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Background: Integrating aerobic exercise (AE) into rehabilitation programs for post-stroke individuals could enhance motor recovery and cardiovascular health by increasing brain-derived neurotrophic factor (BDNF) and the myokine irisin. Chronic stroke survivors typically exhibit elevated matrix metalloproteinase-9 (MMP-9) activity, which is negatively correlated with steps and time in medium cadence, although the impact of AE on this biomarker remains unclear., Objective: To evaluate the effect of high-intensity AE training prior to modified constraint-induced movement therapy (mCIMT) on BDNF and irisin concentration, and on MMP-2 and MMP-9 activity in chronic post-stroke individuals and to associate these results with functional improvements., Methods: Nine participants received AE combined with mCIMT for two weeks, while the control group ( n  = 7) received mCIMT alone. Manual dexterity and functional capacity were assessed before and after the intervention. Serum samples were analyzed for BDNF, irisin, MMP-2 and MMP-9., Results: There were no significant main effects of assessment, group or interaction on molecular biomarkers. However, the AE group had a significant increase in MMP-9 activity post-intervention ( p  = .033; d  = 0.67). For the Box and Block Test, there were significant main effects of assessment ( F [1, 14] = 33.27, p  = .000, η p 2  = 0.70) and group ( F [1, 14] = 5.43, p  = .035, η p 2  = .28). No correlations were found between biomarkers and clinical assessments., Conclusion: AE prior to mCIMT did not influence circulating BDNF and irisin levels but did induce an acute rise in MMP-9 activity, suggesting potential effects on cardiovascular remodeling in this population.

Background: Spaceflights influence intracranial compliance (ICC). P2/P1 ratio, from the intracranial pressure (ICP) waveform, provides information about ICC. Additionally, non-invasive methods for ICC monitoring are needed for spaceflights. Furthermore, astronauts try to maintain good levels of cardiorespiratory fitness before and during spaceflights, not only to sustain exploratory missions, but also to prevent diseases in extreme environments., Objective: to correlate cardiorespiratory fitness levels with the P2/P1 ratio during a microgravity analog [-6° head-down tilt (HDT)]., Method: 34 individuals (11 women), mean age of 31.7 (±6.3) years and BMI 24.2 (±3.2) performed a cardiopulmonary exercise testing (CPET) with an incremental protocol on a cycle ergometer to determine the cardiopulmonary fitness through peak relative oxygen uptake (VO 2 peak) of each individual. On the second test, which was conducted in an interval of 15 days of the CPET, participants remained for 30 min at HDT with P2/P1 ratio acquired using a non-invasive strain gauge sensor. The average of the last 5 min was used for analysis. The mean P2/P1 ratio and relative VO 2 peak were correlated using the Spearman test., Results: Volunteers presented 1.05 ± 0.2 of P2/P1 ratio and VO 2 peak of 47.5 ± 7.6 mL/kg/min. The Spearman test indicated a negative and low correlation between the P2/P1 ratio and VO 2 peak (ρ = -0.388; p = 0.023)., Conclusion: The study suggests that the better the cardiorespiratory fitness, the better ICC in a weightlessness simulation., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Gabriela Nagai Ocamoto reports a relationship with Braincare Desenvolvimento e Inovação Tecnológica S.A. that includes: employment. Gustavo Frigieri reports a relationship with Braincare Desenvolvimento e Inovação Tecnológica S.A. that includes: employment., (© 2024 The Authors.)

Background: The microgravity environment has a direct impact on the cardiovascular system due to the fluid shift and weightlessness that results in cardiac dysfunction, vascular remodeling, and altered Cardiovascular autonomic modulation (CAM), deconditioning and poor performance on space activities, ultimately endangering the health of astronauts. Objective: This study aimed to identify the acute and chronic effects of microgravity and Earth analogues on cardiovascular anatomy and function and CAM. Methods: CINAHL, Cochrane Library, Scopus, Science Direct, PubMed, and Web of Science databases were searched. Outcomes were grouped into cardiovascular anatomic, functional, and autonomic alterations, and vascular remodeling. Studies were categorized as Spaceflight (SF), Chronic Simulation (CS), or Acute Simulation (AS) based on the weightlessness conditions. Meta-analysis was performed for the most frequent outcomes. Weightlessness and control groups were compared. Results: 62 articles were included with a total of 963 participants involved. The meta-analysis showed that heart rate increased in SF [Mean difference (MD) = 3.44; p = 0.01] and in CS (MD = 4.98; p < 0.0001), whereas cardiac output and stroke volume decreased in CS (MD = -0.49; p = 0.03; and MD = -12.95; p < 0.0001, respectively), and systolic arterial pressure decreased in AS (MD = -5.20; p = 0.03). According to the qualitative synthesis, jugular vein cross-sectional area (CSA) and volume were greater in all conditions, and SF had increased carotid artery CSA. Heart rate variability and baroreflex sensitivity, in general, decreased in SF and CS, whereas both increased in AS. Conclusion: This review indicates that weightlessness impairs the health of astronauts during and after spaceflight, similarly to the effects of aging and immobility, potentially increasing the risk of cardiovascular diseases. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42020215515., Competing Interests: Author GO was employed by Brain4care Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Mendes Zambetta, Signini, Ocamoto, Catai, Uliam, Santarnecchi and Russo.)

