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To investigate the effects of propofol and dexmedetomidine combined anesthesia on cerebral oxygen metabolism indexes, oxidative stress and cell pyroptosis factors in patients undergoing cardiac valve replacement (HVR) under cardiopulmonary bypass. 136 patients who underwent HVR under cardiopulmonary bypass in our hospital from March 2021 to December 2022 were selected. Patients were divided into control group (propofol anesthesia) and study group (dexmedetomidine combined with propofol anesthesia) according to the random number table method, with 68 cases in each group. The hemodynamics, oxidative stress index, myocardial injury index, cerebral oxygen metabolism index, cell pyroptosis factors and incidence of adverse reactions were compared between two groups. Time point after open aorta (T1) to after operation(T3), the heart rate (HR) and mean arterial pressure (MAP) in study group were higher than those in control group (P<0.05). 24 h after operation, the superoxide dismutase (SOD) in study group was higher than that in control group, and the malondialdehyde (MDA) was lower than that in control group (P<0.05). 24 h after operation, creatine kinase isoenzyme (CK-MB), N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI) in study group were lower than those in control group (P<0.05). 24 h after operation, the levels of NOD-like receptor protein 3 (NLRP3), cyptate protease 1 (Caspase-1), megaphin D (GSDMD) in study group were lower than those in control group (P<0.05). T1~T3 time points, the arterial-jugular venous oxygen content difference (Da-jvO2) and cerebral oxygen extraction rate (CERO2) in study group were higher than those in control group, and the jugular venous oxygen saturation (SjvO2) was lower than that in control group (P<0.05). There was no difference in the incidence of adverse reactions between two groups (P>0.05). Dexmedetomidine combined with propofol can reduce oxidative stress, inflammatory response and myocardial injury in patients with HVR under cardiopulmonary bypass, and improve brain function. [ABSTRACT FROM AUTHOR]

Perinatal hypoxic-ischaemic encephalopathy (HIE) is the leading cause of irreversible brain damage resulting in serious neurological dysfunction among neonates. We evaluated the feasibility of positron emission tomography (PET) methodology with 15O-labelled gases without intravenous or tracheal cannulation for assessing temporal changes in cerebral blood flow ( CBF ) and cerebral metabolic rate for oxygen ( CMRO2) in a neonatal HIE rat model. Sequential PET scans with spontaneous inhalation of 15O-gases mixed with isoflurane were performed over 14 days after the hypoxic-ischaemic insult in HIE pups and age-matched controls. CBF and CMRO2 in the injured hemispheres of HIE pups remarkably decreased 2 days after the insult, gradually recovering over 14 days in line with their increase found in healthy controls according to their natural maturation process. The magnitude of hemispheric tissue loss histologically measured after the last PET scan was significantly correlated with the decreases in CBF and CMRO2.This fully non-invasive imaging strategy may be useful for monitoring damage progression in neonatal HIE and for evaluating potential therapeutic outcomes. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To probe into the therapeutic effect and mechanism of Ginkgo biloba extract tablets for patients with transient ischemic attack (TIA). METHODS: A total of 80 TIA patients admitted into this hospital from Nov. 2020 to Oct. 2022 were selected and divided into control group and observation group via random number table method, with 40 cases in each group. Both groups were given 100 mg Bayaspirin, 75 mg clopidogrel and 20 mg atorvastatin for once a day; and the observation group was additionally given Ginkgo biloba extract tablets, the course of treatment was 8 weeks for both groups. The age, blood pressure, clinical features, duration of clinical symptoms, diabetes (ABCD2 ) scores, changes of cerebral oxygen metabolism indicators and vascular endothelial function indicators were compared between two groups before and after treatment, the clinical efficacy was compared between two groups, and the influence factors of ineffective treatment were discussed by Logistic regression analysis. The incidence of adverse drug reactions and acute cerebral infarction (ACI) were observed. RESULTS: After treatment, the cerebral venous blood oxygen content and jugular venous blood oxygen saturation of the observation group were higher than those of the control group, the ABCD2 score, plasma inflammatory factor lipoprotein-associated phospholipase A2, soluble vascular cell adhesion molecule-1 and matrix metalloproteinase 9 levels of the observation group were lower than those of the control group, with statistically significant differences (P < 0. 05). The total effective rate of the observation group was 92. 50% (37 / 40), higher than that of the control group (72. 50%, 29 / 40), with statistically significant difference (P<0. 05). Age and concomitant hyperlipidemia were the risk factors for ineffective treatment (OR was 1. 428, 1. 618, respectively, P<0. 05), while the combination of Gginkgo biloba extract was a protective factor for ineffective treatment (OR = 0. 822, P<0. 05). There was no statistically significant difference in the incidences of adverse drug reactions between the observation group and the control group [10. 00% (4 / 40) vs. 5. 00% (2 / 40), P>0. 05]. After 6-month follow-up, the incidence of ACI in the observation group was 2. 50% (1 / 40), lower than 15. 00% (6 / 40) in the control group, with statistically significant difference (P<0. 05). CONCLUSIONS: Ginkgo biloba extract tablets can improve the cerebral oxygen metabolism and vascular endothelial function in TIA patients, promote clinical efficacy with higher safety, and reduce the incidence of ACI. [ABSTRACT FROM AUTHOR]

Objective: First implementation of dynamic oxygen-17 (17O) MRI at 7 Tesla (T) during neuronal stimulation in the human brain. Methods: Five healthy volunteers underwent a three-phase 17O gas (17O2) inhalation experiment. Combined right-side visual stimulus and right-hand finger tapping were used to achieve neuronal stimulation in the left cerebral hemisphere. Data analysis included the evaluation of the relative partial volume (PV)-corrected time evolution of absolute 17O water (H217O) concentration and of the relative signal evolution without PV correction. Statistical analysis was performed using a one-tailed paired t test. Blood oxygen level-dependent (BOLD) experiments were performed to validate the stimulation paradigm. Results: The BOLD maps showed significant activity in the stimulated left visual and sensorimotor cortex compared to the non-stimulated right side. PV correction of 17O MR data resulted in high signal fluctuations with a noise level of 10% due to small regions of interest (ROI), impeding further quantitative analysis. Statistical evaluation of the relative H217O signal with PV correction (p = 0.168) and without (p = 0.382) did not show significant difference between the stimulated left and non-stimulated right sensorimotor ROI. Discussion: The change of cerebral oxygen metabolism induced by sensorimotor and visual stimulation is not large enough to be reliably detected with the current setup and methodology of dynamic 17O MRI at 7 T. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of oral positioning therapy (OPT) combined with hyperbaric oxygen rehabilitation training on cerebral oxygen metabolism, swallowing function, and serum neurological damage indicators in children with severe viral encephalitis complicated with swallowing disorders. Methods: 80 children with severe viral encephalitis and swallowing disorders who were admitted to Southern Theater Command General Hospital from January 2015 to August 2022 were selected. The children were divided into control group (conventional symptomatic treatment, oral swallowing rehabilitation training combined with OPT rehabilitation training) and study group (control group combined with hyperbaric oxygen treatment) using envelope drawing method, with 40 cases each. The efficacy, swallowing function, cerebral oxygen metabolism, and serum neurological damage indicators between the two groups were compared. Result: The total clinical effective rate of the study group after intervention was higher than that of the control group（P＜0.05) .After intervention, the swallowing disorders questionnaire (DDS) scores of the study group in Oral stage, esophageal stage and pharyngeal stage were lower than those of the control group (P＜0.05) .After the intervention, the oxygen saturation (Sjv O2) and cerebral oxygen uptake rate (CERO2) in the study group were higher than those in the control group, and the cerebral arteriovenous oxygen content difference (Da-jv O2) was lower than that in the control group (P＜0.05) .After the intervention, brain derived neurotrophin (BDNF) in the study group was higher than that in the control group, myelin basic protein (MBP), central nervous system specific protein (S100β), neuron specific enolase (NSE), β-Endorphin（β-EP) were lower than those in the control group (P＜0.05) .Conclusion: The combination of OPT rehabilitation training and hyperbaric oxygen therapy can significantly improve swallowing function, cerebral oxygen metabolism, and serum neurological damage indicator levels in children with severe viral encephalitis complicated with swallowing disorders. [ABSTRACT FROM AUTHOR]

