Differential impairment of psychomotor efficiency and processing speed in patients with chronic kidney disease

Differential Attention Functioning in Pediatric Chronic Kidney Disease

Objective

To compare specific attention functions for school-age children with chronic kidney disease (CKD) to those of a typically developing control group.

Methods

A cross-sectional study examined attention dimensions for children and adolescents with CKD (n = 30) in comparison to a typically developing control group (n = 41). The CKD group consisted of those receiving maintenance dialysis (n = 15) and those with mild/moderate CKD treated conservatively (n = 15). Measures aligning with Mirsky’s conceptual multidimensional model of attention were selected to compare groups across five dimensions of attention: Focus/Execute, Sustain, Stability, Shift, and Encode.

Results

Significant group differences were revealed, with the CKD group performing worse than controls on the Focus/Execute, Sustain, and Encode dimensions. The CKD group also had a larger proportion of children with scores one standard deviation or more below the mean on the Shift and Encode domains, suggesting an at-risk level of functioning in these dimensions. Secondary analyses showed disease severity to be correlated with worse attention functions for children with CKD.

Conclusion

Children with CKD may be vulnerable to subtle, specific deficits in numerous attention dimensions relative to their typically developing peers, particularly for those with more severe disease.

Structural and Functional Brain Changes in Hemodialysis Patients with End-Stage Renal Disease: DTI Analysis Results and ALFF Analysis Results

Introduction

The current study aimed to depict intrinsic structural changes and the spontaneous brain activity patterns in voxel level in patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD) by using diffusion-tensor imaging and resting-state functional magnetic resonance (MR) imaging with an amplitude of low-frequency fluctuations (ALFF) algorithm and their clinical relevance.

Materials and Methods

In the study, the diffusion-tensor imaging and resting-state functional MR imaging were performed in forty-two hemodialysis patients with ESRD and 42 healthy control subjects. Neuropsychological and laboratory tests were performed in all subjects. ALFF, fraction anisotropy (FA), and mean diffusivity (MD) values were compared between the two groups. Correlations between ALFF, FA or MD values, and clinical markers were analyzed.

Results

We found that ESRD patients exhibited significantly lower ALFF values in multiple areas, including medial frontal gyrus, limbic lobe, superior frontal gyrus, bilateral lingual gyri, occipital lobe, parahippocampal gyrus, precuneus, while increased ALFF values in medial frontal gyrus than healthy controls. FA values were decreased in medial frontal gyrus, parietal lobe, and left precuneus regions in the ESRD group compared with controls. Importantly, FA for the frontal and parietal lobes was negatively associated with the dialysis duration of ESRD patients, ALFF z-scores for the medial prefrontal cortex (MPFC) were positively correlated with the dialysis duration of ESRD patients and Serum calcium of ESRD patients negatively correlated with FA values in the frontal and parietal lobes (p<0.05).

Conclusion

Our study revealed that both impaired brain structure and function in ESRD patients with routine hemodialysis distributed mainly in the parietal, temporal, and frontal lobes. ESRD patients have cognitive impairment and declined memory ability. Serum calcium and dialysis duration might be associated with the impairment of brain structure and function in patients with ESRD.

The brain in pediatric chronic kidney disease-the intersection of cognition, neuroimaging, and clinical biomarkers

Brain growth and development occur at peak rates in early childhood through adolescence, and for some children, this must happen in conjunction with chronic kidney disease (CKD), associated medical conditions, and their treatment(s). This review provides an overview of key findings to date on the topic of the brain in pediatric CKD. Here, we specifically address the topics of neuroimaging and cognition in pediatric CKD with consideration to biomarkers of disease progression that may impact cognition. Current cognitive data suggest that most children with mild to moderate CKD do not exhibit significant cognitive impairments, but, rather, the presence of somewhat lower intellectual abilities and subtle deficits in selected executive functions. Although promising, modern neuroimaging data remain inconclusive in linking cognitive findings to neuroimaging correlates in the pediatric CKD population. Certainly, it is important to note that even subtle cognitive concerns can present barriers to learning, social functioning, and overall quality of life if not appropriately recognized or addressed. Further longitudinal research utilizing concurrent and targeted cognitive and neuroimaging evaluations is warranted to better understand the impact of CKD progression on brain development and associated neurocognitive outcomes.

