Cerebral white matter burden is linked to cognitive function in patients undergoing hemodialysis

INTRODUCTION

Chronic kidney disease is related to neurodegeneration and structural changes in the brain which might lead to cognitive decline. The Fazekas scale used for assessing white matter hyperintensities (WMHs) was associated with poor cognitive performance. Therefore, this study investigated the associations between the mini-mental status examination (MMSE), Montreal cognitive assessment (MoCA), cognitive abilities screening instrument (CASI), and Fazekas scale in patients under hemodialysis (HD).

METHODS

The periventricular (PV) WMHs and deep WMHs (DWMHs) in brain magnetic resonance images of 59 patients under dialysis were graded using the Fazekas scale. Three cognition function tests were also performed, then multivariable ordinal regression and logistic regression were used to identify the associations between cognitive performance and the Fazekas scale.

RESULTS

There were inverse associations between the three cognitive function tests across the Fazekas scale of PVWMHs (p = .037, .006, and .008 for MMSE, MoCA, and CASI, respectively), but the associations were attenuated in the DWMHs group. In CASI, significant differences were identified in short-term memory, mental manipulation, abstract thinking, language, spatial construction, and name fluency in the PVWMHs group. However, DWMHs were only significantly correlated with abstract thinking and short-term memory.

CONCLUSION

An inverse correlation existed between the Fazekas scale, predominantly in PVWMHs, and cognition in patients undergoing HD. The PVWMHs were associated with cognitive performance assessed by MMSE, MoCA, and CASI, as well as with subdomains of CASI such as memory, language and name fluency in patients undergoing HD.

Acute and Chronic Kidney Dysfunction and Prognosis following Thrombectomy for Ischemic Stroke

INTRODUCTION

Patients with chronic kidney disease (CKD) have an increased risk of stroke, and CKD seems associated with worse outcome after a stroke. The main objective of our study RISOTTO was to evaluate the influence of CKD and acute kidney injury (AKI) on the clinical outcome and mortality of ischemic stroke patients after thrombolysis and/or thrombectomy.

METHODS

This multicenter cohort study included patients in the acute phase of ischemic stroke due to large artery occlusion managed by thrombectomy. Functional outcome at 3 months was assessed by the modified Rankin Scale (mRS).

RESULTS

280 patients were included in the analysis. Fifty-nine patients (22.6%) had CKD. At 3 months, CKD was associated with similar functional prognosis (mRS 3-6: 50.0% vs. 41.7%, p = 0.262) but higher mortality (24.2% versus 9.5%, p = 0.004). In univariate analysis, patients with CKD had a higher burden of white matter hyperintensities (Fazekas score: 1.7 ± 0.8 vs. 1.0 ± 0.8, p = 0.002), lower initial infarct volume with equivalent severity, and lower recanalization success (86.4% vs. 97.0%, p = 0.008) compared to non-CKD patients. Forty-seven patients (20.0%) developed AKI. AKI was associated with poorer 3-month functional outcome (mRS 3-6: 63.8% vs. 49.0%, p = 0.002) and mortality (23.4% versus 7.7%, p = 0.002). In multivariate analysis, AKI appeared as an independent risk factor for poor functional outcome (mRS 3-6: adjOR 2.79 [1.11-7.02], p = 0.029) and mortality (adjOR 2.52 [1.03-6.18], p = 0.043) at 3 months, while CKD was not independently associated with 3-month mortality and poor neurological outcome.

CONCLUSIONS

AKI is independently associated with poorer functional outcome and increased mortality at 3 months. CKD was not an independent risk factor for 3-month mortality or poor functional prognosis.

