Brain Arteriovenous Malformation In Vitro Model for Transvenous Embolization Using 3D Printing and Real Patient Data.

BACKGROUND AND PURPOSE: Transvenous embolization has emerged as a novel technique for treating selected brain AVMs with high reported occlusion rates. However, it requires anatomic and technical skills to be successful and to ensure patient safety. Therefore, training and testing are essential for preparing clinicians to perform these procedures. Our aim was to develop and test a novel, patient-specific brain AVM in vitro model for transvenous embolization by using 3D printing technology. MATERIALS AND METHODS: We developed a brain AVM in vitro model based on real patient data by using stereolithography resin 3D printing. We created a closed pulsed circuit with flow passing from the arterial side to the venous side, and we tested the effect of mean arterial pressure on retrograde nidal filling with contrast injections. Transvenous embolization simulations were conducted for each of the 12 identical models divided into 2 groups (2×6). This involved the use of an ethylene-vinyl alcohol liquid embolic agent injected through microcatheters either without or with a coil in the vein (groups 1 and 2, respectively). RESULTS: Retrograde contrast advance to nidus was directly related to lower mean arterial pressure. Transvenous embolization tests with a liquid embolic agent adequately reproduced the usual embolization plug and push technique. We found no differences between the 2 group conditions, and additional venous coil neither increased nidus penetration nor reduced injection time in the model (57.6 versus 61.2% nidus occlusion rate, respectively). CONCLUSIONS: We were able to develop and test a functional in vitro brain AVM model for transvenous embolization by using 3D printing to emulate its conditions and characteristics. Better contrast penetration was achieved with less mean arterial pressure, and no embolization advantage was found by adding coil to the vein in this model.

Aggression against Nursing Personnel during the First Wave of COVID-19 Pandemic: An Internet-Based Survey.

(1) Background: health care workers, particularly nurses, have been regularly assaulted during the COVID-19 pandemic. Purpose: to evaluate the prevalence and location of assaults against nursing personnel in Latin America, and to determine predictor factors for aggression against nurses. (2) Methods: A cross-sectional online survey was answered by 374 nurses working in health care during the COVID-19 pandemic. The aggression against nurses was estimated using the Victimization Scale. (3) Results: A total of 288 nurses were included in this study. The victimization scale showed that 52.1% of nurses have suffered aggression by the general population during the COVID-19 pandemic. Males were more likely to be attacked than females (p < 0.05). Additionally, males were attacked more frequently on public transport (x2 = 6.72, p = 0.01). The home neighborhood and markets were other locations with a higher risk of being assaulted (OR: 3.39, CI: 1.53-7.50). (4) Conclusions: Our results indicate that nurses in Latin America who work during the COVID-19 pandemic and social isolation have been frequently assaulted by the general public. Males are more frequently attacked than females and the main places of aggression are public transportation, their home neighborhood and supermarkets. Implications for nursing practice: it is necessary to create and implement protocols and guidelines to support nursing personnel during the COVID-19 pandemic. This study was retrospectively registered at the Juarez Autonomous University of Tabasco (103/CIPDACS/2020) on the (08/2020).

An Analytic Equation for Assessing the Thickness of Titanium Nitride Coatings by Energy Dispersive X-ray Spectroscopy in the Scanning Electron Microscope.

In this study, a methodology for assessing the thickness of titanium nitride (TiN) coatings by energy dispersive X-ray spectroscopy (EDS) in the scanning electron microscope is explored. A standardless method is applied, where the film thickness (th) is related to the microscope accelerating voltage (V0), the type of substrate and the ratio between the more intense peaks in the EDS spectrum, arising from both the substrate and the coating (afterwards called the I-ratio, IR). Three different substrates covered with TiN were studied, namely, silicon, glass, and stainless steel. Monte Carlo simulations enabled to state an analytic equation, which allows assessing the coating thickness as follows:th=thcr⋅exp[-ßIR1/n]where IR = Iksubstrate/Ikcoating, thcr (critical thickness) is the largest coating thickness, which is assessable at a fixed V0, ß is a multiplication factor, and n is an exponent, where thcr, ß and n are assessable from V0 and substrate type. Interpolation via the equation presented, using reference thicknesses, allowed thickness predictions with around 80% of datapoints differing less than around 2% from the reference value. A procedure for detecting variations as low as 1.0% in coating thickness regarding the nominal thickness is presented.