Everyday discrimination and subsequent cognitive abilities across five domains

OBJECTIVE

Previous research suggests that everyday discrimination is associated with worse concomitant performance in several cognitive domains, as well as faster subsequent declines in episodic memory. This study aimed to extend knowledge on the specificity, durability, and mechanisms of associations between everyday discrimination and cognition by using a comprehensive neuropsychological battery and a longitudinal mediation design.

METHOD

Participants included 3,304 older adults in the Health and Retirement Study Harmonized Cognitive Assessment Protocol. Discrimination was assessed using the Everyday Discrimination Scale. Depressive symptoms were assessed with the 8-item Center for Epidemiological Studies Depression Scale. Vascular diseases were quantified as the self-reported presence of hypertension, diabetes, and heart disease. Confirmatory factor analysis was used to estimate episodic memory, executive functioning, processing speed, language, and visuoconstruction across a battery of 13 neuropsychological tests. Structural equation models controlled for sociodemographics and baseline cognition ascertained 2 to 4 years prior.

RESULTS

Discrimination was associated with more depressive symptoms and vascular diseases. Depressive symptoms mediated negative effects of discrimination on subsequent functioning across all 5 cognitive domains. Vascular diseases additionally mediated negative effects of discrimination on processing speed. After accounting for mediators, direct negative effects of discrimination remained for executive functioning and visuoconstruction.

CONCLUSIONS

This national longitudinal study in the United States provides evidence for broad and enduring effects of everyday discrimination on cognitive aging, which appear to be partially mediated by mental and physical health. Future research should examine additional mechanisms as well as moderators of these associations to better understand points of intervention. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Patterns and characteristics of cognitive functioning in older patients approaching end stage kidney disease, the COPE-study

BACKGROUND

The prevalence of impaired cognitive functioning in older patients with end stage kidney disease (ESKD) is high. We aim to describe patterns of memory, executive function or psychomotor speed and to identify nephrologic, geriatric and neuroradiologic characteristics associated with cognitive impairment in older patients approaching ESKD who have not yet started with renal replacement therapy (RRT).

METHODS

The COPE-study (Cognitive Decline in Older Patients with ESRD) is a prospective cohort study including 157 participants aged 65 years and older approaching ESKD (eGFR ≤20 ml/min/1.73 m²) prior to starting with RRT. In addition to routinely collected clinical parameters related to ESKD, such as vascular disease burden and parameters of metabolic disturbance, patients received a full geriatric assessment, including extensive neuropsychological testing. In a subgroup of patients (n = 93) a brain MRI was performed.

RESULTS

The median age was 75.3 years. Compared to the normative data of neuropsychological testing participants memory performance was in the 24th percentile, executive function in the 18th percentile and psychomotor speed in the 20th percentile. Independent associated characteristics of impairment in memory, executive and psychomotor speed were high age, low educational level and low functional status (all p-values < 0.003). A history of vascular disease (p = 0.007) and more white matter hyperintensities on brain MRI (p = 0.013) were associated with a lower psychomotor speed.

CONCLUSION

Older patients approaching ESKD have a high prevalence of impaired memory, executive function and psychomotor speed. The patterns of cognitive impairment and brain changes on MRI are suggestive of vascular cognitive impairment. These findings could be of potentially added value in the decision-making process concerning patients with ESKD.

