Recurrent Pleomorphic Xanthoastrocytoma Presenting With Diffuse Leptomeningeal Spread.

We report a case highlighting key clinical, CSF, and imaging findings of recurrent pleomorphic xanthoastrocytoma with leptomeningeal spread.

Structural MRI-Based Measures of Accelerated Brain Aging do not Moderate the Acute Antidepressant Response in Late-Life Depression.

OBJECTIVE: Late-life depression (LLD) is characterized by accelerated biological aging. Accelerated brain aging, estimated from structural magnetic resonance imaging (sMRI) data by a machine learning algorithm, is associated with LLD diagnosis, poorer cognitive performance, and disability. We hypothesized that accelerated brain aging moderates the antidepressant response. DESIGN AND INTERVENTIONS: Following MRI, participants entered an 8-week randomized, controlled trial of escitalopram. Nonremitting participants then entered an open-label 8-week trial of bupropion. PARTICIPANTS: Ninety-five individuals with LLD. MEASUREMENTS: A machine learning algorithm estimated each participant's brain age from sMRI data. This was used to calculate the brain-age gap (BAG), or how estimated age differed from chronological age. Secondary sMRI measures of aging pathology included white matter hyperintensity (WMH) volumes and hippocampal volumes. Mixed models examined the relationship between sMRI measures and change in depression severity. Initial analyses tested for a moderating effect of MRI measures on change in depression severity with escitalopram. Subsequent analyses tested for the effect of MRI measures on change in depression severity over time across trials. RESULTS: In the blinded initial phase, BAG was not significantly associated with a differential response to escitalopram over time. BAG was also not associated with a change in depression severity over time across both arms in the blinded phase or in the subsequent open-label bupropion phase. We similarly did not observe effects of WMH volume or hippocampal volume on change in depression severity over time. CONCLUSION: sMRI markers of accelerated brain aging were not associated with treatment response in this sequential antidepressant trial.

Semi-supervised Machine Learning with MixMatch and Equivalence Classes.

Semi-supervised methods have an increasing impact on computer vision tasks to make use of scarce labels on large datasets, yet these approaches have not been well translated to medical imaging. Of particular interest, the MixMatch method achieves significant performance improvement over popular semi-supervised learning methods with scarce labels in the CIFAR-10 dataset. In a complementary approach, Nullspace Tuning on equivalence classes offers the potential to leverage multiple subject scans when the ground truth for the subject is unknown. This work is the first to (1) explore MixMatch with Nullspace Tuning in the context of medical imaging and (2) characterize the impacts of the methods with diminishing labels. We consider two distinct medical imaging domains: skin lesion diagnosis and lung cancer prediction. In both cases we evaluate models trained with diminishing labeled data using supervised, MixMatch, and Nullspace Tuning methods as well as MixMatch with Nullspace Tuning together. MixMatch with Nullspace Tuning together is able to achieve an AUC of 0.755 in lung cancer diagnosis with only 200 labeled subjects on the National Lung Screening Trial and a balanced multi-class accuracy of 77% with only 779 labeled examples on HAM10000. This performance is similar to that of the fully supervised methods when all labels are available. In advancing data driven methods in medical imaging, it is important to consider the use of current state-of-the-art semi-supervised learning methods from the greater machine learning community and their impact on the limitations of data acquisition and annotation.

Towards Machine Learning Prediction of Deep Brain Stimulation (DBS) Intra-operative Efficacy Maps.

Deep brain stimulation (DBS) has the potential to improve the quality of life of people with a variety of neurological diseases. A key challenge in DBS is in the placement of a stimulation electrode in the anatomical location that maximizes efficacy and minimizes side effects. Pre-operative localization of the optimal stimulation zone can reduce surgical times and morbidity. Current methods of producing efficacy probability maps follow an anatomical guidance on magnetic resonance imaging (MRI) to identify the areas with the highest efficacy in a population. In this work, we propose to revisit this problem as a classification problem, where each voxel in the MRI is a sample informed by the surrounding anatomy. We use a patch-based convolutional neural network to classify a stimulation coordinate as having a positive reduction in symptoms during surgery. We use a cohort of 187 patients with a total of 2,869 stimulation coordinates, upon which 3D patches were extracted and associated with an efficacy score. We compare our results with a registration-based method of surgical planning. We show an improvement in the classification of intraoperative stimulation coordinates as a positive response in reduction of symptoms with AUC of 0.670 compared to a baseline registration-based approach, which achieves an AUC of 0.627 (p < 0.01). Although additional validation is needed, the proposed classification framework and deep learning method appear well-suited for improving pre-surgical planning and personalize treatment strategies.

Estimation of Biological Parameters of Cutaneous Ulcers Caused by Leishmaniasis in an Animal Model Using Diffuse Reflectance Spectroscopy.

