Chronic kidney disease, 24-h blood pressure and small vessel diseases are independently associated with cognitive impairment in lacunar infarct patients

Regional white matter hyperintensity volume predicts persistent cognitive impairment in acute lacunar infarct patients

Background

White matter hyperintensity (WMH) is often described in acute lacunar stroke (ALS) patients. However, the specific relationship between regional WMH volume and persistent cognitive impairment remains unclear.

Methods

We enrolled patients with ALS who were hospitalized at the First Affiliated Hospital of Soochow University between January 2020 and November 2022. All patients were assessed for global cognitive function using the Montreal Cognitive Assessment (MoCA) scale at 14 ± 2 days and 6 months after the onset of ALS. Manifestations of chronic cerebral small vessel disease (CSVD) were assessed via MRI scan. The distributions of regional WMH were segmented, and their relationship with cognitive impairment was evaluated.

Results

A total of 129 patients were enrolled. Baseline frontal WMH volume (OR = 1.18, P = 0.04) was an independent risk factor for long-term cognitive impairment after ALS. Furthermore, the presence of WMH at the genu of the corpus callosum (GCC) at baseline (OR = 3.1, P = 0.033) was strongly associated with persistent cognitive decline. Multivariable logistic regression analysis showed that depression (OR = 6.252, P = 0.029), NIHSS score (OR = 1.24, P = 0.011), and albumin at admission (OR = 0.841, P = 0.032) were also important determinants of long-term cognitive impairment after ALS.

Conclusions

Our study found that WMH, especially frontal WMH volume and the presence of WMH at the GCC at baseline, independently contributed to long-term cognitive decline in ALS patients. This study provides new evidence of the clinical relationship between regional WMH volume and cognitive impairment in ALS patients.

Association between ambulatory blood pressure monitoring patterns with cognitive function and risk of dementia: a systematic review and meta-analysis

BACKGROUND

The objective of this systematic review and meta-analysis is to investigate whether nocturnal blood pressure fall, expressed by dipping patterns according to 24 h ambulatory blood pressure monitoring (ABPM), is associated with abnormal cognitive function (cognitive impairment or dementia).

METHODS

We systematically searched PubMed, Embase, and Cochrane databases to identify original articles through December 2022. We included any study with at least ten participants reporting on all-cause dementia or cognitive impairment incidence (primary outcome) or validated cognitive tests (secondary outcome) among ABPM patterns. We assessed risk of bias using Newcastle-Ottawa Quality Assessment Scale. We pooled odds ratios (OR) and standardized mean differences (SMD) using random-effect models for primary and secondary outcome, respectively.

RESULTS

In the qualitative synthesis, 28 studies examining 7595 patients were included. The pooled analysis of 18 studies showed that dippers had a 51% [OR 0.49(0.35-0.69)] lower risk of abnormal cognitive function and a 63% [OR 0.37(0.23-0.61)] lower risk of dementia alone, compared to non-dippers. Reverse dippers presented an up to sixfold higher risk [OR 6.06(3.15-11.64)] of abnormal cognitive function compared to dippers and an almost twofold higher risk [OR 1.81(1.26-2.6)] compared to non-dippers. Reverse dippers performed worse in global function neuropsychological tests compared with both dippers [SMD - 0.66(- 0.93 to - 0.39)] and non-dippers [SMD - 0.35(- 0.53 to - 0.16)].

CONCLUSION

Dysregulation of the normal circadian BP rhythm, specifically non-dipping and reverse dipping is associated with abnormal cognitive function. Further studies are required to determine potential underlying mechanisms and possible prognostic or therapeutic implications.

PROTOCOL REGISTRATION

PROSPERO database (ID: CRD42022310384).

