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2.
Neurochirurgie ; 70(3): 101518, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38277859

RESUMO

BACKGROUND: The vertebral arteries (VA) play a critical role by supplying nearly one-third of the brain's blood flow, predominantly contributing to the posterior circulation. These arteries may need to be exposed in a various cranial and cervical procedures and offers access to investigate or treat vascular lesions by endovascular means related to the posterior circulation. Given its complex anatomy, which is subject to numerous variations, and its role in supplying vital brain regions, a thorough understanding of the VA's anatomy is paramount for any related procedure. OBJECTIVE: To provide a comprehensive overview of vertebral artery anatomy and its relevance in contemporary clinical practice. METHODS: Dissection of the entire vertebral artery length using cadaveric specimen, combined with a comprehensive literature review. RESULTS: The vertebral artery can be subdivided into four segments. Each of these segments has its own unique topographic anatomy with its variations, anastomoses, and significance in surgery. CONCLUSION: As surgical and endovascular techniques continue to evolve with technological improvements, we are now more equipped than ever to manage complex lesions involving the VA. However, with its increasingly complexity comes the necessity for a deeper and more comprehensive understanding of the VA. Possessing the detailed knowledge of the VA is vital for the successful execution of any procedure involving it.


Assuntos
Artéria Vertebral , Artéria Vertebral/anatomia & histologia , Artéria Vertebral/cirurgia , Humanos , Cadáver , Procedimentos Endovasculares/métodos
3.
Neurochirurgie ; 70(3): 101526, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38277864

RESUMO

BACKGROUND: Vertebral artery dissection (VAD) is an infrequent source of subarachnoid hemorrhage (SAH), with a high mortality rate, primarily due to the risk of rebleeding both before and after medical intervention. This paper provides a comprehensive analysis of the anatomy, pathophysiology, clinical presentation, treatment strategies, and outcomes of intracranial vertebral artery dissections that result in subarachnoid hemorrhage. METHODS: Comprehensive five-year literature review (2018-2022) and a retrospective analysis of patient records from our institution between 2016 and 2022. We included studies with a minimum of 5 patients. RESULTS: The study incorporated ten series from the literature and 22 cases from CHUM. Key anatomical factors increasing the risk of VAD include the vertebral artery's origin from the aortic arch, asymmetry of the vertebral artery, and its tortuosity. Patients may display specific collagen and genetic abnormalities. The occurrence of VAD appears to be more prevalent in men. Those with a ruptured intracranial VAD typically show prodromal symptoms and present with severe SAH. Rebleeding within the first 24 h is frequent. While standard imaging methods are usually adequate for VAD diagnosis, they may not provide detailed information about the perforator anatomy. Treatment approaches include both deconstructive and reconstructive methods. CONCLUSION: Ruptured VAD is a critical, life-threatening condition. Many patients have a poor neurological status at presentation, and rebleeding prior to treatment is a significant concern. Deconstructive techniques are most effective in preventing rebleeding, whereas the efficacy of reconstructive techniques needs more investigation.


Assuntos
Hemorragia Subaracnóidea , Dissecação da Artéria Vertebral , Humanos , Hemorragia Subaracnóidea/cirurgia , Dissecação da Artéria Vertebral/complicações , Dissecação da Artéria Vertebral/cirurgia , Masculino , Feminino , Estudos Retrospectivos , Artéria Vertebral/diagnóstico por imagem , Artéria Vertebral/cirurgia , Pessoa de Meia-Idade , Adulto
4.
Neurochirurgie ; 70(3): 101519, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38280371

