Intra-session test-retest reliability of functional connectivity in infants.

Resting functional MRI studies of the infant brain are increasingly becoming an important tool in developmental neuroscience. Whereas the test-retest reliability of functional connectivity (FC) measures derived from resting fMRI data have been characterized in the adult and child brain, similar assessments have not been conducted in infants. In this study, we examined the intra-session test-retest reliability of FC measures from 119 infant brain MRI scans from four neurodevelopmental studies. We investigated edge-level and subject-level reliability within one MRI session (between and within runs) measured by the Intraclass correlation coefficient (ICC). First, using an atlas-based approach, we examined whole-brain connectivity as well as connectivity within two common resting fMRI networks - the default mode network (DMN) and the sensorimotor network (SMN). Second, we examined the influence of run duration, study site, and scanning manufacturer (e.g., Philips and General Electric) on ICCs. Lastly, we tested spatial similarity using the Jaccard Index from networks derived from independent component analysis (ICA). Consistent with resting fMRI studies from adults, our findings indicated poor edge-level reliability (ICC = 0.14-0.18), but moderate-to-good subject-level intra-session reliability for whole-brain, DMN, and SMN connectivity (ICC = 0.40-0.78). We also found significant effects of run duration, site, and scanning manufacturer on reliability estimates. Some ICA-derived networks showed strong spatial reproducibility (e.g., DMN, SMN, and Visual Network), and were labelled based on their spatial similarity to analogous networks measured in adults. These networks were reproducibly found across different study sites. However, other ICA-networks (e.g. Executive Control Network) did not show strong spatial reproducibility, suggesting that the reliability and/or maturational course of functional connectivity may vary by network. In sum, our findings suggest that developmental scientists may be on safe ground examining the functional organization of some major neural networks (e.g. DMN and SMN), but judicious interpretation of functional connectivity is essential to its ongoing success.

Characterization of the use of a cycle ergometer to assist in the physical therapy treatment of critically ill patients.

OBJECTIVE: The objective of this study was to use a cycle ergometer to assess cardiorespiratory changes during active exercise and to verify patients' satisfaction with this type of activity. METHODS: A single intervention involving active lower limb exercise was performed with a cycle ergometer (without load) for 5 minutes. The following variables were measured before, during and immediately after exercise: heart rate, blood pressure, respiratory rate, peripheral oxygen saturation and the Borg dyspnea scale score. Following the exercise, the patients answered a questionnaire to evaluate their satisfaction with this type of activity. RESULTS: A total of 38 patients (65% male) with a mean age of 48 ± 16 years old participated in the study. Enrolled patients presented a sequential organ failure assessment (SOFA) score of 2 (0 - 5 scale). During the exercise, 16% of the patients used ventilation support and 55% of them were breathing at room air. A comparison of the initial and final values of the variables indicated increases in the heart rate (92 ± 17 beats/min vs. 95 ± 18 beats/min; p<0.05), the respiratory rate (19 ± 8 breaths/min vs. 23 ± 8 breaths/min; p<0.05) and the Borg dyspnea scale score (1.3 ± 1.8 vs. 2.8 ± 2.2; p<0.05). In addition, 85% of the patients reported enjoying the activity. Only 25% of the patients reported some discomfort, and 100% of the patients wanted to repeat this type of activity in future treatments. CONCLUSION: During the cycle ergometer exercises, minor cardiorespiratory changes were observed in the patients. The evaluated patients reported high satisfaction with this type of activity.

Caracterização do uso do cicloergômetro para auxiliar no atendimento fisioterapêutico em pacientes críticos / Characterization of the use of a cycle ergometer to assist in the physical therapy treatment of critically ill patients

OBJETIVO: Analisar as alterações cardiorrespiratórias de pacientes durante o exercício ativo com um cicloergômetro e verificar a aceitação dos pacientes para realizar esse tipo de atividade. MÉTODOS: Foi realizada uma única intervenção de exercício ativo de membros inferiores no cicloergômetro (sem carga) durante 5 minutos. As variáveis frequência cardíaca, pressão arterial, frequência respiratória, saturação periférica de oxigênio e escala de dispneia de Borg foram avaliadas em três momentos: antes, durante e imediatamente após o exercício. Ao final, o paciente respondia um questionário avaliando sua satisfação em relação a esse tipo de atividade. RESULTADOS: Participaram do estudo 38 pacientes (65% masculino) com 48±16 anos e SOFA=2 (0-5). Durante o exercício, 55% estavam em ar ambiente e 16% utilizaram algum tipo de suporte ventilatório. Comparando-se os valores iniciais e finais das variáveis analisadas, verificou-se um aumento apenas nas variáveis frequência cardíaca (92±17 e 95±18; p<0,05), frequência respiratória (19±8 e 23±8; p<0,05) e Borg (1,3±1,8 e 2,8±2,2; p<0,05). Além disso, 85% dos pacientes gostaram muito de realizar esse tipo de atividade. Apenas 25% dos pacientes relataram algum tipo de desconforto, entretanto 100% dos pacientes gostariam de repetir esse tipo de atividade em um próximo atendimento. CONCLUSÃO: Nos pacientes estudados, verificaram-se pequenas alterações cardiorrespiratórias durante o exercício com o cicloergômetro. Os pacientes avaliados relataram alta satisfação com esse tipo de atividade.

OBJECTIVE: The objective of this study was to use a cycle ergometer to assess cardiorespiratory changes during active exercise and to verify patients' satisfaction with this type of activity. METHODS: A single intervention involving active lower limb exercise was performed with a cycle ergometer (without load) for 5 minutes. The following variables were measured before, during and immediately after exercise: heart rate, blood pressure, respiratory rate, peripheral oxygen saturation and the Borg dyspnea scale score. Following the exercise, the patients answered a questionnaire to evaluate their satisfaction with this type of activity. RESULTS: A total of 38 patients (65% male) with a mean age of 48 ± 16 years old participated in the study. Enrolled patients presented a sequential organ failure assessment (SOFA) score of 2 (0 - 5 scale). During the exercise, 16% of the patients used ventilation support and 55% of them were breathing at room air. A comparison of the initial and final values of the variables indicated increases in the heart rate (92±17 beats/min vs. 95±18 beats/min; p<0.05), the respiratory rate (19 ± 8 breaths/min vs. 23±8 breaths/min; p<0.05) and the Borg dyspnea scale score (1.3±1.8 vs. 2.8±2.2; p<0.05). In addition, 85% of the patients reported enjoying the activity. Only 25% of the patients reported some discomfort, and 100% of the patients wanted to repeat this type of activity in future treatments. CONCLUSION: During the cycle ergometer exercises, minor cardiorespiratory changes were observed in the patients. The evaluated patients reported high satisfaction with this type of activity.