Kidney disease and stroke: epidemiology and potential mechanisms of susceptibility

Patients with chronic kidney disease (CKD) have an increased risk of both ischaemic and haemorrhagic stroke compared with the general population. Both acute and chronic kidney impairment are independently associated with poor outcome after the onset of a stroke, after adjustment for confounders. End-stage kidney disease (ESKD) is associated with a 7- and 9-fold increased incidence of both ischaemic and haemorrhagic strokes, respectively, poorer neurological outcome and a 3-fold higher mortality. Acute kidney injury (AKI) occurs in 12% of patients with stroke and is associated with a 4-fold increased mortality and unfavourable functional outcome. CKD patients seem to have less access to revascularisation techniques like thrombolysis and thrombectomy despite their poorer prognosis. Even if CKD patients could benefit from these specific treatments in acute ischaemic stroke, their prognosis remains poor. After thrombolysis, CKD is associated with a 40% increased risk of intracerebral haemorrhage (ICH), a 20% increase in mortality and poorer functional neurological outcomes. After thrombectomy, CKD is not associated with ICH but is still associated with increased mortality, and AKI with unfavourable outcome and mortality. The beneficial impact of gliflozins on the prevention of stroke is still uncertain. Non-traditional risk factors of stroke, like uraemic toxins, can lead to chronic cerebrovascular disease predisposing to stroke in CKD, notably through an increase in the blood-brain barrier permeability and impaired coagulation and thrombosis mechanisms. Preclinical and clinical studies are needed to specifically assess the impact of these non-traditional risk factors on stroke incidence and outcomes, aiming to optimize and identify potential therapeutic targets.

Covert vascular brain injury in chronic kidney disease

Chronic kidney disease (CKD) contributes to the increased risk of stroke and dementia. Accumulating evidence indicates that structural brain abnormalities, such as cerebral small vessel disease, including white matter hyperintensities, lacunes, perivascular spaces, and cerebral microbleeds, as well as brain atrophy, are common in patients with CKD. All of these imaging findings have been implicated in the development of stroke and dementia. The brain and kidney exhibit similar impairments and promote structural brain abnormalities due to shared vascular risk factors and similar anatomical and physiological susceptibility to vascular injury in patients with CKD. This indicates that kidney function has a significant effect on brain aging. However, as most results are derived from cross-sectional observational studies, the exact pathophysiology of structural brain abnormalities in CKD remains unclear. The early detection of structural brain abnormalities in CKD in the asymptomatic or subclinical phase (covert) should enable stroke risk prediction and guide clinicians on more targeted interventions to prevent stroke in patients with CKD. This article summarizes the currently available clinical evidence linking covert vascular brain injuries with CKD.

Effect of air removal with extracorporeal balloon inflation on incidence of asymptomatic cerebral embolism during cryoballoon ablation of atrial fibrillation: A prospective randomized study

Background

It was previously reported, based on a retrospective study, that preliminary removal of air bubbles in heparinized saline water with extracorporeal balloon inflation reduced the incidence of asymptomatic cerebral embolism (ACE). The present study aims to compare the incidence of ACE between a conventional and pre-inflation method during cryoballoon ablation in a prospective randomized controlled study.

Methods

A total of 98 atrial fibrillation patients were enrolled and randomized into conventional and pre-inflation groups. Patients in the pre-inflation group received balloon massaging with preliminary extracorporeal balloon inflation in saline water before the cryoballoon was inserted into the body.

Results

The baseline characteristics were similar between the two groups. Post-procedural 3-Tesla MRI revealed CE in 27.6% of patients. Symptomatic CE only occurred in two patients in the pre-inflation group. One patient had transient dysarthria and mild muscle weakness in one hand; the other patient complained of transient left upper limb weakness, left lower limb paresthesia and dysarthria. The incidence of ACE detected by cerebral MRI did not differ between the two groups to a statistically significant extent (conventional vs. pre-inflation; 22.9% vs. 29.2%; P = 0.49). In the multivariable analysis, eGFR was independently associated with the presence of ACE (odds ratio 0.95; 95% confidence interval 0.907–0.995; P = 0.03).

Conclusion

In this prospective randomized study, the preliminary removal of air bubbles in heparinized saline water with extracorporeal balloon inflation had no impact on the incidence of ACE.