Methylene Blue (MB) is a brain-penetrating drug with putative neuroprotective, antioxidant and metabolic enhancing effects. In vitro studies suggest that MB enhances mitochondrial complexes activity. However, no study has directly assessed the metabolic effects of MB in the human brain. We used in vivo neuroimaging to measure the effect of MB on cerebral blood flow (CBF) and brain metabolism in humans and in rats. Two doses of MB (0.5 and 1 mg/kg in humans; 2 and 4 mg/kg in rats; iv) induced reductions in global cerebral blood flow (CBF) in humans (F(1.74, 12.17)5.82, p = 0.02) and rats (F(1,5)26.04, p = 0.0038). Human cerebral metabolic rate of oxygen (CMRO2) was also significantly reduced (F(1.26, 8.84)8.01, p = 0.016), as was the rat cerebral metabolic rate of glucose (CMRglu) (t = 2.6(16) p = 0.018). This was contrary to our hypothesis that MB will increase CBF and energy metrics. Nevertheless, our results were reproducible across species and dose dependent. One possible explanation is that the concentrations used, although clinically relevant, reflect MB's hormetic effects, i.e., higher concentrations produce inhibitory rather than augmentation effects on metabolism. Additionally, here we used healthy volunteers and healthy rats with normal cerebral metabolism where MB's ability to enhance cerebral metabolism might be limited. [ABSTRACT FROM AUTHOR]

Objectives: Hemodynamic abnormalities and brain development disorders have been reported previously in fetuses and infants with transposition of the great arteries and intact ventricular septum (TGA‐IVS). A ventricular septal defect (VSD) is thought to be an additional risk factor for adverse neurodevelopment, but literature describing this population is sparse. The objectives of this study were to assess fetal cardiac hemodynamics throughout pregnancy, to monitor cerebral hemodynamics and oxygen metabolism in neonates, and to compare these data between patients with TGA‐IVS, those with TGA‐VSD and age‐matched controls. Methods: Cardiac hemodynamics were assessed in TGA‐IVS and TGA‐VSD fetuses and compared with healthy controls matched for gestational age (GA) during three periods: ≤ 22 + 5 weeks (GA1), 27 + 0 to 32 + 5 weeks (GA2) and ≥ 34 + 5 weeks (GA3). Left (LVO), right (RVO) and combined (CVO) ventricular outputs, ductus arteriosus flow (DAF, sum of ante‐ and retrograde flow in systole and diastole), diastolic DAF, transpulmonary flow (TPF) and foramen ovale diameter were measured. Aortic (AoF) and main pulmonary artery (MPAF) flows were derived as a percentage of CVO. Fetal middle cerebral artery and umbilical artery (UA) pulsatility indices (PI) were measured and the cerebroplacental ratio (CPR) was derived. Bedside optical brain monitoring was used to measure cerebral hemoglobin oxygen saturation (SO2) and an index of microvascular cerebral blood flow (CBFi), along with peripheral arterial oxygen saturation (SpO2), in TGA‐IVS and TGA‐VSD neonates. Using hemoglobin (Hb) concentration measurements, these parameters were used to derive cerebral oxygen delivery and extraction fraction (OEF), as well as an index of cerebral oxygen metabolism (CMRO2i). These data were acquired in the early preoperative period (within 3 days after birth and following balloon atrial septostomy) and compared with those of age‐matched healthy controls, and repeat measurements were collected before discharge when vital signs were stable. Results: LVO was increased in both TGA groups compared with controls throughout pregnancy. Compared with controls, TPF was increased and diastolic DAF was decreased in TGA‐IVS fetuses throughout pregnancy, but only during GA1 and GA2 in TGA‐VSD fetuses. Compared with controls, DAF was decreased in TGA‐IVS fetuses throughout pregnancy and in TGA‐VSD fetuses at GA2 and GA3. At GA2, AoF was higher in TGA‐IVS and TGA‐VSD fetuses than in controls, while MPAF was lower. At GA3, RVO and CVO were higher in the TGA‐IVS group than in the TGA‐VSD group. In addition, UA‐PI was lower at GA2 and CPR higher at GA3 in TGA‐VSD fetuses compared with TGA‐IVS fetuses. Within 3 days after birth, SpO2 and SO2 were lower in both TGA groups than in controls, while Hb, cerebral OEF and CMRO2i were higher. Preoperative SpO2 was also lower in TGA‐VSD neonates than in those with TGA‐IVS. From preoperative to predischarge periods, SpO2 and OEF increased in both TGA groups, but CBFi and CMRO2i increased only in the TGA‐VSD group. During the predischarge period, SO2 was higher in TGA‐IVS than in TGA‐VSD neonates, while CBFi was lower. Conclusions: Fetal cardiac and neonatal cerebral hemodynamic/metabolic differences were observed in both TGA groups compared with controls. Compared to those with TGA‐IVS, fetuses with TGA‐VSD had lower RVO and CVO in late gestation. A higher level of preoperative hypoxemia was observed in the TGA‐VSD group. Postsurgical cerebral adaptive mechanisms probably differ between TGA groups. Patients with TGA‐VSD have a specific physiology that warrants further study to improve neonatal care and neurodevelopmental outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Background: Infants born at 29-36 weeks gestational age (GA) are at risk of experiencing neurodevelopmental challenges. We hypothesize that cerebral hemodynamics and oxygen metabolism measured by bedside optical brain monitoring are potential biomarkers of brain development and are associated with neurological examination at term-equivalent age (TEA). Methods: Preterm infants (N D 133) born 29-36 weeks GA and admitted in the neonatal intensive care unit were enrolled in this prospective cohort study. Combined frequency-domain near infrared spectroscopy (FDNIRS) and diffuse correlation spectroscopy (DCS) were used from birth to TEA to measure cerebral hemoglobin oxygen saturation and an index of microvascular cerebral blood flow (CBFi) along with peripheral arterial oxygen saturation (SpO2). In combination with hemoglobin concentration in the blood, these parameters were used to derive cerebral oxygen extraction fraction (OEF) and an index of cerebral oxygen metabolism (CMRO2i). The Amiel-Tison and Gosselin Neurological Assessment was performed at TEA. Linear regression models were used to assess the associations between changes in FDNIRS-DCS parameters from birth to TEA and GA at birth. Logistic regression models were used to assess the associations between changes in FDNIRS-DCS parameters from birth to TEA and neurological examination at TEA. Results: Steeper increases in CBFi (p < 0.0001) and CMRO2i (p D 0.0003) were associated with higher GA at birth. Changes in OEF, CBFi, and CMRO2i from birth to TEA were not associated with neurological examination at TEA. Conclusion: In this population, cerebral FDNIRS-DCS parameters were not associated with neurological examination at TEA. Larger increases in CBFi and CMRO2i from birth to TEA were associated with higher GA. Non-invasive bedside FDNIRS-DCS monitoring provides cerebral hemodynamic and metabolic parameters that may complement neurological examination to assess brain development in preterm infants. [ABSTRACT FROM AUTHOR]

Cardiac surgery utilizing circulatory arrest is most commonly performed under deep hypothermia (∼18°C) to suppress tissue oxygen demand and provide neuroprotection during operative circulatory arrest. Studies investigating the effects of deep hypothermic circulatory arrest (DHCA) on neurodevelopmental outcomes of patients with congenital heart disease give conflicting results. Here, we address these issues by quantifying changes in cerebral oxygen saturation, blood flow, and oxygen metabolism in neonates during DHCA and investigating the association of these changes with postoperative brain injury. Neonates with critical congenital heart disease undergoing DHCA were recruited for continuous intraoperative monitoring of cerebral oxygen saturation (ScO2) and an index of cerebral blood flow (CBFi) using 2 noninvasive optical techniques, diffuse optical spectroscopy (DOS) and diffuse correlation spectroscopy (DCS). Pre- and postoperative brain magnetic resonance imaging (MRI) was performed to detect white matter injury (WMI). Fifteen neonates were studied, and 11/15 underwent brain MRI. During DHCA, ScO2 decreased exponentially in time with a median decay rate of -0.04 min-1. This decay rate was highly variable between subjects. Subjects who had larger decreases in ScO2 during DHCA were more likely to have postoperative WMI (P = 0.02). Cerebral oxygen extraction persists during DHCA and varies widely from patient-to-patient. Patients with a higher degree of oxygen extraction during DHCA were more likely to show new WMI in postoperative MRI. These findings suggest cerebral oxygen extraction should be monitored during DHCA to identify patients at risk for hypoxic-ischemic injury, and that current commercial cerebral oximeters may underestimate cerebral oxygen extraction. [ABSTRACT FROM AUTHOR]