Heterogeneity of White Matter Hyperintensity and Cognitive Impairment in Patients with Acute Lacunar Stroke

Background: The severity of white matter hyperintensity (WMH) in patients with acute lacunar stroke (ALS) may be not completely parallel to cognitive impairment. Controversies persist about the effects of WMH on cognitive dysfunction. It is vital to explore whether the association may be affected by certain factors and whether a subsequent subgroup analysis is necessary. The aim of this study was to evaluate the relationship between WMH and cognitive impairment in acute lacunar stroke patients and the possible causal factors. Methods: We continuously enrolled patients with ALS who were hospitalized at the First Affiliated Hospital of Soochow University between October 2017 and June 2022. The cognitive function of all patients was assessed by using the Montreal Cognitive Assessment (MoCA) scale 14 ± 2 days after the onset of AIS, and the results were adjusted to the education level. The MoCA scale was reevaluated at the 6-month (day 182 ± 7) follow-up by outpatient visit or video. Demographic and clinical data were collected. The manifestations of chronic cerebral small-vessel disease (CSVD), including the total Fazekas score and total CSVD burden score, were assessed with an MRI scan. A mismatch refers to an inconsistency between the severity of WMH and cognitive dysfunction. A Type 1 mismatch refers to cognitive impairment with mild WMH (total Fazekas score = 0−1), and a Type 2 mismatch refers to severe WMH (total Fazekas score = 5−6) in patients with normal cognitive function. Results: Among 213 enrolled ALS patients, 66 patients (31.0%) had cognitive dysfunction, and 40 patients (18.8%) had mismatches. Twenty-seven cases (12.7%) were Type 1 mismatched, and seventeen cases (8.0%) were Type 2 mismatched. Age, gender, fibrinogen and cerebral infarction history were independent risk factors for cognitive impairment in ALS patients. Imaging features, including moderate to severe WMH, deep WMH and the total CSVD burden score, were also independently associated with cognitive impairment. The patients in the mismatched group were older, had more severe deep WMH and had a higher occurrence of depression (p < 0.05). The NIHSS score, depression and microbleeds were significantly different between the Type 1 mismatched group and the matched group (p = 0.018, p = 0.012 and p = 0.047). Patients in the Type 2 mismatched group were male (p = 0.04), had a lower level of fibrinogen (p = 0.005), a lower incidence of CMBs (p = 0.003), a lower total CSVD burden score (p = 0.017), more severe paraventricular WMH (p = 0.035) and milder deep WMH (p = 0.026). Conclusions: Our study examined a homogeneous study cohort of recruited patients with symptomatic ALS. We found heterogeneity between WMH and cognitive function in ALS patients. Despite a similar WMH severity, some baseline clinical features and other conventional CSVD imaging characteristics may account for this heterogeneity phenomenon. Our findings provide data for the early diagnosis and prevention of cognitive impairment in ALS patients and suggest that the severity of WMH is not completely parallel to cognitive impairment. The white matter microstructural injury and remote WMH effects may account for the mismatch phenomenon. More attention should be paid to understanding the underlying mechanisms and finding new imaging markers.

Fiber connectivity density mapping in end-stage renal disease patients: a preliminary study

Abnormal brain structural connectivity of end-stage renal disease(ESRD) is associated with cognitive impairment. However, the characteristics of cortical structural connectivity have not been investigated in ESRD patients. Here, we study structural connectivity of the entire cerebral cortex using a fiber connectivity density(FiCD) mapping method derived from diffusion tensor imaging(DTI) data of 25 ESRD patients and 20 healthy controls, and between-group differences were compared in a vertexwise manner. We also investigated the associations between these abnormal cortical connectivities and the clinical variables using Pearson correlation analysis and multifactor linear regression analysis. Our results demonstrated that the mean global FiCD value was significantly decreased in ESRD patients. Notably, FiCD values were significantly changed(decreased or increased) in certain cortical regions, which mainly involved the bilateral dorsolateral prefrontal cortex(DLPFC), inferior parietal cortex, lateral temporal cortex and middle occipital cortex. In ESRD patients, we found a trend of negative correlation between the increased FiCD values of bilateral middle frontal gyrus and serum creatinine, urea, parathyroid hormone(PTH) levels and dialysis duration. Only the white matter hyperintensity(WMH) scores were significantly negatively correlated with the global FiCD value in multifactor regression analysis. Our results suggested that ESRD patients exhibited extensive impaired cortical structural connectivity, which was related to the severity of WMHs. A compensation mechanism of cortical structural recombination may play a role in how the brain adapts to maintain optimal network function. Additionally, the serum creatinine, urea and PTH levels may be risk factors for brain structural network decompensation in ESRD patients.

