Neurocognitive disorders are frequent among chronic kidney disease (CKD) patients. Identifying and characterizing cognitive impairment (CI) can help to assess the ability of adherence to CKD risk reduction strategy, identify potentially reversible causes of cognitive decline, modify pharmacotherapy, educate the patient and caregiver and provide appropriate patient and caregiver support. Numerous factors are associated with the development and progression of CI in CKD patients and various conditions can influence the results of cognitive assessment in these patients. Here we review clinical warning signs that should lead to cognitive screening; conditions frequent in CKD at risk to interfere with cognitive testing or performance, including specificities of cognitive assessment in dialysis patients or after kidney transplantation; and available tests for screening and observed cognitive patterns in CKD patients.

Background: Cognitive impairment is common in patients with chronic kidney disease (CKD), and early intervention may prevent the progression of this condition.Methods: Here, we review interventions for the complications of CKD (anemia, secondary hyperparathyroidism, metabolic acidosis, harmful effects of dialysis, the accumulation of uremic toxins) and for prevention of vascular events, interventions that may potentially be protective against cognitive impairment. Furthermore, we discuss nonpharmacological and pharmacological methods to prevent cognitive impairment and/or minimize the latter's impact on CKD patients' daily lives.Results: A particular attention on kidney function assessment is suggested during work‐up for cognitive impairment. Different approaches are promising to reduce cognitive burden in patients with CKD but the availabe dedicated data are scarce.Conclusions: There is a need for studies assessing the effect of interventions on the cognitive function of patients with CKD.

Cognitive impairment is a prevalent and debilitating complication in patients with chronic kidney disease (CKD). This position paper, developed by the Cognitive Decline in Nephro-Neurology: European Cooperative Target network, provides guidance on the epidemiology, risk factors, pathophysiology, diagnosis and clinical management of CKD-related cognitive impairment. Cognitive impairment is significantly more common in CKD patients compared with the general population, particularly those undergoing haemodialysis. The development of cognitive impairment is influenced by a complex interplay of factors, including uraemic neurotoxins, electrolytes and acid–base disorders, anaemia, vascular damage, metabolic disturbances and comorbidities like diabetes and hypertension. Effective screening and diagnostic strategies are essential for early identification of cognitive impairment utilizing cognitive assessment tools, neuroimaging and circulating biomarkers. The impact of various drug classes, including antiplatelet therapy, oral anticoagulants, lipid-lowering treatments and antihypertensive drugs, on cognitive function is evaluated. Management strategies encompass pharmacological and non-pharmacological interventions, with recommendations for optimizing cognitive function while managing CKD-related complications. This guidance highlights the importance of addressing cognitive impairment in CKD patients through early detection, careful medication management and tailored therapeutic strategies to improve patient outcomes.

Chronic kidney disease (CKD) is associated with an elevated risk of neurocognitive disorders (NCDs). It remains unclear whether CKD-related NCDs have a specific cognitive pattern or are earlier-onset phenotypes of the main NCDs (vascular NCDs and Alzheimer's disease). We used the Mini Mental State Examination score (MMSE) to assess cognitive patterns in 3003 CKD patients (stage 3–4) followed up over 5 years in the Chronic Kidney Disease–Renal Epidemiology and Information Network (CKD-REIN) cohort. After normalizing MMSE scores to a 0-to-100 scale, the associations between the baseline estimated glomerular filtration rate (eGFR, using the Chronic Kidney Disease Epidemiology Collaboration creatinine formula) and changes in each MMSE domain score were assessed in linear mixed models. Patients (age: 67 ± 13 years old; males: 65%, mean eGFR: 33± 12 mL/min/1.73 m²) had a good baseline cognitive functions: the mean MMSE score was 26.9/30 ± 2.9. After adjustment for age, sex, educational level, depression (past or present), cardiovascular risk factors and cerebrovascular disease, a lower baseline eGFR (per 10 mL/min/1.73 m²) was associated with a 0.53-point decrement [P < .001; 95% confidence interval (CI) (–0.98, –0.08)] for orientation, a 1.04-point decrement [P = .03; 95% CI (–1.96, –0.13)] for attention and calculation, a 0.78-point decrement [P = .003; 95% CI (–1.30, –0.27)] for language, and a 0.94-point decrement [P = .02; 95% CI (–1.75, –0.13)] for praxis. Baseline eGFR was not, however, associated with significant changes over time in MMSE domain scores. A lower eGFR in CKD patients was associated with early impairments in certain cognitive domains: praxis, language and attention domains before an obvious cognitive decline. Early detection of NCD in CKD patients must be performed before clinically cognitive decline using preferably tests assessing executive, attentional functions and language, rather than memory tests. This early cognitive screening could lead to a better management of cognitive impairment and their consequences on CKD management.

Background: Chronic kidney disease (CKD) is associated with cognitive impairment in general population. We assessed the association between kidney and cognitive functions in patients with CKD and the influence of cardiovascular (CV) risk factors, and depression on this association.Methods: The CKD-Renal Epidemiology and Information Network cohort included 3033 patients with CKD stages 3–4, followed for 5 years. Cognitive function was assessed with the Mini-Mental State Examination (MMSE) and estimated glomerular filtration rate (eGFR) with the CKD-Epidemiology Collaboration equation-creatinin formula. Evolution of the MMSE score over time and its association with baseline eGFR were investigated with linear mixed models. We assessed the risk of incident cognitive outcome (hospitalisation or death with relevant International Classification of Disease-10 codes), with a Cox proportional hazard model.Results: The mean age was 66.8, the mean eGFR was 33 mL/min/1.73 m²and 387 patients (13.0%) had an MMSE score below 24 at baseline. A 10 mL/min/1.73 m²decrement of baseline eGFR was associated with a mean MMSE decrease of 0.12 (95% CI 0.04 to 0.19) after adjustment for demographic characteristics, depression, CV risk factors and disease; but baseline eGFR was not associated with MMSE temporal evolution. HR for cognitive outcome during follow-up (median 2.01 years) associated with a 10 mL/min/1.73 m²decrement of baseline eGFR was 1.35 (1.07, 1.70) (p=0.01) after adjustment.Conclusions: In patients with CKD, lower eGFR was associated with worse cognitive performance and incident cognitive events, independently of demographics, CV risk factors and depression.Trial registration number: NCT03381950.

Purpose of review: The risk of cognitive impairment is higher in people with CKD than in the general population. The complex relationship between CKD and cognitive dysfunction has not been extensively characterized. Here, we review epidemiological associations, specific patterns of CKD-related cognitive impairment, the underlying mechanisms, and recently published data on relevant biomarkers. Recent findings: Despite some discrepancies, recent published studies have confirmed that CKD is associated with cognitive function (e.g. incident cognitive events). Although patients with CKD often exhibit impairments in executive functions and attention, it is noteworthy that other cognitive functions (e.g. memory) can be preserved. The key mechanisms described recently include vascular damage, genetic factors, the accumulation of uremic toxins, disruption of the blood–brain barrier, glymphatic system dysfunction, and changes in the gut–brain axis. Kidney function is increasingly seen as a game changer in the interpretation of biomarkers of cognitive impairment and, especially, hallmarks of Alzheimer disease. Summary: The data reviewed here highlight the need for interdisciplinary collaboration between nephrologists and neurologists in the care of patients with CKD at risk of cognitive impairment. In order to further improving diagnosis and therapy, future research must elucidate the mechanisms underlying the CKD–cognitive impairment association and confirm the value of biomarkers.