Oral frailty associated with oral hypokinesia may cause dementia. Functional near-infrared spectroscopy (fNIRS) can be used while the participants are in seating position with few restrictions. Thus, it is useful for assessing brain function, particularly oral motor activity. However, methods for identifying oral motor cortex (OMC) activation via the scalp have not been established. The current study aimed to detect OMC activation, an indicator of activity phase ratio (APR), which reflects increased oxygen consumption (0 < [deoxyhemoglobin (ΔDeoxyHb) or 0 < {[ΔDeoxyHb- oxyhemoglobin (ΔOxyHb)/√2]}, via fNIRS to accurately identify local brain activity. The APR, calculated via zero-set vector analysis, is a novel index for quantifying brain function both temporally and spatially at rest and during tasks. In total, 14 healthy participants performed bite tasks for 3 s per side for 10 times while in the sitting position. Then, time-series data on concentration changes in ΔOxyHb and ΔDeoxyHb were obtained via fNIRS. The anatomical location of the OMC was determined using a pooled data set of three-dimensional magnetic resonance images collected in advance from 40 healthy adults. In the zero-set vector analysis, the average change in ΔOxyHb and ΔDeoxyHb concentrations was utilized to calculate the APR percentage in 140 trials. The significant regions (z-score of ≥2.0) of the APR and ΔOxyHb in the task were compared. During the bite task, the APR significantly increased within the estimated OMC region (56–84 mm lateral to Cz and 4–20 mm anterior to Cz) in both the right and left hemispheres. By contrast, the ΔOxyHb concentrations increased on the bite side alone beyond the OMC region. The mean APR at rest for 2 s before the task showed 59.5%– 62.2% in the left and right OMCs. The average APR for 3 s during the task showed 75.3% for the left OMC and 75.7% for the right OMC during the left bite task, and 65.9% for the left OMC and 80.9% for the right OMC during the right bite task. Interestingly, the average increase in APR for the left and right OMCs for the left bite task and the right bite task was 13.9% and 13.7%, respectively, showing almost a close match. The time course of the APR was more limited to the bite task segment than that of ΔOxyHb or ΔDexyHb concentration, and it increased in the OMC. Hence, the APR can quantitatively monitor both the resting and active states of the OMC in the left and right hemispheres. Using the zero-set vector-based fNIRS, the APR can be a valid indicator of oral motor function and bite force. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To probe into the protective effects of dexmedetomidine combined with sufentanil on cerebral oxygen metabolism and liver function in elderly patients during recovery from general anesthesia. METHODS: A total of 90 patients undergoing surgery in the hospital from Jan. 2020 to Jan. 2021 were selected as the research objects. The patients were divided into the group A (n = 30), group B (n = 30) and group C (n = 30) according to the random number table method. Patients in group A were treated with dexmedetomidine combined with sufentanil by continuous pumping to maintain anesthesia, the group B were given sufentanil alone, and the group C received 0. 9% sodium chloride injection. The incidence of agitation and visual analogue scale (VAS) at different time points were compared among three groups. The heart rate (HR) and mean arterial pressure (MAP) levels before and after surgery were recorded; the cerebral oxygen metabolism [suturation jugular venous blood (SjvO2 ), cerebral oxygen extraction rate (CERO2 )] was recorded before anesthesia induction (T0 ), at the end of surgery (T3 ) and after surgery of 24 h (T4 ). The levels of alanine aminotransferase ( ALT) and aspartate aminotransferase ( AST) at T0, skin incision (T1 ), 5 min after tracheal intubation (T2 ), T3 and T4 were detected in three groups. RESULTS: The MAP and HR levels of three groups before surgery, after surgery of 1 h and 2 h increased first and then decreased. There were significant differences in levels of MAP and HR among three groups after surgery of 1 h and 2 h (P<0. 05). The incidences of agitation in group A, B and C were respectively 3. 33% ( 1 case), 6. 67% ( 2 cases) and 26. 67% (8 cases), the difference was statistically significant (P < 0. 05). There were statistically significant differences in VAS scores within three groups before surgery, after surgery of 1 h and 2 h (P<0. 05), which decreased first and then increased. There were significant differences in VAS scores among three groups after surgery of 1 h and 2 h ( P < 0. 05). There were statistically significant differences in SjvO2 and CERO2 among three groups at T3 and T4 ( P < 0. 05). From T1 to T4, there were significant differences in levels of ALT and AST among three groups (P<0. 05). CONCLUSIONS: Dexmedetomidine combined with sufentanil can reduce the cardiovascular stress and restlessness response of elderly patients during recovery from general anesthesia, and alleviate the pain of patients to a certain extent, improve the cerebral oxygen metabolism, alleviate the brain injury level, effectively inhibit the liver injury and protect the residual liver function of patients. [ABSTRACT FROM AUTHOR]

Brain temperature, a crucial yet under-researched neurophysiological parameter, is governed by the equilibrium between cerebral oxygen metabolism and hemodynamics. Therapeutic hypothermia has been demonstrated as an effective intervention for acute brain injuries, enhancing survival rates and prognosis. The success of this treatment hinges on the precise regulation of brain temperature. However, the absence of comprehensive brain temperature monitoring methods during therapy, combined with a limited understanding of human brain heat transmission mechanisms, significantly hampers the advancement of hypothermia-based neuroprotective therapies. Leveraging the principles of bioheat transfer and MRI technology, this study conducted quantitative analyses of brain heat transfer during mild hypothermia therapy. Utilizing MRI, we reconstructed brain structures, estimated cerebral blood flow and oxygen consumption parameters, and developed a brain temperature calculation model founded on bioheat transfer theory. Employing computational cerebral hemodynamic simulation analysis, we established an intracranial arterial fluid dynamics model to predict brain temperature variations across different therapeutic hypothermia modalities. We introduce a noninvasive, spatially resolved, and optimized mathematical bio-heat model that synergizes model-predicted and MRI-derived data for brain temperature prediction and imaging. Our findings reveal that the brain temperature images generated by our model reflect distinct spatial variations across individual participants, aligning with experimentally observed temperatures. [ABSTRACT FROM AUTHOR]

Objective: To observe the effects of dexmedetomidine combined with sevoflurane on cerebral oxygen metabolism and stress response in elderly patients undergoing laparoscopic gastrointestinal tumor resection. Methods: 100 elderly patients undergoing laparoscopic gastrointestinal tumor resection who were treated in our hospital from January 2020 to December 2020 were divided into control group （n=50, sevoflurane anesthesia） and study group （n=50, dexmedetomidine combined with sevoflurane anesthesia） by random number table method. Hemodynamics, stress response, cerebral oxygen metabolism, cognitive function and adverse reactions of two groups were observed. Results: 60 min （T1） to 30 min （T3） after operation, The heart rate （HR） of the two groups first decreased and then increased compared with the time point before induction of anesthesia （T0）, and the mean arterial pressure （MAP） first increased and then decreased （P<0.05）. HR at T1～T3 time points in the study group were lower than those in the control group （P<0.05）. The dopamine（DA）, epinephrine （AD） and norepinephrine （NE） levels in two groups at 3 d after operation were increased, but the study group was lower than the control group （P<0.05）. The difference of blood oxygen content （DajvO2） and cerebral oxygen uptake rate （CERO2） in both groups at 3d after operation decreased, but the study group was lower than the control group （P<0.05）. The scores of mini mental state examination scale （MMSE） in the study group at 6h, 1d and 3d after operation were higher than those in the control group （P<0.05）There was no significant difference in the incidence of adverse reactions between the two groups （P>0.05）. Conclusion: Sevoflurane combined with dexmedetomidine in elderly patients undergoing laparoscopic gastrointestinal tumor resection can effectively reduce the body’s stress response, reduce the damage of cognitive function, and maintain hemodynamic stability and cerebral oxygen metabolism. [ABSTRACT FROM AUTHOR]

Background and purpose: Regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO2) in whole brain, white matter, gray matter and lenticular nuclei were studied in people living with human immunodeficiency virus (PLHIV) as well as HIV‐associated neurocognitive disorder (HAND). Methods: Treatment‐naïve PLHIV underwent neurocognitive assessment and magnetic resonance (MR) measurement of rCBF and rCMRO2 with repeat after 12 months of antiretroviral therapy (ART). Age‐ and sex‐matched controls underwent single MR measurements. Regional CBF and rCMRO2 were compared amongst symptomatic, asymptomatic, normal HAND and controls using analysis of variance. Longitudinal analysis of HAND worsening (≥1 category) was assessed after 12 months of ART and correlated with rCBF and rCMRO2 measured by MR imaging using the paired‐sample t test. Results: Thirty PLHIV completed baseline and 12‐month assessments (29 with rCMRO2 measurement). At baseline HAND assessment, 13% had no cognitive impairment, 27% had asymptomatic neurocognitive impairment, 60% had mild neurocognitive disorder and none had HIV‐associated dementia. At 12 months, 13% had no cognitive impairment, 20% had asymptomatic neurocognitive impairment, 50% had mild neurocognitive disorder and 17% had HIV‐associated dementia. In those without HAND worsening (N = 21) rCMRO2 remained stable and in those with HAND worsening (N = 8) rCMRO2 measurement declined from baseline to 12 months in white matter (2.05 ± 0.40 to 1.73 ± 0.51, p = 0.03) and lenticular nuclei (4.32 ± 0.39 to 4.00 ± 0.51, p = 0.05). Conclusions: In recently diagnosed PLHIV, no association was found between rCBF or rCMRO2 and cognitive impairment at baseline. There was a reduction in rCMRO2 in those with worsening of cognitive function at 12 months on ART. Reduction in rCMRO2 may be a biomarker of cognitive decline in PLHIV. [ABSTRACT FROM AUTHOR]

