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Objectives: Aortic stenosis (AS) is characterized by obstruction of blood outflow from the left ventricle, which can impair target organ perfusion such as the brain. We hypothesized that hemodynamic changes in AS may lead to dysfunction of cerebral blood flow regulatory mechanisms. The aim of our study was to evaluate neurovascular coupling in patients with AS by Transcranial Doppler ultrasonography. Methods: Neurovascular coupling was assessed using visually evoked cerebral blood flow velocity responses (VEFR) calculated as relative blood flow velocity changes in the posterior cerebral artery upon visual stimulation. We analyzed peak systolic, mean and end diastolic VEFR in 54 patients with severe AS and 43 controls in 10 consecutive cycles of visual stimulation. Repeated‐measures ANOVA test was used to compare cerebral hemodynamic data by group. Results: Patients with AS had significantly higher peak systolic (12.9% ± 5.6% and 10.5% ± 4.5%; p =.009) and mean VEFR (14.4% ± 5.8% and 12.2% ± 4.9%; p =.021) compared to controls, whereas only a tendency for higher end diastolic VEFR was observed (16.7% ± 6.9% and 14.4% ± 6.2%; p =.061). Conclusion: We have shown for the first time that patients with severe AS exhibit higher VEFR than controls indicating dysregulation of neurovascular coupling, which can be one of the factors contributing to development of cognitive decline. [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical effect of butylphthalide combined with urinary kallidinogenase in the treatment of chronic cerebral circulatory insufficiency (CCCI). Methods: A total of 102 CCCI patients admitted to our hospital from October 2020 to December 2021 were retrospectively enrolled in this study. According to the different therapeutic strategy, the patients were divided into combined group (treated with butylphthalide combined with urinary kallidinogenase, n = 51) and butylphthalide group (treated with butylphthalide, n = 51). Blood flow velocity and cerebral blood flow perfusion before and after treatment between the two groups were compared. The clinical efficacy and adverse events of the two groups were analyzed. Results: After treatment, the effective rate of the combined group was significantly higher than the butylphthalide group (p =.015). Before treatment, the blood flow velocity of middle cerebral artery (MCA), vertebral artery (VA), basilar artery (BA) were comparable (p >.05, respectively), while after treatment, the blood flow velocity of MCA, VA, and BA in combined group were faster than those in butylphthalide group (p <.001, respectively). Before treatment, the relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), relative mean transmit time (rMTT) of the two groups were comparable (p >.05, respectively). After treatment, rCBF and rCBV in combined group were higher than those in butylphthalide group (p <.001, respectively), and rMTT in combined group was lower than that in butylphthalide group (p =.001). The rate of adverse events in the two groups were comparable (p =.558). Conclusion: Butylphthalide combined with urinary kallidinogenase can improve the clinical symptoms of CCCI patients, and the effect is promising, which is worthy of clinical application. [ABSTRACT FROM AUTHOR]

Objective: Yangxue Qingnao granules (YXQNG), which translates to granules that tonify the blood and clear liver heat, are widely available in China for the treatment of Chronic Cerebral Circulation Insufficiency (CCCI). This systematic review aimed to evaluate the effectiveness and safety of YXQNG in treating CCCI. Methods: PubMed, the Cochrane Central Register of Controlled Trials, Embase, the Chinese National Knowledge Infrastructure, and the Wanfang Database were searched from their inception to February 2019. Randomized controlled trials of YXQNG used alone or in combination with other drugs against a placebo, with no intervention or used with other drugs in CCCI patients were identified. The reviewers identified studies, extracted data, and assessed the quality of the evidence, independently and in duplicate. The Cochrane risk of bias assessment tool was used for quality assessment. Results: A total of 31 RCTs and 2,877 patients were selected. The meta‐analysis indicated that the ratio between the combined RR of the total effective rate and the 95% confidential interval (95% CI) was 1.21 (1.17, 1.26). The combined MD of transcranial Doppler (TCD) detecting carotid artery, vertebral artery, and basilar artery blood flows (95% CI), respectively, were 8.84 (5.83, 11.85), 4.72 (3.71, 5.73), and 3.89 (3.03, 4.76). The combined MD of plasma viscosity and fibrinogen, respectively, were −0.35 (−0.40, −0.30) and −0.81 (−1.12, −0.50). Serious adverse effects were not reported in all the included trials. Conclusion: This systematic review revealed that YXQNG could increase cerebral blood flow in patients with CCCI and improve their symptoms, with no serious adverse effects. Since the literature reviewed was affected by factors such as lower quality of the included studies, the systematic evaluation's conclusion is not very reliable. Thus, more rigorously designed trials are needed. [ABSTRACT FROM AUTHOR]