Endovascular treatment simulations using a novel in vitro brain arteriovenous malformation model based on three-dimensional printing millifluidic technology.

BACKGROUND: Brain arteriovenous malformations (bAVM) are complex vascular diseases. Several models have been used to simulate endovascular treatments; thus in vitro models have not been widely employed because it has been difficult to recreate realistic phantoms of this disease. OBJECTIVE: To describe the development and evaluate the preliminary experience of a novel bAVM in vitro model for endovascular embolization using millifluidic three-dimensional (3D) printing technology. METHODS: We designed a bAVM phantom starting from simple to more complex designs, composed of a nidus, feeding arteries and draining vein. We recreate the design by using millifluidic technology with stereolithography 3D printing. Structural and functional tests were performed using angiographic images and computer flow dynamics. Treatment simulations with ethylene vinyl alcohol were tested using two different microcatheter position techniques. A Likert-scale questionnaire was applied to perform a qualitative evaluation of the model. RESULTS: We developed a realistic model of a bAVM with hollow channels. The structural evaluation showed a high precision of the 3D printing process. Embolization tests with the liquid agent gave similar sensations and material behaviour as in vivo cases. There were no significant differences between microcatheter position techniques, thus we observed a trend for better nidus filling with a deeper in-nidus position technique. CONCLUSIONS: We were able to create and test a novel bAVM in vitro model with stereolithography 3D printing in resin. It showed a high capacity for simulating endovascular embolization characteristics, with an excellent user experience. It could be potentially used for training and testing of bAVM embolizations.

Intradural Extramedullary Tumors and Associated Syndromes.

Most intradural tumors are located within the intradural extramedullary compartment, and the most common tumors are schwannomas and meningiomas. Other less common neoplasms include neurofibroma, solitary fibrous tumor, myxopapillary ependymoma, lymphoma, metastatic leptomeningeal disease, malignant peripheral nerve sheath tumor, and paraganglioma. Patients usually present with gait ataxia, radicular pain, and motor and sensory deficits due to chronic compressive myelopathy or radiculopathy. MRI is the modality of choice for detecting and evaluating intradural extramedullary spinal tumors. This imaging technique helps narrow the differential diagnosis and therefore decide treatment.

The impact of a two-year long COVID-19 public health restriction program on mechanical thrombectomy outcomes in a stroke network.

OBJECTIVE: The purpose of this study was to evaluate the impact of COVID-19 pandemic public health restrictions on our drip and ship mechanical thrombectomy program in Santiago Chile. MATERIALS AND METHODS: This was a retrospective analysis of a prospectively collected database comparing two cohorts, one during a two-year period before COVID-19 and the second during the two years of the pandemic at our metropolitan stroke program. RESULTS: A total of 100 patients were included in the pre COVID-19 cohort (cohort 1) and 121 in the COVID-19 cohort (cohort 2). There was a significant difference between cohorts, with older patients, different occlusion sites and higher door to arterial puncture time during the COVID-19 period. A non-significant trend for worse 90-day outcomes and higher mortality was present in cohort 2. There were no statistical differences in safety treatment parameters. CONCLUSIONS: COVID-19 pandemic has had a measurable impact on our mechanical thrombectomy program. Results showed similarities to other reported Latin American series, where less robust health systems could adapt less efficiently compared to developed countries. After two years of public health restrictions, there were changes in the treatment population characteristics, delay in some internal management metrics and a non-significant trend to worse 90-day outcomes and higher mortality.

Chronic Pain and Depression are Increased in Outpatient Adults with Somatic Symptoms from Secondary Health Care Services.