Calibrated blood oxygenation level dependent (BOLD) imaging is a multimodal functional MRI technique designed to estimate changes in cerebral oxygen metabolism from measured changes in cerebral blood flow and the BOLD signal. This technique addresses fundamental ambiguities associated with quantitative BOLD signal analysis; however, its dependence on biophysical modeling creates uncertainty in the resulting oxygen metabolism estimates. In this work, we developed a Bayesian approach to estimating the oxygen metabolism response to a neural stimulus and used it to examine the uncertainty that arises in calibrated BOLD estimation due to the presence of unmeasured model parameters. We applied our approach to estimate the CMRO2 response to a visual task using the traditional hypercapnia calibration experiment as well as to estimate the metabolic response to both a visual task and hypercapnia using the measurement of baseline apparent R2' as a calibration technique. Further, in order to examine the effects of cerebral spinal fluid (CSF) signal contamination on the measurement of apparent R2', we examined the effects of measuring this parameter with and without CSF-nulling. We found that the two calibration techniques provided consistent estimates of the metabolic response on average, with a median R2'-based estimate of the metabolic response to CO2 of 1.4%, and R2'- and hypercapnia-calibrated estimates of the visual response of 27% and 24%, respectively. However, these estimates were sensitive to different sources of estimation uncertainty. The R2'-calibrated estimate was highly sensitive to CSF contamination and to uncertainty in unmeasured model parameters describing flow-volume coupling, capillary bed characteristics, and the iso-susceptibility saturation of blood. The hypercapnia-calibrated estimate was relatively insensitive to these parameters but highly sensitive to the assumed metabolic response to CO2.

ObjectiveTo observe the effect of dexmedetomidine-assisted intravenous inhalation combined anesthesia on cerebral oxygen metabolism and serum Th1/Th2 levels in elderly patients with colorectal cancer.MethodFrom April 2018 to May 2020,100 elderly patients undergoing elective laparoscopic radical resection of colorectal cancer were prospectively selected and randomly divided into observation group and control group. Before induction of anesthesia, the loading dose of dexmedetomidine was given at 0.5 μg/kg, and the infusion time was 15 min. After tracheal intubation, 0.4 μg/kg/h dexmedetomidine was continuously pumped, and the infusion was stopped 40 min before the end of the operation. In the control group, the same amount of 0.9% sodium chloride was injected intravenously in the same way. 30 min before induction of anesthesia (T0), immediately before induction of anesthesia (T1), immediately after tracheal intubation (T2), 40 min before operation (T3), and immediately after operation (T4), record the blood oxygen content of the artery and internal jugular vein Difference (D(a-jv)O2), brain oxygen uptake rate (COER%), brain oxygen saturation (rSO2) mean. VAS scale, Ramsay scale, MoCA scale were taken at 6, 12, 24, and 48 h postoperatively to evaluate analgesia, sedation, and cognitive function. And monitor the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), myelin basic protein (MBP), neuron-specific enolase (NSE) and S100β. The occurrence of restlessness and adverse reactions during the recovery period of the two groups were compared.ResultThe levels of D(a-jv)O2, COER%, and rSO2 in the control group and observation group were higher than the preoperative basic values at T2, T3, and T4 (P < 0.05); The levels of D(a-jv)O2, COER%, and rSO2 in the observation group were lower than those in the control group at T2, T3, and T4 (P < 0.05). The VAS score and Ramsay score of the observation group were lower than those of the control group at 6, 12, 24, and 48 h after surgery, while the MoCA score was higher than that of the control group (P < 0.05). In addition, the serum IFN-γ, MBP, NSE and S100β levels of the observation group were lower than those of the control group (P < 0.05), and the ratio of IFN-γ/IL-4 was higher than that of the control group (P < 0.05). The overall incidence of adverse reactions in the observation group was lower than that in the control group [32.0% (16/50) vs. 12.0% (6/50), P < 0.05].ConclusionDexmedetomidine-assisted combined intravenous and inhalation anesthesia is beneficial to reduce perioperative cerebral oxygen metabolism and improve postoperative immunosuppression in elderly patients with colorectal cancer. It has a certain protective effect on nerve injury after operation, thus improving the cognitive function of patients and reducing the occurrence of adverse reactions.

Background: It remains unclear how a single bout of exercise affects brain perfusion, oxygen metabolism, and blood-brain barrier (BBB) permeability. Addressing this unresolved issue is essential to understand the acute changes in cerebral physiology induced by aerobic exercise., Purpose: To dynamically monitor the acute changes in cerebral physiology subsequent to a single aerobic exercise training session using noninvasive MRI measurements., Study Type: Prospective., Population: Twenty-three healthy participants (18-35 years, 10 females/13 males) were enrolled and divided into 10-minute exercising (N = 10) and 20-minute exercising (N = 13) groups., Field Strength/sequence: 3.0 T/Phase Contrast (PC) MRI (gradient echo), T 2 -Relaxation-Under-Spin-Tagging (TRUST) MRI (gradient echo EPI), Water-Extraction-with-Phase-Contrast-Arterial-Spin-Tagging (WEPCAST) MRI (gradient echo EPI) and T 1 -weighted magnetization-prepared-rapid-acquisition-of-gradient-echo (MPRAGE) (gradient echo)., Assessment: A baseline MR measurement plus four repeated MR measurements immediately after 10 or 20 minutes moderate running exercise. MR measurements included cerebral blood flow (CBF) as measured by PC MRI, venous oxygenation (Y v ) and cerebral metabolic rate of oxygen (CMRO 2 ) as assessed by TRUST MRI, water extraction fraction (E), and BBB permeability-surface-area product (PS) as determined by WEPCAST MRI., Statistical Tests: The time dependence of the physiological parameters was studied with a linear mixed-effect model. Additionally, pairwise t-tests comparison of the physiological parameters at each time point was conducted. A P-value of <0.05 was considered statistically significant., Results: There was an initial drop (8.22 ± 2.60%) followed by a recovery in CBF after exercise, while Y v revealed a significant decrease (6.37 ± 0.92%), i.e., an increased oxygen extraction, and returned to baseline at later time points. CMRO 2 showed a trend of increase (5.68 ± 3.04%) and a significant interaction between time and group. In addition, E increased significantly (3.86% ± 0.89) and returned to baseline level at later time points, while PS remained elevated (13.33 ± 4.79%)., Data Conclusion: A single bout of moderate aerobic exercise can induce acute alterations in cerebral perfusion, metabolism, and BBB permeability., Evidence Level: 2 TECHNICAL EFFICACY: Stage 2., (© 2024 International Society for Magnetic Resonance in Medicine.)

