mediante neuroendoscopia con fenestracion quistica con permeabilizacion del acueducto y regresion inmediata de la sintomatologia. Se discuten la fisiopatologia y el diagnostico diferencial de los quistes de velum interpositum.

INTRODUCTION Up to 40% of the patients with cancer have cerebral metastases, so that their incidence in the general population reaches 0.15%. Different treatments for metastases have been described. Most aim to eradicate one or several metastases so as to improve the quality of life and life expectancy of the patients. DEVELOPMENT The main factors determining the prognosis and indication for surgery are age, functional state and extent of the neoplastic disease. The presence of more than one metastasis does not contraindicate surgery. CONCLUSIONS The development of new surgical techniques over the past twenty years has led to a reduction in operative morbidity and mortality. Surgery followed by holocranial radiotherapy is still the method of choice for the treatment of metastases. In cases in which surgical treatment is not indicated, radiosurgery may be done.

A case of spontaneous thrombosis of a previously ruptured anterior communicating artery aneurysm is reported. The patient was referred by another hospital to our service 4 months after the bleeding episode. He had developed a symptomatic normal pressure hydrocephalus, successfully treated by ventriculoperitoneal shunt. Follow-up angiographies, the first performed 4 months and the second 1 year after the bleeding, did not show the aneurysm. Furthermore, the parent artery was not occluded. The literature relative to the subject is reviewed and the possible mechanisms of spontaneous thrombosis are discussed.

An average of 125 head injuries are seen monthly in our Clinic. 20% of them have to be hospitalized due to actual or presumptive neurological implications. Traffic accidents are responsible for more than 85% of these cases.