Progressive encephalopathy in children with chronic renal insufficiency in infancy

Peritoneal dialysis in children, what's different: Your questions answered

Maintenance peritoneal dialysis (PD) is the most used kidney replacement therapy for children with kidney failure throughout the world. Underlying causes of kidney failure, indications for dialysis, body size, and nutritional requirements differ between children and adults on PD. These differences, along with the ongoing growth and development that occurs throughout childhood, impact PD access, prescription, and monitoring in children. This review highlights the unique challenges and management approaches to optimize the care of children on maintenance PD.

The role of neuroimmune and inflammation in pediatric uremia-induced neuropathy

Uremic neuropathy in children encompasses a wide range of central nervous system (CNS), peripheral nervous system (PNS), autonomic nervous system (ANS), and psychological abnormalities, which is associated with progressive renal dysfunction. Clinically, the diagnosis of uremic neuropathy in children is often made retrospectively when symptoms improve after dialysis or transplantation, due to there is no defining signs or laboratory and imaging findings. These neurological disorders consequently result in increased morbidity and mortality among children population, making uremia an urgent public health problem worldwide. In this review, we discuss the epidemiology, potential mechanisms, possible treatments, and the shortcomings of current research of uremic neuropathy in children. Mechanistically, the uremic neuropathy may be caused by retention of uremic solutes, increased oxidative stress, neurotransmitter imbalance, and disturbance of the blood-brain barrier (BBB). Neuroimmune, including the change of inflammatory factors and immune cells, may also play a crucial role in the progression of uremic neuropathy. Different from the invasive treatment of dialysis and kidney transplantation, intervention in neuroimmune and targeted anti-inflammatory therapy may provide a new insight for the treatment of uremia.

Nasogastric Tube Feeding in Infants on Peritoneal Dialysis

Enteral nutritional support is an important component of the care provided to infants receiving long-term peritoneal dialysis. In the majority of published experiences on this subject, the use of the nasogastric tube has facilitated the provision of required calorie and protein intake and resulted in an improved patient outcome. Advantages of the nasogastric route of nutritional support include the ease of administration, while recurrent emesis remains the most troublesome and frequent shortterm complication associated with its use. Impaired oralmotor development may also result from nonoral feeding and should be addressed throughout the course of tube feeding.

The outcome of infants with ESRD receiving CPD has markedly improved since the introduction of NG feedings as a regular component of dialysis patient care. While complications associated with NG feedings have been documented, the benefits associated with this route of nutritional supplementation have been great. Currently, an increasing number of infants/ young children on CPD are receiving supplemental nutrition with the use of the gastrostomy tube/button (31). However, the risks associated with this route of therapy in the CPD population, especially in terms of infection, are as yet not well defined (32). Once the risk/benefit ratio of gastrostomy tube/button placement is determined, future efforts should be directed towards better defining how the two routes of enteral nutritional support (e.g., NG tube, gastrostomy tube/button) may best complement one another.

Neurocognitive and functional outcomes at 5 years of age after renal transplant in early childhood

BACKGROUND

Clinicians often use information about developmental outcomes in decision-making around offering complex, life-saving interventions in children such as dialysis and renal transplant. This information in children with end-stage renal disease (ESRD) is limited, particularly when ESRD onset is in infancy or early childhood.

METHODS

Using data from an ongoing prospective, longitudinal, inception cohort study of children with renal transplant before 5 years of age, we evaluated (1) the risk of adverse neurocognitive and functional outcomes at 5 years of age and (2) predictors of developmental outcomes.

RESULTS

We found evidence of neurocognitive sequelae of ESRD in very young children; however, developmental outcomes appear remarkably better when compared with findings of two or three decades ago. Less time on dialysis predicted higher developmental scores, and hemodialysis was associated with poorer developmental outcomes.

CONCLUSIONS

Our data suggest that renal replacement therapies in young children are associated with acceptable developmental outcome. Programs to identify those with developmental delays and provide early intervention may allow achievement of the child's full potential.