BACKGROUND: Somatic symptom disorder is described as excessive thoughts, feelings, or behaviors related to physical symptoms. The presence of somatic symptoms has been associated with depression, alexithymia, and the presence of chronic pain. Individuals with somatic symptom disorder are frequent attenders of primary health care services. AIM: We focused on investigating if the presence of psychological symptoms, alexithymia, or pain could be risk factors for somatic symptoms in a secondary health care service. METHODS: A cross-sectional and observational study. A total of 136 Mexican individuals who regularly attend a secondary health care service were recruited. The Visual Analogue Scale for Pain Assessment, the Symptom Checklist 90, and the Patient Health Questionnaire-15 were applied. RESULTS: Of all the participants, 45.2% showed somatic symptoms. We observed that these individuals more frequently presented with complaints of pain (χ2 = 18.4, p < .001), as well as more severe (t = -4.6, p < .001), and prolonged (χ2 = 4.9, p = 0.02). They also exhibited higher severity in all psychological dimensions assessed (p < .001). Finally, cardiovascular disease (t = 2.52, p = .01), pain intensity (t = 2.94, p = .005), and SCL-90 depression (t = 7.58, p < .001) were associated with somatic symptoms. CONCLUSIONS: In this study, we observed a high frequency of somatic symptoms in outpatients attending secondary health care services. They may be accompanied by comorbid cardiovascular conditions, higher pain intensity, and other mental health-related symptoms, which may aggravate the general clinical picture presented by the patient seeking health care. The presence and severity of somatization should be taken into consideration in the first and second level health care services for an early mental state evaluation and treatment of these outpatients to have a better clinical assessment and health outcome.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD) in Chile: lessons learned from challenging cases.

BACKGROUND: Anti-Myelin Oligodendrocyte Glycoprotein (MOG) Antibody Associated Disease (MOGAD) is an emerging disorder recognized as a clinical entity distinct from Multiple Sclerosis and Aquaporin-4-positive Neuromyelitis Optica Spectrum Disorders (NMOSD-AQP4+), and its phenotypic spectrum continues to expand. Most information about its clinical course has emerged from retrospective studies, and treatment response both in acute and chronic-relapsing disease is still limited. We aimed to describe the clinical and paraclinical characteristics of monophasic and relapsing, paediatric and adult patients with MOGAD under regular clinical care in Chile, highlighting some challenging cases that are far from being considered benign. METHODS: Observational, retrospective, and prospective longitudinal multicentre study including patients with positive serum MOG-IgG assessed by cell-based assay. RESULTS: We include 35 patients, 71% women, median age at onset 30 years (range 1-68), 23% had paediatric onset, with a median disease-duration 24 months (range 12-348). In the whole cohort, the most frequent symptoms at onset were isolated optic neuritis (ON) (34%) and myelitis (22%). Encephalitis with seizures or encephalomyelitis was the most common presentation in paediatric-onset patients 75% (n = 6), compared to 11% (n = 3) of the adult-onset patients (p < 0.001). A relapsing course was observed in 34%, these patients were younger (25 vs. 34 years, p = 0.004) and with a longer disease duration (64 vs. 6 months, p = 0.004) compared to monophasic patients. Two patients developed encephalitis with seizures/status epilepticus, with concomitant positive CSF anti-NMDAR-IgG. Chronic immunotherapy was ever prescribed in 77%, the most frequent was rituximab (35%). Relapses under chronic immunotherapy occurred in 5/27 patients (18.5%), two of them under rituximab, one paediatric patient who started combined therapy with monthly IVIG and one adult patient that switched to satralizumab plus mycophenolate. The median EDSS at the last follow-up was 1.5 (range 0-6.0). CONCLUSION: In Chile, patients with MOGAD exhibit a wide spectrum of clinical presentations at disease onset and during relapses. Close monitoring is needed, particularly in younger patients with short follow-up periods.

Increased Levels of HbA1c in Individuals with Type 2 Diabetes and Depression: A Meta-Analysis of 34 Studies with 68,398 Participants.

Glycosylated hemoglobin is used to diagnose type 2 diabetes mellitus and assess metabolic control. Depression itself has been associated with high levels of HbA1c in individuals with T2DM. The association between diabetes and depression suggests the usefulness of determining HbA1c as a biological marker of depressive symptoms. The aim of this study was to determine HbA1c levels in individuals with T2DM with vs. without depression. Additionally, we analyzed the influence of pharmacological treatments, time of evolution, and complications of disease. We performed a literature search in different databases published up to January 2020. A total of 34 articles were included. Our results showed that individuals with T2DM with depression showed increased levels of HbA1c in comparison to individuals with T2DM without depression (d = 0.18, 95% CI: 0.12−0.29, p(Z) < 0.001; I2 = 85.00). We also found that HbA1c levels remained elevated in individuals with T2DM with depression who were taking hypoglycemic drugs (d = 0.20 95% CI: 0.11−0.30, p(Z) < 0.001; I2 = 86.80), in individuals with less than 10 years of evolution (d = 0.17 95% CI: 0.09−0.26, p(Z) = 0.001; I2 = 66.03) and in individuals with complications of the disease (d = 0.17, 95% CI: 0.07−0.26, p(Z) < 0.001; I2 = 58.41). Our results show that HbA1c levels in individuals with T2DM with depression are significantly increased compared to controls with T2DM without depression. Additionally, these levels remained elevated in individuals who were taking hypoglycemic drugs, those with less than 10 years of disease evolution, and those with complications related to diabetes. It is necessary to examine the existence of a diabetes−HbA1c−depression connection.

