Music therapy with adult burn patients in the intensive care unit: short-term analysis of electrophysiological signals during music-assisted relaxation.

Burn patients often face elevated pain, anxiety, and depression levels. Music therapy adds to integrative care in burn patients, but research including electrophysiological measures is limited. This study reports electrophysiological signals analysis during Music-Assisted Relaxation (MAR) with burn patients in the Intensive Care Unit (ICU). This study is a sub-analysis of an ongoing trial of music therapy with burn patients in the ICU. Electroencephalogram (EEG), electrocardiogram (ECG), and electromyogram (EMG) were recorded during MAR with nine burn patients. Additionally, background pain levels (VAS) and anxiety and depression levels (HADS) were assessed. EEG oscillation power showed statistically significant changes in the delta (p < 0.05), theta (p = 0.01), beta (p < 0.05), and alpha (p = 0.05) bands during music therapy. Heart rate variability tachograms high-frequencies increased (p = 0.014), and low-frequencies decreased (p = 0.046). Facial EMG mean frequency decreased (p = 0.01). VAS and HADS scores decreased - 0.76 (p = 0.4) and - 3.375 points (p = 0.37) respectively. Our results indicate parasympathetic system activity, attention shifts, reduced muscle tone, and a relaxed state of mind during MAR. This hints at potential mechanisms of music therapy but needs to be confirmed in larger studies. Electrophysiological changes during music therapy highlight its clinical relevance as a complementary treatment for ICU burn patients.Trial registration: Clinicaltrials.gov (NCT04571255). Registered September 24th, 2020. https//classic.clinicaltrials.gov/ct2/show/NCT04571255.

Effect of low-level LASER therapy versus CAD/CAM Michigan splint on patients with Temporomandibular Muscle Disorders: a randomized clinical trial / Efeito da terapia LASER de baixa potência versus placa de Michigan CAD/CAM em pacientes com Distúrbios Temporomandibulares musculares: um ensaio clínico randomizado

Objective: This study aimed to evaluate the efficacy and sustainability of using low level LASER therapy and CAD/CAM Michigan splint on improving the range of mandibular movements, muscle activity and reducing the pain. Material and Methods: 56 female patients were randomly divided into two groups. Group A: Patients received applications of low-level LASER therapy using semiconductor InGaAsp diode LASER type 940 nm with continuous mode of operation, applied for 180 sec per session for 12 sessions. Group B: Patients received Michigan splint of 2 mm thickness constructed on their upper teeth, the splint was 3D digitally printed. Electromyography was used to evaluate muscle activity, visual analogue scale was used to evaluate the pain intensity, ARCUS digma facebow was used to evaluate range of mandibular movements, and maximum mouth opening was taken using a millimeter ruler. They were measured before the beginning of the treatment, and at three and six month follow-up periods. Results: The results revealed that both low-level LASER therapy and Michigan splint reduce the myofascial pain, improved the range of the mandibular movements, and the muscles activity, but the effect of the low-level LASER therapy was more profound and sustainable. After 6 months from the beginning of the treatment, changes in masseter muscle activity (P= 0.001; effect size= 1.757), pain intensity (P= 0.003; effect size= 3), and range of mandibular movement (P= 0.001, effect size= 1.729) differed significantly between the two groups. Conclusions: Low-level LASER therapy had a better and more sustainable effect on reducing the pain intensity and improving the muscle activity as well as the mandibular movement when compared to Michigan splint (AU)