Revealing the Influences of Sex Hormones and Sex Differences in Atrial Fibrillation and Vascular Cognitive Impairment

The impacts of sex differences on the biology of various organ systems and the influences of sex hormones on modulating health and disease have become increasingly relevant in clinical and biomedical research. A growing body of evidence has recently suggested fundamental sex differences in cardiovascular and cognitive function, including anatomy, pathophysiology, incidence and age of disease onset, symptoms affecting disease diagnosis, disease severity, progression, and treatment responses and outcomes. Atrial fibrillation (AF) is currently recognized as the most prevalent sustained arrhythmia and might contribute to the pathogenesis and progression of vascular cognitive impairment (VCI), including a range of cognitive deficits, from mild cognitive impairment to dementia. In this review, we describe sex-based differences and sex hormone functions in the physiology of the brain and vasculature and the pathophysiology of disorders therein, with special emphasis on AF and VCI. Deciphering how sex hormones and their receptor signaling (estrogen and androgen receptors) potentially impact on sex differences could help to reveal disease links between AF and VCI and identify therapeutic targets that may lead to potentially novel therapeutic interventions early in the disease course of AF and VCI.

Impact of Circadian Blood Pressure Pattern on Silent Cerebral Small Vessel Disease: A Systematic Review and Meta-Analysis

Background

Abnormal circadian blood pressure (BP) variations during sleep, specifically the non‐dipping (<10% fall in nocturnal BP) and reverse‐dipping patterns (rise in nocturnal BP), have been associated with an increased risk of cardiovascular events and target organ damage. However, the relationship between abnormal sleep BP variations and cerebral small vessel disease markers is poorly established. This study aims to assess the association between non‐dipping and reverse‐dipping BP patterns with markers of silent cerebral small vessel disease.

Methods and Results

MEDLINE, Embase, and Cochrane Databases were searched from inception through November 2019. Studies that reported the odds ratios (ORs) for cerebral small vessel disease markers in patients with non‐dipping or reverse‐dipping BP patterns were included. Effect estimates from the individual studies were extracted and combined using the random‐effect, generic inverse variance method of DerSimonian and Laird. Twelve observational studies composed of 3497 patients were included in this analysis. The reverse‐dipping compared with normal dipping BP pattern was associated with a higher prevalence of white matter hyperintensity with a pooled adjusted OR of 2.00 (95% CI, 1.13–2.37; I²=36%). Non‐dipping BP pattern compared with normal dipping BP pattern was associated with higher prevalence of white matter hyperintensity and asymptomatic lacunar infarction, with pooled ORs of 1.38 (95% CI, 0.95–2.02; I²=52%) and 2.33 (95% CI, 1.30–4.18; I²=73%), respectively. Limiting to only studies with confounder‐adjusted analysis resulted in a pooled OR of 1.38 (95% CI, 0.95–2.02; I²=52%) for white matter hyperintensity and 1.44 (95% CI, 0.97–2.13; I²=0%) for asymptomatic lacunar infarction.

Conclusions

The non‐dipping and reverse‐dipping BP patterns are associated with neuroimaging cerebral small vessel disease markers.

Blood Pressure Circadian Variation, Cognition and Brain Imaging in 90+ Year-Olds

Purpose: To analyze the relationship between blood pressure (BP) variables, including circadian pattern, and cognition in 90+ year-olds.

Methods: Twenty-four hour ambulatory BP monitoring was completed on 121 participants drawn from a longitudinal study of aging and dementia in the oldest-old. Various measures of BP and its variability, including nocturnal dipping, were calculated. Each person was given both a neuropsychological test battery covering different cognitive domains and a neurological examination to determine cognitive status. Seventy-one participants had a brain magnetic resonance imaging (MRI) scan.