Prevalence and Prognosis of Coexisting Frailty and Cognitive Impairment in Patients on Continuous Ambulatory Peritoneal Dialysis

The aim of this study was to investigate the prevalence of coexisting frailty and cognitive impairment and its association with clinical outcomes in patients on continuous ambulatory peritoneal dialysis (CAPD). Patients on CAPD started to enroll from 2014 to 2016 and ended follow-up by 2017. Frailty was assessed by clinical frailty scale (CFS), and cognitive function was assessed by Montreal Cognitive Assessment (MoCA). Totally 784 CAPD patients were recruited, with median duration of PD 30.7 (8.9~54.3) months. The mean age was 48.8 ± 14.6 years, 320 (40.8%) patients were female and 130 (16.6%) had diabetic nephropathy. Patients with cognitive impairment were more than those with frailty (55.5% vs. 27.6%). Coexisting frailty and cognitive impairment was present in 23.9% patients. Pathway analysis showed that CFS score was negatively associated with MoCA score (β = −0.69, P < 0.001). Coexisting frailty and cognitive impairment was associated with decreased patient survival rate (Log-rank = 84.33, P < 0.001) and increased peritonitis rate (0.22 vs. 0.11, 0.15 and 0.12 episodes per patient year, respectively; all P < 0.001). It was concluded that there was a relatively high prevalence of coexisting frailty and cognitive impairment among patients on CAPD. Frailty was positively associated with cognitive impairment. Coexisting frailty and cognitive impairment increased the risk of adverse outcomes.

Correlates of cognitive impairment in patients with chronic kidney failure on haemodialysis: Systematic review and meta-analysis

AIM

To review and identify correlates of cognitive impairment in patients with chronic kidney failure (CKF) on haemodialysis.

BACKGROUND

The literature is consistent with regard to the high prevalence of cognitive impairment among patients with CKF on haemodialysis and its dependence on multidimensional risk factors.

DESIGN

Systematic review and meta-analysis based on Cochrane Handbook and PRISMA.

DATA SOURCES

Electronic searches of the MEDLINE, EMBASE, Cochrane Library databases and major Korean databases were used. Only original research that assessed correlates of cognitive impairment in patients with CKF on haemodialysis and published between 2004-2016 in English or Korean were included.

REVIEW METHODS

Studies were selected according to the PICOS: Population (chronic kidney failure patients with cognitive impairment on haemodialysis); Intervention (not applicable); Comparison (healthy controls or patients with chronic kidney failure on haemodialysis without cognitive impairment); Outcome (cognitive impairment); and Study design (primarily nonexperimental correlational studies and studies with experimental, quasi-experimental, or pre-post cohort designs). Q-test and I² index were used to examine study homogeneity.

RESULTS

A total of 39 studies were finally included. Age, gender, stroke history, difficulties in activities of daily life, haemoglobin levels, pain, sleep difficulties, and depression were found to be significant correlates of cognitive impairment.

CONCLUSIONS

Nurses should be aware that the risk of cognitive impairment in patients with CKF on haemodialysis can be significantly higher for elders, women and in patients with a stroke, greater difficulties in activities of daily living, lower haemoglobin concentrations, higher pain levels, sleep difficulties, or depression.

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.

Risk for cognitive impairment across 22 measures of cognitive ability in early-stage chronic kidney disease

Background

Chronic kidney disease (CKD) is a significant risk factor for cognitive impairment. Previous studies have examined differences in cognitive impairment between persons with and without CKD using multiple cognitive outcomes, but few have done this for an extensive battery of cognitive tests. We relate early-stage CKD to two indices of impairment for 22 measures of cognitive ability.

Methods

The study was community-based and cross-sectional with 898 individuals free from dementia and end-stage renal disease. Estimated glomerular filtration rate (eGFR) was calculated using the chronic kidney disease epidemiology collaboration equation and classified as <60 or ≥60 mL/min/1.73 m2, based on consensus definitions of Stage 3 or greater CKD. The eGFR classifications were related to modest [≥1 standard deviation (SD) below the mean] and severe (≥1.5 SD below the mean) impairment on each measure using logistic regression analyses adjusting for potential risk factors.