Gender Differences in Suicide and Homicide Rates in Mexico City during 2019.

Suicides and homicides are public health problems around the world. The rates of suicide and homicide have increased in the past years. The objectives of this study are to estimate the rates of suicide and homicide in Mexico City, and to determine the rates of suicide and homicide by sex in the different municipalities of Mexico City during 2019. Data analyzed were obtained from files of governmental organizations in Mexico City. From the general victims-in-research-folders, we choose "victims of crime" or "loss of life by suicide" that happened in 2019. Sex and municipality of residence were obtained. The rate of suicide was of 5.65 cases per 100,000 habitants. Stratified by gender and by municipalities, the highest rates observed were 6.8 suicides per 100,000 males and 29.6 suicides per 100,000 females. The sex ratio was 4.2:1 (males: females). Regarding homicides, the rates were 16.68 homicides per 100,000 females and 67.41 homicides per 100,000 males. The Venustiano Carranza Municipality showed the highest homicide rate in men with 131.72 homicides per 100,000 males. The homicide sex ratio was 7.8:1. The findings of the present study highlight that death by suicide is more common in men with 7.8 more times than in women. The municipalities with higher deaths by suicide have lower rates of homicides and the municipalities with higher deaths by suicide showed lower rates of suicide in men.

Circumflex Scapular Artery Pseudoaneurysm as an Unusual Source of Emboli in Recurrent Posterior Circulation Stroke.

OBJECTIVE: To present a rare cause of recurrent posterior embolic strokes originating from a partially thrombosed pseudoaneurysm of a shoulder artery after arthroscopy. MATERIALS AND METHODS: The clinical history, complementary studies and follow-up were reviewed. RESULTS: The patient was successfully embolized and presented no new ischemic episodes at the 3-month follow-up visit. CONCLUSIONS: Shoulder artery pseudoaneurysm should be considered as an unusual source of posterior embolic strokes.

Papilledema: A Review of the Pathophysiology, Imaging Findings, and Mimics.

Increased intracranial pressure is the most common cause of papilledema. Multiple etiologies such as cerebral edema, hydrocephalus, space occupying lesions, infection, and idiopathic intracranial hypertension among others should be considered. Imaging plays a critical role in the detection of pathologies that can cause papilledema. MRI with contrast and CE-MRV, in particular, are key for the diagnosis of idiopathic intracranial hypertension. This review will focus in common and infrequent causes of papilledema, the role of imaging in patients with papilledema as well as its potential mimickers.

Functional Dysconnectivity in Ventral Striatocortical Systems in 22q11.2 Deletion Syndrome.

22q11.2 deletion syndrome (22q11.2DS) is a genetic neurodevelopmental disorder that represents one of the greatest known risk factors for psychosis. Previous studies in psychotic subjects without the deletion have identified a dopaminergic dysfunction in striatal regions, and dysconnectivity of striatocortical systems, as an important mechanism in the emergence of psychosis. Here, we used resting-state functional MRI to examine striatocortical functional connectivity in 22q11.2DS patients. We used a 2 × 2 factorial design including 125 subjects (55 healthy controls, 28 22q11.2DS patients without a history of psychosis, 10 22q11.2DS patients with a history of psychosis, and 32 subjects with a history of psychosis without the deletion), allowing us to identify network effects related to the deletion and to the presence of psychosis. In line with previous results from psychotic patients without 22q11.2DS, we found that there was a dorsal to ventral gradient of hypo- to hyperstriatocortical connectivity related to psychosis across both patient groups. The 22q11.2DS was additionally associated with abnormal functional connectivity in ventral striatocortical networks, with no significant differences identified in the dorsal system. Abnormalities in the ventral striatocortical system observed in these individuals with high genetic risk to psychosis may thus reflect a marker of illness risk.