Objetivo: Este estudo teve como objetivo avaliar a eficácia e a durabilidade do uso da terapia LASER de baixa potência e da placa de Michigan CAD/CAM na melhora da amplitude dos movimentos mandibulares, atividade muscular e redução da dor. Material e Métodos: 56 pacientes do sexo feminino foram divididos aleatoriamente em dois grupos. Grupo A: os pacientes receberam aplicações de terapia LASER de baixa potência utilizando diodo semicondutor InGaAsp LASER tipo 940 nm em modo contínuo de operação, aplicado por 180 segundos por sessão durante 12 sessões. Grupo B: os pacientes receberam a placa de Michigan com uma espessura de 2 mm confeccionada sobre a arcada superior, a placa foi impressa digitalmente em 3D. A eletromiografia foi utilizada para avaliar a atividade muscular, a escala visual analógica foi utilizada para avaliar a intensidade da dor, o arco facial ARCUS digma foi utilizado para determinar a amplitude dos movimentos mandibulares e a abertura máxima da boca foi medida com uma régua milimétrica. Todas as medidas foram realizadas antes do início do tratamento e nos períodos de acompanhamento de três e seis meses. Resultados: Os resultados revelaram que tanto a terapia LASER de baixa potência como a placa de Michigan reduziram a dor miofascial, aumentaram a amplitude dos movimentos mandibulares e melhoraram a atividade muscular, mas o efeito da terapia LASER de baixa potência foi mais profundo e duradouro. Após 6 meses do início do tratamento, as alterações na atividade do músculo masseter (P= 0. 001; tamanho do efeito= 1,757), intensidade da dor (P= 0,003; tamanho do efeito= 3), e amplitude de movimento mandibular (P= 0,001, tamanho do efeito= 1,729) diferiram significativamente entre os dois grupos. Conclusão: A terapia com LASER de baixa potência teve um efeito melhor e mais duradouro na redução da intensidade da dor e na melhora da atividade muscular, bem como do movimento mandibular, quando comparada à placa de Michigan(AU)

Childhood focal compressive mononeuropathies during the COVID-19 pandemic in Buenos Aires, Argentina.

INTRODUCTION/AIMS: Focal peripheral neuropathies are infrequently seen in pediatric patients. The COVID-19 pandemic has disrupted normal life for many people, including complete lockdowns and school closing for long periods of time in many countries, which prompted children to stay at home. Our aim is to assess whether there has been an increased incidence of focal compressive peripheral neuropathies in the pediatric population during COVID-19-associated lockdown. METHODS: Clinical, electrophysiological, and imaging characteristics were reviewed for patients referred to the electrodiagnostic (EDx) laboratory with suspicion of a focal neuropathy. The incidence of focal compressive peripheral neuropathies seen during the period of March to September 2020 was compared with the same time period in 2019. RESULTS: An increased incidence of focal neuropathies was seen in 2020 (31%) compared with 2019 (6.8%). During 2020, 7 fibular (peroneal) mononeuropathies and 2 ulnar neuropathies were diagnosed. Most patients with focal neuropathies were underweight and acknowledged prolonged screen time periods. Electrophysiological findings consisted of mostly demyelinating lesions with an overall good clinical outcome. DISCUSSION: In this study we raise awareness about a possible increased incidence of focal compressive peripheral neuropathies in children during COVID-19-associated lockdown, which may be prevented with changing positions during sedentary activities.

Enhancing classification of preterm-term birth using continuous wavelet transform and entropy-based methods of electrohysterogram signals.

Introduction: Despite vast research, premature birth's electrophysiological mechanisms are not fully understood. Prediction of preterm birth contributes to child survival by providing timely and skilled care to both mother and child. Electrohysterography is an affordable, noninvasive technique that has been highly sensitive in diagnosing preterm labor. This study aimed to choose the more appropriate combination of characteristics, such as electrode channel and bandwidth, as well as those linear, time-frequency, and nonlinear features of the electrohysterogram (EHG) for predicting preterm birth using classifiers. Methods: We analyzed two open-access datasets of 30 minutes of EHG obtained in regular checkups of women around 31 weeks of pregnancy who experienced premature labor (P) and term labor (T). The current approach filtered the raw EHGs in three relevant frequency subbands (0.3-1 Hz, 1-2 Hz, and 2-3Hz). The EHG time series were then segmented to create 120-second windows, from which individual characteristics were calculated. The linear, time-frequency, and nonlinear indices of EHG of each combination (channel-filter) were fed to different classifiers using feature selection techniques. Results: The best performance, i.e., 88.52% accuracy, 83.83% sensitivity, and 93.22% specificity, was obtained in the 2-3 Hz bands using Medium Frequency, Continuous Wavelet Transform (CWT), and entropy-based indices. Interestingly, CWT features were significantly different in all filter-channel combinations. The proposed study uses small samples of EHG signals to diagnose preterm birth accurately, showing their potential application in the clinical environment. Discussion: Our results suggest that CWT and novel entropy-based features of EHG could be suitable descriptors for analyzing and understanding the complex nature of preterm labor mechanisms.