Cutaneous leishmaniasis (CL) is a neglected tropical disease that requires novel tools for its understanding, diagnosis, and treatment follow-up. In the cases of other cutaneous pathologies, such as cancer or cutaneous ulcers due to diabetes, optical diffuse reflectance-based tools and methods are widely used for the investigation of those illnesses. These types of tools and methods offer the possibility to develop portable diagnosis and treatment follow-up systems. In this article, we propose the use of a three-layer diffuse reflectance model for the study of the formation of cutaneous ulcers caused by CL. The proposed model together with an inverse-modeling procedure were used in the evaluation of diffuse-reflectance spectral signatures acquired from cutaneous ulcers formed in the dorsal area of 21 golden hamsters inoculated with Leishmanisis braziliensis. As result, the quantification of the model's variables related to the main biological parameters of skin were obtained, such as: diameter and volumetric fraction of keratinocytes, collagen; volumetric fraction of hemoglobin, and oxygen saturation. Those parameters show statistically significant differences among the different stages of the CL ulcer formation. We found that these differences are coherent with histopathological manifestations reported in the literature for the main phases of CL formation.

Alterations of network synchrony after epileptic seizures: An analysis of post-ictal intracranial recordings in pediatric epilepsy patients.

OBJECTIVE: Post-ictal EEG alterations have been identified in studies of intracranial recordings, but the clinical significance of post-ictal EEG activity is undetermined. The purpose of this study was to examine the relationship between peri-ictal EEG activity, surgical outcome, and extent of seizure propagation in a sample of pediatric epilepsy patients. METHODS: Intracranial EEG recordings were obtained from 19 patients (mean age = 11.4 years, range = 3-20 years) with 57 seizures used for analysis (mean = 3.0 seizures per patient). For each seizure, 3-min segments were extracted from adjacent pre-ictal and post-ictal epochs. To compare physiology of the epileptic network between epochs, we calculated the relative delta power (Δ) using discrete Fourier transformation and constructed functional networks based on broadband connectivity (conn). We investigated differences between the pre-ictal (Δpre, connpre) and post-ictal (Δpost, connpost) segments in focal-network (i.e., confined to seizure onset zone) versus distributed-network (i.e., diffuse ictal propagation) seizures. RESULTS: Distributed-network (DN) seizures exhibited increased post-ictal delta power and global EEG connectivity compared to focal-network (FN) seizures. Following DN seizures, patients with seizure-free outcomes exhibited a 14.7% mean increase in delta power and an 8.3% mean increase in global connectivity compared to pre-ictal baseline, which was dramatically less than values observed among seizure-persistent patients (29.6% and 47.1%, respectively). SIGNIFICANCE: Post-ictal differences between DN and FN seizures correlate with post-operative seizure persistence. We hypothesize that post-ictal deactivation of subcortical nuclei recruited during seizure propagation may account for this result while lending insights into mechanisms of post-operative seizure recurrence.

Independent Preoperative Predictors of Prolonged Length of Stay after Laparoscopic Appendectomy in Patients Over 30 Years of Age: Experience from a Single Institution.

Prompt discharge after laparoscopic appendectomy (LA) is a marker of quality of care, fiscally desirable and feasible in select patients. Patients over 30 comprise a more heterogeneous cohort known to experience worse outcomes after LA. We aimed to identify easily available preoperative risk factors portending a postoperative length of stay ≥2 days among patients above age 30. In this investigation, 296 included patients from a single institution who underwent LA for acute appendicitis from 2010 to 2014 were retrospectively reviewed for preoperative demographics, laboratory studies, comorbidities, presentation characteristics, radiographic finding, and other rationally selected factors for association with postoperative length of stay ≥2 days. Bivariate and multivariate analysis was conducted to determine independent risk factors, which were subsequently modeled via receiver-operating characteristic curve generation and Kaplan-Meier analysis. "Classic" presentation [odds ratio (OR) = 0.5, P = .02], elevated red cell distribution width (RDW; OR = 1.5/% increase, P = 0.004) as well as evidence of rupture on CT (OR = 6.9, P < 0.001) were independently associated with postoperative length of stay ≥ 2 days. Modeling length of stay using these factors generated an area under the curve of 0.713 ± 0.037. Kaplan-Meier analysis of "classic" presentation, elevated RDW, and evidence of rupture on CT through the fifth postoperative day generated log-rank P values of 0.02, 0.05, and ≤ 0.001, respectively. In summary, lack of "classic" presentation, elevated RDW, and CT evidence of rupture are novel risk factors for prolonged postoperative length of stay in LA patients over 30. These findings may help target patients most appropriate for prompt discharge.

Spatiotemporal Mapping of Interictal Spike Propagation: A Novel Methodology Applied to Pediatric Intracranial EEG Recordings.

