Circadian parameter as a possible indicator of gait performance and daily activity levels in chronic stroke survivors.

Stroke recovery is a critical public health problem. It involves cognitive and physical impairments leading to physical inactivity. In addition, there are also sleep problems and disruption of the circadian rhythm. In this paper, we analyze the relation between cognitive impairments level, walking performance, sleep and circadian parameters of a group of chronic stroke survivors. Five stroke survivors enrolled in the study. The clinical assessments were: cognitive function (MoCA), the 10 meter-walking test (10MWT), and the 6 minutes walking test (6MWT). The circadian rhythm parameters were obtained for at least one week wearing the actimeters. There was a positive correlation between the duration of the main sleep episode and the MoCA scores. There were significant correlations between the 10MWT and 6MWT and the circadian parameters that were positive for most active period (M10), Interdaily stability (IS), Mesor and Amplitude and negative for intradaily variability (IV). Our results indicate that gait speed and resistance are correlated to circadian rhythm synchronization, lower rhythm variability and more defined activity-rest episodes. This preliminary study underscores the importance of including a continuous measure of sleep and activity cycles in the assessment of stroke survivors.

Tirotoxicosis por enfermedad trofoblástica gestacional: revisión a partir de 3 casos / Thyrotoxicosis due to gestational trophoblastic disease: clinical cases

La enfermedad trofoblástica gestacional (ETG) es una complicación del embarazo poco común. Corresponde a un espectro de lesiones proliferativas del tejido trofoblástico: Mola Hidatiforme (MH) en sus formas parcial y completa, Coriocarcinoma, Tumor Trofoblástico y Tumor Trofoblástico Epiteloide. Los distintos tipos de ETG presentan en común la hipersecreción de gonadotrofina coriónica humana (hCG). La hCG es una hormona glicoproteica con una estructura muy similar a la TSH, por lo cual puede estimular la función tiroidea en condiciones fisiológicas y en algunas condiciones patológicas. La ETG puede cursar con hipertiroidismo, el cual puede variar en intensidad, desde una presentación asintomática con alteración leve de hormonas tiroideas a un cuadro de hipertiroidismo manifiesto. Se presentan 3 casos clínicos de pacientes con ETG, específicamente MH que evolucionaron con tirotoxicosis transitoria. Los casos presentaron un cuadro leve de hipertiroidismo con pocos síntomas asociados. La taquicardia fue el único síntoma en la mayoría de los casos. En todas las pacientes las hormonas tiroideas se normalizaron después del tratamiento de la ETG. Conclusión: Se debe tener presente la posibilidad de hipertiroidismo en toda paciente con ETG. Un alto nivel de sospecha permitirá identificar a aquellas pacientes que cursen con hipertiroidismo, permitiendo así un diagnóstico y tratamiento oportuno.

Gestational trophoblastic disease (GTD) is a rare complication of pregnancy. GTD includes a group of proliferative lesions of trophoblastic tissue: partial and complete hydatidiform mole, choriocarcinoma, epithelioid trophoblastic tumor, and placental site trophoblastic tumor. The different types of GTD have in common the hypersecretion of human chorionic gonadotropin (hCG). HCG is a glycoprotein hormone with a similar structure to TSH. In physiological and pathological conditions hCG can stimulate thyroid function. GTD can present with hyperthyroidism, which can vary in intensity, from an asymptomatic presentation with mild alteration of thyroid hormones to a manifest hyperthyroidism. We present 3 clinical cases of patients with GTD thyrotoxicosis. All cases presented mild hyperthyroidism. Tachycardia was the only symptom in most cases. In all patients thyroid hormones return to normal after treatment of GTD. Conclusion: In patients with GTD the possibility of hyperthyroidism should be kept in mind. A high level of suspicion will allow to identifying patients with hyperthyroidism.

Elbow movement estimation based on EMG with NARX Neural Networks.