Objective: The effects of remifentanil and dexmedetomidine on cerebral oxygen metabolism, hemodynamics and cognitive function in patients undergoing hip replacement under general anesthesia. Methods: A total of 100 patients undergoing hip arthroplasty who were admitted to our hospital from June 2016 to October 2019 were selected. Using random number table method, they were divided into control group and study group, each with 50 cases. Patients in the control group were given remifentanil under anesthesia, and the study group was combined with dexmedetomidine on the basis of the control group. The hemodynamics, cerebral oxygen metabolism and cognitive function of the two groups were compared. The incidence of adverse reactions during surgery. Results: The mean arterial pressure (MAP) and heart rate (HR) of the two groups showed a downward trend from 30 min (T1) to the end of the operation (T2), but the study group was higher than the control group (P<0.05). Arterial blood oxygen content (CaO 2 ) and internal jugular venous blood oxygen content (CjvO 2 ) in the two groups at T1～T2 time points showed a downward trend, and the study group was lower than the control group (P<0.05); the two groups T1～T2 time The blood oxygen saturation (SjvO 2 ) of the jugular venous bulb showed an increasing trend, and the study group was higher than the control group (P<0.05). The scores of the Concise Mental State Scale (MMSE) before operation to 7 days after operation in the two groups decreased and then increased (P<0.05); the MMSE scores of the study group were higher than those of the control group at 3 and 7 days after operation (P <0.05). The incidence of cognitive dysfunction (POCD) in the study group was lower than that in the control group at 3 days and 7 days after operation (P<0.05). There was no difference in the incidence of adverse reactions between the two groups (P>0.05). Conclusion: Dexmedetomidine combined with remifentanil as an anesthesia plan for hip replacement patients under general anesthesia can reduce hemodynamic fluctuations, maintain the balance of cerebral oxygen supply and demand, reduce the risk of POCD, and has good safety. [ABSTRACT FROM AUTHOR]

Infant hydrocephalus poses a severe global health burden; 80% of cases occur in the developing world where patients have limited access to neurosurgical care. Surgical treatment combining endoscopic third ventriculostomy and choroid plexus cauterization (ETV/CPC), first practiced at CURE Children’s Hospital of Uganda (CCHU), is as effective as standard ventriculoperitoneal shunt (VPS) placement while requiring fewer resources and less post-operative care. Although treatment focuses on controlling ventricle size, this has little association with treatment failure or long-term outcome. This study aims to monitor the progression of hydrocephalus and treatment response, and investigate the association between cerebral physiology, brain growth, and neurodevelopmental outcomes following surgery. We will enroll 300 infants admitted to CCHU for treatment. All patients will receive pre/post-operative measurements of cerebral tissue oxygenation (SO2), cerebral blood flow (CBF), and cerebral metabolic rate of oxygen consumption (CMRO2) using frequency-domain near-infrared combined with diffuse correlation spectroscopies (FDNIRS-DCS). Infants will also receive brain imaging, to monitor tissue/ventricle volume, and neurodevelopmental assessments until two years of age. This study will provide a foundation for implementing cerebral physiological monitoring to establish evidence-based guidelines for hydrocephalus treatment. This paper outlines the protocol, clinical workflow, data management, and analysis plan of this international, multi-center trial.

BACKGROUND: The inhalational anesthetic sevoflurane is often used in craniocerebral surgery for its advantages of quick onset, stable circulation, high safety, and few adverse reactions. However, it can also lead to abnormal blood pressure and heart rate, as well as restlessness and pain. Therefore, an auxiliary anesthetic is needed to help reduce adverse reactions. Dexmedetomidine is a potent and highly selective α2 adrenergic receptor agonist that has anti-anxiety, hypnotic, analgesic, sedative, and sympatholytic properties. Dexmedetomidine has been shown to reduce restlessness after sevoflurane inhalation anesthesia and minimize perioperative hemodynamic fluctuation. However, its application in craniocerebral surgery should be validated. OBJECTIVE: To investigate the efficacy of dexmedetomidine in craniocerebral surgery under sevoflurane inhalation anesthesia. METHODS: The prospective, single-center, randomized, controlled study will be performed in Taihe Hospital (Shiyan, China). The 1308 patients to be included in this study will be randomly divided into a trial group and control group (n=654 patients per group) based on a table of random permutations. In both groups, sevoflurane will be used for induction of anesthesia for craniocerebral surgery. In the trial group, 1 μg/kg dexmedetomidine will be injected intravenously for 10 minutes commencing 15 minutes before anesthesia induction, and then continuously pumped at 0.3 μg/kg per hour until 30 minutes before surgery. In the control group, 0.9% sodium chloride injection will be administered in the same way and at the same injection rate. This trial was approved by the Ethics Review Committee of Taihe Hospital on December 8, 2015 (Approval No. 2015GJJ-087). Participants will not be blind to the study protocol or procedure, and will provide signed informed consent. This study was registered with Chinese Clinical Trial Registry on March 2, 2020 (registration No. ChiCTR2000030459). Protocol version: 1.0. RESULTS AND CONCLUSION: The primary outcome of this study is recovery time. Secondary outcomes of this study include anesthesia, recovery, and adverse events, as well as vital signs, stress index, and cerebral metabolic rate of oxygen consumption at different time points (before and after administration of the loading dose of dexmedetomidine, during anesthesia induction, at the beginning of craniocerebral surgery, during craniocerebral surgery, at the end of craniocerebral surgery, and at the time of recovery). A pilot study involving 190 patients who underwent craniocerebral surgery was performed between March 2016 and February 2017. These 190 patients randomly received either sevoflurane anesthesia (n=95, control group) or dexmedetomidine and sevoflurane anesthesia (n=95, trial group). Results of the pilot group showed that anesthesia time, intraoperative bleeding volume, intraoperative infusion volume, recovery time, and extubation time were similar between trial and control groups (P > 0.05). However, compared with the control group, the administered dosages of vasoactive drugs ephedrine and esmolol were significantly lower (P < 0.05) in the trial group. Heart rate and electroencephalography bispectral index after administration of the loading dose of dexmedetomidine, during anesthesia induction, at the beginning of craniocerebral surgery, during craniocerebral surgery, at the end of craniocerebral surgery, and at the time of recovery were significantly higher in the trial group compared with the control group (P < 0.05). At the beginning of craniocerebral surgery, during craniocerebral surgery, at the end of craniocerebral surgery, and at the time of recovery, mean arterial pressure in the trial group was significantly higher compared with the control group (P < 0.05). After administration of the loading dose of dexmedetomidine, during anesthesia induction, at the beginning of craniocerebral surgery, during craniocerebral surgery, at the end of craniocerebral surgery, and at the time of recovery, blood glucose level in the trial group was significantly higher compared with the control group (P < 0.05). After administration of the loading dose of dexmedetomidine, during anesthesia induction, and at the beginning of craniocerebral surgery, cortisol concentrations in the trial group were significantly lower compared with the control group (P < 0.05). During craniocerebral surgery, at the end of craniocerebral surgery, and at the time of recovery, jugular bulb venous blood oxygen saturation, difference in oxygen content between arterial and jugular venous blood, and cerebral metabolic rate of oxygen consumption in the trial group were significantly higher compared with the control group (P < 0.05). Findings from this study will help determine whether dexmedetomidine can reduce hemodynamic fluctuation, lower stress index, and protect the brain in patients who undergo craniocerebral surgery under inhalation anesthesia with sevoflurane. The results can provide evidence to support clinical application of dexmedetomidine combined with sevoflurane for craniocerebral surgery. [ABSTRACT FROM AUTHOR]

Objective: To compare the effects of different anesthesia schemes on hemodynamics of patients undergoing supratentorial tumor surgery. Patients who underwent supratentorial tumor surgery in our hospital from October 2017 to October 2019 were randomly divided into study group (n=40) and control group (n=40). The patients in the control group were anesthetized with dexmedetomidine and the patients in the study group were anesthetized with isoflurane. Before anesthesia induction (T0), 30 minutes after anesthesia (T1), 1 hour after anesthesia (T2) and at the end of operation (T3), hemodynamic indexes (heart rate (HR), mean arterial pressure (MAP) and cerebral oxygen metabolism (SjvO2) were observed and compared between two groups, the arterial oxygen content (CaO2), cerebral venous oxygen content (CjvO2), cerebral oxygen uptake rate (CERO2)], and the anesthesia effect (excellent, good, bad) and operation related indexes (operation time, anesthesia time, recovery time, infusion volume) of both groups were analyzed. Compared with T0, the MAP and HR of both groups decreased from T1 to T2, which were significantly lower in the control group than those in the study group (P<0.05); compared with T0, the MAP and HR of both groups increased from T3(P<0.05); compared with T0, T1, T3, the MAP and HR of both groups were lower at T2, and the MAP and HR of control group were lower than those in study group (P<0.05); compared with T0, the CjvO2 of the study group and the control group increased significantly at T1 to T3. The CjvO2 at T1, T2 and T3 in the study group were higher than those in the control group (P<0.05), while the CERO2 were lower than those in the control group (P<0.05), and there was no significant difference in the between the SjvO2 and CaO2 between from T0 to T3 two groups (P>0.05); compared with the control group, the excellent rate of anesthesia effect in the study group was higher (P<0.05), the recovery time was significantly shorter (P<0.05). There was no significant difference in operation time, anesthesia time and infusion volume between two groups (P>0.05). Dexmedetomidine has a good anesthetic effect on patients undergoing supratentorial tumor surgery. It can effectively stabilize the hemodynamics, reduce the cerebral oxygen metabolism, and shorten the recovery time. [ABSTRACT FROM AUTHOR]