Association Between White Matter Hyperintensities and Chronic Kidney Disease: A Systematic Review and Meta-Analysis

Objectives

Previous studies of the associations between white matter hyperintensities (WMH) and chronic kidney disease (CKD) were still conflicting; therefore, our study aimed to conduct a systematic review of all of the available research on this topic and a meta-analysis of the association between WMH and CKD among observational studies.

Setting and Design

Systematic review and meta-analysis.

Outcome Measures

Severity of WMH.

Methods and Participants

All relevant studies in public databases were examined until 15 November 2020. Two independent reviewers assessed all the included studies using the Cross-Sectional/Prevalence Study Quality (CSSQ) scale, and then literature review and meta-analyses were undertaken.

Results

We pooled the odds ratio (OR) for the presence of WMH, periventricular hyperintensities (PVH), and deep subcortical white matter hyperintensities (DWMH) of patients with CKD vs. non-CKD patients by subgroup analysis, and the results obtained were WMH OR 2.07, 95% CI [1.58, 2.70], PVH OR 2.41, 95% CI [1.90, 3.05], and DWMH OR 2.11, 95% CI [1.60, 2.80], respectively. The main outcome showed that patients with CKD were more likely to have WMH in the brain compared to the normal controls. Another meta-analysis showed a statistically significant decline in renal function in patients with moderate to severe WMH compared with those with no to mild WMH.

Conclusions

The findings indicated that patients with CKD were more likely to experience WMH than demographically matched controls. On the other hand, patients with moderate to severe WMH in the brain had poor renal function more frequently than those with no to mild WMH.

Neurological Soft Signs in Non-diabetic End Stage Renal Disease Patients: Evaluation and Prediction

Patients on hemodialysis suffer from several serious complex neurological complications resulting in significant disability. Early detection of these complications during the asymptomatic phase may consent to early intervention to prevent or minimize the disability. To assess and predict neurological soft signs (NSS) in non-diabetic end-stage renal disease (ESRD) patients on hemodialysis (HD) who do not suffer any apparent neurological symptoms. An analytical, cross-sectional study was done in Hemodialysis units in the Suez Canal University Hospitals. 96 ESRD adult patients on hemodialysis are exposed to: Medical history was taken via personal interview, laboratory tests, and clinical assessment of NSS using Heidelberg scale, and brain CT was done for 50 high-risk patients (hypertensive or those on dialysis for more than 5 years) to detect the presence of any probable neuro-radiological brain abnormalities. 79.2% of our studied ESRD patients on HD had positive NSS with a mean value of total score 8.5 ± 5.9. Strong positive correlations were present between NSS and Hb levels, duration of hemodialysis, and hypertension. CT had revealed no abnormality. NSS represent a reliable, affordable tool for regular bedside assessment of ESRD patients with HD who do not suffer any neurological symptoms for early detection of asymptomatic neurological lesions, especially since the CT brain scan did not show such changes early. The duration of hemodialysis, Hb level, and hypertension were independent predictors for the occurrence of silent neurological lesions in ESRD patients.

Silent neurological lesions detected by magnetic resonance imaging: Relationship to hyperparathyroidism among end-stage renal disease young patients on haemodialysis

BACKGROUND

End-stage renal disease (ESRD) patients on haemodialysis (HD) suffer from several peripheral and central neurological complications. They are at high risk for developing silent neurological lesions (SNL) that may be detected accidentally by magnetic resonance imaging (MRI). Many factors are implicated in the development of neurological deficits in ESRD patients on HD.

AIM OF THE WORK

Evaluation of SNL in young ESRD patients by using MRI and assessing its correlation with hyperparathyroidism.

METHODS

The study involved 48 young ESRD patients (mean age of 19.6 ± 6 years) with HD and do not have any apparent abnormalities in the neurological examination. Laboratory investigations and conventional brain MRI were done on all.

RESULTS

79.2% have SBI and 45.8% have white matter lesions. Regression analysis revealed that calcium level and duration of dialysis were independent predictor factors for the presence of silent brain MRI lesions (P = .034 & 0.045 respectively). ROC curve showed that parathyroid hormone (PTH) level >585 pg/mL, duration of dialysis >2 years, and calcium level >7.5 mg/dL predicted the presence of SNL.