The use of the electrical activity from the muscles may provide a natural way to control exoskeletons or other robotic devices seamlessly. The major challenges to achieve this goal are human motor redundancy and surface electromyography (sEMG) variability. The goal of this work is to find a feature extraction and classification procedures to estimate accurately elbow angular trajectory by means of a NARX Neural Network. The processing time-step should be small enough to make it feasible its further use for online control of an exoskeleton. In order to do so we analysed the Biceps and Triceps Brachii data from an elbow flexo-extension Coincident Timing task performed in the horizontal plane. The sEMG data was pre-processed and its energy was divided in five frequency intervals that were fed to a Nonlinear Auto Regressive with Exogenous inputs (NARX) Neural Network. The estimated angular trajectory was compared with the measured one showing a high correlation between them and a RMSE error maximum of 7 degrees. The procedure presented here shows a reasonably good estimation that, after training, allows real-time implementation. In addition, the results are encouraging to include more complex tasks including the shoulder joint.

Hipertiroidismo en personas mayores de 65 años: serie de casos de un hospital universitario / Thyrotoxicosis in the elderly: case series report from a university hospital

Introducción: En Chile en las últimas décadas ha aumentado la población de personas mayores de 65 años. La tirotoxicosis en este grupo está asociada a complicaciones como fibrilación auricular (FA), insuficiencia cardiaca (ICC), osteoporosis y aumento de la mortalidad. En algunos casos puede presentarse con síntomas no específicos, cuadro conocido como hipertiroidismo apático. Objetivos: Evaluar las características clínicas de la tirotoxicosis en personas mayores. Método: Serie de casos retrospectiva. Se analizaron fichas clínicas de pacientes mayores de 65 años con el diagnóstico de tirotoxicosis controlados en nuestro centro entre enero de 2012 y mayo de 2018. Resultados: En el periodo estudiado 54 pacientes fueron diagnosticados de tirotoxicosis. Se excluyen 4 por datos incompletos. El 80% corresponden a mujeres. La mediana de edad fue 71 años (rango 65-94), sin diferencias por género (p=0,61). La etiología más frecuente fue enfermedad de Graves (EG) en 64%, seguido por bocio multinodular hiperfuncionante en 20%, adenoma tóxico en 10% y asociada a fármacos en 6%. De los pacientes con EG, 28% presentó orbitopatía distiroidea (OD) clínicamente evidente. Un 30% se diagnosticó en contexto de baja de peso, deterioro cognitivo o patología cardiovascular, sin presentar síntomas clásicos de hipertiroidismo. Un 16% presentó FA, 14% ICC y 6% fractura osteoporótica. El 28% fue diagnosticado durante una hospitalización o requirió ser hospitalizado durante los meses siguientes. Los mayores de 75 años presentan una mayor probabilidad de hipertiroidismo apático (OR 5,1, IC95% 1,15-22,7 p=0,01). Además, las complicaciones aumentan en mayores de 75 años, encontrándose en este grupo todos los casos de FA. Conclusiones: La etiología más común de tirotoxicosis fue la EG, a diferencia de lo reportado en otras poblaciones. Un número importante de pacientes debutó sin síntomas clásicos de hipertiroidismo, principalmente mayores de 75 años, por lo que se debe tener una alta sospecha en este grupo etario.

Introduction: Hyperthyroidism in the elderly can produce severe complications such as atrial fibrillation (AF), heart failure (CHF) and osteoporosis. In the elderly, thyrotoxicosis may have only nonspecific symptoms, known as apathetic hyperthyroidism. Objective: To evaluate the clinical characteristics of thyrotoxicosis in the elderly. Methods: Retrospective case series. We reviewed clinical records of patients with thyrotoxicosis older than 65 years, between January 2012 and March 2019. Results: During this period, 54 patients were diagnosed with thyrotoxicosis. Four patients were excluded due to incomplete data. 80% were women. The average age was 73 years (range 65-94), without age difference between gender (p=0,61). The most frequent etiology was Graves' disease in 64%. Hyperfunctioning multinodular goiter was confirmed in 20%, toxic adenoma in 10% and drug-associated in 6%. Twenty eight percent of Graves' disease patients had dysthyroid orbitopathy. Thirty percent presented as apathetic hyperthyroidism. Sixteen percent of the patients presented AF, 14% CHF, and 6% osteoporotic fracture. Twenty-eight percent were diagnosed during hospitalization or required hospitalization in the following months. Those older than 75 years had a greater probability of presenting apathetic hyperthyroidism (OR 5.1, 95% CI 1.15- 22.7 p=0.01). Complications increase in this age group, with all cases of AF. Conclusions: The most common etiology of thyrotoxicosis in this group was GD. This differs from other populations. A significant number of patients presented without classic symptoms of hyperthyroidism, especially in people older than 75 years. Special attention should be paid to atypical symptoms of hyperthyroidism in this group.