Results: Participants ranged in age from 90 to 102 years (mean = 93), about two-thirds were female, and nearly 80% had at least some college education. Mean nocturnal dips differed significantly between cognitively normal (n = 97) and impaired individuals (n = 24), with cognitively normal participants having on average greater nocturnal dips [6.6% vs. 1.3%, p = 0.006 for systolic BP (SBP); 11% vs. 4.4%, p = 0.002 for diastolic BP (DBP)]. Nocturnal dips were also related to performance on select cognitive test scores (especially those related to language, recent memory and visual-spatial ability), with individuals who performed below previously established median norms having significantly smaller nocturnal dips (both SBP and DBP) than those above the median. DBP reverse dippers had larger mean white matter hyperintensities (WMH as percent of total brain volume; 1.7% vs. 1.2%, 1.1% and 1.0% in extreme dippers, dippers, non-dippers) and a greater proportion had lobar cerebral microbleeds (CMBs; 44% vs. 0%, 7%, 16%, p < 0.05). Impaired participants had higher mean WMH than those with normal cognition (1.6% vs. 1.0% p = 0.03) and more tended to have CMB (31% vs. 20%, p = n.s.).

Conclusion: These findings suggest that cognitive dysfunction is associated with dysregulation in the normal circadian BP pattern. Further study is warranted of the potential role of WHM and CMB as mediators of this association.

Positive correlation between cognitive impairment and renal microangiopathy in patients with type 2 diabetic nephropathy: a multicenter retrospective study

Objective

This study was performed to explore the correlation between cognitive impairment and renal microangiopathy in patients with type 2 diabetic nephropathy (T2DN) by detecting changes in cognitive function and cerebral metabolism in these patients with different stages of T2DN.

Methods

Prospectively maintained databases were reviewed from 2006 to 2017. Blood biochemical indexes and the urinary albumin excretion rate (UAER) were measured in all participants. Cognitive function was assessed by the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment Scale (MoCA). Cognitive impairment was the primary endpoint. Renal microangiopathy was the secondary endpoint. Pearson correlation analysis was used to assess correlations.

Results

Two hundred sixteen patients with type 2 diabetes mellitus (T2DM) were divided into three groups according to their UAER: T2DM without nephropathy (n=72), early T2DM with nephropathy (n=74), and the clinical stage of early T2DM with nephropathy (n=70). Healthy participants were selected as the normal control group (n=70). Pearson correlation analysis demonstrated that the total MMSE and MoCA score was negatively correlated with the UAER (r=−0.327) and positively correlated with the estimated glomerular filtration rate (r=0.428) in patients with T2DN.

Conclusions

The present study showed a positive correlation between cognitive impairment and renal microangiopathy in patients with T2DN.

High Circulatory Phosphate Level Is Associated with Cerebral Small-Vessel Diseases

High phosphate is linked to vascular calcification and endothelial dysfunction; however, its relationship with cerebral small-vessel diseases (CSVDs) is still unknown. Study subjects were prospectively recruited from the community-based I-Lan Longitudinal Aging Study. CSVDs including lacunes, white matter hyperintensities (WMHs), and cerebral microbleeds were evaluated using 3T magnetic resonance images. Multivariate analyses were performed to study the associations between circulatory phosphate level and the presence of CSVDs. In vitro experiments included human brain microvascular endothelial cell (HBMEC) studies and western blotting. The present study included 186 subjects (age [mean ± standard deviation, range] 64.7 ± 8.6, 50-86.8 years; 93 men). Multivariate analysis revealed that circulatory phosphate levels > 3.925 mg/dL were associated with severe WMH with an odds ratio of 3.7 (95% confidence interval = 1.3-10.6) independent of age, sex, traditional vascular risk factors, total cholesterol, renal function, or circulatory calcium level. The in vitro study revealed a downregulation of tight junction protein (zona occludens-1, occludin, and claudin-5) expression in HBMECs after 48 h of treatment with high phosphate (2.5/5 mM). We are the first to report a relationship between circulatory phosphate and CSVDs. Our results suggest that high circulatory phosphate level might be a novel risk factor for CSVD, possibly by impairing BBB structures.

The relationship between ambulatory blood pressure variability and enlarged perivascular spaces: a cross-sectional study

OBJECTIVES

Recent studies reported that 24-hour ambulatory blood pressure variability (ABPV) was associated with lacunar infarction and white matter hyperintensities (WMH). However, the relationship between ABPV and enlarged perivascular spaces (EPVS) has not been investigated. Thus, our study aimed to investigate whether ABPV is associated with EPVS by 24-hour ambulatory blood pressure monitoring (ABPM).