Background: Intracranial compliance (ICC) has been studied to complement the interpretation of intracranial pressure (ICP) in neurocritical care and help predict brain function deterioration. It has been reported that ICC is related to maintaining ICP stability despite changes in intracranial volume. However, this has not been properly translated to clinical practice. Therefore, the main objective of this scoping review was to map the key concepts of ICC in the literature. This review also aimed to characterize the relationship between ICC and ICP and systematically describe the outcomes used to assess ICC using both invasive and non-invasive measurement methods. Methods: This review included the following: (1) population: animal and humans, (2) concept of compliance or its inverse "elastance," and (3) context: neurocritical care. Therefore, literature searches without a time frame were conducted on several databases using a combination of keywords and descriptors. Results and Discussion: 43,339 articles were identified, and 297 studies fulfilled the inclusion criteria after the selection process. One hundred and five studies defined ICC. The concept was organized into three main components: physiological definition, clinical interpretation, and localization of the phenomena. Most of the studies reported the concept of compliance related to variations in volume and pressure or its inverse (elastance), primarily in the intracranial compartment. In addition, terms like "accommodation," "compensation," "reserve capacity," and "buffering ability" were used to describe the clinical interpretation. The second part of this review describes the techniques (invasive and non-invasive) and outcomes used to measure ICC. A total of 297 studies were included. The most common method used was invasive, representing 57-88% of the studies. The most commonly assessed variables were related to ICP, especially the absolute values or pulse amplitude. ICP waveforms should be better explored, along with the potential of non-invasive methods once the different aspects of ICC can be measured. Conclusion: ICC monitoring could be considered a complementary resource for ICP monitoring and clinical examination. The combination and validation of invasive/non-invasive or non-invasive measurement methods are required., Competing Interests: GF, CYH, and DLSJ were employed by the company Braincare Desenvolvimento e Inovação Tecnológica S.A. TLR, SB, and NNR were health consultants for the company Braincare Desenvolvimento e Inovação Tecnológica S.A. GNO and RMZ received financial support in the form of research grant from the company Braincare Desenvolvimento e Inovação Tecnológica S.A. The funder Braincare Desenvolvimento e Inovação Tecnológica S.A. had the following involvement: study design., (Copyright © 2021 Ocamoto, Russo, Mendes Zambetta, Frigieri, Hayashi, Brasil, Rabelo and Spavieri Júnior.)

Introduction: Upper limb movements are affected frequently by brain ischemia (BI). Mechanisms involved in recovery and compensatory movements have developed several studies. However, less attention is given to skeletal muscles, where neuromuscular junction (NMJ) has an important role on muscle tropism and functional performance., Methods: Animals were divided into two groups: control (C) and BI. Then, animals were skilled to perform single-pellet retrieval task, following these procedures: habituation, shaping, and single-pellet retrieval task. BI was induced using stereotaxic surgery in order to apply endothelin-1 in motor cortex, representative of movements of dominant paw. Reaching task performance was evaluated by single-pellet retrieval task 1 day before BI induction, 4 and 15 days after BI induction. After that, biceps, triceps, fingers flexor, and extensor muscles were extracted. NMJ was assessed in morphometric characteristics (total area, total perimeter, and feret). Muscle fiber cross-sectional area and connective tissue percentage were also evaluated for characterization. Student's t test was used for comparisons between C and BI groups. Tau Kendall's correlation was applied among variables from BI group., Results: An increase in all NMJ morphometric parameters, as well as increase of atrophy and fibrosis in BI group compared with C. There was a high level of direct correlation between mean values of NMJ morphometry with percentage of success in reaching task in BI group., Conclusion: Brain ischemia-induced NMJ compensatory expansion, muscle atrophy, and fibrosis in forelimb muscles that are related to reaching performance., (© 2020 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.)