Neurological Complications of Renal Disease

Neurological manifestations related to electrolyte disorders, drug toxicity, and uremia are common in chronic kidney disease (CKD). Seizures and coma are frequent complications of acute renal insufficiency (uremia), whereas peripheral neuropathy and encephalopathy, observed in progressive uremia, are terminal events. Failure to excrete metabolic products causes their accumulation and can lead to severe intoxication. Clinically, the signs and symptoms of uremia can vary widely, depending on the biological characteristics of the patient, the specific type of renal disease, and the time of the uremic intoxication. CKD is an increasing problem worldwide and is now being recognized as a global health burden particularly for cardiovascular and cerebrovascular ischemic events. Despite improvements in the medical management of advanced CKD, including dialysis and transplantation, patients manifest a number of symptoms that neurologists are often confronted with. Appropriate drug dosing, awareness of potential side effects of medications, prompt diagnosis, and treatment are essential in preventing neurological long-term morbidity and mortality.

Health-related quality of life in patients with pediatric onset of end-stage renal disease: state of the art and recommendations for clinical practice

Health-related quality of life (HRQoL) is increasingly recognized as a key outcome in both clinical and research settings in the pediatric population with end-stage renal disease (ESRD). This review aims to: (1) summarize the current knowledge on HRQoL and socioprofessional outcomes and (2) provide strategies for incorporation of HRQoL assessment into clinical practice. Studies report that pediatric patients with ESRD have significantly lower HRQoL scores compared with children with other chronic diseases. Patients treated by dialysis are at particularly high risk for impaired HRQoL. Furthermore, patients more often have impaired neurocognitive functioning and lower academic achievement. Important determinants of impaired HRQoL include medical factors (i.e., receiving dialysis, disabling comorbidities, cosmetic side effects, stunted growth), sociodemographic factors (i.e., female gender, non-Western background) and psychosocial factors (i.e., noneffective coping strategies). Contrary to the situation in childhood, adult survivors of pediatric ESRD report a normal mental HRQoL. Despite this subjective feeling of well-being, these patients have on average experienced significantly more difficulties in completing their education, developing intimate relationships, and securing employment. Several medical and psychosocial strategies may potentially improve HRQoL in children with ESRD. Regular assessment of HRQoL and neurocognitive functioning in order to identify areas in which therapies and interventions may be required should be part of standard clinical care.

Neurocognitive, Social-Behavioral, and Adaptive Functioning in Preschool Children with Mild to Moderate Kidney Disease

OBJECTIVE

The negative impact of end-stage kidney disease on cognitive function in children is well established, but no studies have examined the neurocognitive, social-behavioral, and adaptive behavior skills of preschool children with mild to moderate chronic kidney disease (CKD).

METHOD

Participants included 124 preschool children with mild to moderate CKD, aged 12 to 68 months (median = 3.7 years), and an associated mean glomerular filtration rate (GFR) of 50.0 mL·min·1.73 m. In addition to level of function and percent of participants scoring ≥1 SD below the test mean, regression models examined the associations between biomarkers of CKD (GFR, anemia, hypertension, seizures, and abnormal birth history), and developmental level/IQ, attention regulation, and parent ratings of executive functions, social-behavior, and adaptive behaviors.

RESULTS

Median scores for all measures were in the average range; however, 27% were deemed at risk for a developmental level/IQ <85, 20% were at-risk for attention variability, and parent ratings indicated 30% and 37% to be at risk for executive dysfunction and adaptive behavior problems, respectively. Approximately 43% were deemed at risk on 2 or more measures. None of the disease-related variables were significantly associated with these outcomes, although the presence of hypertension approached significance for attention variability (p < .09). Abnormal birth history and lower maternal education were significantly related to lower developmental level/IQ; seizures were related to lower parental ratings of executive function and adaptive behavior; and abnormal birth history was significantly related to lower ratings of adaptive behavior. When predicting risk status, the logistic regression did evidence both higher GFR and the lack of anemia to be associated with more intact developmental level/IQ.

CONCLUSION

These findings suggest relatively intact functioning for preschool children with mild to moderate CKD, but the need for ongoing developmental surveillance in this population remains warranted, particularly for those with abnormal birth histories, seizures, and heightened disease severity.

Animal models of pediatric chronic kidney disease. Is adenine intake an appropriate model?

Pediatric chronic kidney disease (CKD) has peculiar features. In particular, growth impairment is a major clinical manifestation of CKD that debuts in pediatric age because it presents in a large proportion of infants and children with CKD and has a profound impact on the self-esteem and social integration of the stunted patients. Several factors associated with CKD may lead to growth retardation by interfering with the normal physiology of growth plate, the organ where longitudinal growth rate takes place. The study of growth plate is hardly possible in humans and justifies the use of animal models. Young rats made uremic by 5/6 nephrectomy have been widely used as a model to investigate growth retardation in CKD. This article examines the characteristics of this model and analyzes the utilization of CKD induced by high adenine diet as an alternative research protocol.

