Stroke and renal dysfunction

Kidney-brain axis in the pathogenesis of cognitive impairment

The kidney-brain axis is a bidirectional communication network connecting the kidneys and the brain, potentially affected by inflammation, uremic toxin, vascular injury, neuronal degeneration, and so on, leading to a range of diseases. Numerous studies emphasize the disruptions of the kidney-brain axis may contribute to the high morbidity of neurological disorders, such as cognitive impairment (CI) in the natural course of chronic kidney disease (CKD). Although the pathophysiology of the kidney-brain axis has not been fully elucidated, epidemiological data indicate that patients at all stages of CKD have a higher risk of developing CI compared with the general population. In contrast to other reviews, we mentioned some commonly used medicines in CKD that may play a pivotal role in the pathogenesis of CI. Revealing the pathophysiology interactions between kidney damage and brain function can reduce the potential risk of future CI. This review will deeply explore the characteristics, indicators, and potential pathophysiological mechanisms of CKD-related CI. It will provide a theoretical basis for identifying CI that progresses during CKD and ultimately prevents and treats CKD-related CI.

Early detection of stroke at the sudden sensorineural hearing loss stage

Background and purpose

Sudden sensorineural hearing loss (SSNHL) can be a prodromal symptom of ischemic stroke, especially posterior circulation strokes in the anterior inferior cerebellar artery (AICA) area. Early diagnosis and optimal treatment for vascular SSNHL provide an opportunity to prevent more extensive area infarction. The objective of our research was to find clues that suggest stroke at the stage of isolated sudden hearing loss.

Methods

We retrospectively investigated the medical records of patients who received an initial diagnosis of sudden sensorineural hearing loss upon admission from January 2017 to December 2022 at Capital Medical University Affiliated Beijing Tiantan Hospital. Among these patients, 30 individuals who developed acute ischemic stroke during their hospital stay were enrolled as the case group. To create a control group, we matched individuals from the nonstroke idiopathic SSNHL patients to the case group in terms of age (±3 years old) at a ratio of 1:4. We collected the clinical characteristics, pure tone hearing threshold test results, and imaging information for all patients included in the study.

Results

Three models were constructed to simulate different clinical situations and to identify vascular sudden sensorineural hearing loss (SSNHL). The results revealed that patients with SSNHL who had three or more stroke risk factors, bilateral hearing loss, moderately severe to total hearing loss, and any intracranial large artery stenosis and occlusion (≥50%) were at a higher risk of developing ischemic stroke during hospitalization. Consistent with previous studies, the presence of vertigo at onset also played a significant role in the early detection of upcoming stroke.

Conclusion

Clinicians should be alert to SSNHL patients with bilateral hearing loss, moderately severe to total hearing loss and other aforementioned features. Early pure tone audiometric hearing assessment and vascular assessment are necessary for high-risk patients with SSNHL.

Peripheral Organ Injury After Stroke

Stroke is a disease with high incidence, mortality and disability rates. It is also the main cause of adult disability in developed countries. Stroke is often caused by small emboli on the inner wall of the blood vessels supplying the brain, which can lead to arterial embolism, and can also be caused by cerebrovascular or thrombotic bleeding. With the exception of recombinant tissue plasminogen activator (rt-PA), which is a thrombolytic drug used to recanalize the occluded artery, most treatments have been demonstrated to be ineffective. Stroke can also induce peripheral organ damage. Most stroke patients have different degrees of injury to one or more organs, including the lung, heart, kidney, spleen, gastrointestinal tract and so on. In the acute phase of stroke, severe inflammation occurs in the brain, but there is strong immunosuppression in the peripheral organs, which greatly increases the risk of peripheral organ infection and aggravates organ damage. Nonneurological complications of stroke can affect treatment and prognosis, may cause serious short-term and long-term consequences and are associated with prolonged hospitalization and increased mortality. Many of these complications are preventable, and their adverse effects can be effectively mitigated by early detection and appropriate treatment with various medical measures. This article reviews the pathophysiological mechanism, clinical manifestations and treatment of peripheral organ injury after stroke.

Predictive Value of Total Small-Vessel Disease Score for Recurrent Stroke in Patients Undergoing MaintenanceHemodialysis

OBJECTIVES

We sought to examine the validity of the total small-vessel disease (SVD) score in patients receiving maintenance hemodialysis by investigating its predictive value for recurrent stroke.