Repercusión psicológica en niñoscon Trastorno del espectro autista duranteel confinamiento por COVID-19

Introducción: el mundo vive una situación compleja relacionada con la COVID-19, causada por el SARS-CoV-2,Cuba no está exenta de esta situación. A la par de esta pandemia aparecen alteraciones psicológicas relacionadas con la enfermedad y el confinamiento. Los niños con trastornos mentales son muy vulnerables. El manejo de las conductas disruptivas que se presentan perturba al niño y al adulto que enfrenta la contingencia quien tiene fallas en enfrentarlas y resolverlas. Objetivo: describir las alteraciones psicológicas de los niños con Trastornos del espectro autista durante el confinamiento por COVID-19 y estimular a la familia en la autogestión de recursos psicológicos para el control de conductas desajustadas.Método: se realizó una búsqueda bibliográfica en bases de datos Medline/Pubmed, Elseiver, Scielo y Google académico. Se utilizó descriptores como pandemia, confinamiento, Trastornos del espectro autista, salud mental. Resultados: se encontró que durante situaciones críticas como lo es esta pandemia, se presentan alteraciones en la salud mental de niños con Trastornos del espectro autista. La agresividad, los trastornos del sueño, la irritabilidad, gritos y aparición de conductas estereotipadas son la más frecuente. El confinamiento puede resultar muy complejo para el niño autista quien reacciona desproporcionadamente a cambios en su rutina diaria. Conclusiones: brindando una caracterización de las manifestaciones en niños con este trastorno a partir del confinamiento por COVID-19 y brindando los recursos psicológicos y orientaciones generales a los padres para la atención inmediata a las alteraciones presentadas por estos niños para sobrellevar mejor el periodo de confinamiento.[AU]

Behavioural characterisation of chronic unpredictable stress based on ethologically relevant paradigms in rats.

The chronic unpredictable stress (CUS) paradigm is extensively used in preclinical research. However, CUS exhibits translational inconsistencies, some of them resulting from the use of adult rodents, despite the evidence that vulnerability for many psychiatric disorders accumulates during early life. Here, we assessed the validity of the CUS model by including ethologically-relevant paradigms in juvenile rats. Thus, socially-isolated (SI) rats were submitted to CUS and compared with SI (experiment 1) and group-housed controls (experiment 1 and 2). We found that lower body-weight gain and hyperlocomotion, instead of sucrose consumption and preference, were the best parameters to monitor the progression of CUS, which also affected gene expression and neurotransmitter contents associated with that CUS-related phenotype. The behavioural characterisation after CUS placed locomotion and exploratory activity as the best stress predictors. By employing the exploratory factor analysis, we reduced each behavioural paradigm to few latent variables which clustered into two general domains that strongly predicted the CUS condition: (1) hyper-responsivity to novelty and mild threats, and (2) anxiety/depressive-like response. Altogether, the analyses of observable and latent variables indicate that early-life stress impairs the arousal-inhibition system leading to augmented and persistent responses towards novel, rewarding, and mildly-threatening stimuli, accompanied by lower body-weight gain.

Chilaiditi / No disponible

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Assessment of postural control after sleep deprivation with a low-cost portable force plate.

It is well-known that acute sleep deprivation affects negatively postural control. The analysis of sleep quality during long periods and its impact on motor control and learning performance are crucial aspects of human health. Nevertheless, there is conflicting evidence regarding which postural control variables are more prone to change due to sleep deprivation. Moreover, very few clinicians have at their disposal expensive force plates to measure such variables, so the use of a low-cost portable device could be very interesting. Therefore, we aimed to identify which posture control variables, obtained from a low-cost plate, are more sensitive to sleep deprivation. In order to do so, we have performed a set of experiments with volunteers before and after a night without sleep. Eight participants took part of the study and had their balance measured by a Wii Balance Board before and after one night of sleep deprivation. They were asked to keep a quiet stance on top of the plate with their eyes open and closed, in a balanced design. The main results showed that, regardless the visual information, sleep deprivation has deepest impact on the anterior-posterior center of pressure displacement. Sleep deprivation without visual information had a more pronounced (large effect size) impact on the mean sway in the anterior-posterior direction and its distribution variation. The information that sleep deprivation has a more meaningful impact on anterior-posterior center of pressure excursion may help clinicians and healthcare professionals to better deal with its implications.