CONCLUSION

The duration of HD and hyperparathyroidism (HPT) were independent predictors for the presence of SNL. MRI brain is considered as a mandatory affordable tool for HD patients >2 years and has HPT for early detection of SNL to help early intervention and avoid neurological complications and disabilities.

CENTRAL NERVOUS SYSTEM RESPONSE TO CHRONIC KIDNEY DISEASE

Due to the aging of the human population, the prevalence of chronic diseases such as chronic kidney disease (CKD) is increasing every year. Chronic kidney disease is a general term that refers to heterogeneous disorders that affect kidney structure and function. Decrease in glomerular filtration can be defined as chronic and progressive deterioration in fluid-solute balance, metabolic and endocrine functions of the kidney. CKD often affects the elderly. With the advancement of age, some structural and functional changes occur in the kidneys. Therefore, the number of patients suffering from mild and moderate CKD is expected to increase in the future.CKD leads to the deep metabolic and hemodynamic changes that damage other organs, such as the heart and brain. CNS abnormalities and cognitive deficits progress with the severity of CBS and occurs mostly among hemodialysis patients. It also has great socio-economic effects on individuals. Since symptoms of CKD are not often found in patients, early recognition of risk factors is the main point. For this reason, it is necessary to identify possible protective and preventive treatments to be applied in at-risk groups and to examine these mechanisms for the treatment of the disease. This review provides available information on the relevant mechanisms.

Review of the structural and functional brain changes associated with chronic kidney disease

Chronic kidney disease (CKD) leads to profound metabolic and hemodynamic changes, which damage other organs, such as heart and brain. The brain abnormalities and cognitive deficit progress with the severity of the CKD and are mostly expressed among hemodialysis patients. They have great socio-economic impact. In this review, we present the current knowledge of involved mechanisms.

Relationship between white matter hyperintensities and chronic kidney disease in patients with acute lacunar stroke

BACKGROUND AND PURPOSE

Previous studies have revealed a relationship between chronic kidney disease (CKD) and white matter hyperintensities (WMH). However, studies on the WMH and CKD in acute stroke patients are rare, and the conclusion is consistent. Our study aimed to investigate the relationship between the severity of WMH and CKD in acute lacunar infarction patients.

METHODS

Consecutive acute lacunar infarction patients were recruited in this cross-sectional study. All patients were divided into two groups according to the severity of periventricular WMH (PVWMH) and deep WMH (DWMH). We dichotomized the severity of WMH (PVWMH and DWMH, separately) into mild group (Fazekas scores 0-1) and moderate-severe group (Fazekas scores 2-3). Estimated glomerular filtration rate (eGFR), proteinuria, vascular risk factors, and clinical features were compared between these two groups. Multivariable logistic regression analysis was used to investigate the association between the severity of WMH and risk factors.

RESULTS

A total of 993 acute lacunar infarction patients aged 25-95 years were enrolled. The proportions of participants presenting moderate-severe group PVWMH and DWMH were 46.6% and 38.6%, respectively. Patients with moderate-severe PVWMH had higher age (P < 0.001) and higher incidence of stroke history (P < 0.001) than those in mild group. The level of serum creatinine and the presence of CKD were significantly higher while the eGFR was significantly lower in patients with moderate-severe PVWMH than those with mild PVWMH. Patients with moderate-severe DWMH (n = 383) also had higher age (P < 0.001) and often had a history of stroke (P < 0.001). But the association between the severity of DWMH and eGFR was not found. Multivariable logistic regression analyses showed stage 2 CKD and stage 3 CKD were independently associated with moderate-severe PVWMH, but not DWMH.

CONCLUSIONS

Our study demonstrates that CKD was independently associated with moderate-severe PVWMH in patients with acute lacunar infarction, but not DWMH. PVWMH and DWMH may have distinct pathophysiology.