METHODS

We identified 159 patients who showed acute ischemic stroke while receiving maintenance hemodialysis at our institute between January 1, 2008, and December 31, 2020; retrospectively calculated the total SVD score for each patient; and extracted data on demographic factors and comorbidities that could potentially affect recurrent stroke. Death was thought to be a potential competing risk for recurrent stroke because the perceived risk of death was considerably higher than the risk of recurrent stroke in these patients. Thus, we investigated the association between the total SVD score and recurrent stroke by analyzing the competing risk of non-stroke death.

RESULTS

The median (interquartile range) age was 72 (62-80) years. A total of 38 (23.9%) recurrent strokes occurred, and 69 (43.4%) patients died during the 505 patient-year follow-up study. The estimated cumulative incidence of recurrent stroke at five years was 13.3%, 13.4%, 24.1%, 50%, and 60% for scores of 0 to 4, respectively, and the hazard ratio (HR), adjusted for variables that had been reported to be risk factors of stroke in dialysis patients, per unit increase in the score was 1.72 (95% CI, 1.34-2.21; p<0.001).

CONCLUSION

A higher total SVD score was associated with an increased risk of recurrent stroke in patients undergoing maintenance hemodialysis.

Prevalence of Stroke and Stroke Risk Factors in a South-Western Community of Nepal

BACKGROUND

Stroke related studies in Nepal are primarily hospital-based and mainly from the capital city.

OBJECTIVES

We aimed to estimate the prevalence of stroke and stroke risk factors in the South-Western community of Nepal.

METHODS

A cross-sectional study was conducted from May to August 2018 among 549 randomly selected Nepalese participants from diverse ethnicity, aged ≥15 years, in a region with the availability of neurological support facilities. Data were collected using a stroke questionnaire designed for the purpose. Stroke was identified by enumerators using the Balance-Eyes-Face-Arms-Speech-Time (BEFAST) scale, and a senior neurologist confirmed it. We assessed the presence of major risk factors associated with stroke.

RESULTS

The crude and age-standardised prevalence of stroke were 2368 and 2967 per 100,000 respectively. Of all the surveyed participants, 61% (n=335) reported consumption of full-fat dairy products >3 days per week, 87.6% (n=481) reported a high intake of salt (>5 g/day), 83.6% (n=459) with a low intake of fruits and vegetables (<400 g/day), 45.2% (n=248) with perceived stress related to work or home, 51.6% (n=283) with financial stress (283, 51.6%), 86.7% (n=457) with low high-density lipoprotein, 96.2% (n=507) with high blood urea nitrogen, 47.1% (n=356) were either overweight or obese 20.4% (n=112) with hypertension and 6.2% (n=34) with diabetes.

CONCLUSIONS

The prevalence of stroke in the community of the South-Western part of Nepal is relatively higher than that estimated in South-Asia and global context. Our findings suggest an urgent community intervention, particularly with healthy lifestyles changes for future stroke prevention in the high-risk group.

Cerebro-renal interaction and stroke

Stroke is an event causing a disturbance in cerebral function leading to death and disability worldwide. Both acute kidney injury and chronic kidney disease (CKD) are associated with an increased risk of stroke and cerebrovascular events. The underlying mechanistic approach between impaired renal function and stroke is limitedly explored and has attracted researchers to learn more for developing therapeutic intervention. Common risk factors such as hypertension, hyperphosphatemia, atrial fibrillation, arteriosclerosis, hyperhomocysteinemia, blood-brain barrier disruption, inflammation, etc. are observed in the general population, but are high in renal failure patients. Also, risk factors like bone mineral metabolism, uremic toxins, and anemia, along with the process of dialysis in CKD patients, eventually increases the risk of stroke. Therefore, early detection of risks associated with stroke in CKD is imperative, which may decrease the mortality associated with it. This review highlights mechanisms by which kidney dysfunction can lead to cerebrovascular events and increase the risk of stroke in renal impairment.

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.

Chronic Kidney Disease and Outcome Following Endovascular Thrombectomy for Acute Ischemic Stroke

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) is present in 20% to 35% of acute ischemic stroke patients and may increase the risk of poor functional outcome or death. We aimed to determine whether CKD was associated with worse outcome in stroke patients treated with endovascular thrombectomy (EVT).

