scholarly journals Head-Down Tilt Bed Rest Improves Executive Function Amongst Younger Adults: A Pilot Project

2021 ◽  
Author(s):  
Said Mekari ◽  
René Murphy ◽  
Andrew MacKinnon ◽  
Quinn Hollohan ◽  
Samantha Macdougall ◽  
...  
Keyword(s):  
Stroop Task ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Bed Rest ◽  
Pilot Project ◽  
Microgravity Environment ◽  
Acute Bout ◽  
Executive Performance ◽  
Early Effects ◽  
The Brain

Abstract Purpose Microgravity has been shown to be a significant stressor on the cardiovascular system and the brain due to the redistribution of fluids that occurs in the absence of gravitational force, but there is scarce literature surrounding the effects of microgravity on cerebral hemodynamics and cognition. Understanding the early effects that simulated gravity has on cognitive function is essential for developing proper physical and cognitive countermeasures to assure safe and effective cognitive/decisions making while astronauts prepare for the initial launch or when they arrive in a microgravity environment. Therefore, this study aims to determine how an acute simulation of microgravity would alter cerebral oxygenation and executive functions. Methods Sixty-five young healthy participants (22±6 years, 21 females) completed a thirty (30) minute horizontal (00 tilt) followed by a 90-min -6° head-down-tilt (HDT) protocol. Cerebral oxygenation in the prefrontal cortex was monitored throughout the testing session using near-infrared spectroscopy. Cognition was also measured using a computerized Stroop Task. Results Our results demonstrate that cerebral oxygenation was higher during HDT compared to the horizontal supine position (9.11±1.3 vs 7.51±1.8, p=0.02). For the cognitive results, the non-executive performance of the Stroop task remained stable during HDT (652.46± 19.3 vs. 632.49±14.5, p=0.09). However, reaction time during the executive task performance was improved after the HDT (1058±195 msec to 950±158 msec, p<0.01). Conclusion Our results suggest that an acute bout of simulated microgravity can enhance executive functioning.

scholarly journals Hyperspectral Near Infrared Assessment Of The Brain In Cardiac Arrest

2021 ◽  
Author(s):  
Thu Nga Nguyen
Keyword(s):  
Cardiac Arrest ◽  
Oxygen Saturation ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Cerebral Hypoperfusion ◽  
Invasive Technique ◽  
Breath Holding ◽  
Transcatheter Aortic Valve ◽  
Neurological Injuries ◽  
The Brain

Two-thirds of out-of-hospital cardiac arrest patients, who survive to hospital admission, die in the hospital from neurological injuries related to cerebral hypoperfusion. Hyperspectral near infrared spectroscopy (hNIRS) is a non-invasive technique that measures the major chromophores in the brain, such as oxygenated hemoglobin, deoxygenated hemoglobin and cytochrome C oxidase (CCO), an intracellular marker of oxygen consumption. We have demonstrated that hNIRS can detect changes in cerebral oxygenation and metabolism in patients undergoing transcatheter aortic valve insertion (TAVI) – a procedure that temporarily induces sudden hypotension and hypoperfusion that mimics cardiac arrest. Using multi-distance hNIRS, we found that while measured regional oxygen saturation (rSO2) changes resulted mainly from the extra-cerebral tissues, CCO changes during cardiac arrests occurred mainly in the brains of patients. We also applied the hNIRS algorithm based on the “2-layer model” to the data to measure cerebral oxygen saturation and CCO in patients during the procedure. We found that changes in all the parameters scale with the thickness of the extra-cerebral layer. Finally, the results of the comparison of breath holding measurement by using multispectral NIRS algorithm with the selected wavelength combinations from a previous study on animal suggests that changes in CCO could be measured, however wavelengths need to be further optimized for the adult patients.

scholarly journals Caffeine Effect on Cognitive Function during a Stroop Task: fNIRS Study

