Neurological complications of systemic hypertension

Recurrence of ischaemic stroke using epidemiology and neuroimaging: A retrospective study in Gansu Province

Objectives

This retrospective study aimed to investigate the clinical and imaging recurrence of ischaemic stroke (IS), and to evaluate the risk factors for recurrence. A combined clinical and imaging diagnostic model is important for stroke prevention and management.

Methods and materials

In accordance with the inclusion and exclusion criteria, we retrospectively analysed consecutively hospitalised patients with acute IS at the Affiliated Hospital of Gansu University of Chinese Medicine. Based on the epidemiological and imaging results, stroke episodes were divided into four categories: clinical first episode (CFE), clinical recurrence (CR), imaging first episode (IFE), and imaging recurrence (IR). Based on the above categories and clinical practice, a joint diagnostic system for IS was established for the first time, including the following five types: IFE, IR, CFE and IFE, CFE and IR, and CR and IR. A binomial logistic regression analysis was conducted to determine the factors which contributed to CR and IR.

Results

In total, 280 patients were assessed. The CR rate was 22.9% (64/280) and the IR rate was 62.9% (176/280). The only predictor of CR was hypertension (P = 0.019, odds ratio [OR] = 3.041, 95% confidence interval [95%CI] = 1.200-7.704). The factors of hypertension (P < 0.001, OR = 3.551, 95%CI = 1.781-7.080) and age (P = 0.031, OR = 1.031, 95%CI = 1.003-1.060) were predictors of IR.

Conclusion

The IR rates for IS were three times higher than the CR rates. The key to preventing IR and CR in IS was the management of blood pressure. Neuroimaging examinations were important for the early detection of IFE and IR in elderly patients with hypertension. A combined clinical imaging diagnostic model was developed for the first time.

Endothelial Cells and the Cerebral Circulation

Endothelial cells form the innermost layer of all blood vessels and are the only vascular component that remains throughout all vascular segments. The cerebral vasculature has several unique properties not found in the peripheral circulation; this requires that the cerebral endothelium be considered as a unique entity. Cerebral endothelial cells perform several functions vital for brain health. The cerebral vasculature is responsible for protecting the brain from external threats carried in the blood. The endothelial cells are central to this requirement as they form the basis of the blood-brain barrier. The endothelium also regulates fibrinolysis, thrombosis, platelet activation, vascular permeability, metabolism, catabolism, inflammation, and white cell trafficking. Endothelial cells regulate the changes in vascular structure caused by angiogenesis and artery remodeling. Further, the endothelium contributes to vascular tone, allowing proper perfusion of the brain which has high energy demands and no energy stores. In this article, we discuss the basic anatomy and physiology of the cerebral endothelium. Where appropriate, we discuss the detrimental effects of high blood pressure on the cerebral endothelium and the contribution of cerebrovascular disease endothelial dysfunction and dementia. © 2022 American Physiological Society. Compr Physiol 12:3449-3508, 2022.

Short-Term Pharmacological Induction of Arterial Stiffness and Hypertension with Angiotensin II Does Not Affect Learning and Memory and Cerebral Amyloid Load in Two Murine Models of Alzheimer's Disease

Given the unprecedented rise in the world's population, the prevalence of prominent age-related disorders, like cardiovascular disease and dementia, will further increase. Recent experimental and epidemiological evidence suggests a mechanistic overlap between cardiovascular disease and dementia with a specific focus on the linkage between arterial stiffness, a strong independent predictor of cardiovascular disease, and/or hypertension with Alzheimer's disease. In the present study, we investigated whether pharmacological induction of arterial stiffness and hypertension with angiotensin II (1 µg·kg-1·min-1 for 28 days via an osmotic minipump) impairs the progression of Alzheimer's disease in two mouse models (hAPP23+/- and hAPPswe/PSEN1dE9 mice). Our results show increased arterial stiffness in vivo and hypertension in addition to cardiac hypertrophy after angiotensin II treatment. However, visuospatial learning and memory and pathological cerebral amyloid load in both Alzheimer's disease mouse models were not further impaired. It is likely that the 28-day treatment period with angiotensin II was too short to observe additional effects on cognition and cerebral pathology.