Meningitis tuberculosa: un desafío diagnóstico en pediatría

Resumen La meningitis por Mycobacterium tuberculosis es infrecuente en pediatría y su diagnóstico definitivo representa un desafío clínico. Presentamos el caso de un lactante de dos años, que presentó un cuadro de meningitis crónica. Se logró el diagnóstico tras la sospecha imagenológica y la confirmación tras la búsqueda seriada del complejo M. tuberculosis por RPC en LCR y en biopsia de tejido cerebral. A pesar de sus complicaciones, el paciente respondió favorablemente al tratamiento antituberculoso. En Chile, la tuberculosis es infrecuente en niños y los síntomas son generalmente inespecíficos. Los hallazgos en RM cerebral asociados a alteraciones del LCR permiten sospechar el compromiso meníngeo precozmente. Se recomienda iniciar el tratamiento antituberculoso empírico ante la sospecha, ya que mejora el pronóstico. A pesar de los avances diagnósticos y terapéuticos, la meningitis tuberculosa sigue teniendo una alta tasa de complicaciones y un pronóstico ominoso.

Abstract Mycobacterium tuberculosis meningitis is rare in the pediatric population and its definitive diagnosis represents a clinical challenge. We present the case of a 2-year-old infant with chronic meningitis. Diagnosis was accomplished by suggestive radiological findings and serial search for M. tuberculosis complex by real-time polymerase chain reaction (qPCR) in cerebrospinal fluid (CSF) and in brain tissue. Despite the complications, the patient evolved favorably with the tuberculosis treatment. In Chile, tuberculosis is a rare disease in children and symptoms are generally nonspecific. Brain MRI findings associated with CSF alterations allow early suspicion of MTBC. Start of empirical antituberculosis treatment upon suspicion is recommended given it is associated with better prognosis. Despite diagnostic and therapeutic advances, MTBC continues to have a high complication rate and an ominous prognosis.

Abnormal nodal and global network organization in resting state functional MRI from subjects with the 22q11 deletion syndrome.

The 22q11 deletion syndrome is a genetic disorder associated with a high risk of developing psychosis, and is therefore considered a neurodevelopmental model for studying the pathogenesis of schizophrenia. Studies have shown that localized abnormal functional brain connectivity is present in 22q11 deletion syndrome like in schizophrenia. However, it is less clear whether these abnormal cortical interactions lead to global or regional network disorganization as seen in schizophrenia. We analyzed from a graph-theory perspective fMRI data from 40 22q11 deletion syndrome patients and 67 healthy controls, and reconstructed functional networks from 105 brain regions. Between-group differences were examined by evaluating edge-wise strength and graph theoretical metrics of local (weighted degree, nodal efficiency, nodal local efficiency) and global topological properties (modularity, local and global efficiency). Connectivity strength was globally reduced in patients, driven by a large network comprising 147 reduced connections. The 22q11 deletion syndrome network presented with abnormal local topological properties, with decreased local efficiency and reductions in weighted degree particularly in hub nodes. We found evidence for abnormal integration but intact segregation of the 22q11 deletion syndrome network. Results suggest that 22q11 deletion syndrome patients present with similar aberrant local network organization as seen in schizophrenia, and this network configuration might represent a vulnerability factor to psychosis.

[Emotional and psychological status of nursing staff attacked during the COVID-19 pandemic in Latin America]. / Estado emocional y psicológico del personal de enfermería agredido durante la pandemia de COVID-19 en Latinoamérica.

INTRODUCTION: The new COVID-19 disease is worldwide. During the pandemic, attacks on healthcare staff have increased. The objective of the study was to know the incidence of aggression towards nursing staff and to evaluate the main emotional and psychological symptoms experienced during the COVID-19 pandemic in Latin America. METHOD: A cross-sectional survey was applied to nursing staff of Spanish-speaking Latin American countries. Sociodemographic information was obtained concerning aggression, psychological symptoms, and emotional state. Descriptive statistics were applied in frequencies and percentages, means and standard deviation. RESULTS: 310 people from Mexico (65.2%), Argentina (5.8%), Colombia (5.2%), Honduras (5.2%), Costa Rica (4.5%) and other Latin American countries (14.1%) participated. 78.1% were women, with an average age of 35.2 years. 79.6% of the sample reported being attacked or discriminated against. The most common emotions were fear of getting sick (73.7%), sleep disturbances (33.4%), fear of infecting their relatives (33.4%). The mental health disorders reported were anxiety (29.2%), sadness (10.4%) and increased appetite (8.8%). The most frequent locations of aggression were the street and public transport. Our results suggest a high incidence of aggression against nursing staff during the pandemic; in any case, the staff present emotional and mental disturbances. It is necessary to develop safety and security policies for nursing staff and provide mental health care to staff who are on the first line of defence against COVID-19.