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yafei Yuan ◽  
Guanghao Li ◽  
Haoran Ren ◽  
Wei Chen
Keyword(s):  
Cognitive Function ◽  
Task Performance ◽  
Stroop Task ◽  
Near Infrared ◽  
Brain Activity ◽  
Brain Activation ◽  
Infrared Light ◽  
Functional Near Infrared Spectroscopy ◽  
Feedback Information ◽  
The Brain

Acting as a brain stimulant, coffee resulted in heightening alertness, keeping arousal, improving executive speed, maintaining vigilance, and promoting memory, which are associated with attention, mood, and cognitive function. Functional near-infrared spectroscopy (fNIRS) is a noninvasive optical method to monitor brain activity by measuring the absorption of the near-infrared light through the intact skull. This study is aimed at acquiring brain activation during executing task performance. The aim is to explore the effect of coffee on cognitive function by the fNIRS neuroimaging method, particularly on the prefrontal cortex regions. The behavioral experimental results on 31 healthy subjects with a Stroop task indicate that coffee can easily and effectively modulate the execute task performance by feedback information of the response time and accuracy rate. The findings of fNIRS showed that apparent hemodynamic changes were detected in the bilateral VLPFC regions and the brain activation regions varied with different coffee conditions.

scholarly journals Cerebral metabolic response to submaximal exercise

1999 ◽  
Vol 87 (5) ◽  
pp. 1604-1608 ◽  
Author(s):  
Kojiro Ide ◽  
Allan Horn ◽  
Niels H. Secher
Keyword(s):  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Metabolic Response ◽  
Molar Ratio ◽  
Moderate Exercise ◽  
Lactate Metabolism ◽  
Low Intensity ◽  
Norepinephrine Spillover ◽  
Low Intensity Exercise ◽  
The Brain

We studied cerebral oxygenation and metabolism during submaximal cycling in 12 subjects. At two work rates, middle cerebral artery blood velocity increased from 62 ± 3 to 63 ± 3 and 70 ± 5 cm/s as did cerebral oxygenation determined by near-infrared spectroscopy. Oxyhemoglobin increased by 10 ± 3 and 25 ± 3 μmol/l ( P < 0.01), and there was no significant change in brain norepinephrine spillover. The arterial-to-internal-jugular-venous (a-v) difference for O2 decreased at low-intensity exercise (from 3.1 ± 0.1 to 2.9 ± 0.1 mmol/l; P < 0.05) and recovered at moderate exercise (to 3.3 ± 0.1 mmol/l). The profile for glucose was similar: its a-v difference tended to decrease at low-intensity exercise (from 0.55 ± 0.05 to 0.50 ± 0.02 mmol/l) and increased during moderate exercise (to 0.64 ± 0.04 mmol/l; P < 0.05). Thus the molar ratio (a-v difference, O2 to glucose) did not change significantly. However, when the a-v difference for lactate (0.02 ± 0.03 to 0.18 ± 0.04 mmol/l) was taken into account, the O2-to-carbohydrate ratio decreased (from 6.1 ± 0.4 to 4.7 ± 0.3; P < 0.05). The enhanced cerebral oxygenation suggests that, during exercise, cerebral blood flow increases in excess of the O2demand. Yet it seems that during exercise not all carbohydrate taken up by the brain is oxidized, as brain lactate metabolism appears to lower the balance of O2-to-carbohydrate uptake.

scholarly journals PlanHab: hypoxia exaggerates the bed-rest-induced reduction in peak oxygen uptake during upright cycle ergometry

2016 ◽  
Vol 311 (2) ◽  
pp. H453-H464 ◽  
Author(s):  
Michail E. Keramidas ◽  
Roger Kölegård ◽  
Igor B. Mekjavic ◽  
Ola Eiken
Keyword(s):  
Oxygen Uptake ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Vastus Lateralis ◽  
Bed Rest ◽  
Peak Oxygen Uptake ◽  
Cycle Ergometry ◽  
Vastus Lateralis Muscle ◽  
Before And After ◽  
Exercise Induced