Results

A total of 146 individuals (16.3%) had eGFR <60 mL/min/1.73 m2 (mean 51.6 ± 10.1 mL/min/1.73 m2). These participants had significantly greater risk for modestly impaired abilities in the scanning and tracking and visual-spatial organization/memory (VSOM) domains after accounting for comorbidity-related risk factors [odds ratios (ORs) between 1.68 and 2.16], as well as greater risk for severely impaired functioning in the language domain (OR = 2.65).

Conclusions

Participants with eGFR <60 mL/min/1.73 m2 were at higher risk for cognitive impairment than those with eGFR ≥60 mL/min/1.73 m2 on the majority of cognitive abilities, specifically those within the VSOM, Language, and scanning and tracking domains. Targeted screening for cognitive deficits in kidney disease patients early in their disease course may be warranted.

Association of blood pressure variability and neurocognition in children with chronic kidney disease

BACKGROUND

Children with chronic kidney disease (CKD) and hypertension have increased blood pressure variability (BPV), which has been associated with lower neurocognitive test scores in adults. Children with CKD are at risk for decreased neurocognitive function. Our objective was to determine whether children with CKD and increased BPV had worse performance on neurocognitive testing compared with children with CKD and lower BPV.

METHODS

This was a cross-sectional and longitudinal analysis of the relation between BPV and neurocognitive test performance in children ≥6 years enrolled in the Chronic Kidney Disease in Children (CKiD) study. Visit-to-visit BPV was assessed by the standard deviation of visit BPs (BPV-SD) and average real variability (ARV). Ambulatory BPV was assessed by SD of wake and sleep periods on 24-h ambulatory BP monitoring.

RESULTS

We assessed 650 children with a mean follow-up period of 4.0 years. Children with systolic visit-to-visit BPV in the upper tertile had lower scores on Delis-Kaplan Executive Function System (D-KEFS) Verbal Category Switching than those with BPV in the lower tertile (BPV-SD, 8.3 vs. 9.5, p = 0.006; ARV, 8.5 vs. 9.6, p = 0.02). On multivariate analysis, the association between lower Category Switching score and increased BPV remained significant after controlling for mean BP, demographic characteristics, and disease-related variables [BPV-SD, β = -0.7, 95 % confidence interval (CI) -1.28 to -0.12; ARV, β = -0.54, CI -1.05 to -0.02). Ambulatory BPV was not independently associated with any cognitive measure.

CONCLUSIONS

Higher systolic visit-to-visit BPV was independently associated with decreased D-KEFS Category Switching scores in children with mild-to-moderate CKD.

Spatial Disassociation of Disrupted Functional Connectivity for the Default Mode Network in Patients with End-Stage Renal Disease

PURPOSE

To investigate the aberrant functional connectivity of the default mode network (DMN) in patients with end-stage renal disease (ESRD) and their clinical relevance.

MATERIALS AND METHODS

Resting-state functional MRI data were collected from 31 patients with ESRD (24 men, 24-61 years) and 31 age- and gender-matched healthy controls (HCs, 21 men, 26-61years). A whole-brain seed-based functional connectivity analysis of these collected R-fMRI data was performed by locating the seeds in the posterior cingulate cortex (PCC) and ventromedial prefrontal cortex (vmPFC) to investigate the functional connectivity of the posterior and anterior DMN over the whole brain, respectively.

RESULTS

Compared to the HCs, the patients exhibited significantly decreased functional connectivity with the PCC in the left middle temporal gyrus, the right anterior cingulate gyrus, and the bilateral medial superior frontal gyrus. For the vmPFC seed, only the right thalamus showed significantly decreased functional connectivity in the patients with ESRD compared to HCs. Interestingly, functional connectivity between the PCC and right medial superior frontal gyrus exhibited a significantly positive correlation with the hemoglobin level in the patients.