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Consecutive EVT patients were identified from a prospective registry and dichotomized into patients with and without CKD, defined as an eGFR of less than 60 mL/min/1.73m². The primary outcome was 3-month mortality following EVT. Secondary outcomes included symptomatic intracerebral hemorrhage (defined by the Safe Implementation of Thrombolysis in Stroke-Monitoring Study), early neurological recovery (defined as change in National Institutes of Health Stroke Scale [NIHSS] score of ≥8 at 24 hours or an NIHSS of 0-1 at 24 hours) and functional independence (defined as a modified Rankin Scale [mRS] score of 0, 1 or 2) at 3 months.

RESULTS

378 EVT patients (223 men; mean ± SD age 65 ± 15 years) were included. The median (IQR) admission eGFR was 71 (58-89) mL/min/1.73 m² and 117 (31%) patients had CKD. Multiple logistic regression adjusted for potential confounders demonstrated that CKD was a significant predictor of lower rates of functional independence (OR = .54, 95% CI, .31 to .90, P = .02), higher mRS scores (common OR = 1.78, 95% CI, 1.14 to 2.81, P = .01), and increased mortality (OR = 2.19, 95% CI, 1.16 to 4.12, P = .01). There was no association between CKD and early neurological recovery (OR = .92, 95% CI, .55 to 1.49, P = .71) or symptomatic intracerebral hemorrhage (OR = 1.18, 95% CI, .38 to 3.69, P = .77).

CONCLUSIONS

CKD was a significant predictor of worse functional outcome and mortality in stroke patients treated with EVT. The presence of CKD should not preclude patients from proceeding to EVT, but may help with prognostication and improve shared decision-making between patients, families and physicians.

Clinical Variables and Genetic Risk Factors Associated with the Acute Outcome of Ischemic Stroke: A Systematic Review

Stroke is a complex disease and one of the main causes of morbidity and mortality among the adult population. A huge variety of factors is known to influence patient outcome, including demographic variables, comorbidities or genetics. In this review, we expound what is known about the influence of clinical variables and related genetic risk factors on ischemic stroke outcome, focusing on acute and subacute outcome (within 24 to 48 hours after stroke and until day 10, respectively), as they are the first indicators of stroke damage. We searched the PubMed data base for articles that investigated the interaction between clinical variables or genetic factors and acute or subacute stroke outcome. A total of 61 studies were finally included in this review. Regarding the data collected, the variables consistently associated with acute stroke outcome are: glucose levels, blood pressure, presence of atrial fibrillation, prior statin treatment, stroke severity, type of acute treatment performed, severe neurological complications, leukocyte levels, and genetic risk factors. Further research and international efforts are required in this field, which should include genome-wide association studies.

Effect of Baseline Kidney Function on the Risk of Recurrent Stroke and on Effects of Intensive Blood Pressure Control in Patients With Previous Lacunar Stroke: A Post Hoc Analysis of the SPS3 Trial (Secondary Prevention of Small Subcortical Strokes)

Background We conducted a post hoc analysis of the SPS3 (Secondary Prevention of Small Subcortical Strokes) Trial to examine the association of chronic kidney disease (CKD) with recurrent stroke, and to assess whether baseline renal function modifies the effects of intensive systolic blood pressure control in patients with previous stroke. Methods and Results A total of 3020 patients with recent magnetic resonance imaging-defined symptomatic lacunar infarctions were randomized to a systolic blood pressure target of <130 mm Hg versus 130 to 149 mm Hg. Predefined primary outcomes were (all-recurrent) stroke and a composite of stroke, acute myocardial infarction, or all-cause death; secondary outcomes were acute myocardial infarction, all-cause death, and intracerebral hemorrhage individually. Among 3017 patients with baseline estimated glomerular filtration rate measurements, we evaluated, using Cox proportional hazards models, the association of CKD with recurrent stroke and effects of the blood pressure targets on outcomes using baseline estimated glomerular filtration rate both as a categorical and linear variable. Regardless of the randomized treatment, CKD at baseline was significantly associated with an increased risk of the primary cardiovascular composite outcome (hazard ratio, 1.7; 95% CI, 1.4-2.1), and all-recurrent stroke (1.5; 1.1-2.0). However, the effects of the lower systolic blood pressure intervention on the primary outcome were not influenced by baseline CKD status (P for interaction=0.62). Conclusions CKD increases the risk of recurrent stroke by 50% in patients with previous lacunar stroke. We found no definitive evidence that renal dysfunction modifies the effects of systolic blood pressure control in patients with previous stroke. Conclusive evidence for this will require adequately powered studies with moderate-to-advanced CKD. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00059306.