RESUMO

BACKGROUND AND OBJECTIVES: The pathophysiology of spontaneous vertebral artery dissecting aneurysms (SVADA) is poorly understood. Our goal is to investigate the hemodynamic factors contributing to their formation using computational fluid dynamics (CFD) and deep learning algorithms. METHODS: We have developed software that can use patient imagery as input to recreate the vertebrobasilar arterial system, both with and without SVADA, which we used in a series of three patients. To obtain the kinematic blood flow data before and after the aneurysm forms, we utilized numerical methods to solve the complex Navier-Stokes partial differential equations. This was accomplished through the application of a finite volume solver (OpenFoam/Helyx OS). Additionally, we trained a neural ordinary differential equation (NODE) to learn and replicate the dynamical streamlines obtained from the computational fluid dynamics (CFD) simulations. RESULTS: In all three cases, we observed that the equilibrium of blood pressure distributions across the VAs, at a specific vertical level, accurately predicted the future SVADA location. In the two cases where there was a dominant VA, the dissection occurred on the dominant artery where blood pressure was lower compared to the contralateral side. The SVADA sac was characterized by reduced wall shear stress (WSS) and decreased velocity magnitude related to increased turbulence. The presence of a high WSS gradient at the boundary of the SVADA may explain its extension. Streamlines generated by CFD were learned with a neural ordinary differential equation (NODE) capable of capturing the system's dynamics to output meaningful predictions of the flow vector field upon aneurysm formation. CONCLUSION: In our series, asymmetry in the vertebrobasilar blood pressure distributions at and proximal to the site of the future SVADA accurately predicted its location in all patients. Deep learning algorithms can be trained to model blood flow patterns within biological systems, offering an alternative to the computationally intensive CFD. This technology has the potential to find practical applications in clinical settings.


Assuntos
Pressão Sanguínea , Aprendizado Profundo , Hemodinâmica , Dissecação da Artéria Vertebral , Humanos , Hemodinâmica/fisiologia , Dissecação da Artéria Vertebral/fisiopatologia , Pressão Sanguínea/fisiologia , Algoritmos , Artéria Vertebral/fisiopatologia , Hidrodinâmica , Masculino , Pessoa de Meia-Idade , Simulação por Computador , Feminino , Aneurisma Intracraniano/fisiopatologia
5.
Sci Rep ; 13(1): 21875, 2023 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-38072852

RESUMO

Pneumatic transportation systems (PTS) were recently proposed as a method to carry ready-for-injection diluted monoclonal antibodies (mAbs) from the pharmacy to the bedside of patients. This method reduces transportation time and improves the efficiency of drug distribution process. However, mAbs are highly sensitive molecules for which subtle alterations may lead to deleterious clinical effects. These alterations can be caused by various external factors such as temperature, pH, pressure, and mechanical forces that may occur during transportation. Hence, it is essential to ensure that the mAbs transported by PTS remain stable and active throughout the transportation process. This study aims to determine the safety profile of PTS to transport 11 routinely used mAbs in a clinical setting through assessment of critical quality attributes (CQA) and orthogonal analysis. Hence, we performed aggregation/degradation profiling, post-translational modifications identification using complementary mass spectrometry-based methods, along with visible and subvisible particle formation determination by light absorbance and light obscuration analysis. Altogether, these results highlight that PTS can be safely used for this purpose when air is removed from the bags during preparation.


Assuntos
Anticorpos Monoclonais , Farmácia , Humanos , Anticorpos Monoclonais/química , Fenômenos Mecânicos , Meios de Transporte/métodos
6.
BMC Cancer ; 23(1): 1178, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38041077

RESUMO

BACKGROUND: Many patients treated for breast cancer (BC) complain about cognitive difficulties affecting their daily lives. Recently, sleep disturbances and circadian rhythm disruptions have been brought to the fore as potential contributors to cognitive difficulties in patients with BC. Yet, studies on these factors as well as their neural correlates are scarce. The purpose of the ICANSLEEP-1 (Impact of SLEEP disturbances in CANcer) study is to characterize sleep using polysomnography and its relationship with the evolution of cognitive functioning at both the behavioral and the neuroanatomical levels across treatment in BC patients treated or not with adjuvant chemotherapy. METHODS: ICANSLEEP-1 is a longitudinal study including BC patients treated with adjuvant chemotherapy (n = 25) or not treated with adjuvant chemotherapy (n = 25) and healthy controls with no history of BC (n = 25) matched for age (45-65 years old) and education level. The evaluations will take place within 6 weeks after inclusion, before the initiation of chemotherapy (for BC patients who are candidates for chemotherapy) or before the first fraction of radiotherapy (for BC patients with no indication for chemotherapy) and 6 months later (corresponding to 2 weeks after the end of chemotherapy). Episodic memory, executive functions, psychological factors, and quality of life will be assessed with validated neuropsychological tests and self-questionnaires. Sleep quantity and quality will be assessed with polysomnography and circadian rhythms with both actigraphy and saliva cortisol. Grey and white matter volumes, as well as white matter microstructural integrity, will be compared across time between patients and controls and will serve to further investigate the relationship between sleep disturbances and cognitive decline. DISCUSSION: Our results will help patients and clinicians to better understand sleep disturbances in BC and their relationship with cognitive functioning across treatment. This will aid the identification of more appropriate sleep therapeutic approaches adapted to BC patients. Improving sleep in BC would eventually help limit cognitive deficits and thus improve quality of life during and after treatments. TRIAL REGISTRATION: NCT05414357, registered June 10, 2022. PROTOCOL VERSION: Version 1.2 dated March 23, 2022.