Objective: To study the sedative effect of dexmedetomidine in elderly patients with prostate cancer undergoing three hole LRP, and its effect on nerve function and brain oxygen metabolism. Methods:From August 2016 to December 2019, 78 patients with LRP under general anesthesia in our hospital were randomly selected and divided into control group and observation group according to the random number table method, 39 cases in each group. During the operation, the observation group was given dextromethoridine, while the control group was given the same amount of normal saline. The changes of cognitive function index (MoCA score, POCD incidence rate), neurological function index (TGF - β 1, NSE, IGF-1), brain oxygen metabolism index (PaO2, map, PaCO2, rSO2) before and after operation were compared between the two groups. The visual analogue score (VAS), the amount of analgesic drugs and the times of pressing the analgesic pump were compared between the two groups. The incidence of adverse reactions was compared between the two groups. Results:Before operation, there was no significant difference in cognitive function index, neurological function index and brain oxygen metabolism index between the two groups (P > 0.05). On the first and third days after operation, MOCA score of the two groups was significantly lower, MOCA score of the observation group was significantly higher than that of the control group, POCD incidence of the observation group was significantly lower than that of the control group; on the third day after operation, TGF - β 1 and IGF-1 of the two groups were significantly lower, TGF - β 1 and IGF-1 of the observation group were significantly lower -The NSE in the observation group was significantly lower than that in the control group (P < 0.05). In this study, 1 hour after the establishment of pneumoperitoneum, PaCO2 and rSO2 in the two groups were significantly increased, 6 hours and 12 hours after the operation, the VAS score of the observation group was lower than that of the control group, and the dosage of analgesic pump and the number of times of compression of the analgesic pump were significantly lower than that of the control group (P < 0.05). There was no difference in the incidence of adverse reactions between the two groups (P> 0.05). Conclusion:DEX has a good sedative effect on the elderly prostate cancer patients undergoing LRP with three hole method. It has little effect on nerve function and brain oxygen metabolism, and has a good safety. [ABSTRACT FROM AUTHOR]

Management of deep hypothermic (DH) cardiopulmonary bypass (CPB), a critical neuroprotective strategy, currently relies on non-invasive temperature to guide cerebral metabolic suppression during complex cardiac surgery in neonates. Considerable inter-subject variability in temperature response and residual metabolism may contribute to the persisting risk for postoperative neurological injury. To characterize and mitigate this variability, we assess the sufficiency of conventional nasopharyngeal temperature (NPT) guidance, and in the process, validate combined non-invasive frequency-domain diffuse optical spectroscopy (FD-DOS) and diffuse correlation spectroscopy (DCS) for direct measurement of cerebral metabolic rate of oxygen (CMRO 2). During CPB, n = 8 neonatal swine underwent cooling from normothermia to 18℃, sustained DH perfusion for 40 min, and then rewarming to simulate cardiac surgery. Continuous non-invasive and invasive measurements of intracranial temperature (ICT) and CMRO 2 were acquired. Significant hysteresis (p < 0.001) between cooling and rewarming periods in the NPT versus ICT and NPT versus CMRO 2 relationships were found. Resolution of this hysteresis in the ICT versus CMRO 2 relationship identified a crucial insufficiency of conventional NPT guidance. Non-invasive CMRO 2 temperature coefficients with respect to NPT (Q 10 = 2.0) and ICT (Q 10 = 2.5) are consistent with previous reports and provide further validation of FD-DOS/DCS CMRO 2 monitoring during DH CPB to optimize management. [ABSTRACT FROM AUTHOR]

Background: We aimed to explore the effect of comprehensive cerebral protection on cerebral oxygen metabolism and vascular endothelial function in elderly patients with acute cerebral infarction. Methods: A total of 168 elderly patients with acute cerebral infarction treated in The First Affiliated Hospital of Nanchang University, China from January 2016 to January 2018 were selected. The patients were divided into a control group and an observation group using random number method, n=84. Patients in the observation group were given comprehensive cerebral protection treatment, and patients in the control group were treated with conventional standardized treatments. The changes of cerebral oxygen metabolism, hemorheology and vascular endothelial function before and after treatment were compared between the two groups. Results: After treatment, oxygen content in arteries and internal jugular veins (Da-vO2), ofoxygen uptake fraction (OEF), Oxygen saturation (SpO2), nitric oxide (NO) were increased in both groups in comparison to before treatment, jugular venous oxygen saturation (SjvO2), brain oxygen uptake rate (ERO2), endothelin (ET), intracranial pressure (ICP), whole blood viscosity, plasma viscosity, reduced viscosity of whole blood, and hematocrit were decreased. However, the changes in the observation group were larger than those in the control group, the difference was statistically significant (P

• Cerebral oxygen metabolism was evaluated in the rat cerebral hypoperfusion model. • Elevated oxygen extraction fraction was observed in broad areas in the acute phase. • Decreased oxygen metabolism was persistent mainly in the anterior cerebral artery area. • Astrocyte activation in the cortical area was prominent in both phases. • White matter rarefaction and impairment of working memory in the chronic phase were found. This study was aimed at evaluating the regional changes in the cerebral metabolic rate of oxygen (CMRO 2) in relation to the cerebral blood flow (CBF) in the bilateral common carotid artery occlusion (BCAO) rat model. Ligation of the bilateral common carotid arteries (or a sham operation in control animals) was performed in 10-week-old male Wistar rats. O-15 PET images were acquired in the subacute phase (1 week after the surgery) and chronic phase (6 weeks after the surgery) with the animals under anesthesia, using a small-animal PET system and the O-15 gas steady-state inhalation method with arterial blood sampling developed in our previous study. Histopathological staining by Klüver-Barrera method and immunocytochemistry staining by glial fibrillary acidic protein were performed. Cognitive function was tested by using the apparatus of Y-maze. Significantly lower CBF and higher oxygen extraction fraction were observed in broad areas of the cerebrum in the subacute phase in the BCAO rats, with recovery in the chronic phase. A stable decrease of the CMRO 2 in the subacute phase of arterial occlusion and later was observed in the BCAO rat model, mainly in the anterior cerebral artery territory. Atrophy and rarefaction of corpus callosum were found in the BCAO in the chronic phase. Activity of astrocytes in the BCAO was prominent in the both phases. Working memory was impaired in the BCAO in the chronic phase. Regional changes in cerebral perfusion and oxygen metabolism in the subacute and chronic phases of arterial occlusion were clarified in a rat model of BCAO by quantitative O-15 PET based on the steady-state method. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of transcutaneous electrical acupoint stimulation (TEAS) on cerebral oxygen metabolism,postoperative cognitive function and analgesic effect in elderly patients undergoing hip replacement. Methods: 91 patients who underwent hip replacement in our hospital from January 2016 to July 2018 were selected as the research subjects. The subjects were randomly divided into control group (n=45) and research group (n=46) according to the digital table method. The control group was given routine anesthesia and the research group was given TEAS on the basis of the control group. The cerebral oxygen metabolism, postoperative cognitive function and analgesic effect were compared between the two groups, and the occurrence of adverse reactions in the two groups was recorded. Results: The venous blood oxygen content (CjvO2) increased at 20 minutes after the onset of hypotension (T1), 40 minutes after the onset of hypotension (T2) and 20 minutes after the cessation of hypotension (T3), and the research group was higher than the control group (P<0.05). The cerebral arterial venous oxygen content difference (Da-CjvO2) and cerebral extraction rate of oxygen (CERO2) of the two groups was lower than that at T0 time points, and that of the research group was lower than that of the control group (P<0.05). The Mini-Mental state examine (MMSE) scores at 72 hours after operation in both groups were lower than those at 24 hours before operation, but those in the research group were higher than those in the control group (P<0.05). Postoperative cognitive dysfunction(POCD) in the research group was lower than that in the control group (P<0.05). Compared with those before operation, the visual analogue scale (VAS) scores of the two groups increased at 8 hours, 24 hours and 48 hours after operation (P<0.05). However, the VAS scores of the research group at 8 hours, 24 hours and 48 hours after operation were lower than those of the control group (P<0.05). There was no significant difference in the total incidence of adverse reactions between the two groups (P>0.05). Conclusions: TEAS has a definite analgesic effect on elderly patients undergoing hip replacement. It can effectively improve cerebral oxygen metabolism and cognitive function, and it has a high clinical application value. [ABSTRACT FROM AUTHOR]