Aluminum-induced entropy in biological systems: implications for neurological disease

Over the last 200 years, mining, smelting, and refining of aluminum (Al) in various forms have increasingly exposed living species to this naturally abundant metal. Because of its prevalence in the earth's crust, prior to its recent uses it was regarded as inert and therefore harmless. However, Al is invariably toxic to living systems and has no known beneficial role in any biological systems. Humans are increasingly exposed to Al from food, water, medicinals, vaccines, and cosmetics, as well as from industrial occupational exposure. Al disrupts biological self-ordering, energy transduction, and signaling systems, thus increasing biosemiotic entropy. Beginning with the biophysics of water, disruption progresses through the macromolecules that are crucial to living processes (DNAs, RNAs, proteoglycans, and proteins). It injures cells, circuits, and subsystems and can cause catastrophic failures ending in death. Al forms toxic complexes with other elements, such as fluorine, and interacts negatively with mercury, lead, and glyphosate. Al negatively impacts the central nervous system in all species that have been studied, including humans. Because of the global impacts of Al on water dynamics and biosemiotic systems, CNS disorders in humans are sensitive indicators of the Al toxicants to which we are being exposed.

Duration of chronic kidney disease reduces attention and executive function in pediatric patients

Chronic kidney disease (CKD) in childhood is associated with neurocognitive deficits. Affected children show worse performance on tests of intelligence than their unaffected siblings and skew toward the lower end of the normal range. Here we further assessed this association in 340 pediatric patients (ages 6 to 21) with mild-moderate CKD in The Chronic Kidney Disease in Childhood cohort from 48 pediatric centers in North America. Participants underwent a battery of age-appropriate tests including Conner’s Continuous Performance Test-II (CPT-II), Delis- Kaplan Executive Function System Tower task, and the Digit Span Backwards task from the age-appropriate Wechsler Intelligence Scale. Test performance was compared across the range of estimated GFR and duration of CKD with relevant covariates including maternal education, household income, IQ, blood pressure and preterm birth. Among the 340 patients, 35% had poor performance (below the mean by1.5 or more standard deviations) on at least one test of executive function. By univariate nonparametric comparison and multiple logistic regression, longer duration of CKD was associated with increased odds ratio for poor performance on the CPT-II Errors of Commission, a test of attention regulation and inhibitory control. Thus, in a population with mild to moderate CKD, the duration of disease rather than estimated GFR was associated with impaired attention regulation and inhibitory control.

Long-term neurocognitive outcomes of patients with end-stage renal disease during infancy

BACKGROUND

End-stage renal disease (ESRD) during infancy has been associated with poor short-term neurocognitive outcomes. Limited information exists regarding long-term outcomes.

METHODS

Neurocognitive outcomes for 12 patients diagnosed with ESRD during the first 16 months of life were assessed. Nine patients (mean age: 11 years) were compared to their healthy siblings (mean age: 10 years) on measures of intellectual and executive functioning, memory, and academic achievement using paired-samples t tests.

RESULTS

Patients' Full Scale IQ (FSIQ) scores (M = 78, SD = 16.1) were significantly lower than sibling controls (M = 94, SD = 18.9; p < 0.03). For patients, FSIQ negatively correlated with total months on dialysis (r = -0.6, p < 0.04), as did WISC-IV Processing Speed (r = -0.6, p < 0.05). Patients' scores on the Metacognition Index of the BRIEF (M = 61.4, SD = 16.3) were significantly higher (indicating greater risk for dysfunction) than siblings (M = 46.7, SD = 6.4; p < 0.04). Patients' scores (M = 84, SD = 19) on the WIAT-II-A Total Achievement were significantly lower than siblings (M = 103, SD = 20, p < 0.01). Younger age at transplant was associated with higher scores on measures of Processing Speed (r = -0.7, p < 0.05), as well as higher scores on measures of executive functioning, memory, and academic achievement.

CONCLUSIONS

In summary, patients diagnosed with ESRD as infants had intellectual and metacognitive functioning significantly lower than sibling controls. Fewer months on dialysis and younger age at transplant were associated with better outcomes.