Prevalence and Risk Factors of Silent Brain Infarction in Patients with Aortic Stenosis

Introduction

Silent brain infarction (SBI) is an independent risk factor for subsequent symptomatic stroke in the general population. Although aortic stenosis (AS) is also known to be associated with an increased risk of future symptomatic stroke, little is known regarding the prevalence and risk factors for SBI in patients with AS.

Methods

The study population comprised 83 patients with severe AS with no history of stroke or transient ischemic attack and paralysis or sensory impairment (mean age 75 ± 7 years). All patients underwent brain magnetic resonance imaging to screen for SBI and multidetector-row computed tomography to quantify the aortic valve calcification (AVC) volume. Comprehensive transthoracic and transesophageal echocardiography were performed to evaluate left atrial (LA) abnormalities, such as LA enlargement, spontaneous echo contrast, or abnormal LA appendage emptying velocity (<20 cm/s), and complex plaques in the aortic arch.

Results

SBI was detected in 38 patients (46%). Multiple logistic regression analysis indicated that CHA₂DS₂-VASc score and estimated glomerular filtration rate (eGFR) were independently associated with SBI (p < 0.05), whereas LA abnormalities and AVC volume were not. When patients were divided into 4 groups according to CHA₂DS₂-VASc score and eGFR, the group with a higher CHA₂DS₂-VASc score (≥4) and a lower eGFR (<60 mL/min/1.73 m²) had a greater risk of SBI than the other groups (p < 0.05).

Conclusion

These findings indicate that AS is associated with a high prevalence of SBI, and that the CHA₂DS₂-VASc score and eGFR are useful for risk stratification.

Cerebrovascular Disease and Cognition in Chronic Kidney Disease Patients

Chronic kidney disease (CKD) affects both brain structure and function. Patients with CKD have a higher risk of both ischemic and hemorrhagic strokes. Age, prior disease history, hypertension, diabetes, atrial fibrillation, smoking, diet, obesity, and sedimentary lifestyle are most common risk factors. Renal-specific pathophysiologic derangements, such as oxidative stress, chronic inflammation, endothelial dysfunction, vascular calcification, anemia, gut dysbiosis, and uremic toxins are important mediators. Dialysis initiation constitutes the highest stroke risk period. CKD significantly worsens stroke outcomes. It is essential to understand the risks and benefits of established stroke therapeutics in patients with CKD, especially in those on dialysis. Subclinical cerebrovascular disease, such as of silent brain infarction, white matter lesions, cerebral microbleeds, and cerebral atrophy are more prevalent with declining renal function. This may lead to functional brain damage manifesting as cognitive impairment. Cognitive dysfunction has been linked to poor compliance with medications, and is associated with greater morbidity and mortality. Thus, understanding the interaction between renal impairment and brain is important in to minimize the risk of neurologic injury in patients with CKD. This article reviews the link between chronic kidney disease and brain abnormalities associated with CKD in detail.

Uremic Toxic Blood-Brain Barrier Disruption Mediated by AhR Activation Leads to Cognitive Impairment during Experimental Renal Dysfunction

BACKGROUND

Uremic toxicity may play a role in the elevated risk of developing cognitive impairment found among patients with CKD. Some uremic toxins, like indoxyl sulfate, are agonists of the transcription factor aryl hydrocarbon receptor (AhR), which is widely expressed in the central nervous system and which we previously identified as the receptor of indoxyl sulfate in endothelial cells.

METHODS

To characterize involvement of uremic toxins in cerebral and neurobehavioral abnormalities in three rat models of CKD, we induced CKD in rats by an adenine-rich diet or by 5/6 nephrectomy; we also used AhR^-/- knockout mice overloaded with indoxyl sulfate in drinking water. We assessed neurologic deficits by neurobehavioral tests and blood-brain barrier disruption by SPECT/CT imaging after injection of ^99mTc-DTPA, an imaging marker of blood-brain barrier permeability.