Effect of metabolic enzymes on acceleration ability in exercise fatigue / Efeito das enzimas metabólicas na capacidade de aceleração na fadiga por exercício / Efecto de las enzimas metabólicas sobre la capacidad de aceleración en la fatiga por ejercicio

ABSTRACT Introduction Study the relationship between the metabolic enzyme and the biological image, filtered by an adaptive filtering algorithm. Objective The research aims to In this study, human metabolic enzymes were evaluated by electrocardiogram and electromyogram images, and an adaptive filtering algorithm removed the noises in the images. Methods The electrocardiogram and electromyogram images at different periods were obtained, and the calculation method and application scope of the adaptive filtering algorithm were analysed. Results Adaptive filter was designed by the combination of adaptive filtering algorithm and dynamic information. Therefore, the artefact of the image was removed. Conclusions The adaptive filtering algorithm can effectively remove the noise or artefact in electrocardiogram and electromyogram signals. The optimal image information can be obtained. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMO Introdução Estudar a relação entre a enzima metabólica e a imagem biológica filtrada por um algoritmo de filtragem adaptativa. Objetivo O objetivo da pesquisa, neste estudo, é avaliar enzimas metabólicas humanas por meio de imagens de eletrocardiograma e eletromiograma, sendo que um algoritmo de filtragem adaptativa eliminou o ruído nas imagens. Métodos Imagens de eletrocardiograma e eletromiograma foram obtidas em diferentes períodos e foram analisados o método de cálculo e o escopo de aplicação do algoritmo de filtragem adaptativa. Resultados a filtragem adaptativa foi projetada combinando um algoritmo de filtragem adaptativa e informações dinâmicas. Portanto, o artefato foi removido da imagem. Conclusões O algoritmo de filtragem adaptativa pode efetivamente eliminar ruído ou artefato em sinais de eletrocardiograma e eletromiograma. Informações de imagem ideais podem ser obtidas. Nível de evidência II; Estudos terapêuticos: investigação dos resultados do tratamento.

RESUMEN Introducción Estudiar la relación entre la enzima metabólica y la imagen biológica, filtrada por un algoritmo de filtrado adaptativo. Objetivo La investigación tiene como objetivo, en este estudio, evaluar las enzimas metabólicas humanas mediante imágenes de electrocardiograma y electromiograma, y un algoritmo de filtrado adaptativo eliminó los ruidos en las imágenes. Métodos Se obtuvieron las imágenes de electrocardiograma y electromiograma en diferentes períodos y se analizó el método de cálculo y alcance de aplicación del algoritmo de filtrado adaptativo. Resultados El filtrado adaptativo se diseñó mediante la combinación de un algoritmo de filtrado adaptativo e información dinámica. Por lo tanto, se eliminó el artefacto de la imagen. Conclusiones El algoritmo de filtrado adaptativo puede eliminar eficazmente el ruido o artefacto en las señales de electrocardiograma y electromiograma. Se puede obtener la información de imagen óptima. Nivel de evidencia II; Estudios terapéuticos: investigación de los resultados del tratamiento.

Phase Entropy Analysis of Electrohysterographic Data at the Third Trimester of Human Pregnancy and Active Parturition.

Phase Entropy (PhEn) was recently introduced for evaluating the nonlinear features of physiological time series. PhEn has been demonstrated to be a robust approach in comparison to other entropy-based methods to achieve this goal. In this context, the present study aimed to analyze the nonlinear features of raw electrohysterogram (EHG) time series collected from women at the third trimester of pregnancy (TT) and later during term active parturition (P) by PhEn. We collected 10-min longitudinal transabdominal recordings of 24 low-risk pregnant women at TT (from 35 to 38 weeks of pregnancy) and P (>39 weeks of pregnancy). We computed the second-order difference plots (SODPs) for the TT and P stages, and we evaluated the PhEn by modifying the k value, a coarse-graining parameter. Our results pointed out that PhEn in TT is characterized by a higher likelihood of manifesting nonlinear dynamics compared to the P condition. However, both conditions maintain percentages of nonlinear series higher than 66%. We conclude that the nonlinear features appear to be retained for both stages of pregnancy despite the uterine and cervical reorganization process that occurs in the transition from the third trimester to parturition.