The study examined the effects of hypoxia and horizontal bed rest, separately and in combination, on peak oxygen uptake (V̇o2 peak) during upright cycle ergometry. Ten male lowlanders underwent three 21-day confinement periods in a counterbalanced order: 1) normoxic bed rest [NBR; partial pressure of inspired O2(PiO2) = 133.1 ± 0.3 mmHg]; 2) hypoxic bed rest (HBR; PiO2= 90.0 ± 0.4 mmHg), and 3) hypoxic ambulation (HAMB; PiO2= 90.0 ± 0.4 mmHg). Before and after each confinement, subjects performed two incremental-load trials to exhaustion, while inspiring either room air (AIR), or a hypoxic gas (HYPO; PiO2= 90.0 ± 0.4 mmHg). Changes in regional oxygenation of the vastus lateralis muscle and the frontal cerebral cortex were monitored with near-infrared spectroscopy. Cardiac output (CO) was recorded using a bioimpedance method. The AIR V̇o2 peakwas decreased by both HBR (∼13.5%; P ≤ 0.001) and NBR (∼8.6%; P ≤ 0.001), with greater drop after HBR ( P = 0.01). The HYPO V̇o2 peakwas also reduced by HBR (−9.7%; P ≤ 0.001) and NBR (−6.1%; P ≤ 0.001). Peak CO was lower after both bed-rest interventions, and especially after HBR (HBR: ∼13%, NBR: ∼7%; P ≤ 0.05). Exercise-induced alterations in muscle and cerebral oxygenation were blunted in a similar manner after both bed-rest confinements. No changes were observed in HAMB. Hence, the bed-rest-induced decrease in V̇o2 peakwas exaggerated by hypoxia, most likely due to a reduction in convective O2transport, as indicated by the lower peak values of CO.

scholarly journals Hyperspectral Near Infrared Assessment Of The Brain In Cardiac Arrest

2021 ◽  
Author(s):  
Thu Nga Nguyen
Keyword(s):  
Cardiac Arrest ◽  
Oxygen Saturation ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Cerebral Hypoperfusion ◽  
Invasive Technique ◽  
Breath Holding ◽  
Transcatheter Aortic Valve ◽  
Neurological Injuries ◽  
The Brain

Two-thirds of out-of-hospital cardiac arrest patients, who survive to hospital admission, die in the hospital from neurological injuries related to cerebral hypoperfusion. Hyperspectral near infrared spectroscopy (hNIRS) is a non-invasive technique that measures the major chromophores in the brain, such as oxygenated hemoglobin, deoxygenated hemoglobin and cytochrome C oxidase (CCO), an intracellular marker of oxygen consumption. We have demonstrated that hNIRS can detect changes in cerebral oxygenation and metabolism in patients undergoing transcatheter aortic valve insertion (TAVI) – a procedure that temporarily induces sudden hypotension and hypoperfusion that mimics cardiac arrest. Using multi-distance hNIRS, we found that while measured regional oxygen saturation (rSO2) changes resulted mainly from the extra-cerebral tissues, CCO changes during cardiac arrests occurred mainly in the brains of patients. We also applied the hNIRS algorithm based on the “2-layer model” to the data to measure cerebral oxygen saturation and CCO in patients during the procedure. We found that changes in all the parameters scale with the thickness of the extra-cerebral layer. Finally, the results of the comparison of breath holding measurement by using multispectral NIRS algorithm with the selected wavelength combinations from a previous study on animal suggests that changes in CCO could be measured, however wavelengths need to be further optimized for the adult patients.

