Shifting concepts of autoregulation: Commentary to 'Static autoregulation in humans'.

Advances in imaging techniques have transformed our understanding of cerebral autoregulation. Older imaging techniques provided measurements of cerebral blood flow (CBF) that reflected the average CBF over a window of 10-20 minutes. A key finding, dating back to 1959, was that CBF remained more or less stable over a remarkably wide range of changes in blood pressure.

Long-Term Longitudinal Course of Cognitive and Motor Symptoms in Patients With Cerebral Small Vessel Disease.

Background And Objectives: Patients with cerebral small vessel disease (SVD) show a heterogenous clinical course. The aim of the current study was to investigate the longitudinal course of cognitive and motor function in patients who developed parkinsonism, dementia, both, or none.

Methods: Participants were from the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort study, a prospective cohort of patients with SVD.

Study protocol for the Heads-Up trial: a phase II randomized controlled trial investigating head-up tilt sleeping to alleviate orthostatic intolerance in Parkinson's Disease and parkinsonism.

Background: In persons with Parkinson's Disease (PD) or certain forms of atypical parkinsonism, orthostatic hypotension is common and disabling, yet often underrecognized and undertreated. About half of affected individuals also exhibit supine hypertension. This common co-occurrence of both orthostatic hypotension and supine hypertension complicates pharmacological treatments as the treatment of the one can aggravate the other.

Cerebrovascular CO reactivity and dynamic cerebral autoregulation through the eighth decade of life and their implications for cognitive decline.

Aging is accompanied by a decrease in cerebral blood flow (CBF), especially in the presence of preclinical cognitive decline. The role of cerebrovascular physiology including regulatory mechanisms of CBF in processes underlying aging and subclinical cognitive decline is, however, not fully understood. We explored changes in cerebrovascular CO reactivity and dynamic cerebral autoregulation (dCA) through the eighth decade of life, and their relation with early cognitive decline.

Antihypertensives in dementia: Good or bad for the brain?

We discuss the current evidence for both benefit and harm of antihypertensive treatment in people with dementia. We conclude that there is a lack of evidence to support the claim that there is an increased risk of cerebral hypoperfusion with antihypertensive treatment in dementia, and that there is growing evidence which refutes this claim.

Transfer function analysis of dynamic cerebral autoregulation: A CARNet white paper 2022 update.

Cerebral autoregulation (CA) refers to the control of cerebral tissue blood flow (CBF) in response to changes in perfusion pressure. Due to the challenges of measuring intracranial pressure, CA is often described as the relationship between mean arterial pressure (MAP) and CBF. Dynamic CA (dCA) can be assessed using multiple techniques, with transfer function analysis (TFA) being the most common.

Hemodynamic and structural brain measures in high and low sedentary older adults.

Due to its cardiovascular effects sedentary behaviour might impact cerebrovascular function in the long term, affecting cerebrovascular regulatory mechanisms and perfusion levels. Consequently this could underly potential structural brain abnormalities associated with cognitive decline. We therefore assessed the association between sedentary behaviour and brain measures of cerebrovascular perfusion and structural abnormalities in community-dwelling older adults.

Transient cerebral blood flow responses during microgravity.

Purpose: A number of studies has well described central cardiovascular changes caused by changing gravity levels as they occur e.g. during parabolic flight.

Diagnostic accuracy of office blood pressure compared to home blood pressure in patients with mild cognitive impairment and dementia.

Background: Hypertension and cognitive impairment often coexist in older people. Office blood pressure measurement is a poor indicator for diagnosing hypertension in the general population. However, its diagnostic accuracy has not been substantially studied in patients with cognitive impairment.

Improved Cerebrospinal Fluid-Based Discrimination between Alzheimer's Disease Patients and Controls after Correction for Ventricular Volumes.

Cerebrospinal fluid (CSF) biomarkers may support the diagnosis of Alzheimer's disease (AD). We studied if the diagnostic power of AD CSF biomarker concentrations, i.e.

Measuring prefrontal cortical activity during dual task walking in patients with Parkinson's disease: feasibility of using a new portable fNIRS device.

Background: Many patients with Parkinson's disease (PD) have difficulties in performing a second task during walking (i.e., dual task walking).

Angiotensin II, hypertension and angiotensin II receptor antagonism: Roles in the behavioural and brain pathology of a mouse model of Alzheimer's disease.

Elevated angiotensin II causes hypertension and contributes to Alzheimer's disease by affecting cerebral blood flow. Angiotensin II receptor blockers may provide candidates to reduce (vascular) risk factors for Alzheimer's disease. We studied effects of two months of angiotensin II-induced hypertension on systolic blood pressure, and treatment with the angiotensin II receptor blockers, eprosartan mesylate, after one month of induced hypertension in wild-type C57bl/6j and AβPPswe/PS1ΔE9 (AβPP/PS1/Alzheimer's disease) mice.