EMG-Based Control in a Test Platform for Exoskeleton with One Degree of Freedom.

There are several efforts to use the electrical signals generated by the human muscles to control virtual or even physical devices. It is expected that, the development of this method will provide a natural way to control these devices, requiring little user training, depending on the task complexity. With respect to the control of exoskeletons from the electric signals generated by the muscles, it is desirable that the exoskeleton acts in synergy with the user using surface electromyography (sEMG) signals to detect user intentions. One of the challenges of this approach is the variability of the sEMG signals due to factors such as electrode positioning and conditions of the volunteer at the time of acquisition. In previous work, a procedure based on an Autoregressive with Exogenous Input (ARX) linear model was developed to translate sEMG from biceps, triceps and brachioradialis muscles to elbow joint angle. In this work, we developed a method based on a Genetic Algorithm (GA) to update the ARX model coefficients online to minimize the training periods and we have used the EMG signals to control a one-degree of freedom exoskeleton.vThe GA was able to obtain ARX model coefficients that generate the joint angle reference from the EMG signals. In addition, the joint angle references generated from the offline sEMG from three muscles via an ARX model were used to control a device. At this point we are carrying out tests with the exoskeleton using real-time signals from sEMG.

Daytime sleepiness affects gait auditory synchronization ability.

Sleep disturbances in modern life lead to cognitive and motor performance impairments in everyday tasks such as gait. The most common symptom of these disturbances is daytime sleepiness, which can be assessed by questionnaires such as the Epworth Sleep Scale (ESS). The ESS evaluates sleep health and daytime dysfunction. The goal of this study is to assess the influence of sleepiness on a motorauditory synchrony task, rhythmed gait. High and low sleepiness clusters were formed based on the participants ESS scores. Walking on a treadmill, two different rhythmic auditory stimulus conditions were set with a metronome: isochronous and non-isochronous. Reflective markers on both heels with seven infrared cameras were used to assess the difference between footfall and metronome beep, what is named synchronization error (SE). There was a tendency to anticipate the beep in the HS group when compared to the LS group only in the non-isochronous stimulus condition that was statistically significant. Sleep disturbances that generate daytime sleepiness may bring detrimental effects on brain areas that could be responsible for the real-time adjustment of gait and sustained attention. These impairments may be responsible for the larger synchronization error with larger relative phase of the group with high sleepiness. More studies are necessary involving other parameters of sleep and gait to identify sleep disturbances through gait analysis.

Elbow Joint Angle Estimation with Surface Electromyography Using Autoregressive Models.

This paper presents a method to estimate the elbow joint angle from surface electromyography (sEMG) measurements of biceps, triceps and brachioradialis. This estimation is of major importance for the design of human robot interfaces based on sEMG. It is also relevant to model the muscular system and to design biomimetic mechanisms. However, the processing and interpretation of electromyographic signals is challenging due to nonlinearities, unmodeled muscle dynamics, noise and interferences. In order to determine an estimation model and a calibration procedure for the model parameters, a set of experiments were carried out with six subjects. The experiments consisted of series of continuous (cyclical) and discrete elbow flexo-extensions with three different loads (i.e. 0 kg, 1.5kg and 3 kg). The sEMG data from the biceps brachii, triceps brachii and brachioradialis and the joint angle were recorded. Four different modeling techniques were evaluated: State Space (SS), Autoregressive with Exogenous Input (ARX), Autoregressive Moving-Average with Exogenous Input (ARMAX), Autoregressive Integrated Moving-Average with Exogenous Input (ARIMAX). After the model was selected, a second experiment was performed in order to validate the estimation procedure. The results show a procedure to estimate the EMG-to-angle relation with high correlation and low meansquare- root errors with respect to the measured angle data.

Correction: Development of an optimized AAV2/5 gene therapy vector for Leber congenital amaurosis owing to defects in RPE65.

The authors originally published this article under the incorrect license type; this has now been corrected and is published under the CC-BY license.