Improving EEG Muscle Artifact Removal With an EMG Array.

Removal of artifacts induced by muscle activity is crucial for analysis of the electroencephalogram (EEG), and continues to be a challenge in experiments where the subject may speak, change facial expressions, or move. Ensemble empirical mode decomposition with canonical correlation analysis (EEMD-CCA) has been proven to be an efficient method for denoising of EEG contaminated with muscle artifacts. EEMD-CCA, likewise the majority of algorithms, does not incorporate any statistical information of the artifact, namely, electromyogram (EMG) recorded over the muscles actively contaminating the EEG. In this paper, we propose to extend EEMD-CCA in order to include an EMG array as information to aid the removal of artifacts, assessing the performance gain achieved when the number of EMG channels grow. By filtering adaptively (recursive least squares, EMG array as reference) each component resulting from CCA, we aim to ameliorate the distortion of brain signals induced by artifacts and denoising methods. We simulated several noise scenarios based on a linear contamination model, between real and synthetic EEG and EMG signals, and varied the number of EMG channels available to the filter. Our results exhibit a substantial improvement in the performance as the number of EMG electrodes increase from 2 to 16. Further increasing the number of EMG channels up to 128 did not have a significant impact on the performance. We conclude by recommending the use of EMG electrodes to filter components, as it is a computationally inexpensive enhancement that impacts significantly on performance using only a few electrodes.

Behavioural, electrocorticographic, and electromyographic alterations induced by Nerium oleander ethanolic extract: Anticonvulsant therapeutics assessment.

Nerium oleander Linn. is an Apocynaceae shrub which is among the most toxic ornamental plants. Although seizures are one of the symptoms associated with N. Oleander poisoning in humans, only a few studies are available on the behavioural and electrophysiological alterations caused by this plant poisoning. This study aimed at providing a thorough description of the electroencephalographic (EEG) and electromyographic (EMG) profiles throughout the experimental poisoning of Wistar rats (200-250 g) using ethanolic extract of N. oleander (EENO). Further, seizure control was assessed using different anticonvulsants. Male Wistar rat's behaviour was assessed upon EENO (150 mg/kg) administration and the animals were evaluated for muscle and neural activities through EMG and EEG recordings, respectively. The behavioural test showed two distinct phases of CNS activity: Phase I - myorelaxation and depression, and Phase II - excitability (agitated behaviour and seizures). Such phases were consistent with the EEG and EMG tracing patterns attained. Within the first 400 s of the recordings, during Phase I, the EMG showed no tracing amplitude variation. Later, the tracing pattern was changed and an intensification of the muscle contraction power in higher frequencies was observed during Phase II. The EEG showed initially a slight flattening in the tracings with a reduction in the intensity of the signal as per spectrogram of frequency attained. Thereafter, during Phase II, much higher amplitude tracings could be noted with an intensification of the signal, compatible with seizures. Seizure control was evaluated using four agents: phenytoin, phenobarbital, diazepam and scopolamine (at 10 mg/kg in all cases). While scopolamine was not effective in the seizure control, diazepam was the most efficient drug for the attenuation of the poisoning. Our results indicate the possibility of including phenytoin, phenobarbital and diazepam, mainly the latter, in the poisoning therapeutic protocol, including for those individuals who could be more susceptible to the poisoning by Nerium oleander as in the case of epileptic patients.

Electrophysiological responses in Amazonian fish species Bryconops caudomaculatus (Osteichthyes: Characiformes) as biomarkers of xenobiotic toxicity.