Background Neuroimaging studies can shed light on the neurobiological underpinnings of autism spectrum disorders ( ASD). Studies of the resting brain have shown both altered baseline metabolism from PET/ SPECT and altered functional connectivity ( FC) of intrinsic brain networks based on resting-state fMRI. To date, however, no study has investigated these two physiological parameters of resting brain function jointly, or explored the relationship between these measures and ASD symptom severity. Methods Here, we used pseudo-continuous arterial spin labeling with 3D background-suppressed GRASE to assess resting cerebral blood flow ( CBF) and FC in 17 youth with ASD and 22 matched typically developing ( TD) children. Results A pattern of altered resting perfusion was found in ASD versus TD children including frontotemporal hyperperfusion and hypoperfusion in the dorsal anterior cingulate cortex. We found increased local FC in the anterior module of the default mode network ( DMN) accompanied by decreased CBF in the same area. In our cohort, both alterations were associated with greater social impairments as assessed with the Social Responsiveness Scale ( SRS-total T scores). While FC was correlated with CBF in TD children, this association between FC and baseline perfusion was disrupted in children with ASD. Furthermore, there was reduced long-range FC between anterior and posterior modules of the DMN in children with ASD. Conclusion Taken together, the findings of this study - the first to jointly assess resting CBF and FC in ASD - highlight new avenues for identifying novel imaging markers of ASD symptomatology. [ABSTRACT FROM AUTHOR]

Background and Purpose Cerebrovascular reactivity ( CVR), measures the ability of the cerebrovasculature to respond to vasoactive stimuli such as CO2. CVR is often expressed as the ratio of cerebral blood flow change to CO2 change. We examine several factors affecting this measurement: blood pressure, stimulus pattern, response analysis and subject position. Methods Step and ramp increases in CO2 were implemented in nine subjects, seated and supine. Middle cerebral artery blood flow velocity ( MCAv), and mean arterial pressure ( MAP) were determined breath-by-breath. Cerebrovascular conductance ( MCAc) was estimated as MCAv/ MAP. CVR was calculated from both the relative and absolute measures of MCAc and MCAv responses. Results MAP increased with CO2 in some subjects so that relative CVR calculated from conductance responses were less than those calculated from CVR calculated from velocity responses. CVR measured from step responses were affected by the response dynamics, and were less than those calculated from CVR measured from ramp responses. Subject position did not affect CVR. Conclusions (1) MAP increases with CO2 and acts as a confounding factor for CVR measurement; (2) CVR depends on the stimulus pattern used; (3) CVR did not differ from the sitting versus supine in these experiments; (4) CVR calculated from absolute changes of MCAv was less than that calculated from relative changes. [ABSTRACT FROM AUTHOR]

Background The day-to-day causes of stress are called daily hassles. Daily hassles are correlated with ill health. Biofeedback (BF) is one of the tools used for acquiring stress-coping skills. However, the anatomical correlates of the effects of BF with long training periods remain unclear. In this study, we aimed to investigate this. Methods Participants were assigned randomly to two groups: the intervention group and the control group. Participants in the intervention group performed a biofeedback training (BFT) task (a combination task for heart rate and cerebral blood flow control) every day, for about 5 min once a day. The study outcomes included MRI, psychological tests (e.g., Positive and Negative Affect Schedule, Center for Epidemiologic Studies Depression Scale, and Brief Job Stress Questionnaire), and a stress marker (salivary cortisol levels) before (day 0) and after (day 28) the intervention. Results We observed significant improvements in the psychological test scores and salivary cortisol levels in the intervention group compared to the control group. Furthermore, voxel-based morphometric analysis revealed that compared to the control group, the intervention group had significantly increased regional gray matter (GM) volume in the right lateral orbitofrontal cortex, which is an anatomical cluster that includes mainly the left hippocampus, and the left subgenual anterior cingulate cortex. The GM regions are associated with the stress response, and, in general, these regions seem to be the most sensitive to the detrimental effects of stress. Conclusions Our findings suggest that our BFT is effective against the GM structures vulnerable to stress. [ABSTRACT FROM AUTHOR]

Background: Complex blood flow patterns are a well‐known phenomenon at the carotid bifurcation. However, unlike for the descending aorta, a blood flow reversal has not been detected at the carotid bifurcation, so far. Methods: In 17 subjects, flow patterns with focus on blood flow reversal were examined at the carotid bifurcation with vector flow imaging. Results: We found a blood flow reversal from the external carotid artery (ECA) into the internal carotid artery (ICA) in 13 of 25 (52%) carotid bifurcations. The blood flow reversal ranged 5.3 ± 1.7 mm (range 2.6–8.3 mm) distally to the beginning of the ECA and lasted 105 ± 59 ms (range 32–225 ms). The mean peak systolic velocity within the blood flow reversal was 12.5 ± 4.6 cm/s (range 5–18 cm/s). Conclusion: A blood flow reversal from the ECA into the ICA during the systole is a frequent finding at the carotid bifurcation. Considering ischemic stroke, retrograde embolism from plaques in the proximal ECA into the ICA might play a role. A blood flow reversal from the external into the internal carotid artery (ICA) during the systole is a frequent finding at the carotid bifurcation. Considering ischemic stroke, retrograde embolism from plaques in the proximal external carotid artery into the ICA might play a role. [ABSTRACT FROM AUTHOR]