CONCLUSION

Our findings suggest a spatially specific disruption of functional connectivity in the DMN in patients with ESRD, thereby providing novel insights into our understanding of the neurophysiology mechanism that underlies the disease.

The impact of hemodialysis on cognitive dysfunction in patients with end-stage renal disease: a resting-state functional MRI study

To investigate the effect of hemodialysis (HD) on cognitive dysfunction in patients with end-stage renal disease (ESRD) using resting-state functional MR imaging (rs-fMRI) with regional homogeneity (ReHo) and functional connectivity algorithms. The rs-fMRI data were acquired in 58 ESRD patients (HD patients, n = 32, 22 male and 10 female, mean age 36.5 ± 9.6 years; non-HD ESRD patients, n = 26, 16 male and 10 female, mean years of 35.6 ± 8.2) and 32 healthy controls (22 male and 10 female, mean years of 32.7 ± 8.8). A battery of neuropsychological and blood laboratory tests were prescribed. The Kendall's coefficient of concordance (KCC) was used to measure ReHo for each subject. The ReHo maps were compared by using ANOVA tests among HD, non-HD, and healthy control groups. Regions showing ReHo differences between HD and non-HD patients were defined as seeds for further functional connectivity analysis. A multiple regression analysis was performed to evaluate the relationships between ReHo index and neuropsychological tests, serum creatinine and urea levels, disease and dialysis duration. Compared with healthy controls, both HD patients and non-HD patients showed decreased ReHo in the multiple areas of bilateral frontal, parietal and temporal lobes. Compared with the non-HD, HD patients showed decreased ReHo mainly in default mode network (DMN) including bilateral precuneus, posterior cingulate cortex, inferior parietal lobe, right postcentral gyrus, bilateral superior temporal gyri, right supramarginal gyrus and right angular gyrus. Some reduced ReHo brain regions correlated with some neuropsychological tests, serum creatinine and urea levels, and dialysis duration. Brain regions with ReHo reduction showed increased region-to-region functional network in HD patients compared with non-HD patients. Widespreadly decreased ReHo values were found in both HD and non-HD patients. Lower ReHo values mainly in the DMN correlated with cognition impairments were observed in HD patients compared with non-HD patients, while increased functional connectivity was found between these brain regions. HD might have an adverse effect on the cognitive function in ESRD patients.

Aberrant functional connectome in neurologically asymptomatic patients with end-stage renal disease

Purpose

This study aimed to investigate the topological organization of intrinsic functional brain networks in patients with end-stage renal disease (ESRD).

Materials and Methods

Resting-state functional MRI data were collected from 22 patients with ESRD (16 men, 18–61 years) and 29age- and gender-matched healthy controls (HCs, 19 men, 32–61 years). Whole-brain functional networks were obtained by calculating the interregional correlation of low-frequency fluctuations in spontaneous brain activity among 1,024 parcels that cover the entire cerebrum. Weighted graph-based models were then employed to topologically characterize these networks at different global, modular and nodal levels.

Results

Compared to HCs, the patients exhibited significant disruption in parallel information processing over the whole networks (P< 0.05). The disruption was present in all the functional modules (default mode, executive control, sensorimotor and visual networks) although decreased functional connectivity was observed only within the default mode network. Regional analysis showed that the disease disproportionately weakened nodal efficiency of the default mode components and tended to preferentially affect central or hub-like regions. Intriguingly, the network abnormalities correlated with biochemical hemoglobin and serum calcium levels in the patients. Finally, the functional changes were substantively unchanged after correcting for gray matter atrophy in the patients.

Conclusion

Our findings provide evidence for the disconnection nature of ESRD’s brain and therefore have important implications for understanding the neuropathologic substrate of the disease from disrupted network organization perspective.