Assuntos
Neoplasias da Mama , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológico , Quimioterapia Adjuvante/efeitos adversos , Ritmo Circadiano , Cognição , Estudos Longitudinais , Qualidade de Vida , Sono , Estudos de Casos e Controles
7.
Int J Comput Assist Radiol Surg ; 18(8): 1469-1478, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36598652

RESUMO

PURPOSE: There is no objective way to measure the amount of manipulation and retraction of neural tissue by the surgeon. Our goal is to develop metrics quantifying dynamic retraction and manipulation by instruments during neurosurgery. METHODS: We trained a convolutional neural network (CNN) to analyze microscopic footage of neurosurgical procedures and thereby generate metrics evaluating the surgeon's dynamic retraction of brain tissue and, using an object tracking process, evaluate the surgeon's manipulation of the instruments themselves. U-Net image segmentation is used to output bounding polygons around cerebral parenchyma of interest, as well as the vascular structures and cranial nerves. A channel and spatial reliability tracker framework is used in conjunction with our CNN to track desired surgical instruments. RESULTS: Our network achieved a state-of-the-art intersection over union ([Formula: see text]) for biological tissue segmentation. Multivariate statistical analysis was used to evaluate dynamic retraction, tissue handling, and instrument manipulation. CONCLUSION: Our model enables to evaluate dynamic retraction of soft tissue and manipulation of instruments during a surgical procedure, while accounting for movement of the operative microscope. This model can potentially provide the surgeon with objective feedback about the movement of instruments and its effect on brain tissue.


Assuntos
Neurocirurgia , Humanos , Inteligência Artificial , Reprodutibilidade dos Testes , Procedimentos Neurocirúrgicos , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Processamento de Imagem Assistida por Computador/métodos
8.
Age Ageing ; 51(3)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35298587

RESUMO

INTRODUCTION: with ageing, the risk of falling increases. It has been reported that fall frequency may depend on the time of the day, suggesting a possible circadian rhythm of postural control. The objective was to test whether postural control in older adults followed a circadian rhythm. Then, in order to examine the possible functions involved in circadian variations in balance performances, circadian rhythm of sleepiness and vertical perception were also tested. METHODS: eight participants (70.7 ± 4.7 years) were included. Baseline circadian rhythm profile was assessed through continuous core temperature measurement. Static and dynamic balance, subjective sleepiness and fatigue, and verticality perception were measured at 2:00, 6:00, 10:00, 14:00, 18:00 and 22:00, on separate weeks in a random order. RESULTS: temperature followed a circadian rhythm, with lowest temperature occurring at 03:50. Circadian rhythm was detected for the centre of pressure displacement length and velocity, in dynamic condition eyes closed, with lowest performances occurring at 18:33 and 16:59, respectively. Subjective sleepiness and fatigue also followed circadian rhythm with lowest sleepiness occurring at 15:46 and 15:50, for the Karolinska Sleeping Scale and the Visual Analogic Scale of fatigue, respectively. Finally, the vertical perception was not significantly following a circadian rhythm. CONCLUSION: older adults present a circadian rhythm of balance, in particular in more challenging conditions, and the lowest performances occurred in the late afternoon These circadian rhythms could explain some of the falls happening at this time in community-dwelling older adults.