Regional brain atrophy is related to social cognition impairment in multiple sclerosis.

BACKGROUND: Multiple sclerosis exhibits specific neuropathological phenomena driving to both global and regional brain atrophy. At the clinical level, the disease is related to functional decline in cognitive domains as the working memory, processing speed, and verbal fluency. However, the compromise of social-cognitive abilities has concentrated some interest in recent years despite the available evidence suggesting the risk of disorganization in social life. Recent studies have used the MiniSEA test to assess the compromise of social cognition and have found relevant relationships with memory and executive functions, as well as with the level of global and regional brain atrophy. OBJECTIVE: The present article aimed to identify structural changes related to socio-cognitive performance in a sample of patients with relapsing-remitting multiple sclerosis. METHODS: 68 relapsing-remitting multiple sclerosis Chilean patients and 50 healthy control subjects underwent MRI scans and neuropsychological evaluation including social-cognition tasks. Total brain, white matter, and gray matter volumes were estimated. Also, voxel-based morphometry was applied to evaluate regional structural changes. RESULTS: Patients exhibited lower scores in all neuropsychological tests. Social cognition exhibited a significant decrease in this group mostly related to the declining social perception. Normalized brain volume and white matter volume were significantly decreased when compared to healthy subjects. The regional brain atrophy analysis showed that changes in the insular cortex and medial frontal cortices are significantly related to the variability of social-cognitive performance among patients. CONCLUSIONS: In the present study, social cognition was only correlated with the deterioration of verbal fluency, despite the fact that previous studies have reported its link with memory and executive functions. The identification of specific structural correlates supports the comprehension of this phenomenon as an independent source of cognitive disability in these patients.

Regional brain atrophy is related to social cognition impairment in multiple sclerosis / La atrofia cerebral regional se relaciona con el deterioro de la cognición social en sclerosis múltiple

ABSTRACT Background: Multiple sclerosis exhibits specific neuropathological phenomena driving to both global and regional brain atrophy. At the clinical level, the disease is related to functional decline in cognitive domains as the working memory, processing speed, and verbal fluency. However, the compromise of social-cognitive abilities has concentrated some interest in recent years despite the available evidence suggesting the risk of disorganization in social life. Recent studies have used the MiniSEA test to assess the compromise of social cognition and have found relevant relationships with memory and executive functions, as well as with the level of global and regional brain atrophy. Objective: The present article aimed to identify structural changes related to socio-cognitive performance in a sample of patients with relapsing-remitting multiple sclerosis. Methods: 68 relapsing-remitting multiple sclerosis Chilean patients and 50 healthy control subjects underwent MRI scans and neuropsychological evaluation including social-cognition tasks. Total brain, white matter, and gray matter volumes were estimated. Also, voxel-based morphometry was applied to evaluate regional structural changes. Results: Patients exhibited lower scores in all neuropsychological tests. Social cognition exhibited a significant decrease in this group mostly related to the declining social perception. Normalized brain volume and white matter volume were significantly decreased when compared to healthy subjects. The regional brain atrophy analysis showed that changes in the insular cortex and medial frontal cortices are significantly related to the variability of social-cognitive performance among patients. Conclusions: In the present study, social cognition was only correlated with the deterioration of verbal fluency, despite the fact that previous studies have reported its link with memory and executive functions. The identification of specific structural correlates supports the comprehension of this phenomenon as an independent source of cognitive disability in these patients.