Hyperglycemia is associated with poor in-hospital outcome in elderly patients with acute ischemic stroke

Fasting hyperglycemia is associated with poor neurologic outcome in acute ischemic stroke (AIS), but its relationship with in-hospital outcome in elderly patients remains largely unknown. To assess the association of in-hospital outcome with fasting plasma glucose (FPG) levels at admission in individuals with AIS.This retrospective propensity score-matched case-control study included patients aged over 60 years suffering from AIS and who were admitted to the emergency department from November 2013 to October 2016. Subjects were grouped into the poor-outcome and good-outcome groups based on mortality and intensive care unit (ICU) admission.The poor- and good-outcome groups comprised 74 and 1927 cases, respectively, before propensity score matching (PSM), and 74 and 296 cases, respectively, after PSM. Univariable logistic regression analysis showed that initial FPG after admission was associated with poor in-hospital outcome. Multivariable logistic regression analysis showed that initial FPG after admission was an independent predictor of poor in-hospital outcome (odds ratio = 1.11, 95% confidence interval: 1.037-1.188, P = .003).This study used PSM and strongly suggests that FPG is an independent predictive factor of poor in-hospital outcome in elderly patients with AIS. High initial FPG levels after admission may predict poor in-hospital outcome. Prospective studies are needed to confirm these findings.

The Impact of Uremic Toxins on Cerebrovascular and Cognitive Disorders

Individuals at all stages of chronic kidney disease (CKD) have a higher risk of developing cognitive disorders and dementia. Stroke is also highly prevalent in this population and is associated with a higher risk of neurological deterioration, in-hospital mortality, and poor functional outcomes. Evidence from in vitro studies and in vivo animal experiments suggests that accumulation of uremic toxins may contribute to the pathogenesis of stroke and amplify vascular damage, leading to cognitive disorders and dementia. This review summarizes current evidence on the mechanisms by which uremic toxins may favour the occurrence of cerebrovascular diseases and neurological complications in CKD.

Abnormal admission kidney function predicts higher mortality in stroke patients

Objectives:

To to investigate the impact of abnormal kidney function on stroke outcome.

Methods:

This was a retrospective cohort of stroke patients admitted to King Abdulaziz University Hospital in Kingdom of Saudi Arabia between 2010 and 2014. Serum creatinine and urine protein were collected at admis-sion. We defined proteinuria as urine protein dipstick ≥+1. Estimated glomerular filtration (eGFR) rate was calculated by Modification of Diet in Renal Disease Study equation in mL/min/1.73m². Abnormal kidney disease was defined as Creatinine>126 mg/dl or eGFR<60. Clinical characteristics and outcomes including one-year mortality and 30-day readmission were compared between patients with versus (vs.) without abnormal kidney function and/or proteinuria.

Results:

Out of 548 patients, 507 had creatinine measurement at admission and 193 patients had ab-normal kidney function. These patients tended to be older (median age 67 years vs. 60.5 for those with normal kidney function), men (66.7% vs. 54.3%), and hypertensive (96% vs. 88%). Diabetes prevalence did not differ between the 2 groups. Proteinuria was not associ-ated with future mortality. Abnormal kidney function was a significant predictor of post-stroke one-year mortality (adjusted OR=2.5, 95% CI=1.4 to 4.6; p-value=0.003).

Conclusion:

Abnormal kidney function doubled the risk of one-year mortality post stroke in our cohort. High-risk groups, including older hypertensive men, could be targeted for aggressive moni-toring and early treatment of risk factors.

Value of the CHA2DS2-VASc score and Fabry-specific score for predicting new-onset or recurrent stroke/TIA in Fabry disease patients without atrial fibrillation

Objectives

To evaluate potential risk factors for stroke or transient ischemic attacks (TIA) and to test the feasibility and efficacy of a Fabry-specific stroke risk score in Fabry disease (FD) patients without atrial fibrillation (AF).

Background

FD patients often experience cerebrovascular events (stroke/TIA) at young age.

Methods

159 genetically confirmed FD patients without AF (aged 40 ± 14 years, 42.1% male) were included, and risk factors for stroke/TIA events were determined. All patients were followed up over a median period of 60 (quartiles 35–90) months. The pre-defined primary outcomes included new-onset or recurrent stroke/TIA and all-cause death.