Assuntos
Ritmo Circadiano , Sonolência , Idoso , Fadiga/diagnóstico , Humanos , Percepção , Equilíbrio Postural
9.
Sleep ; 45(4)2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-34624895

RESUMO

Rest-activity rhythm (RAR) disruptions are frequently associated with chemotherapy in breast cancer (BC), but they are less known in BC with endocrine therapy (ET). The aim of this ancillary study was to characterize the RAR and estimated sleep characteristics from actigraphy in BC patients either treated (ET+) or untreated with ET (ET-), compared to healthy controls (HC) and using a cross-sectional design. Eighteen ET+, 18 ET-, and 16 HC completed questionnaires and wore wrist actigraphs at home for 2 weeks. Parametric and nonparametric RAR, sleep parameters, and quality of life were compared between groups (p < .05). BC groups presented lower daytime activity than HC according to RAR analysis (mesor and M10 parameters). Compared to HC, ET- had lower inter-daily stability and ET+ had greater sleep complaints. Compared to ET-, ET+ had lower sleep efficiency, more time awake, and higher activity levels at night, as assessed with actigraphy. Our results suggest an effect of cancer independent of treatment on RAR in BC, highlighting the need for further investigation of this topic. In contrast, sleep as assessed with actigraphy seems modified only during ET which matches with patients' sleep complaints. Further longitudinal studies would aid in confirming the latter hypothesis.


Assuntos
Neoplasias da Mama , Actigrafia/métodos , Neoplasias da Mama/tratamento farmacológico , Ritmo Circadiano , Estudos Transversais , Feminino , Humanos , Qualidade de Vida , Descanso , Sono
10.
J Cancer Surviv ; 16(6): 1339-1354, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-34609702

RESUMO

PURPOSE: Cancer-related fatigue (CRF) is a common and distressing symptom of cancer that may persist for years following treatment completion. However, little is known about the pathophysiology of CRF. Using a comprehensive group of gold-standard physiological and psychosocial assessments, this study aimed to identify correlates of CRF in a heterogenous group of cancer survivors. METHODS: Using a cross-sectional design to determine the physiological and psychosocial correlates of CRF, ninety-three cancer survivors (51 fatigued, 42 non-fatigued) completed assessments of performance fatigability (i.e. the decline in muscle strength during cycling), cardiopulmonary exercise testing, venous blood samples for whole blood cell count and inflammatory markers and body composition. Participants also completed questionnaires measuring demographic, treatment-related, and psychosocial variables. RESULTS: Performance fatigability, time-to-task-failure, peak oxygen uptake (V̇O2peak), tumor necrosis factor-α (TNF-α), body fat percentage, and lean mass index were associated with CRF severity. Performance fatigability, V̇O2peak, TNF-α, and age explained 35% of the variance in CRF severity. Those with clinically-relevant CRF reported more pain, more depressive symptoms, less perceived social support, and were less physically active than non-fatigued cancer survivors. CONCLUSIONS: The present study utilised a comprehensive group of gold-standard physiological and psychosocial assessments and the results give potential insight into the mechanisms underpinning the association between physical inactivity, physical deconditioning and CRF. IMPLICATIONS FOR CANCER SURVIVORS: Given the associations between CRF and both physiological and psychosocial measures, this study identifies targets that can be measured by rehabilitation professionals and used to guide tailored interventions to reduce fatigue.


Assuntos
Sobreviventes de Câncer , Neoplasias , Humanos , Estudos Transversais , Fator de Necrose Tumoral alfa , Neoplasias/complicações , Inquéritos e Questionários , Fadiga/complicações
12.
Curr Oncol ; 28(2): 1170-1182, 2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33802111

RESUMO

Cancer-related fatigue can continue long after curative cancer treatment. The aim of this study was to investigate sleep and rest-activity cycles in fatigued and non-fatigued cancer survivors. We hypothesized that sleep and rest-activity cycles would be more disturbed in people experiencing clinically-relevant fatigue, and that objective measures of sleep would be associated with the severity of fatigue in cancer survivors. Cancer survivors (n = 87) completed a 14-day wrist actigraphy measurement to estimate their sleep and rest-activity cycles. Fatigue was measured using the Functional Assessment of Chronic Illness Therapy Fatigue Scale (FACIT-F). Participants were dichotomised into two groups using a previously validated score (fatigued n = 51 and non-fatigued n = 36). The participant's perception of sleep was measured using the Insomnia Severity Index (ISI). FACIT-F score was correlated with wake after sleep onset (r = -0.28; p = 0.010), sleep efficiency (r = 0.26; p = 0.016), sleep onset latency (r = -0.31; p = 0.044) and Insomnia Severity Index (ISI) score (r = -0.56; p < 0.001). The relative amplitude of the rest-activity cycles was lower in the fatigued vs. the non-fatigued group (p = 0.017; d = 0.58). After treatment for cancer, the severity of cancer-related fatigue is correlated with specific objective measures of sleep, and there is evidence of rest-activity cycle disruption in people experiencing clinically-relevant fatigue.