RESUMEN Antecedentes: La esclerosis múltiple presenta fenómenos neuropatológicos específicos que conducen a la atrofia cerebral global y regional. A nivel clínico, la enfermedad está relacionada con el deterioro funcional de los dominios cognitivos como la memoria de trabajo, la velocidad de procesamiento y la fluidez verbal. Sin embargo, el compromiso de las habilidades socio-cognitivas ha concentrado cierto interés en los últimos años debido a la evidencia disponible que sugiere el riesgo de desorganización en la vida social. Estudios recientes han utilizado la prueba MiniSEA para evaluar el compromiso de la cognición social y han encontrado relaciones relevantes con la memoria y funciones ejecutiva, así como con el nivel de atrofia cerebral global y regional. Objetivo: El presente artículo tiene como objetivo identificar cambios estructurales relacionados con el rendimiento sociocognitivo en una muestra de pacientes con esclerosis múltiple recurrente-remitente. Métodos: 68 pacientes Chilenos con esclerosis múltiple recurrente-remitente y 50 sujetos de control sanos se sometieron a resonancias magnéticas y evaluación neuropsicológica, incluidas las tareas de cognición social. Se estimaron los volúmenes cerebrales totales, de materia blanca y materia gris. Además, se aplicó la morfometría basada en vóxel para evaluar los cambios estructurales regionales. Resultados: Los pacientes muestran puntuaciones más bajas en todas las pruebas neuropsicológicas. La cognición social exhibe una disminución significativa en este grupo principalmente relacionada con la disminución de la percepción social. El volumen normalizado del cerebro y el volumen de la materia blanca disminuyeron significativamente en comparación con los sujetos sanos. El análisis regional de atrofia cerebral mostró que los cambios en la corteza insular y la corteza frontal medial están significativamente relacionados con la variabilidad del rendimiento sociocognitivo entre los pacientes. Conclusiones: En el presente estudio, la cognición social sólo se correlacionó con el deterioro de la fluencia verbal, a pesar de que estudios previos han reportado su vinculación con la memoria y funciones ejecutivas. La identificación de correlatos estructurales específicos apoya la comprensión de este fenómeno como una fuente independiente de discapacidad cognitiva en estos pacientes.

Variación fenotípica de los peces Curimata mivartii (Characiformes: Curimatidae) y Pimelodus grosskopfii (Siluriformes: Pimelodidae) en hábitats lóticos y lénticos / Phenotypic variation of the fishes Curimata mivartii (Characiformes: Curimatidae) and Pimelodus grosskopfii (Siluriformes: Pimelodidae) in lotic and lentic habitats

Resumen Introducción: A pesar de su importancia en el rendimiento de la natación y la eficacia biológica individual, la forma del cuerpo y las variaciones de tamaño en respuesta a la velocidad del flujo de agua siguen siendo desconocidas para la mayoría de los peces migratorios de agua dulce en el Neotrópico. Objetivo: Contrastar la hipótesis de variación fenotípica en el tamaño y la conformación del cuerpo de dos especies de peces dulceacuícolas que enfrentan cambios de velocidad a través de sus migraciones en dos ríos pertenecientes a una cuenca neotropical. Métodos: Se utilizó la morfometría geométrica basada en hitos para estudiar las variaciones en el tamaño y la conformación del cuerpo para dos especies de peces Curimata mivartii y Pimelodus grosskopfii en hábitats lóticos y lénticos de la cuenca Colombiana del Magdalena-Cauca. Resultados: Los individuos de C. mivartii de dos hábitats lóticos fueron similares en tamaño y significativamente más grandes que los del hábitat léntico, mientras que los individuos de P. grosskopfii fueron similares en ambos hábitats. Ambas especies mostraron cuerpos más hidrodinámicos en hábitats lóticos y formas corporales más robustas en hábitats lénticos. Conclusión: Ambas especies exhiben cambios fenotípicos en la forma del cuerpo concordantes con las predicciones previas sobre las variaciones morfológicas de los peces. Esta información es relevante para predecir cambios en respuesta a la heterogeneidad ambiental, especialmente inducidos por actividades antropogénicas que cambian las velocidades del agua en el río.

Abstract Introduction: Despite their importance in swimming performance and individual fitness, body shape and size variations in response to water flow velocity remain unknown for most migratory freshwater fishes in the Neotropics. Objective: Test the hypothesis of phenotypic variation in the size and body shape of two species of freshwater fishes that encounter changes in water velocity across their migrations in two rivers that belong to a single Neotropical basin. Methods: Landmark-based geometric morphometrics was used to study variations in body size and shape for the fish species Curimata mivartii and Pimelodus grosskopfii in lotic and lentic habitats of the Colombian Magdalena-Cauca Basin. Results: Individuals of C. mivartii from two lotic habitats were similar in size and both were significantly bigger than those from lentic habitats, whereas individuals of P. grosskopfii were similar in size in both habitats. Both species showed more streamlined bodies in lotic habitats and deeper body shapes in lentic habitats. Conclusions: Both species exhibit phenotypic changes in body shape concordant with previous predictions on morphological variations of fishes. This information is relevant to predict changes in response to environmental heterogeneity, especially those induced by anthropogenic activities that change the water velocity in the river.