Autismo de alto funcionamiento. Presentación de un paciente

RESUMEN: Los trastornos del espectro autista forman parte de los problemas de salud mental y son catalogados como trastornos generalizados del desarrollo. Pueden detectarse a edades muy tempranas y su disfuncionalidad tiene un impacto considerable, no solo para el correcto desarrollo y bienestar de la persona afectada sino también para los familiares, por la elevada carga de cuidados personalizados que necesitan. Se describe la evolución de un adolescente de 14 años de edad, con trastornos del lenguaje, pocas relaciones interpersonales, tendencia a coleccionar objetos, habilidades manuales, inteligencia normal, vinculado a la enseñanza especial por trastorno del lenguaje; al comenzar la secundaria, se produjo un empeoramiento de sus síntomas. Fue ingresado para ser estudiado, y se llegó al diagnóstico de autismo de alto funcionamiento. La estimulación temprana y el tratamiento psicopedagógico individualizado, estructurado y adaptado al entorno, resultaron indispensables para una mejor evolución del paciente.[AU]

Cochlear obliteration following a translabyrinthine approach and its implications in cochlear implantation.

The most frequent sequelae following a translabyrinthine approach for vestibular schwannoma resection is complete hearing loss on the affected side. Such patients could benefit from a cochlear implant, provided that two essential requisites are met before surgery: a preserved cochlear nerve and a patent cochlea to accommodate the electrode array. The goal of our study is to determine the prevalence and extent of cochlear ossification following a translabyrinthine approach. Postoperative MRI of 41 patients were retrospectively reviewed. Patients were classified according to the degree of cochlear obliteration into three groups (patent cochlea, partially obliterated cochlea and totally obliterated cochlea). The interval between surgery and the first MRI was studied as well as its relationship with the rate of cochlear ossification. At first postoperative MRI (mean interval of 20 months), 78% of patients showed some degree of cochlear ossification. Differences were found in the time interval between surgery and first MRI for each group, showing a smaller interval of time the patent cochlea group (p > 0.05). When MRI was performed before the first year after surgery, a larger rate of patent cochlea was found (p > 0.05). The present study suggests that cochlear ossification is a time-depending process, whose grounds are still to be defined.

Biomechanical procedure to assess sleep restriction on motor control and learning.

The analysis of sleep quality during long periods and its impact on motor control and learning performance are crucial aspects for human health. The aim of this study is to analyze effects of chronic sleep restriction on motor performance. It is intended to establish motor control indicators in sleep quality analysis. A wearable actigraphy that records accelerometry, ambient light, and body temperature was used to monitor the sleep habits of 12 healthy subjects for two weeks before performing motor control and learning tests. The day of the motor test, the subjects filled two questionnaires about the quality of sleep (Pittsburgh Sleep Quality Index - PSQI) and sleepiness (Epworth Sleepiness Scale - ESS). Afterwards they performed a coincident timing task that consisted of hitting a virtual target falling on the screen with the hand. An elbow flexion in the horizontal plane had to be performed on the correct time to reach the real target on a table at the same time as the virtual target on the screen. The subjects performed three sets of acquisition and transfer blocks of the coincident timing task. The subjects were clustered in two groups based on the PSQI and ESS scores. Actigraphy and motor control parameters (L5, correct responses, time variance) were compared between groups and experimental sets. The group with better sleep parameters did show a constant performance across blocks of task acquisition while the bad sleeper group improved from the first to the second acquisition block. Despite of this improvement, their performance is not better than the one of the good sleepers group. Although the number of subjects is low and it should be increased, these results indicate that the subjects with better sleep converged rapidly to a high level of performance, while the worse sleepers needed more trials to learn the task and their performance was not superior to the other group.

Pronóstico a largo plazo, reingresos y años potenciales de vida perdidos de los pacientes jóvenes tras un ingreso por insuficiencia cardiaca / Long-term prognosis, readmissions and potential years of life lost in young patients after a hospital admission for heart failure

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First case of Nocardia amamiensis pulmonary infection in Mexico.

We report a case of Nocardia amamiensis pulmonary infection in a 43-year-old immunocompromised woman. The patient was treated with imipenem/cilastatin and trimethoprim/sulfamethoxazole and had a favourable outcome. It is important that laboratories perform species identification to understand the epidemiology and susceptibility patterns of the different Nocardia spp.