Oxygen dependency and precision of cytochrome oxidase signal from full spectral NIRS of the piglet brain

2000 ◽  
Vol 279 (5) ◽  
pp. H2202-H2209 ◽  
Author(s):  
R. Springett ◽  
J. Newman ◽  
M. Cope ◽  
D. T. Delpy
Keyword(s):  
Cytochrome Oxidase ◽  
Oxidation State ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Maximum Reduction ◽  
Total Hemoglobin ◽  
Near Infrared Spectra ◽  
Fitting Algorithm ◽  
Cerebral Saturation ◽  
The Brain

Oxidation changes of the copper A (CuA) center of cytochrome oxidase in the brain were measured during brief anoxic swings at both normocapnia and hypercapnia (arterial Pco 2 ≈55 mmHg). Hypercapnia increased total hemoglobin from 37.5 ± 9.1 to 50.8 ± 12.9 μmol/l (means ± SD; n = 7), increased mean cerebral saturation (SmcO2 ) from 65 ± 4 to 77 ± 3%, and oxidized CuA by 0.43 ± 0.23 μmol/l. During the onset of anoxia, there were no significant changes in the CuA oxidation state until SmcO2 had fallen to 43 ± 5 and 21 ± 6% at normocapnia and hypercapnia, respectively, and the maximum reduction during anoxia was not significantly different at hypercapnia (1.49 ± 0.40 μmol/l) compared with normocapnia (1.53 ± 0.44 μmol/l). Residuals of the least squares fitting algorithm used to convert near-infrared spectra to concentrations are presented and shown to be small compared with the component of attenuation attributed to the CuAsignal. From these observations, we conclude that there is minimal interference between the hemoglobin and CuA signals in this model, the CuA oxidation state is independent of cerebral oxygenation at normoxia, and the oxidation after hypercapnia is not the result of increased cerebral oxygenation.

scholarly journals Regional Cerebral Oxygenation Changes Monitored with Near Infrared Spectroscopy Device During Spinal Neurosurgery in Prone Position and Postoperative Cognitive Dysfunction

2017 ◽  
Vol 17 (1) ◽  
pp. 3-7
Author(s):  
Sniedze Murniece ◽  
Indulis Vanags ◽  
Biruta Mamaja
Keyword(s):  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Prone Position ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Cerebral Oxygen Saturation ◽  
Control Group ◽  
Study Group ◽  
Cerebral Oxygen ◽  
The Brain

Summary Introduction. The adverse effects of hypoxia are well known, especially regarding the brain, and can lead to postoperative cognitive disturbances. On the other hand, the brain is still one of the least monitored organs intraoperatively. Near infrared spectroscopy devices are non-invasive continuous cerebral oxygenation monitoring devices that can also be used intraoperatively. Prone position used during spinal neurosurgery is of particular importance regarding physiological changes that can occur in the human body and can lead to reduced blood and oxygen supply of the brain. Aim of the Study. The aim of the study was to determine whether prone position used during spinal neurosurgery impacts cerebral oxygenation and patients’ cognitive performance after the surgery. Material and methods. 40 patients were included in the study (32 study group, 8 control group). Patients were scheduled for spinal neurosurgery in prone position. All patients received standard general anaesthesia. In the study group regional cerebral oxygen saturation (rScO2) was continuously monitored using INVOS 4100 near infrared spectroscopy device. During the surgery every 5 minutes in study and control group medium non–invasive blood pressure, heart rate, peripheral oxygen saturation, exhaled CO2 and cerebral oxygenation measurements were fixed. We also fixed intraoperative blood loss and duration of the operation. Cognitive function was assessed in both groups using Montreal - Cognitive Assessment (MoCA) scale before surgery and two days after the surgery. Results. We didn’t observe any significant changes in our calculated medium rScO2 intraoperative values. During induction of anaesthesia when patients were lying supine rScO2 above the right cerebral hemisphere was rScO2 72±9.7%, above the left cerebral hemisphere 71± 9.7%. Cerebral oxygen saturation in prone position was rScO2 R 74±10.7% and rScO2 L 74±10.1%. At the end of the surgery when patients were lying supine again rScO2 R was 74±9.3% and rScO2 L was 74±7.9%. We didn’t observe any differences in medium MoCA scores when comparing study and control group. MoCA score before surgery in the study group was 24.1±2.9 points and 24.6±4.1 points in the control group. MoCA performed 2 days after the surgery was 24.6 ±3.2 points in study group and 24.6±2.4 points in control group. Conclusions. No significant changes were observed in medium MoCA scores between patients who intraoperatively received noninvasive cerebral oxygen saturation monitoring and patients who did not receive it. Despite medium calculated MoCA scores, individually we observed postoperative cognitive function impairment for MoCA 1-2 points in 5 out of 8 patients in the control group, but in the study group only 1 patient out of 32 showed cognitive dysfunction. Intraoperative regional cerebral oxygen saturation monitoring can help to obviate cerebral desaturation that can lead to postoperative cognitive decline.