DESIGN

We conducted this study as a cross-sectional study.

SETTINGS

The study was based on patients who presented for physical examinations in our hospital from May 2013 to June 2016.

PARTICIPANTS

Patients with both brain MRI scans and 24-hour ABPM were included and patients with acute stroke, a history of severe stroke and some other severe diseases were excluded. A total of 573 Chinese patients were prospectively enrolled in this study.

PRIMARY AND SECONDARY OUTCOME MEASURES

EPVS in basal ganglia (BG) and white matter (WM) were identified on MRI and classified into three categories by the severity. WMH were scored by the Fazekas scale. Coefficient of variation (CV) and SD were considered as metrics of ABPV. Spearman correlation analysis and ordinal logistic regression analysis were used to assess the relationship between ABPV and EPVS.

RESULTS

There were statistical differences among the subgroups stratified by the severity of EPVS in BG in the following ABPV metrics: SD and CV of systolic blood pressure (SBP), CV of diastolic blood pressure (DBP) in 24 hours, daytime and nighttime and SD of DBP in nighttime. The above ABPV metrics were positively associated with the degree of EPVS. The association was unchanged after adjusting for confounders. Spearman correlation analysis showed ABPV was not related to the degree of EPVS in the WM.

CONCLUSION

ABPV was independently associated with EPVS in BG after controlling for blood pressure, but not in the WM. Pathogenesis of EPVS in BG and WM might be different.

Plasma homocysteine and cerebral small vessel disease as possible mediators between kidney and cognitive functions in patients with diabetes mellitus

Cognitive impairment is more prevalent in those with decreased kidney function. We tested a hypothesis that an increased homocysteine and/or cerebral small vessel diseases (SVDs) mediate the link between kidney and cognitive functions in a cross-sectional study in 143 type 2 diabetes patients without diagnosis of dementia or prior stroke. The exposure and outcome variables were estimated glomerular filtration rate (eGFR) and cognitive performance evaluated with Modified Mini-Mental State (3 MS) examination, respectively. The candidate mediators were plasma homocysteine concentration, and SVDs including silent cerebral infarction, cerebral microbleed, periventricular hyperintensity, and deep and subcortical white matter hyperintensity by magnetic resonance imaging. In multiple regression models adjusted for 12 potential confounders, eGFR was positively associated with 3 MS score, inversely with homocysteine, but not significantly with the presence of any type of SVD. The association of eGFR with 3 MS remained significant when each of the SVDs was added to the model, whereas it disappeared when homocysteine was included in place of SVD. Mediation analysis indicated nearly significant mediation of homocysteine (P = 0.062) but no meaningful mediations of SVDs (P = 0.842-0.930). Thus, homocysteine, not SVDs, was shown to be the possible mediator between kidney and cognitive functions in patients with type 2 diabetes mellitus.

Chronic kidney disease-related physical frailty and cognitive impairment: a systemic review

AIM

The objective of this review was to assess chronic kidney disease-related frailty and cognitive impairment, as well as their probable causes, mechanisms and the interventions.

METHODS

Studies from 1990 to 2015 were reviewed to evaluate the relationship between chronic kidney disease and physical frailty and cognitive impairment. Of the 1694 studies from the initial search, longitudinal studies (n = 22) with the keywords "Cognitive and CKD" and longitudinal or cross-sectional studies (n = 5) with the keywords "Frailty and CKD" were included in final analysis.

RESULTS

By pooling current research, we show clear evidence for a relationship between chronic kidney disease and frailty and cognitive impairment in major studies. Vascular disease is likely an important mediator, particularly for cognitive impairment. However, non-vascular factors also play an important role. Many of the other mechanisms that contribute to impaired cognitive function and increased frailty in CKD remain to be elucidated. In limited studies, medication therapy did not obtain the ideal effect. There are limited data on treatment strategies, but addressing the vascular disease risk factors earlier in life might decrease the subsequent burden of frailty and cognitive impairment in this population. Multidimensional interventions, which address both microvascular health and other factors, may have substantial benefits for both the cognitive impairments and physical frailty in this vulnerable population.