Late-onset depressive symptoms increase the risk of dementia in small vessel disease.

Objective: We prospectively investigated the role of depressive symptoms (DS) on all-cause dementia in a population with small vessel disease (SVD), considering onset age of DS and cognitive performance.

Methods: The RUN DMC study (Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort) is a prospective cohort study among 503 older adults with SVD on MRI without dementia at baseline (2006), with a follow-up of 5 years (2012). Kaplan-Meier curves stratified for DS and dementia risk were compared using log-rank test.

The Role of the Frontal Lobe in Complex Walking Among Patients With Parkinson's Disease and Healthy Older Adults: An fNIRS Study.

Background: Gait is influenced by higher order cognitive and cortical control mechanisms. Functional near infrared spectroscopy (fNIRS) has been used to examine frontal activation during walking in healthy older adults, reporting increased oxygenated hemoglobin (HbO2) levels during dual task walking (DT), compared with usual walking.

Objective: To investigate the role of the frontal lobe during DT and obstacle negotiation, in healthy older adults and patients with Parkinson's disease (PD).

CSF d-serine concentrations are similar in Alzheimer's disease, other dementias, and elderly controls.

Cerebrospinal fluid (CSF) levels of d-serine were recently reported as a potential new biomarker for Alzheimer's disease (AD), showing a perfect distinction between AD patients and healthy controls. In this study, we aimed to confirm these results and extend these previous findings to dementia with Lewy bodies and frontotemporal dementia. d-Serine levels in CSF of 29 AD patients, 8 dementia with Lewy bodies patients, 14 frontotemporal dementia patients, and 28 nondemented controls were measured using ultra-high-performance liquid chromatography-tandem mass spectrometry.

Validation of microRNAs in Cerebrospinal Fluid as Biomarkers for Different Forms of Dementia in a Multicenter Study.

MicroRNAs (miRNAs) regulate translational inhibition of proteins, but are also detected in body fluids, including cerebrospinal fluid (CSF), where they may serve as disease-specific biomarkers. Previously, we showed differential expression of miR-146a, miR-29a, and miR-125b in the CSF of Alzheimer's disease (AD) patients versus controls. In this study, we aim to confirm these findings by using larger, independent sample cohorts of AD patients and controls from three different centers.

Hourly analysis of cerebrospinal fluid glucose shows large diurnal fluctuations.

Cerebrospinal fluid analysis is important in the diagnostics of many neurological disorders. Since the influence of food intake on the cerebrospinal fluid glucose concentration and the cerebrospinal fluid/plasma glucose ratio is largely unknown, we studied fluctuations in these parameters in healthy adult volunteers during a period of 36 h. Our observations show large physiological fluctuations of cerebrospinal fluid glucose and the cerebrospinal fluid/plasma glucose ratio, and their relation to food intake.

How measurement artifacts affect cerebral autoregulation outcomes: A technical note on transfer function analysis.

Cerebral autoregulation (CA) is the mechanism that aims to maintain adequate cerebral perfusion during changes in blood pressure (BP). Transfer function analysis (TFA), the most reported method in literature to quantify CA, shows large between-study variability in outcomes. The aim of this study is to investigate the role of measurement artifacts in this variation.

Structural network efficiency predicts conversion to dementia.

Objective: To examine whether structural network connectivity at baseline predicts incident all-cause dementia in a prospective hospital-based cohort of elderly participants with MRI evidence of small vessel disease (SVD).

Methods: A total of 436 participants from the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort (RUN DMC), a prospective hospital-based cohort of elderly without dementia with cerebral SVD, were included in 2006. During follow-up (2011-2012), dementia was diagnosed.

Transfer function analysis of dynamic cerebral autoregulation: A white paper from the International Cerebral Autoregulation Research Network.

Cerebral autoregulation is the intrinsic ability of the brain to maintain adequate cerebral perfusion in the presence of blood pressure changes. A large number of methods to assess the quality of cerebral autoregulation have been proposed over the last 30 years. However, no single method has been universally accepted as a gold standard.

The Combined Effect of Neuropsychological and Neuropathological Deficits on Instrumental Activities of Daily Living in Older Adults: a Systematic Review.

To date, studies have consistently demonstrated associations between either neuropsychological deficits or neuroanatomical changes and instrumental activities of daily living (IADL) in aging. Only a limited number of studies have evaluated morphological brain changes and neuropsychological test performance concurrently in relation to IADL in this population. As a result, it remains largely unknown whether these factors independently predict functional outcome.