scholarly journals The utility of cerebral oxygenation monitoring in premature neonates

2020 ◽  
Vol 89 (4) ◽  
pp. e485
Author(s):  
Saudamini Nesargi ◽  
Alexander Nitsch ◽  
Martin Wolf
Keyword(s):  
Infrared Spectroscopy ◽  
Preterm Infants ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Ductus Arteriosus ◽  
Neurological Outcomes ◽  
Standard Set ◽  
Oxygenation Monitoring ◽  
The Brain

Near-infrared spectroscopy allows the measurement of cerebral oxygenation in preterm infants. This study aimed to demonstrate several highly relevant clinical situations in preterm infants in which the standard set of monitoring parameters without near-infrared spectroscopy is not sufficient to detect possible adverse situations, possibly resulting in severe complications, i.e. adverse neurological outcomes. The examples include situations of low blood pressure, persistent open ductus arteriosus, malfunctioning autoregulation of the brain oxygenation, and periods of irregular breathing. Without near-infrared spectroscopy, it is impossible to determine whether such a situation imposes any risk for the brain, whereas the measurement of cerebral oxygenation as an additional source of information enables the clinician to recognise these conditions and modify treatment or use countermeasures to protect the patient from brain damage and ensuing lifelong disabilities.

scholarly journals Near-Infrared Spectroscopy (NIRS) in Traumatic Brain Injury (TBI)

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1586
Author(s):  
María Roldán ◽  
Panayiotis A. Kyriacou
Keyword(s):  
Traumatic Brain Injury ◽  
Infrared Spectroscopy ◽  
Brain Injury ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Noninvasive Monitoring ◽  
Infrared Light ◽  
Cochrane Library ◽  
The Brain

Traumatic brain injury (TBI) occurs when a sudden trauma causes damage to the brain. TBI can result when the head suddenly and violently impacts an object or when an object pierces the skull and enters brain tissue. Secondary injuries after traumatic brain injury (TBI) can lead to impairments on cerebral oxygenation and autoregulation. Considering that secondary brain injuries often take place within the first hours after the trauma, noninvasive monitoring might be helpful in providing early information on the brain’s condition. Near-infrared spectroscopy (NIRS) is an emerging noninvasive monitoring modality based on chromophore absorption of infrared light with the capability of monitoring perfusion of the brain. This review investigates the main applications of NIRS in TBI monitoring and presents a thorough revision of those applications on oxygenation and autoregulation monitoring. Databases such as PubMed, EMBASE, Web of Science, Scopus, and Cochrane library were utilized in identifying 72 publications spanning between 1977 and 2020 which were directly relevant to this review. The majority of the evidence found used NIRS for diagnosis applications, especially in oxygenation and autoregulation monitoring (59%). It was not surprising that nearly all the patients were male adults with severe trauma who were monitored mostly with continue wave NIRS or spatially resolved spectroscopy NIRS and an invasive monitoring device. In general, a high proportion of the assessed papers have concluded that NIRS could be a potential noninvasive technique for assessing TBI, despite the various methodological and technological limitations of NIRS.

Movement of Prefrontal Blood Volume during Stroop Task using Near-infrared

2016 ◽  
Vol 136 (1) ◽  
pp. 86-91
Author(s):  
Shingo Takahashi ◽  
Naoki Kodama ◽  
Naoko Kosugi ◽  
Hiroshi Takeuchi
Keyword(s):  
Blood Volume ◽  
Stroop Task ◽  
Near Infrared
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