Cerebro-renal interactions: impact of uremic toxins on cognitive function

Cognitive impairment (CI) associated with chronic kidney disease (CKD) has received attention as an important problem in recent years. Causes of CI with CKD are multifactorial, and include cerebrovascular disease, renal anemia, secondary hyperparathyroidism, dialysis disequilibrium, and uremic toxins (UTs). Among these causes, little is known about the role of UTs. We therefore selected 21 uremic compounds, and summarized reports of cerebro-renal interactions associated with UTs. Among the compounds, uric acid, indoxyl sulfate, p-cresyl sulfate, interleukin 1-β, interleukin 6, TNF-α, and PTH were most likely to affect the cerebro-renal interaction dysfunction; however, sufficient data have not been obtained for other UTs. Notably, most of the data were not obtained under uremic conditions; therefore, the impact and mechanism of each UT on cognition and central nervous system in uremic state remains unknown. At present, impacts and mechanisms of UT effects on cognition are poorly understood. Clarifying the mechanisms and establishing novel therapeutic strategies for cerebro-renal interaction dysfunction is expected to be subject of future research.

Altered pattern of spontaneous brain activity in the patients with end-stage renal disease: a resting-state functional MRI study with regional homogeneity analysis

PURPOSE

To investigate the pattern of spontaneous neural activity in patients with end-stage renal disease (ESRD) with and without neurocognitive dysfunction using resting-state functional magnetic resonance imaging (rs-fMRI) with a regional homogeneity (ReHo) algorithm.

MATERIALS AND METHODS

rs-fMRI data were acquired in 36 ESRD patients (minimal nephro-encephalopathy [MNE], n = 19, 13 male, 37±12.07 years; non-nephro-encephalopathy [non-NE], n = 17, 11 male, 38±12.13 years) and 20 healthy controls (13 male, 7 female, 36±10.27 years). Neuropsychological (number connection test type A [NCT-A], digit symbol test [DST]) and laboratory tests were performed in all patients. The Kendall's coefficient of concordance (KCC) was used to measure the regional homogeneity for each subject. The regional homogeneity maps were compared using ANOVA tests among MNE, non-NE, and healthy control groups and post hoc t -tests between each pair in a voxel-wise way. A multiple regression analysis was performed to evaluate the relationships between ReHo index and NCT-A, DST scores, serum creatinine and urea levels, disease and dialysis duration.

RESULTS

Compared with healthy controls, both MNE and non-NE patients showed decreased ReHo in the multiple areas of bilateral frontal, parietal and temporal lobes. Compared with the non-NE, MNE patients showed decreased ReHo in the right inferior parietal lobe (IPL), medial frontal cortex (MFC) and left precuneus (PCu). The NCT-A scores and serum urea levels of ESRD patients negatively correlated with ReHo values in the frontal and parietal lobes, while DST scores positively correlated with ReHo values in the bilateral PCC/precuneus, MFC and inferior parietal lobe (IPL) (all P<0.05, AlphaSim corrected). No significant correlations were found between any regional ReHo values and disease duration, dialysis duration and serum creatinine values in ESRD patients (all P>0.05, AlphaSim corrected).

CONCLUSION

Diffused decreased ReHo values were found in both MNE and non-NE patients. The progressively decreased ReHo in the default mode network (DMN), frontal and parietal lobes might be trait-related in MNE. The ReHo analysis may be potentially valuable for elucidating neurocognitive abnormalities of ESRD patients and detecting the development from non-NE to MNE.