Assuntos
Sobreviventes de Câncer , Neoplasias , Actigrafia , Fadiga/diagnóstico , Fadiga/epidemiologia , Fadiga/etiologia , Humanos , Neoplasias/complicações , Descanso , Sono
13.
Data Brief ; 35: 106794, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33604424

RESUMO

We present here a data set generated from a multinational survey on opinions of university community members on the prospect of consuming food grown with human urine as fertiliser and about their urine recycling perceptions in general. The data set comprises answers from 3,763 university community members (students, faculty/researchers, and staff) from 20 universities in 16 countries and includes demographic variables (age bracket, gender, type of settlement of origin, academic discipline, and role in the university). Questions were designed based on Ajzen's theory of planned behaviour to elicit information about three components of behavioural intention-attitudes, subjective norms, and perceived behavioural control. Survey questions covered perceived risks and benefits (attitudes), perceptions of colleagues (injunctive social norm) and willingness to consume food grown with cow urine/faeces (descriptive social norm), and willingness to pay a price premium for food grown with human urine as fertiliser (perceived behavioural control). We also included a question about acceptable urine recycling and disposal options and assessed general environmental outlook via the 15-item revised New Ecological Paradigm (NEP) scale. Data were collected through a standardised survey instrument translated into the relevant languages and then administered via an online form. Invitations to the survey were sent by email to university mailing lists or to a systematic sample of the university directory. Only a few studies on attitudes towards using human urine as fertiliser have been conducted previously. The data described here, which we analysed in "Willingness among food consumers at universities to recycle human urine as crop fertiliser: Evidence from a multinational survey" [1], may be used to further understand potential barriers to acceptance of new sanitation systems based on wastewater source separation and urine recycling and can help inform the design of future sociological studies.

14.
Sci Total Environ ; 765: 144438, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33418332

RESUMO

Source-separating sanitation systems offer the possibility of recycling nutrients present in wastewater as crop fertilisers. Thereby, they can reduce agriculture's impacts on global sources, sinks, and cycles for nitrogen and phosphorous, as well as their associated environmental costs. However, it has been broadly assumed that people would be reluctant to perform the new sanitation behaviours that are necessary for implementing such systems in practice. Yet, few studies have tried to systematically gather evidence in support of this assumption. To address this gap, we surveyed 3763 people at 20 universities in 16 countries using a standardised questionnaire. We identified and systematically assessed cross-cultural and country-level explanatory factors that were strongly associated with people's willingness to consume food grown using human urine as fertiliser. Overall, 68% of the respondents favoured recycling human urine, 59% stated a willingness to eat urine-fertilised food, and only 11% believed that urine posed health risks that could not be mitigated by treatment. Most people did not expect to pay less for urine-fertilised food, but only 15% were willing to pay a price premium. Consumer perceptions were found to differ greatly by country and the strongest predictive factors for acceptance overall were cognitive factors (perceptions of risks and benefits) and social norms. Increasing awareness and building trust among consumers about the effectiveness of new sanitation systems via cognitive and normative messaging can help increase acceptance. Based on our findings, we believe that in many countries, acceptance by food consumers will not be the major social barrier to closing the loop on human urine. That a potential market exists for urine-fertilised food, however, needs to be communicated to other stakeholders in the sanitation service chain.