Sublethal exposures to environmental pollutants may cause changes in physiological parameters. Thus, knowledge of basal physiological rates of the species and the development of methods to quantify these rates are extremely important. Considering the scarcity of cardiac and muscle physiological studies in native Amazonian fish species and that no evaluation of electrophysiological responses by exposure to a stressor has been reported in Bryconops caudomaculatus, the aim of this study was to develop techniques of electromyographic and electrocardiographic recordings of normal responses, during toxicity induction and short-term recovery. A total of 9 animals were used, divided into two groups: control group (n = 4) and treated group (n = 5), with records lasting 5 min. The results showed that the basal electromyographic records indicate that the studied species has a very intense swimming activity, whereas the basal cardiac parameters clearly showed the patterns in P wave tracing, QRS complex, T wave and Q-T and R-R intervals. During exposure to the stressor, muscle activity ceased presenting intense decrease and myorelaxant effect expected. Electrocardiographic responses confirmed cardiotoxicity with intense bradycardia, ventricular bigeminism, prolongation of QRS complex duration and cardiac arrhythmias, indicating cardiac dysfunction. It was concluded that the electrophysiological responses are excellent biomarkers and showed the susceptibility of the species to the tested substance. In addition, the electrocardiogram and the electromyogram are excellent techniques to reflect the degree of environmental stress when organisms are exposed to toxic substances in the environment.

Utilidad de la electrohisterografía como técnica de monitorización uterina en el ámbito clínico: revisión bibliográfica / Usefulness of the electrohysterography in the clinical field as a technique for uterine monitoring: a literature review

Resumen ANTECEDENTES: El análisis del registro de superficie de la actividad mioeléctrica uterina, o electrohisterograma, es uno de los marcadores biofísicos más prometedores para evaluar las contracciones y el estado electrofisiológico del útero. A pesar de las evidencias derivadas de la información clínica que proporciona el análisis electrohisterográfico, hasta la fecha no se ha logrado el esfuerzo significativo para introducir esta técnica en la práctica médica. OBJETIVO: Mostrar la evidencia disponible acerca de la utilidad de la electrohisterografía como técnica alternativa para la monitorización de la actividad uterina en el ámbito clínico. METODOLOGÍA: Búsqueda bibliográfica en las bases de datos de PubMed, Google Scholar y Scopus, con las palabras clave: electrohysterogram, uterine electromyography y electrohysterography. RESULTADOS: Se seleccionaron 65 artículos originales, 5 de revisión y 1 capítulo de libro con metodología adecuada, claridad y relevancia clínica, enfocados en la aplicación clínica del electrohisterograma. CONCLUSIÓN: Las técnicas de monitoreo convencional de la actividad uterina tienen limitaciones para establecer, oportunamente, el diagnóstico de distocias durante el trabajo de parto. El análisis de registros electrohisterográficos permite explicar las alteraciones detectadas en la actividad eléctrica uterina, mediante el aporte de información del estado funcional, incluso predecir posibles complicaciones durante el trabajo de parto.

Abstract BACKGROUND: The analysis of the surface myoelectric activity of the uterus electrohysterogram (EHG) has proved to be one of the most promising biophysical markers for the evaluation of uterine contractions and the electrophysiological state of the uterus. However, despite the emerging evidence that the analysis of EHG provides valuable clinical information, there has not been a meaningful effort to apply this technique for clinical monitoring. OBJECTIVE: To show the available evidence of the usefulness of electrohysterography in the clinical field as a technique for uterine monitoring. METHODOLOGY: a literature search was performed in PubMed, Google Scholar and Scopus databases with the following keywords: electrohysterogram, uterine electromyography and electrohysterography. RESULTS: 65 original research papers, 5 review papers and 1 book chapter with adequate methodology, clarity and clinical relevance were selected according to the focus of the clinical application of the EHG. CONCLUSION: Conventional monitoring of uterine activity lack the ability to accurately diagnose dystocias during labor. On the other hand, the analysis of electrohysterographic recordings has made possible to elucidate alterations in the uterine electrical activity by providing information of the functional state of the uterus, and even, to predict possible complications during labor.

Clove oil induces anaesthesia and blunts muscle contraction power in three Amazon fish species.