CONCLUSIONS

Chronic kidney disease is a potential cause of frailty and cognitive impairment. Vascular and non-vascular factors are the possible causes. The mechanism of chronic kidney disease-induced physical frailty and cognitive impairment suggests that multidimensional interventions may be effective therapeutic strategies in the early stage of chronic kidney disease. Geriatr Gerontol Int 2017; 17: 529-544.

Chronic Management of Hypertension after Stroke: The Role of Ambulatory Blood Pressure Monitoring

Hypertension is the most important potentially reversible risk factor for stroke in all age groups; high blood pressure (BP) is also associated with increased risk of recurrent stroke in patients who have already had an ischemic or hemorrhagic event. Twenty-four hour ambulatory BP monitoring (ABPM) has become an important tool for improving the diagnosis and management of hypertension, and is increasingly used to assess patients with hypertension. Nevertheless, although ABPM devices are increasingly used for assessment of hypertension, their value in the chronic management of hypertension in patients with stroke has not been systematically studied. In fact, among large-scale randomized trials for secondary stroke prevention, only the Morbidity and Mortality After Stroke, Eprosartan Compared With Nitrendipine for Secondary Prevention trial included 24-hour ABPM. ABPM has demonstrated chronic disruption of the circadian rhythm of BP after acute phase of stroke and has shown higher sensitivity compared to office BP in evaluating the effectiveness of antihypertensive treatment among stroke survivors. High 24-hour BP is an independent predictor for cerebrovascular events, brain microbleeds, and subsequent development of dementia. Nevertheless, although stroke care guidelines endorse the importance of hypertension management, the specific role of ABPM among stroke survivors after the acute phase of disease has not been established. Further studies are needed to clarify whether routine application of ABPM among these patients should be recommended.

Hyperbaric area index calculated from ABPM elucidates the condition of CKD patients: the CKD-JAC study

BACKGROUND

High prevalence of masked hypertension as well as persistent hypertension was observed in the Chronic Kidney Disease Japan Cohort (CKD-JAC) study. We proposed a novel indicator of blood pressure (BP) load, hyperbaric area index (HBI), calculated from ambulatory blood pressure monitoring (ABPM) data. The characteristic of this index and its relationship with kidney function were also evaluated.

METHODS

The CKD-JAC study, enrolled 2,977 patients, is a prospective observational study started in September 2007. ABPM was conducted in a sub-group from September 2007 to April 2010 and baseline ABPM data of 1,075 subjects (63.4 % male, 60.7 years old) were analyzed.

RESULTS

Mean systolic HBI of male and female patients were 242.3 and 176.5 mmHg×h, respectively. HBI sensitively reflected sex (54.7 mmHg×h higher in males than in females), seasonal effects (51.6 mmHg×h higher in winter than in summer), and advancing CKD stage [(16.5 mmHg×h higher) per -10 mL/min/1.73 m(2) in eGFR]. The HBI was a significant factor to associate with reduced kidney function, after adjusting with nocturnal BP change (NBPC), sex, and other variables (p value <0.001).

CONCLUSIONS

Our findings suggested that HBI might be a novel sensitive indicator for the reduction of kidney function, independent of patterns of NBPC.

MRI features of Binswanger's disease predict prognosis and associated pathology

Objective

To identify the prevalence of MRI features of Binswanger’s disease (BD), specifically MRI with diffuse white matter lesions and scattered multiple lacunes (BD-MRI), and to describe neurological features and pathological outcomes of a community-based cohort study.

Methods

Of 697 participants (all 75 years old), 503 completed neurological examinations at baseline and were followed-up every 30 months thereafter with MRIs, the mini-mental state examination (MMSE) and the Unified Parkinson Disease Rating Scale-Motor Section (UPDRSM). Data from participants with BD-MRI were compared with those from participants with predominant white matter lesions (WML-MRI), scattered multiple lacunes (ML-MRI), or normal MRIs.

