Background: We used transcranial Doppler ultrasonography to examine the cerebral blood flow response to orthostatic stress in the middle and posterior cerebral circulations and to determine the effects of healthy aging on regional cerebral blood flow regulation.
Methods: Continuous simultaneous middle (MCA) and posterior (PCA) cerebral artery blood flow velocities (BFV) and mean arterial pressure (MAP) were measured in response to standing from a sitting position in 13 younger (30 +/- 7 years) and 13 older (73 +/- 4 years) healthy participants.
Results: The older participants had a significantly larger decline in MAP (-31% +/- 3 in the older and -21% +/- 2 in the younger) and a smaller increase in heart rate (HR) (15 bpm +/- 1 in the older, 24 bpm +/- 2 in the younger) during the posture change. Despite a larger decline in MAP, the older participants had a decline very similar to that of the younger participants in BFVs in both vascular territories. This was associated with a significantly larger vasodilatory response in the MCA and PCA vascular territories of the older participants. There were no regional differences of the cerebrovascular resistance and BFV responses to orthostasis in the younger participants. However, in the older participants, there was a significantly larger BFV decline and a smaller vasodilatory response in the PCA as compared to the MCA territory.
Conclusions: Healthy aging is associated with preserved cerebrovascular adaptation to orthostatic hypotension. However, in older persons, the PCA territory blood flow may be more vulnerable to reduced perfusion during orthostatic stress.
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http://dx.doi.org/10.1093/gerona/60.11.1484 | DOI Listing |
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Weill Cornell Medicine, New York City, NY, USA.
Background: Early detection of Alzheimer's disease (AD) can improve prognosis, given new anti-amyloid therapies. Both positron emission tomography (PET) and magnetic resonance (MR) imaging biomarkers are currently used (1). 48F-Fluorodeoxyglucose-PET (FDG-PET) can detect neurodegeneration-related hypometabolism but is costly and not easily accessible (2).
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Tulane University, New Orleans, LA, USA.
Background: Vascular dementia (VaD), the second most common cause of dementia, is characterized by cognitive decline due to reduced cerebral blood flow and blood-brain barrier disruption. Current evidence demonstrates that not only are VaD patients at higher risk of severe COVID-19 illness and mortality, but also that pre-existing cognitive dysfunction/dementia is associated with increased COVID-19 incidence. Conversely, SARS-CoV-2 infection alone worsens dementia-related mild cognitive impairment (MCI) and increases risk of cognitive decline, supported by similar fMRI findings demonstrating hypoperfusion.
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January 2025
The Cadre Medical Department, Guizhou Provincial People's Hospital, Guiyang, China.
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January 2025
Academy of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
Introduction: Taohong Siwu decoction (THSWD), a traditional prescription for enhancing blood circulation and eliminating blood stasis, primarily comprises peach kernel, safflower, angelica, chuanxiong, and rehmannia. Modified Taohong Siwu decoction (MTHSWD), an advanced version of THSWD, incorporates additional ingredients such as epimedium, cinnamon, and salvia miltiorrhiza. This addition serves to augment its efficacy in warming yang and promoting blood circulation.
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