Clove oil is used as an anaesthetic for many species of fish worldwide; however, relatively few studies have assessed its effectiveness on Amazon fish species and no compelling evidence has ever been reported on the relaxant properties of this oil for skeletal muscle of fish. Thus, the objective of this study was to evaluate the latencies to deep anaesthesia and recovery, along with the myorelaxant effect of clove oil on three Amazon fish species: cardinal tetra, Paracheirodon axelrodi, banded cichlid, Heros severus and angelfish, Pterophyllum scalare, submitted to short-term anaesthetic baths. Fish were assayed in three groups of 60 fish each and individually anaesthetized in a completely randomized design with six clove oil concentrations using 10 fish/species/concentration. Electromyographic recordings from dorsal muscle were performed during stages of induction and recovery in which nine fish/species/stage were used. Deep anaesthesia was attained for all concentrations tested, and no mortalities were observed throughout the experiments and after a 48-h observation period. Concentration of 90 µL L-1 and above promoted fast deep anaesthesia (< 3 min) and calm recovery in angelfish and cardinal tetra, whereas the concentration of 60 µL L-1 sufficed to quickly anaesthetize banded cichlid. Times to full recovery were not significantly contrasting among species and occurred within appropriate time threshold (< 5 min). Clove oil exerted a conspicuous depression of muscle contraction power, and therefore can be effectively used as a muscle relaxant agent for P. scalare, P. axelrodi, H. severus and potentially, for other fish species.

Salt controls feeding decisions in a blood-sucking insect.

Salts are necessary for maintaining homeostatic conditions within the body of all living organisms. Like with all essential nutrients, deficient or excessive ingestion of salts can result in adverse health effects. The taste system is a primary sensory modality that helps animals to make adequate feeding decisions in terms of salt consumption. In this work we show that sodium and potassium chloride salts modulate the feeding behavior of Rhodnius prolixus in a concentration-dependent manner. Feeding is only triggered by an optimal concentration of any of these salts (0.1-0.15M) and in presence of the phagostimulant ATP. Conversely, feeding solutions that do not contain salts or have a high-salt concentration (>0.3M) are not ingested by insects. Notably, we show that feeding decisions of insects cannot be explained as an osmotic effect, because they still feed over hyperosmotic solutions bearing the optimal salt concentration. Insects perceive optimal-salt, no-salt and high-salt solutions as different gustatory information, as revealed the electromyogram recordings of the cibarial pump. Moreover, because insects do a continuous gustatory monitoring of the incoming food during feeding, sudden changes beyond the optimal sodium concentration decrease and even inhibit feeding. The administration of amiloride, a sodium channel blocker, noticeably reduces the ingestion of the optimal sodium solution but not of the optimal potassium solution. Salt detection seems to occur at least through two salt receptors, one amiloride-sensitive and another amiloride-insensitive. Our results confirm the importance of the gustatory system in R. prolixus, showing the relevant role that salts play on their feeding decisions.

Physiological characterization of the hematophagy of Ornithodoros rostratus (Acari: Argasidae) on live hosts.

Ornithodoros rostratus is an argasid tick and its importance is based on its hematophagy and the resulting transmission of pathogens such as Rickettsia rickettsii and Coxiella burnetii to its vertebrate hosts. In the face of a lack of physiological studies related to hematophagy in argasid ticks, this paper aims to identify and characterize the events that occur throughout the feeding by O. rostratus on live hosts. Electrical signals and alterations on the feeding site were monitored using intravital microscopy and electromyography. The analyses allowed for the characterization of four distinct events: suction, salivation, chelicerae movements and inactivity. Feeding was divided into two distinct phases: (1) penetration of mouthparts (when only salivation and chelicerae movements occurred) and the formation of the feeding pool (salivation and chelicerae movements with the first signs of suction) and (2) engorgement, during which chelicerae movements ceased and blood intake took place in feeding complexes (salivation followed by suction). Variations in patterns of the electrical signals, suction frequency and salivation showed four distinct sub-phases: (2a) suction with electrical signals of irregular shape, increased suction frequency and decreased salivation frequency throughout blood feeding; (2b) suction with electrical signals of symmetrical shape, high suction rates (3.8 Hz on average) and feeding complexes lasting for 7.7 s; (2c) suction with electrical signals of irregular shape, high suction frequency and feeding complex lasting 11.5 s; and (2d) electrical signals with no profile and the longest feeding complexes (14.5 s). Blood feeding ended with the withdrawal of the mouthparts from the host's skin.