Results

Prior stroke/TIA (HR 19.97, P < .001), angiokeratoma (HR 4.06, P = .010), elevated creatinine (HR 3.74, P = .011), significant left ventricular hypertrophy (HR 4.07, P = .017), and reduced global systolic strain (GLS, HR 5.19, P = .002) remained as independent risk predictors of new-onset or recurrent stroke/TIA in FD patients without AF. A Fabry-specific score was established based on above defined risk factors, proving somehow superior to the CHA₂DS₂-VASc score in predicting new-onset or recurrent stroke/TIA in this cohort (AUC 0.87 vs. 0.75, P = .199).

Conclusions

Prior stroke/TIA, angiokeratoma, renal dysfunction, left ventricular hypertrophy, and global systolic dysfunction are independent risk factors for new-onset or recurrent stroke/TIA in FD patients without AF. It is feasible to predict new or recurrent cerebral events with the Fabry-specific score based on the above defined risk factors. Future studies are warranted to test if FD patients with high risk for new-onset or recurrent stroke/TIA, as defined by the Fabry-specific score (≥ 2 points), might benefit from antithrombotic therapy. Clinical trial registration HEAL-FABRY (evaluation of HEArt invoLvement in patients with FABRY disease, NCT03362164).

Electronic supplementary material

The online version of this article (10.1007/s00392-018-1285-4) contains supplementary material, which is available to authorized users.

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.

Reduced Stroke Risk After Parathyroidectomy in End-Stage Renal Disease: A 13-Year Population-Based Cohort Study

Research information on the risk of stroke in patients with dialysis-dependent end-stage renal disease (ESRD) who have undergone parathyroidectomy (PTX) is scant. We used a nationwide health insurance claims database to select all patients with dialysis-dependent ESRD age 18 years and older for the study population. Of the patients with ESRD, we selected 1083 patients who had undergone PTX between 1998 and 2006 as the PTX group and frequency-matched 1083 patients with ESRD by sex, age, years since the disease diagnosis, and the year of undergoing PTX as the non-PTX group. We used a multivariate Cox proportional hazards regression analysis to measure the risk of stroke for the PTX group compared with the non-PTX group after adjusting for sex, age, premium-based income, urbanization, and comorbidity. The mean follow-up periods were 6.08 and 5.38 years for the PTX and non-PTX groups, respectively. After adjusting for previously mentioned variables, significant risk reductions of stroke (adjusted hazard ratio = 0.57, 95% confidence interval = 0.41-0.79), particularly those of hemorrhagic stroke (adjusted hazard ratio = 0.34, 95% confidence interval = 0.20-0.57), with PTX were observed. Chronologically, the risk of stroke in the PTX group decreased in the second year after PTX and persisted for >3 years. PTX reduces the risk of stroke, particularly that of hemorrhagic stroke, in patients with dialysis-dependent ESRD. Other factors for risk reduction include sex (females), an age <65 years, and the presence of comorbidity.

Ischemic stroke: the impact of renal dysfunction on 1-year mortality

BACKGROUND

Atherosclerosis is accelerated in patients with different stages of chronic renal failure. Renal dysfunction predicts mortality in patients with myocardial infarction and congestive heart failure. Less is known about the impact of renal dysfunction on mortality after ischemic stroke. The aim of the study was to investigate the impact of renal dysfunction on 1-year mortality.

PATIENTS AND METHODS

All 390 patients (207 men and 183 women) suffered from ischemic stroke in 1-year period were included in our study. Telephonic follow-up after 1 year was performed. The mean age of our patients was 71.0 ± 11.6 years, ranged from 36 to 96 years. Glomerular filtration rate (GFR) was calculated according to abbreviated Modification of Diet in Renal Disease formula. At admission and at discharge National Institutes of Health Stroke Scale (NIHSS) were performed.

RESULTS

The mean GFR in our patients was 66.0 ± 20.68 ml/min/1.73 m(2). There were 123 (31.5 %) deaths in 1-year period. Patients who died were older (P < 0.001), had higher NIHSS at admission and at discharge (both P < 0.001), higher high-sensitive C-reactive protein (P = 0.002), lower albumin (P < 0.001), lower GFR (P = 0.044), had more frequent atrial fibrillation (P < 0.001), and were less frequent actual smokers (P = 0.003). No differences in presence of diabetes and hypertension, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides between patients who died or survived were found. With Cox multivariable regression analysis age (P = 0.037), gender (P = 0.005), NIHSS at admission (P = 0.005) and discharge (P < 0.001), albumin (P = 0.005) and also GFR (P = 0.025) were predictors of 1-year mortality.

CONCLUSIONS

In patients with ischemic stroke, renal dysfunction (decreased GFR) was associated with 1-year mortality. GFR was independent predictor of mortality.