Objective: To study the influence of different anesthesia depths on the cerebral oxygen metabolism and stress response during general anesthesia surgery as well as the postoperative cognitive function in elderly patients. Method: Prospective study was designed, and the elderly patients undergone general anesthesia surgery in our hospital between March 2015 and March 2017 were selected and randomly divided into the three groups: group A with Narcotrend index 25-35; the group B with Narcotrend index 35-45; the group C with Narcotrend index 45- 55. Before induction (T0), during surgery (T1), at extubation (T2) and 30 min after extubation (T3), cerebral oxygen metabolism indexes arterio-venous oxygen content difference (Da-jvO2) and cerebral oxygen extraction rate as well as stress indexes norepinephrine, epinephrine, cortisol and growth hormone were measured; 1, 3, 5 and 7 d after surgery, mini-mental state examination was adopted to evaluate cognitive function, and the serum neuron-specific enolase, S100B and β amyloid 1-42 were measured. Results: At T1, T2 and T3, Da-jvO2 levels of group A and group B were obviously higher than those of group C whereas cerebral oxygen extraction rate levels as well as serum norepinephrine, norepinephrine, cortisol and growth hormone contents were lower than those of group C; 1, 3, 5 and 7 d after surgery, mini-mental state examination scores of group B and group C were significantly higher than those of group A, while serum neuron-specific enolase, S100B and β amyloid 1-42 contents of group B and group C were significantly lower than those of group A. Conclusion: The anesthesia depth with Narcotrend index 35-45 can control cerebral oxygen metabolism, reduce stress response and improve postoperative cognitive function. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of sevoflurane and propofol on hemodynamics, cerebral oxygen metabolism and analgesia during maintenance of paediatric anaesthesia. Methods: A total of 134 paediatric patients undergoing surgical anaesthesia in the General Surgery Department of Children's Hospital of Nanjing Medical University from July 2016 to July 2017 were anesthetised with propofol (control group, n = 67) or sevoflurane (study group, n = 67). The hemodynamics, cerebral oxygen metabolism index, analgesic effect and adverse reaction were determined in both groups and compared. Results: Heart rate (HR) differed significantly between the two groups in the A3 stage (p < 0.05). Systolic and diastolic blood pressures (SBP and DBP) were statistically different between the two groups in the A2 stage (p < 0.05). In the A2 and A3 stages, jugular venous blood oxygen saturation (SjvO2) was higher in the study group, and the differential between arterial oxygen and jugular venous blood oxygen saturation (Da-jvO2) and cerebral oxygen extraction rate (CERO2) were lower than corresponding values in the control group (p < 0.05). In both groups of patients, SjvO2 in A3 stage was lower than that in A2 stage (p < 0.05), and Da-jvO2 and CERO2 were higher in A3 stage than those in A2 stage (p < 0.05). Conclusion: Sevoflurane and propofol maintain balance in cerebral oxygen metabolism and hemodynamic stability when used as paediatric anaesthesia. However, sevoflurane is superior to propofol in protecting the brain tissue of children from damage. [ABSTRACT FROM AUTHOR]

Background: To investigate the effect of edaravone on the postoperative cognitive function and cerebral oxygen metabolism in elderly patients with spinal surgery. Methods: One hundred and twenty patients undergoing elective thoracolumbar surgery, aged 65–75 years, were randomly divided into two groups: edaravone group (Group E, n=60) and control group (Group C, n=60). At 30 minutes before anesthesia, the patients in Group E received 0.5 mg/kg edaravone, while the patients in Group C received the same volume of normal saline. Mini-mental state examination (MMSE) was performed at 1 day before the operation, and 1 day and 4 days after the operation. Results: A total of 26 patients in both groups had postoperative cognitive dysfunction. Compared with the preoperative MMSE scores, postoperative MMSE scores decreased significantly in both groups (p

Objective: To investigate the effect of remifentanil on the cognitive function and cerebral oxygen metabolism in patients with intracranial aneurysms after acute hypervolemic hemodilution（AHH）. Methods: A total of 92 patients, who underwent intracranial aneurysm clipping in Suining Central Hospital from May 2015 to December 2016, were selected and were randomly divided into study group（n=46） and control group（n=46）. The study group was treated with remifentanil, and the control group was treated with nitroglycerin. Mean arterial pressure（MAP） and heart rate（HR） of the patients in the two groups before AHH（T0）, after AHH（T1）, before lowering blood pressure（T2）, 30 min after lowering blood pressure（T3）, 5 min after aneurysm clipping（T4） were recorded. The arterial and venous blood oxygen saturation（SAO2, SjvO2）, arterial oxygen partial pressure（PAO2）, and arterial oxygen partial pressure（PjvO2）were counted at T2-T4 time points. The arterial oxygen content（CAO2）, internal jugular vein oxygen content（CjvO2）, arterial internal jugular bulb oxygen deficit（Da-jvO2）, arterial bulb lactate difference（VADL） and brain oxygen uptake rate（CERO2） were calculated.The cognitive functions of two groups were evaluated by the Mini Mental State Scale（MMSE） before operation, 3 d and 7 d after operation. Results: Compared with the T2 time point, the MAP was decreased significantly in the two groups at T3 and T4 time points（P<0.05）. The HR in the control group was increased significantly, but the HR in the study group was decreased significantly（P<0.05）. The SaO2 of the two groups was 100%. At T3 and T4 time points, SjvO2 and CjvO2 in the study group were significantly higher than those at T2 time point,which was higher than those in the control group, and the differences were statistically significant（P<0.05）; the Da-jvO2 and CERO2 were significantly lower than at T2 time point, which were lower than those in the control group,and the differences were statistically significant（P<0.05）. There were no significant differences in the PaO2, CaO2, PjvO2, VADL between the two groups（P>0.05）.There were no significant differences in MMSE scores between the two groups before operation, 3 d and 7 d after operation（P>0.05）; the MMSE scores of the two groups before operation and 7 d after operation were higher than those of the two groups 3 d after operation（P<0.05）. Conclusion: Remifentanil in the acute hypervolemic hemodilution with intracranial aneurysm clipping can effectively maintain the stability of hemodynamics of patients, at the same time,the rate of cerebral oxygen metabolism can be effectively controlled. Compared with nitroglycerin, remifentanil is superior in acute hypervolemic hemodilution, but there is no obvious improvement in cognitive function. [ABSTRACT FROM AUTHOR]

Objective: To investigate the influence of ulinastatin on the cerebral oxygen metabolism inflammatory factors and renal function of patients with severe craniocerebral injury. Methods: 98 cases of SCCI patients were randomly divided into the control group (n=49) and the observation group (n=49). The control group was given routine symptomatic treatment, while the observation group was treated with ulinastatin on the basis of control group. The cerebral oxygen metabolism (SjvO2, CaO2, A-vDO2 and CERO2), inflammatory factors (TNF-α, IL-6 and IL-10) and renal function (BUN and Cr) were compared between the two groups before and at 3 d, 7 d after treatment. Results: No significant difference of SjvO2, CaO2, A-vDO2, CERO2, TNF-α, IL-6, IL-10, BUN and Cr levels between the two groups before treatment (P>0.05). At 3d, 7d after treatment, the levels of SjvO2, CaO2 and IL-10 in the observation group were significantly higher than those in the control group, the levels of A-vDO2, CERO2, TNF-α, IL-6, BUN and Cr were significantly lower than those in the control group(P<0.05). Conclusion: Ulinastatin could effectively improve the cerebral oxygen metabolismand renal function, relieve the inflammatory response in the treatment of SCCI. [ABSTRACT FROM AUTHOR]

Summary Background To investigate the effect of edaravone on the postoperative cognitive function and cerebral oxygen metabolism in elderly patients with spinal surgery. Methods One hundred and twenty patients undergoing elective thoracolumbar surgery, aged 65–75 years, were randomly divided into two groups: edaravone group (Group E, n = 60) and control group (Group C, n = 60). At 30 minutes before anesthesia, the patients in Group E received 0.5 mg/kg edaravone, while the patients in Group C received the same volume of normal saline. Mini-mental state examination (MMSE) was performed at 1 day before the operation, and 1 day and 4 days after the operation. Results A total of 26 patients in both groups had postoperative cognitive dysfunction. Compared with the preoperative MMSE scores, postoperative MMSE scores decreased significantly in both groups ( p < 0.05) and the reduction in the 1-day postoperative MMSE scores in Group E was remarkably lower than that in Group C ( p < 0.05). Conclusion Edaravone can reduce the incidence of early postoperative cognitive dysfunction in elderly patients. The underlying mechanism may be related to improvement of cerebral oxygen metabolism. [ABSTRACT FROM AUTHOR]