Synchronized cortical activity is implicated in both normative cognitive functioning and many neurologic disorders. For epilepsy patients with intractable seizures, irregular synchronization within the epileptogenic zone (EZ) is believed to provide the network substrate through which seizures initiate and propagate. Mapping the EZ prior to epilepsy surgery is critical for detecting seizure networks in order to achieve postsurgical seizure control. However, automated techniques for characterizing epileptic networks have yet to gain traction in the clinical setting. Recent advances in signal processing and spike detection have made it possible to examine the spatiotemporal propagation of interictal spike discharges across the epileptic cortex. In this study, we present a novel methodology for detecting, extracting, and visualizing spike propagation and demonstrate its potential utility as a biomarker for the EZ. Eighteen presurgical intracranial EEG recordings were obtained from pediatric patients ultimately experiencing favorable (i.e., seizure-free, n = 9) or unfavorable (i.e., seizure-persistent, n = 9) surgical outcomes. Novel algorithms were applied to extract multichannel spike discharges and visualize their spatiotemporal propagation. Quantitative analysis of spike propagation was performed using trajectory clustering and spatial autocorrelation techniques. Comparison of interictal propagation patterns revealed an increase in trajectory organization (i.e., spatial autocorrelation) among Sz-Free patients compared with Sz-Persist patients. The pathophysiological basis and clinical implications of these findings are considered.

Prevalencia de consumo de alcohol y sustancias psicoactivas en víctimas de accidentes de tránsito. Servicio de urgencias, Hospital de San José, Bogotá DC. Colombia / Prevalence of alcohol and psychoactive substances in road traffic accident victims. Emergency department, Hospital de San José, Bogotá DC. Colombia

En Colombia no existen estudios sobre el tema, por lo cual este trabajo pretende determinar la prevalencia de consumo de alcohol y sustancias psicoactivas en los pacientes que ingresan al servicio de urgencias del Hospital de San José víctimas de accidentes de tránsito. Métodos: estudio observacional de corte transversal. Se incluyeron todos los pacientes que ingresaron a urgencias víctimas de accidente de tránsito, aplicando una encuesta elaborada por los autores. Se procesaron muestras de sangre en quienes no se pudo recolectar orina por diferentes causas. Resultados: la prevalencia de consumo de alcohol fue 4.83% y sustancias psicoactivas 20.15%. Se evaluaron 124 pacientes, hombres 55.5%, edad promedio 34 años, la condición de víctima más frecuente fue en calidad de peatón 44% y 46% presentaron lesiones a nivel de las extremidades. Conclusiones: es sorprendente cómo la presencia de sustancias psicoactivas es mayor en nuestros pacientes. Ojalá esta prevalencia pueda generar políticas para su detección como primera causa generadora de accidentes de tránsito...

Colombia has no studies on this topic thus this work intends to determine the prevalence of alcohol and psychoactive substances consumption in patients admitted to the emergency room at Hospital de San José as victims of a road traffic accident. Methods: cross-sectional observational study. All victims of road traffic accidents who were admitted to the emergency room were included. A survey designed by the authors was applied. Blood samples were examined in those where a urine sample could not be collected for any reason. Results: the prevalence of alcohol consumption was 4.83% and for psychoactive substances 20.15%. One hundred twenty four patients were evaluated, men 55.5%, mean age, 34 years, most frequently (44%) they were pedestrian accident victims, and 46% presented with lesions of the extremities. Conclusions: it is surprising how the presence of psychoactive substances is greater in our patients. Let´s hope this prevalence, as the primary cause of traffic accidents, may generate detection policies...

Risa y salud: abordajes terapéuticos: [revisión] / Laugther and health: therapeutic approaches: [review]

La terapia de la risa hoy en día es utilizada en diversas clínicas y hospitales del mundo como medida coadyuvante en pro del bienestar físico, psicológico, social y emocional de los pacientes. En nuestro país es un tema que poco se conoce y por lo cual es de suma importancia dar a conocer en el ámbito nacional los múltiples beneficios que genera en la salud de las personas. El payaso hospitalario, como protagonista principal, ejerce una importante labor y a través de él se busca lograr una relación armoniosa con el paciente, con el objetivo de mejorar su percepción de la enfermedad, lograr una adecuada adaptación hospitalaria, disminuir los niveles de ansiedad y generar un bienestar global. En Bucaramanga existe la Fundación Corazón en Parches, que se ha encargado de llevar un mensaje de amor y compasión a los pacientes hospitalizados, en especial en edad pediátrica, aplicando la risoterapia a cabalidad, recordando que lo más importante no es curar una enfermedad sino tratar a un paciente que tiene una enfermedad, implementando una visión holística.

Laughter therapy is now used in many hospitals and clinics worldwide as adjunctive measure in favor of physical, psychological, social and emotional development of patients. Our country is a topic that little is known and therefore it is of utmost importance to share national generates multiple benefits in human health. The hospital clown as the main character has an important work and through it seeks to achieve a harmonious relationship with the patient, with the aim of improving their perception of the disease, hospital achieve adequate adaptation, lower levels of anxiety and generate as such a global welfare. In Bucaramanga exists Fundación Corazón en Parches, who have managed to bring a message of love and compassion to hospitalized patients, especially pediatric patients, using the fully laughter therapy, and recalling the most important thing is not to cure a disease but treating a patient having a disease by implementing a holistic view.