RESULTS

In CKD rats, we found cognitive impairment in the novel object recognition test, the object location task, and social memory tests and an increase of blood-brain barrier permeability associated with renal dysfunction. We found a significant correlation between ^99mTc-DTPA content in brain and both the discrimination index in the novel object recognition test and indoxyl sulfate concentrations in serum. When we added indoxyl sulfate to the drinking water of rats fed an adenine-rich diet, we found an increase in indoxyl sulfate concentrations in serum associated with a stronger impairment in cognition and a higher permeability of the blood-brain barrier. In addition, non-CKD AhR^-/- knockout mice were protected against indoxyl sulfate-induced blood-brain barrier disruption and cognitive impairment.

CONCLUSIONS

AhR activation by indoxyl sulfate, a uremic toxin, leads to blood-brain barrier disruption associated with cognitive impairment in animal models of CKD.

Deterioration of Cerebral Oxygenation by Aortic Arch Calcification Progression in Patients Undergoing Hemodialysis: A Cross-Sectional Study

Background

Near-infrared spectroscopy revealed that the regional saturation of oxygen (rSO₂) in cerebral tissue is lower in hemodialysis (HD) patients than in healthy subjects. However, no study has examined the changes in cerebral oxygenation by aortic arch calcification (AAC) progression in HD patients.

Methods

A total of 104 HD patients were divided into four groups by AAC grade determined using chest radiography: 23 patients at grade 0, 24 at grade 1, 30 at grade 2, and 27 at grade 3. Differences in clinical parameters, including cerebral rSO₂, among AAC grades were investigated and atherosclerotic parameters affecting cerebral rSO₂ values were identified.

Results

Cerebral rSO₂ significantly decreased as AAC progressed (AAC grade 3 versus grade 0, p < 0.01 versus grade 1, p < 0.05). Multivariate logistic regression analysis was performed using parameters with p values < 0.20 in univariate analysis between cerebral rSO₂ values less than the mean and atherosclerotic parameters. AAC grades 2 and 3, serum phosphate level, and history of smoking were factors associated with the cerebral rSO₂ decrease.

Conclusions

Cerebral rSO₂ significantly decreased as AAC progressed and was independently associated with higher AAC grade, serum phosphate level, and history of smoking.

Kidney dysfunction and silent brain infarction in generally healthy adults

BACKGROUND

The association between silent brain infarction (SBI) and estimated glomerular filtration rate (eGFR)-based kidney dysfunction has not yet been definitively confirmed. This study aimed to investigate the association in generally healthy adults without a previous history of stroke or overt kidney disease.

METHODS

The data from the screening health check-up program in the Seoul National University Hospital Health Promotion Center from January 1, 2009 to December 31, 2013 were used. A total of 2594 subjects who underwent brain MRI as part of health screening were included. SBIs were identified using T2-weighted and FLAIR images. Kidney dysfunction was defined as eGFR<60ml/min/1.73m². To assess the effect of kidney dysfunction on the small perforating branches of cerebral vessels, subgroup analysis was performed using the presence of SLI as a dependent variable.

RESULTS

The mean age was 56.8±9.3years, and 1422 subjects (54.8%) were male. The mean eGFR level was 81.9±15.4ml/min/1.73m². The prevalence rates of kidney dysfunction and SBI were 5.1% and 7.1%, respectively. A higher proportion of subjects with SBI had kidney dysfunction than subjects without SBI (14.6% vs. 4.4%). The number of SBI lesions tended to increase with the progression of kidney dysfunction (p for trend<0.001). In multivariate logistic regression analyses, kidney dysfunction was significantly associated with the presence of SBI (adjusted odd ratio=1.99 to 2.21 in all four models). The same significant association was consistently identified in subgroup analyses using silent lacunar infarction (adjusted odd ratio=1.71 to 1.87 in all four models).

CONCLUSION

Kidney dysfunction was found to be an independent risk factor for the presence and number of SBI in generally healthy adults. Physicians treating patients with a decreased creatinine-based eGFR level should try to identify and modify the coexisting risk factors of stroke followed by SBI.

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.