Morfología de la cadera y media de contracción muscular en bipedestación en la parálisis cerebral / Morphologie de la hanche et moyenne de contraction musculaire en position bipède dans la paralysie cérébrale / Hip morphology and average muscle contraction when standing in cerebral palsy

Introducción: en la parálisis cerebral la articulación de la cadera es una de las más afectadas; sus alteraciones conllevan complicaciones importantes. Aunque su desarrollo se relaciona con trastorno del tono muscular y desequilibrio entre el grupo abductor y el adductor no existen datos objetivos que permitan cuantificar la proporción exacta entre las contracciones de ambos grupos musculares, a partir de la cual esta articulación se encuentra en riesgo. Objetivos: mostrar en una población con parálisis cerebral la media global del porcentaje de contracción de los grupos abductores (µ por ciento Abd) y adductores (µ por ciento Add) de cadera en bipedestación y compararla con los distintos grados de alteración de dicha articulación. Métodos: se midió la actividad muscular en bipedestación de los grupos abductor y adductor en 19 caderas, de 10 sujetos con parálisis cerebral utilizando un electromiógrafo de superficie. Los resultados se expresaron en porcentaje respecto a la contracción máxima isométrica obtenida previamente en los mismos grupos musculares. Las caderas se valoraron utilizando estudios radiológicos. Resultados: la media del porcentaje de contracción del grupo adductor supera a la del grupo abductor en las caderas subluxadas y luxadas. En el estudio por casos, al comparar resultados individuales con la media global para nuestra población no se consigue una asociación significativa. Conclusiones: se intuye que aunque el grupo adductor es un factor importante en el desarrollo de la patología coxofemoral, no es útil como indicador del estado articular aun utilizando medias de población con alteraciones neurológicas(AU)

Introduction: the hip joint is one of the most affected joint in cerebral palsy and its alterations are one of the most important complications. Although its development is related to muscle tone disorder and imbalance between abductor and adductor groups, there are no objective data that allow us to quantify the exact proportion between contractions of both muscle groups from which this joint is at risk. Objective: show, in a population with cerebral palsy, the mean of contraction percentage of hip abductors (µ pecent Abd) and adductors (µ percent Add) groups when standing and compare it with the different degrees of alteration of this joint. Methods: muscle activity of the abductors and adductors groups when standing was measured in 19 hips of 10 subjects with cerebral palsy using a surface electromyography. Results were expressed in percentage regarding the maximum isometric contraction previously obtained in the same muscle groups. Hips were assessed using radiological studies. Results: the mean percentage of contraction of the adductor group exceeds the adductor group in subluxated and luxated hips. In these case studies, a significant association when comparing individual results with the overall mean for our population is not achieved. Conclusions: although the adductor group is an important step in the development of hip pathology factor, it is not useful as an indicator of this joint stage, even using population means suffering neurological disorders(AU)

Introduction: l'articulation de la hanche est l'une des structures les plus souvent touchées dans la paralysie cérébrale; son altération provoque des complications importantes. Bien que son évolution soit associée à un trouble du tonus musculaire et de l'équilibre entre le groupe abducteur et le groupe adducteur, il n`y a pas de données objectives permettant de calculer la proportion exacte entre les contractions de tous ces deux groupes musculaires, à partir de laquelle cette articulation est en risque. Objectifs: le but de ce travail est de montrer la moyenne totale du pourcentage de contractions du groupe abducteur (µ pourcent Add) de la hanche en position bipède dans une population atteinte de paralysie cérébrale, et de la comparer avec les différents grades d'altération de cette articulation. Méthodes: on a mesuré l'activité musculaire en position bipède des groupes abducteur et adducteur de 10 patients (19 hanches), atteints de paralysie cérébrale, en utilisant un électromyographe de surface. Les résultats sont exprimés en pourcentage par rapport à la contraction maximale isométrique obtenue préalablement dans les mêmes groupes musculaires. On a évalué les hanches en faisant des examens radiologiques. Résultats: la moyenne du pourcentage de contraction du groupe adducteur supère celle du groupe abducteur dans les hanches subluxées et luxées. Dans l'étude des cas, on n'a pas obtenu une association significative en comparant les résultats individuels avec la moyenne totale de notre population. Conclusions: bien que le groupe adducteur soit un facteur clé dans l'évolution de la pathologie coxofémorale, il n'est pas utile comme indicateur de l'état articulaire, même en utilisant des moyennes de populations atteintes d'altérations neurologiques.