Results

Fourteen BD-MRI patients (2.8%) were detected at baseline. The mean MMSE scores in the BD-MRI, WML-MRI, ML-MRI, and normal MRIs groups were 26.4, 28.2, 28.4, and 28.5, respectively, and the mean UPDRSM scores were 9.1, 1.3, 3.1, and 1.7, respectively. At the 30-month follow-up, mortality rates in the normal MRIs, WML-MRI and ML-MRI were 4%, 9.1%, and 22.2%, respectively, and follow-up MRIs were available for 80%, 82%, and 61% of the participants, respectively. In the BD-MRI, however, five patients were deceased, and only five follow-up individual MRIs were available (33.3%). Autopsies were performed on six of eight BD-MRI brains, and these brains fulfilled the pathological criteria for BD independent of Alzheimer disease pathology. All these six individuals also showed systemic atherosclerosis and renal arterio-arteriolosclerosis.

Interpretation

The BD-MRI participants had poor prognoses and showed pure BD pathology with advanced systemic vascular disease. BD-MRI appears to be a predictor of vascular neurocognitive impairment.

Stroke and renal dysfunction

Stroke is the most frequent neurological disease and represents a continuously evolving medical and social problem. Chronic kidney disease (CKD) is also an important worldwide public health problem. Renal dysfunction carries a substantial risk of cardiovascular morbidity and mortality and an independent, graded association between renal function and cardiovascular events was found. In the last 15years the link between CKD and cerebrovascular disease has become more apparent. Patients with end stage renal disease treated with maintenance hemodialysis have a much higher incidence of stroke than the general population and stroke is one of the major causes of death in these patients. Nowadays ischemic subtype of stroke is present in approximately 70% of dialysis patients. In population based studies conflicting results have been reported about the association between stroke and CKD before replacement therapy. However, in high risk patients, defined by the presence of either cardiovascular disease or cardiovascular risk factors, different stages of CKD are clearly associated with subsequent stroke. In patients with stroke the exact prevalence of renal dysfunction is not known. Reported prevalence from a few published studies is up to 38% and it is higher than that in age-matched control groups. Furthermore, in patients suffering from stroke renal dysfunction is associated with short and long term mortality. The most effective treatment of stroke in patients with CKD is not known and further studies are needed.

Should an elderly patient with stage V CKD and dementia be started on dialysis?

The burden of cognitive impairment appears to increase with progressive renal disease, such that the prevalence of dementia among those starting dialysis, or those already established on dialysis, is high. The appropriateness of dialysis initiation in this population has been questioned, and current Renal Physician Association guidelines suggest forgoing dialysis in individuals who have dementia and lack awareness of self and environment. Patients are, however, also entitled to equal rights and respect, equal access to health care services, and an opportunity to engage in shared decision-making processes, particularly if there is concern over reversibility of disease. This article discusses, on the basis of principles of beneficence and nonmaleficence, the arguments in favor of and against dialysis use, and the process of determining an appropriate care plan. Factors discussed include the current societal trend toward a technological imperative, premature fatalism, survival benefits, and the implications of providing care to patients who are unable to express their tolerance for symptoms associated with the treatment or lack of treatment.

Association between physical performance and all-cause mortality in CKD

In older adults, measurements of physical performance assess physical function and associate with mortality and disability. Muscle wasting and diminished physical performance often accompany CKD, resembling physiologic aging, but whether physical performance associates with clinical outcome in CKD is unknown. We evaluated 385 ambulatory, stroke-free participants with stage 2-4 CKD enrolled in clinic-based cohorts at the University of Washington and University of Maryland and Veterans Affairs Maryland Healthcare systems. We compared handgrip strength, usual gait speed, timed up and go (TUAG), and 6-minute walking distance with normative values and constructed Cox proportional hazards models and receiver operating characteristic curves to test associations with all-cause mortality. Mean age was 61 years and the mean estimated GFR was 41 ml/min per 1.73 m(2). Measures of lower extremity performance were at least 30% lower than predicted, but handgrip strength was relatively preserved. Fifty deaths occurred during the median 3-year follow-up period. After adjustment, each 0.1-m/s decrement in gait speed associated with a 26% higher risk for death, and each 1-second longer TUAG associated with an 8% higher risk for death. On the basis of the receiver operating characteristic analysis, gait speed and TUAG more strongly predicted 3-year mortality than kidney function or commonly measured serum biomarkers. Adding gait speed to a model that included estimated GFR significantly improved the prediction of 3-year mortality. In summary, impaired physical performance of the lower extremities is common in CKD and strongly associates with all-cause mortality.