Effect of Kidney Dysfunction on Cerebral Cortical Thinning in Elderly Population

Chronic kidney disease has been linked to cognitive impairment and morphological brain change. However, less is known about the impact of kidney functions on cerebral cortical thickness. This study investigated the relationship between kidney functions and global or lobar cerebral cortical thickness (CTh) in 259 non-demented elderly persons. Forty-three participants (16.7%) had kidney dysfunction, which was defined as either a glomerular filtration rate (GFR) of <60 ml/min/1.73 m² or presence of proteinuria. Kidney dysfunction was associated with lower global (β = −0.05, 95% CI = −0.08 to −0.01) as well as frontal, parietal, temporal, occipital, and insular lobar CTh. In the stratified analysis, the associations were more pronounced in women, APOEε4 non-carriers, and participants with a lower cognitive score. Besides, kidney dysfunction significantly increased the risk of cortical thinning, defined as being the lowest CTh tertile, in the insular lobe (adjusted odds ratio = 2.74, 95% CI = 1.31−5.74). Our results suggested that kidney dysfunction should be closely monitored and managed in elderly population to prevent neurodegeneration.

Prognostic Relationships between Microbleed, Lacunar Infarction, White Matter Lesion, and Renal Dysfunction in Acute Ischemic Stroke Survivors

BACKGROUND

It is well known that renal dysfunction and cerebral small-vessel disease (SVD), including microbleed, lacunar infarction, and white matter lesion (WML), are associated with poor prognosis after ischemic stroke. However, the prognostic relationship between renal dysfunction and SVD has not been well evaluated in acute ischemic stroke survivors. Therefore, in this study, we evaluated the prognostic relationships between estimated glomerular filtration rate (eGFR) and cerebral SVD after acute ischemic stroke.

METHODS

We retrospectively reviewed the clinical and radiological data of acute ischemic stroke survivors with decreased eGFR (<60 mL/min/1.73 m², n = 128) and controls (eGFR ≥60 mL/min/1.73 m², n = 128). The presence of SVD was evaluated according to magnetic resonance imaging performed on admission. Mortality data were obtained from medical chart reviews and telephone interviews.

RESULTS

Patients with silent lacunar infarction, WML, or microbleed had lower eGFR than patients without such lesions (60.4 ± 34.8 versus 87.5 ± 28.4 mL/min/1.73 m², 60.5 ± 37.1 versus 73.9 ± 33.3 mL/min/1.73 m², and 57.6 ± 33.3 versus 73.9 ± 32.9 mL/min/1.73 m², respectively). In addition, the multivariate adjusted odds ratio for the presence of SVD increased inversely with eGFR. Three-year survival was lower in patients with renal dysfunction and each type of SVD. The presence of WML was an independent risk factor for cardiovascular death.

CONCLUSIONS

Renal impairment was associated with the presence of SVD in acute ischemic stroke survivors. Both renal impairment and the presence of SVD were predictors of poor poststroke survival.

Neurological complications in chronic kidney disease patients

Chronic kidney disease (CKD) is associated with a high prevalence of cerebrovascular disorders such as stroke, white matter diseases, intracerebral microbleeds and cognitive impairment. This situation has been observed not only in end-stage renal disease patients but also in patients with mild or moderate CKD. The occurrence of cerebrovascular disorders may be linked to the presence of traditional and non-traditional cardiovascular risk factors in CKD. Here, we review current knowledge on the epidemiological aspects of CKD-associated neurological and cognitive disorders and discuss putative causes and potential treatment. CKD is associated with traditional (hypertension, hypercholesterolaemia, diabetes etc.) and non-traditional cardiovascular risk factors such as elevated levels of oxidative stress, chronic inflammation, endothelial dysfunction, vascular calcification, anaemia and uraemic toxins. Clinical and animal studies indicate that these factors may modify the incidence and/or outcomes of stroke and are associated with white matter diseases and cognitive impairment. However, direct evidence in CKD patients is still lacking. A better understanding of the factors responsible for the elevated prevalence of cerebrovascular diseases in CKD patients may facilitate the development of novel treatments. Very few clinical trials have actually been performed in CKD patients, and the impact of certain treatments is subject to debate. Treatments that lower LDL cholesterol or blood pressure may reduce the incidence of cerebrovascular diseases in CKD patients, whereas treatment with erythropoiesis-stimulating agents may be associated with an increased risk of stroke but a decreased risk of cognitive disorders. The impact of therapeutic approaches that reduce levels of uraemic toxins has yet to be evaluated.