Attention and information processing in end stage renal disease and effect of hemodialysis: a bedside study

The neurobehavioral syndrome of uremia in chronic kidney disease affects the functioning of the central nervous system. Cognitive impairment is one of the most important manifestations of this dysfunction. The process of hemodialysis is known to bring about conflicting changes in the cognitive status of patients. In the present study an assessment of cognitive status of patients with end stage renal disease was done in comparison to controls before and after a session of hemodialysis using simple bedside paper-pencil tests. Thirty patients of end stage renal disease on maintenance dialysis for at least one month with MMSE score >24 were assessed one hour before and one hour after hemodialysis using Digit Symbol Substitution Test, One Letter and Three Letter Cancellations tasks. Their results were compared to age and sex matched healthy controls. The patients with end stage renal disease had significantly lower performance in cognitive tests in comparison to controls. The performance improved 1 hour after hemodialysis in comparison to pre-dialysis values. However, the values after dialysis were significantly lower than in controls, thereby indicating that though the cognitive functions improved after hemodialysis, they did not reach the control levels. There was also a significant change in the biochemical parameters after dialysis. We conclude that patients with end stage renal disease suffered from cognitive impairment which improved on hemodialysis due to removal of metabolic waste products.

Prevalence and pattern of neurocognitive impairment in nigerians with stages 3 to 5 chronic kidney disease

Background. Cognitive impairment with its negative effect on quality of life has been reported in chronic kidney disease (CKD). The paucity of the literature on cognitive impairment in Africans with CKD prompted this study. Objectives. To determine the frequency and pattern of cognitive impairment in patients with stages 3 to 5 CKD. Methods. We studied 79 consecutive consenting adults with a National Kidney Foundation (NKF) stage 3 to 5 CKD based on their estimated glomerular filtration rate using the Cockcroft-Gault formula. The controls consisted of healthy demographically matched subjects. Community screening instrument for dementia (CSI'D), trail making test A (TMTA), and trail making test B (TMTB) were used for cognitive assessment. Results. More CKD patients had cognitive impairment compared with controls using CSI'D (51.9% versus 2.5%, P < 0.001); TMTA (53.2% versus 0%, P < 0.001); and TMTB (40% versus 0%, P < 0.001). The odds of having cognitive impairment increased in the presence of CKD when assessed using CSI'D (OR = 2.026; CI = 1.607-2.555); TMTA (OR = 3.13; CI = 2.40-4.09) and TMTB (OR = 3.22; CI = 2.42-4.25). CKD patients performed poorer on tests of executive function TMTA (P < 0.001) and TMTB (P < 0.001) while CSI'D showed significantly lower scores on multiple cognitive domains. Conclusions. Significant cognitive impairment in multiple domains exists among Nigerians with CKD.

Neurocognitive profile of an adult sample with chronic kidney disease

Chronic kidney disease (CKD) is a common and debilitating illness that impacts neurocognitive function. However, the majority of previous studies varied in methodologic design and rigor, thus minimizing definitive conclusions. The present study was designed to determine the impact of CKD on neurocognitive function through specific examination of CKD factors and therapeutic interventions. We evaluated 120 CKD outpatients and 41 healthy donors (controls) in terms of neurocognitive function, anxiety, and depressive symptomatology, and somnolence. Information regarding medical and treatment history was recorded. Twenty-three percent of CKD patients presented with cognitive impairment. Stage 5 patients had lower scores (p < .05) compared with controls and patients in stage 3 and 4 on measures of global cognitive function. No differences in global cognitive function were found between stage 3 and 4 patients and controls. A greater proportion of patients undergoing hemodialysis relative to those treated with peritoneal dialysis showed impairment on measures of memory functions. Results suggest that stage 5 CKD patients may present with impaired cognitive functions. Anemia appeared to be a key variable that may explain the memory impairment in this sample. Future longitudinal investigations of CKD are warranted to determine the trajectory of cognitive impairment.

Neuropsychiatric complications of chronic kidney disease

Evidence is emerging that cognitive impairment, delirium and depression are very common in patients with renal disease. All of these conditions are associated with prolonged hospitalization and an increased risk of mortality. A good understanding of these conditions is key to their prevention, early intervention and management. This Review summarizes the clinical features of various forms of cognitive dysfunction that occur in individuals with renal disease and describes the evidence for the high burden of disease in such patients.