Assuntos
Fertilizantes , Reciclagem , Comportamento do Consumidor , Alimentos , Humanos , Inquéritos e Questionários , Águas Residuárias
15.
Chronobiol Int ; 38(1): 90-102, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33317340

RESUMO

Animal and human studies demonstrate anatomical and functional links between the vestibular nuclei and the circadian timing system. This promotes the hypothesis of a circadian rhythm of vestibular function. The objective of this study was to evaluate the vestibular function through the vestibulo-ocular reflex using a rotatory chair at different times of the day to assess circadian rhythmicity of vestibular function. Two identical studies evaluating temporal variation of the vestibulo-ocular reflex (VOR) were performed, the first in young adults (age: 22.4 ± 1.5 y), and the second in older adults (70.7 ± 4.7 y). The slow phase velocity and time constant of the VOR were evaluated in six separate test sessions, i.e., 02:00, 06:00, 10:00, 14:00, 18:00, and 22:00 h. In both studies, markers of circadian rhythmicity (temperature, fatigue, and sleepiness) displayed expected usual temporal variation. In young adults, the time constant of the VOR showed variation throughout the day (p < .005), being maximum 12:25 h (06:00 h test session) before the acrophase of temperature circadian rhythm. In older adults, the slow phase velocity and time constant also displayed temporal variation (p < .05). Maximum values were recorded at 10:35 h (06:00 h test session) before the acrophase of temperature circadian rhythm. The present study demonstrates that vestibular function is not constant throughout the day. The implication of the temporal variation in vestibular system in equilibrium potentially exposes the elderly, in particular, to differential risk during the 24 h of losing balance and falling.


Assuntos
Ritmo Circadiano , Vestíbulo do Labirinto , Adulto , Idoso , Animais , Humanos , Reflexo Vestíbulo-Ocular , Rotação , Adulto Jovem
16.
J Neurophysiol ; 124(4): 1131-1143, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32877296

RESUMO

It is unclear whether motor fatigability and perceived fatigue share a common pathophysiology in people with multiple sclerosis (PwMS). This cross-sectional investigation explored the relationship between the mechanisms of motor fatigability from cycling and fatigue severity in PwMS. Thirteen highly fatigued (HF) and thirteen nonfatigued (LF) PwMS and thirteen healthy controls (CON) completed a step test until volitional exhaustion on an innovative cycle ergometer. Neuromuscular evaluations involving femoral nerve electrical stimulation and transcranial magnetic stimulation were performed every 3 min throughout cycling. One-way ANOVA at baseline and exhaustion uncovered evidence of consistently smaller motor evoked potential (MEP) amplitudes (P = 0.011) and prolonged MEP latencies (P = 0.041) in HF as well as a greater decline in maximal voluntary contraction force (HF: 63 ± 13%; LF: 75 ± 13%; CON: 73 ± 11% of pre; P = 0.037) and potentiated twitch force (HF: 35 ± 13%; LF: 50 ± 16%; CON: 47 ± 17% of pre; P = 0.049) in HF at volitional exhaustion. Hierarchical regression determined that fatigue severity on the Fatigue Severity Scale was predicted by prolonged MEP latencies (change in r2 = 0.389), elevated peripheral muscle fatigability (change in r2 = 0.183), and depressive symptoms (change in r2 = 0.213). These findings indicate that MS-related fatigue is distinguished by disrupted corticospinal responsiveness, which could suggest progressive pathology, but fatigability from whole body exercise and depressive symptoms also influence perceptions of fatigue in PwMS.NEW & NOTEWORTHY The etiology of fatigability from whole body exercise was examined for the first time to accurately elucidate the relationship between fatigue and fatigability in multiple sclerosis (MS). Compromised corticospinal responsiveness predicted fatigue severity, providing a novel, objective indicator of fatigue in MS. Although the impaired corticomotor transmission did not aggravate muscle activation in this group of people with multiple sclerosis (PwMS) of lower disability, heightened muscle fatigability was seen to contribute to perceptions of fatigue in PwMS.


Assuntos
Exercício Físico , Esclerose Múltipla/fisiopatologia , Fadiga Muscular , Tratos Piramidais/fisiopatologia , Adulto , Potencial Evocado Motor , Feminino , Nervo Femoral/fisiopatologia , Humanos , Contração Isométrica , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiopatologia , Tempo de Reação
17.
Chronobiol Int ; 37(8): 1244-1251, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32845722