Objective: To explore the continuous sedation and brain protective effect of dexmedetomidine severe craniocerebral injury patients after operation. Methods: A total of 90 cases of severe craniocerebral injury patients treated in hospital from July 2013 to July 2015 were randomly divided into observation group 45 cases and control group 45 cases, patients in the control group were given fentanyl general anesthesia, while the patients in the observation group were given Dex anesthesia. The changes of S-100β protein, MAP,PCO2, SpO2, HR and cerebral oxygen metabolism indexes at different time points were compared. Results: There were no significant differences in Ca-jv DO2, CERO2 and Sjv O2 between the two groups before and after operation(P>0.05). From T1~T4, the MAP and HR significantly decreased in observation group, and compared with T0 the difference with statistically significant(P < 0.05), and the MAP and HR in observation group were significantly lower than those in the control group in same period(P < 0.05). From T1~T4, serum S-100βincreased in the two groups, which was significantly higher than that of T0(P < 0.05), and the observation group was significantly lower than that of the control group in same period(P < 0.05). Conclusion: Postoperative continuous intravenous infusion of dexmedetomidine had sedative and analgesic effects for severe craniocerebral injury patients, and in a certain extent protected the brain tissue. [ABSTRACT FROM AUTHOR]

Calibrated blood oxygenation level dependent (BOLD) imaging is a multimodal functional MRI technique designed to estimate changes in cerebral oxygen metabolism from measured changes in cerebral blood flow and the BOLD signal. This technique addresses fundamental ambiguities associated with quantitative BOLD signal analysis; however, its dependence on biophysical modeling creates uncertainty in the resulting oxygen metabolism estimates. In this work, we developed a Bayesian approach to estimating the oxygen metabolism response to a neural stimulus and used it to examine the uncertainty that arises in calibrated BOLD estimation due to the presence of unmeasured model parameters. We applied our approach to estimate the CMRO 2 response to a visual task using the traditional hypercapnia calibration experiment as well as to estimate the metabolic response to both a visual task and hypercapnia using the measurement of baseline apparent R 2 ′ as a calibration technique. Further, in order to examine the effects of cerebral spinal fluid (CSF) signal contamination on the measurement of apparent R 2 ′, we examined the effects of measuring this parameter with and without CSF-nulling. We found that the two calibration techniques provided consistent estimates of the metabolic response on average, with a median R 2 ′-based estimate of the metabolic response to CO 2 of 1.4%, and R 2 ′- and hypercapnia-calibrated estimates of the visual response of 27% and 24%, respectively. However, these estimates were sensitive to different sources of estimation uncertainty. The R 2 ′-calibrated estimate was highly sensitive to CSF contamination and to uncertainty in unmeasured model parameters describing flow-volume coupling, capillary bed characteristics, and the iso-susceptibility saturation of blood. The hypercapnia-calibrated estimate was relatively insensitive to these parameters but highly sensitive to the assumed metabolic response to CO 2 . [ABSTRACT FROM AUTHOR]

Low doses of the carbonic anhydrase inhibitor acetazolamide provides accelerated acclimatization to high-altitude hypoxia and prevention of cerebral and other symptoms of acute mountain sickness. We previously observed increases in cerebral O2 metabolism (CMRO2) during hypoxia. In this study, we investigate whether low-dose oral acetazolamide (250 mg) reduces this elevated CMRO2 and in turn might improve cerebral tissue oxygenation (PtiO2) during acute hypoxia. Six normal human subjects were exposed to 6 h of normobaric hypoxia with and without acetazolamide prophylaxis. We determined CMRO2 and cerebral PtiO2 from MRI measurements of cerebral blood flow (CBF) and cerebral venous O2 saturation. During normoxia, low-dose acetazolamide resulted in no significant change in CBF, CMRO2, or PtiO2. During hypoxia, we observed increases in CBF [48.5 (SD 12.4) (normoxia) to 65.5 (20.4) ml·100 ml−1·min−1 (hypoxia), P < 0.05] and CMRO2 [1.54 (0.19) to 1.79 (0.25) μmol·ml−1·min−1, P < 0.05] and a dramatic decline in PtiO2 [25.0 to 11.4 (2.7) mmHg, P < 0.05]. Acetazolamide prophylaxis mitigated these rises in CBF [53.7 (20.7) ml·100 ml−1·min−1 (hypoxia + acetazolamide)] and CMRO2 [1.41 (0.09) μmol·ml−1·min−1 (hypoxia + acetazolamide)] associated with acute hypoxia but also reduced O2 delivery [6.92 (1.45) (hypoxia) to 5.60 (1.14) mmol/min (hypoxia + acetazolamide), P < 0.05]. The net effect was improved cerebral tissue PtiO2 during acute hypoxia [11.4 (2.7) (hypoxia) to 16.5 (3.0) mmHg (hypoxia + acetazolamide), P < 0.05]. In addition to its renal effect, low-dose acetazolamide is effective at the capillary endothelium, and we hypothesize that local interruption in cerebral CO2 excretion accounts for the improvements in CMRO2 and ultimately in cerebral tissue oxygenation during hypoxia. This study suggests a potentially pivotal role of cerebral CO2 and pH in modulating CMRO2 and PtiO2 during acute hypoxia. [ABSTRACT FROM AUTHOR]

Because oxidative metabolism is the primary form of energy production in the brain, the amount of oxygen consumed by the brain, denoted by a physiological parameter termed cerebral metabolic rate of oxygen (CMRO 2 ), represents a key marker for tissue viability and brain function. Quantitative assessment of cerebral oxygen metabolism in the neonate may provide an important marker in better understanding normal brain development and in making diagnosis and treatment decisions in neonatal brain injuries. Measurement of CMRO 2 in humans has been a challenging task, particularly in neonates. Recently, several promising techniques have been proposed to quantify neonatal CMRO 2 and the purpose of this article is to provide a technical review of these techniques. Among these, we will focus the review on the NIRS optic based methods and MRI methods which are non-invasive, have been applied in normal and sick newborns and show great potentials. Potential clinical prospects of CMRO 2 techniques are discussed in the context of their advantages, challenges and limitations. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the effects of ulinastatin on cerebral oxygen metabolism and C-reactive protein (CRP) levels in patients with severe traumatic brain injury (sTBI). A total of 92 patients with sTBI, admitted to the First Affiliated Hospital of Xinxiang Medical University (Xinxiang, China), were randomly divided into control and observation groups. The control group received conventional therapy plus a placebo (0.9% sodium chloride), while the observation group were administered conventional therapy plus 200,000 units ulinastatin via intravenous injection twice a day for seven days. Arterial and jugular venous blood was collected for blood gas analysis. The jugular venous blood lactate (JVBL), jugular venous bulb oxygen saturation (SjvO2), arteriovenous oxygen content difference (AVDO2) and cerebral extraction of oxygen (CEO2) levels were measured on day 1, 3, 5 and 7, as well as the level of CRP in the peripheral blood. In the control group, the level of JVBL decreased as compared with the level at day 1, however, no statistically significant differences were observed (P>0.05). By contrast, the observation group exhibited a significant reduction in the level of JVBL (P<0.05), which was also significantly lower compared with the control group (P<0.05). Statistically significant differences were observed between the two groups with regard to SjvO2, AVDO2 and CEO2 on day 3, 5 and 7. The CRP levels in the two groups increased and peaked on day 3. However, the CRP level in the observation group significantly decreased on day 5 (35.27±15.18 mg/l) and day 7 (22.65±10.48 mg/l), which was lower compared with the control group (56.19±13.24 mg/l and 47.36±15.73 mg/l, respectively); statistically significant differences were observed (P<0.05). Therefore, ulinastatin effectively improved cerebral oxygen metabolism and reduced the CRP level in patients with sTBI. [ABSTRACT FROM AUTHOR]

Neural-vascular coupling (NVC) is the process by which oxygen and nutrients are delivered to metabolically active neurons by blood vessels. Murine models of NVC disruption have revealed its critical role in healthy neural function. We hypothesized that, in humans, aging exerts detrimental effects upon the integrity of the neural-glial-vascular system that underlies NVC. To test this hypothesis, calibrated functional magnetic resonance imaging (cfMRI) was used to characterize age-related changes in cerebral blood flow (CBF) and oxygen metabolism during visual cortex stimulation. Thirty-three younger and 27 older participants underwent cfMRI scanning during both an attention-controlled visual stimulation task and a hypercapnia paradigm used to calibrate the blood-oxygen-level-dependent signal. Measurement of stimulus-evoked blood flow and oxygen metabolism permitted calculation of the NVC ratio to assess the integrity of neural-vascular communication. Consistent with our hypothesis, we observed monotonic NVC ratio increases with increasing visual stimulation frequency in younger adults but not in older adults. Age-related changes in stimulus-evoked cerebrovascular and neurometabolic signal could not fully explain this disruption; increases in stimulus-evoked neurometabolic activity elicited corresponding increases in stimulus-evoked CBF in younger but not in older adults. These results implicate age-related, demand-dependent failures of the neural-glial-vascular structures that comprise the NVC system., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)