Association of mild kidney dysfunction with silent brain lesions in neurologically normal subjects

Background

Chronic kidney disease (CKD) has been closely associated with stroke. Although a large number of studies reported the relationship between CKD and different types of asymptomatic brain lesions, few comprehensive analyses have been performed for all types of silent brain lesions.

Methods

We performed a cross-sectional study involving 1,937 neurologically normal subjects (mean age 59.4 years). Mild CKD was defined as an estimated glomerular filtration rate between 30 and 60 ml/min/1.73 m² or positive proteinuria.

Results

The prevalence of mild CKD was 8.7%. Univariate analysis revealed an association between CKD and all silent brain lesions, including silent brain infarction, periventricular hyperintensity, subcortical white matter lesion, and microbleeds, in addition to hypertension and diabetes mellitus after adjusting for age and sex. In binary logistic regression analysis, the presence of CKD was a significant risk factor for all types of silent brain lesions, independent of other risk factors.

Conclusions

These results suggest that mild CKD is independently associated with all types of silent brain lesions, even in neurologically normal subjects.

Cerebral small vessel disease and chronic kidney disease

Chronic kidney disease, defined by a decreased glomerular filtration rate or albuminuria, is recognized as a major global health burden, mainly because it is an established risk factor for cardiovascular and cerebrovascular diseases. The magnitude of the effect of chronic kidney disease on incident stroke seems to be higher in persons of Asian ethnicity. Since the kidney and brain share unique susceptibilities to vascular injury due to similar anatomical and functional features of small artery diseases, kidney impairment can be predictive of the presence and severity of cerebral small vessel diseases. Chronic kidney disease has been reported to be associated with silent brain infarcts, cerebral white matter lesions, and cerebral microbleeds, independently of vascular risk factors. In addition, chronic kidney disease affects cognitive function, partly via the high prevalence of cerebral small vessel diseases. Retinal artery disease also has an independent relationship with chronic kidney disease and cognitive impairment. Stroke experts are no longer allowed to be ignorant of chronic kidney disease. Close liaison between neurologists and nephrologists can improve the management of cerebral small vessel diseases in kidney patients.

Two different clinical entities of small vessel occlusion in TOAST classification

BACKGROUND

Small deep infarcts might be classified into 2 types: lacunar and branchatheromatous infarcts. However, since their initial description, small deep infarcts were still regarded as the same category of the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification, small vessel occlusion (SVO). We hypothesized that the 2 types of small deep infarcts would be distinct clinical entities. This study was conducted to investigate the clinical characteristics in the 2 groups of patients according to lesion pattern and combined atherosclerotic diseases.

METHODS

We included patients with small deep infarcts in the subcortical area. The patients were divided into 2 groups: (1) island lesions and (2) linear lesions on coronal diffusion weighted imaging. The status of the relevant artery was categorized as no stenosis, non-significant (<50% of luminal narrowing) and significant (≥ 50% of luminal narrowing). We compared the clinical and imaging characteristics of two lesion types according to various arterial status.

RESULTS

This study analyzed a total of 248 patients. Independent factors for island lesions on coronal DWI were male, severe leukoaraiosis, microbleeds, abnormal glycated hemoglobin (HbA1C), and abnormal estimated glomerular filtration ratio (eGFR) adjusted by age, sex, and initial National Institutes of Health Stroke Scale. In addition, in patients without significant relevant arterial stenosis, island lesion patterns were more frequently associated with severe periventricular white matter hyperintensity, diabetes mellitus, abnormal eGFR and abnormal HbA1C than linear lesion patterns.

CONCLUSION

This study demonstrated that SVO of TOAST classifications had different imaging and clinical characteristics according to the lesion patterns of coronal imaging. It suggests that two types of SVO should be regarded as the different categories of stroke classification.