RESUMO

The vestibular system is responsible for sensing every angular and linear head acceleration, mainly during periods of motor activity. Previous animal and human experiments have shown biological rhythm disruptions in small rodents exposed to a hypergravity environment, but also in patients with bilateral vestibular loss compared to a control population. This raised the hypothesis of the vestibular afferent influence on circadian rhythm synchronization. The present study aimed to test the impact of vestibular stimulation induced by a rotatory chair on the rest/activity rhythm in human subjects. Thirty-four healthy adults underwent both sham (SHAM) and vestibular stimulation (STIM) sessions scheduled at 18:00 h. An off-vertical axis rotation on a rotatory chair was used to ecologically stimulate the vestibular system by head accelerations. The rest/activity rhythm was continuously registered by actigraphy. The recording started one week before the first session (BASELINE), continued in the week between the two sessions and one week after the second session. Vestibular stimulation caused a significant decrease in the average activity level in the evening following the vestibular stimulation. A significant phase advance in the rest/activity rhythm occurred two days after the 18:00 h vestibular stimulation session. Moreover, the level of motion sickness symptoms increased significantly after vestibular stimulation. The present study confirms previous results on the effect of vestibular stimulation and the role of vestibular afferents on circadian biological rhythmicity. Our results support the hypothesis of the implication of vestibular afferents as non-photic stimuli acting on circadian rhythms.


Assuntos
Ritmo Circadiano , Descanso , Actigrafia , Adulto , Animais , Cabeça , Humanos , Rotação
18.
Sci Rep ; 10(1): 9216, 2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32514078

RESUMO

Input from the light/dark (LD) cycle constitutes the primary synchronizing stimulus for the suprachiasmatic nucleus (SCN) circadian clock. However, the SCN can also be synchronized by non-photic inputs. Here, we hypothesized that the vestibular system, which detects head motion and orientation relative to gravity, may provide sensory inputs to synchronize circadian rhythmicity. We investigated the resynchronization of core temperature (Tc) circadian rhythm to a six-hour phase advance of the LD cycle (LD + 6) using hypergravity (2 G) as a vestibular stimulation in control and bilateral vestibular loss (BVL) rats. Three conditions were tested: an LD + 6 exposure alone, a series of seven 2 G pulses without LD + 6, and a series of seven one-hour 2 G pulses (once a day) following LD + 6. First, following LD + 6, sham rats exposed to 2 G pulses resynchronized earlier than BVL rats (p = 0.01), and earlier than sham rats exposed to LD + 6 alone (p = 0.002). Each 2 G pulse caused an acute drop of Tc in sham rats (-2.8 ± 0.3 °C; p < 0.001), while BVL rats remained unaffected. This confirms that the vestibular system influences chronobiological regulation and supports the hypothesis that vestibular input, like physical activity, should be considered as a potent time cue for biological rhythm synchronization, acting in synergy with the visual system.


Assuntos
Ritmo Circadiano/fisiologia , Hipergravidade , Animais , Locomoção , Masculino , Fotoperíodo , Ratos , Ratos Long-Evans , Temperatura
19.
Sci Rep ; 10(1): 6030, 2020 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-32242040

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

20.
Sci Rep ; 9(1): 18432, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31804545

RESUMO

Hypothalamic orexin neurons are involved in various physiological functions, including thermoregulation. The orexinergic system has been considered as a potent mediator of the exercise response. The present study describes how the antagonization of the orexinergic system by a dual orexin receptor antagonist (DORA) modifies the thermoregulatory process during exercise. Core Body Temperature (CBT) and Spontaneous Locomotor Activity (SLA) of 12 male Wistar rats were recorded after either oral administration of DORA (30 mg/kg or 60 mg/kg) or placebo solution, both at rest and in exercise conditions with treadmill running. DORA ingestion decreased SLA for 8 hours (p < 0.001) and CBT for 4 hours (p < 0.01). CBT (°C) response was independent of SLA. The CBT level decreased from the beginning to the end of exercise when orexin receptors were antagonized, with a dose-dependent response (39.09 ± 0.36 and 38.88 ± 0.28 for 30 and 60 mg/kg; p < 0.001) compared to placebo (39.29 ± 0.31; p < 0.001). CBT increased during exercise was also blunted after DORA administration, but without dose effects of DORA. In conclusion, our results favor the role of orexin in the thermoregulation under stress related to exercise conditions.


Assuntos
Regulação da Temperatura Corporal/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Antagonistas dos Receptores de Orexina/farmacologia , Receptores de Orexina/metabolismo , Animais , Temperatura Corporal/fisiologia , Regulação da Temperatura Corporal/fisiologia , Hipotálamo/citologia , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Masculino , Modelos Animais , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Condicionamento Físico Animal , Ratos
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