Influence of muscle activity on musculotendinous stiffness quantification in stunted, prepubertal children.

The quick-release technique to estimate musculotendinous (MT) stiffness has been extensively used over the last years, in both animals and humans, to gain insights in the adaptive process of the series elastic component (SEC). Recently, MT stiffness quantification, i.e., SEC behavior, has been revisited for subjects not able to fully activate their muscles (effects of long-term spaceflight or non-mature muscles). Such a phenomenon can also be encountered in stunted children. So, the aim of the present study was to analyze the effect of stunting on MT stiffness taking into account possible defect in muscle activation. For this study, 20 eutrophic children (EU) with an average age of 9years±4months were compared to 11age matched stunted children (S) evaluated by the height-to-age index. The MT stiffness index was obtained with regard to stiffness-torque and stiffness-soleus EMG relationships. The children of the S group presented a significantly lower Maximal Voluntary Contraction (MVC) in plantar flexion in comparison with children of the EU group (-37.8%). The significantly lower MT stiffness index for S children (-42.6%) was evidenced only when quantified with regard to the stiffness-soleus EMG relationship (66.5±42.8 vs. 38.2±19.9 Nmrad(-1)%(-1)). Possible delay in fiber type differentiation or tendinous structure maturation can account for the lower MT stiffness index in S children. In conclusion, stunting during early childhood delays the differentiation and maturation processes of musculotendinous structures as shown by the lower MT stiffness quantified with regards to muscle activity, also altered for stunted prepubertal children.

Wakefulness-promoting role of the inferior colliculus.

The inferior colliculus (IC) is a mesencephalic auditory nucleus involved in several functions including the analysis of the frequency and intensity of sounds as well as sound localization. In addition to auditory processes, the IC controls the expression of defensive responses. The objective of the present study was to test the hypothesis that the IC contributes to the maintenance of wakefulness. For this purpose, several experimental approaches were performed in urethane-anesthetized guinea pigs. Electrical or chemical stimulation of the IC resulted in electroencephalographic (EEG) desynchronization, theta rhythm in the hippocampus and an increase in heart rate; all of these effects suggest an arousal reaction. Furthermore, by means of extracellular unit recordings, we determined that most IC neurons increased their spontaneous and tone-evoked responses in association with EEG desynchronization. We also studied the effect on sleep and wakefulness of bilateral acute inhibition of the IC by microinjections of muscimol (a GABAA agonist), as well as the effect of bilateral IC lesions in chronically-instrumented (drug-free) guinea pigs. Acute (via muscimol microinjections), but not chronic (via electrolytic lesions) inhibition of the IC decreased wakefulness., We conclude that the IC plays an active role in the maintenance of wakefulness. Further, we propose that this nucleus may mediate arousal responses induced by biologically significant sounds.

A simple test of muscle coactivation estimation using electromyography

In numerous motor tasks, muscles around a joint act coactively to generate opposite torques. A variety of indexes based on electromyography signals have been presented in the literature to quantify muscle coactivation. However, it is not known how to estimate it reliably using such indexes. The goal of this study was to test the reliability of the estimation of muscle coactivation using electromyography. Isometric coactivation was obtained at various muscle activation levels. For this task, any coactivation measurement/index should present the maximal score (100% of coactivation). Two coactivation indexes were applied. In the first, the antagonistic muscle activity (the lower electromyographic signal between two muscles that generate opposite joint torques) is divided by the mean between the agonistic and antagonistic muscle activations. In the second, the ratio between antagonistic and agonistic muscle activation is calculated. Moreover, we computed these indexes considering different electromyographic amplitude normalization procedures. It was found that the first algorithm, with all signals normalized by their respective maximal voluntary coactivation, generates the index closest to the true value (100%), reaching 92 ± 6%. In contrast, the coactivation index value was 82 ± 12% when the second algorithm was applied and the electromyographic signal was not normalized (P < 0.04). The new finding of the present study is that muscle coactivation is more reliably estimated if the EMG signals are normalized by their respective maximal voluntary contraction obtained during maximal coactivation prior to dividing the antagonistic muscle activity by the mean between the agonistic and antagonistic muscle activations.