Peritoneal dialysis in infants and young children

Although end-stage renal disease is rare in infants and young children, its development can be associated with significant morbidity and mortality and only through the provision of experienced, multidisciplinary care can a favorable outcome be anticipated. Peritoneal dialysis is the renal replacement modality of choice for this age group and serves as an essential bridge until successful renal transplantation can occur. In this review, we discuss the practice of peritoneal dialysis in infants including the unique ethical and technical considerations facing pediatric nephrologists and caregivers. In addition, we review current guidelines concerning nutrition, growth, and adequacy, as well as the literature on complications and outcomes.

Neurocognitive functioning of children and adolescents with mild-to-moderate chronic kidney disease

BACKGROUND AND OBJECTIVES

Few data exist on the neurocognitive functioning of children with mild-to-moderate chronic kidney disease (CKD). The primary objectives of this paper are (1) to determine the neurocognitive status in this population and (2) to identify sociodemographic and health-status variables associated with neurocognitive functioning.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a cross-sectional study of 368 children, aged 6 to 16 years, from the Chronic Kidney Disease in Children (CKiD) cohort. Median iGFR was 43 ml/min per 1.73 m(2), and the median duration of CKD was 8.0 years. Approximately 26% had underlying glomerular disease. Measures of intelligence, academic achievement, attention regulation, and executive functioning were obtained at study entry. The prevalence of neurocognitive deficits was determined by comparing participant scores on each measure of neurocognitive functioning with normative data. The association between hypothesized predictors of neurocognitive dysfunction was evaluated using multivariate regression analyses.

RESULTS

Neurocognitive functioning was within the average range for the entire group; however, 21% to 40% of participants scored at least one SD below the mean on measures of intelligence quotient (IQ), academic achievement, attention regulation, or executive functioning. Higher iohexol-based GFR (iGFR) predicted a lesser risk for poor performance on measures of executive function. Participants having elevated proteinuria (i.e., urine protein/creatinine >2) scored lower on verbal IQ, full-scale IQ, and attention variability than those without elevated proteinuria.

CONCLUSIONS

Whereas most children with mild-to-moderate CKD have no major neurocognitive deficits, a substantial percentage did show neurocognitive dysfunction that places them at risk for poor long-term educational and occupational outcomes.

Current advances in chronic kidney disease in children: growth, cardiovascular, and neurocognitive risk factors

Linear growth and neurocognitive development are two of the most important differences between adults and children, in terms of clinical issues that must be addressed in patients with chronic kidney disease (CKD). Correction of metabolic acidosis, nutritional deficiency, and renal osteodystrophy improve linear growth, but many children require administration of growth hormone to achieve normal growth. A variety of neurocognitive deficits occur in children with CKD, although there has been an improvement in outcome via improved dialysis, correction of malnutrition, and decreased aluminum exposure. Although growth and neurocognitive development are delayed, cardiovascular complications are accelerated in children with CKD, and are reflected in a dramatic increase in cardiovascular mortality compared with healthy children. Other early cardiovascular complications in children with CKD include left ventricular hypertrophy, cardiac dysfunction, and vascular calcifications.

Head circumference and development in young children after renal transplantation

BACKGROUND

Growth impairment, microcephaly and developmental delay in young children with chronic renal failure improve after successful renal transplantation. There have been few reports on head circumference (HC) and development after transplantation.

METHOD

Standard deviation scores (SDS) of height and HC and developmental quotient (DQ) after successful renal transplantation were evaluated in 12 recipients under 5 years of age. At the time of transplantation their mean age was 2.5 years and mean bodyweight was 9.0 kg.

RESULTS

Mean height SDS was -3.0 at transplantation and increased to -2.3 at 1 year after transplant (P = 0.002). Mean HC-SDS increased from -1.4 to -0.9 at 1 year after transplant (P = 0.02). As for each category of DQ examined 1 year after transplant, mean scores of gross motor function, basic practice, personal relations, speech and recognition increased from 69 to 90 (P = 0.007), from 77 to 102 (P = 0.02), from 87 to 103 (P = 0.04), from 71 to 90 (P = 0.0006), and from 88 to 101 (P = 0.03), respectively.

CONCLUSION

In young children, physical growth, HC growth and DQ scores increased 1 year after transplantation. Dialysis and transplantation program should be planned in young children with end-stage renal failure in anticipation of growth and development of each patient.

Posterior reversible encephalopathy syndrome in the pediatric renal population

Posterior reversible leukoencephalopathy syndrome (PRES) clinically presents with seizures, severe headaches, and mental and visual changes. Our goal was to describe the clinical features, triggering factors, neuro-imaging findings, and electroencephalogram (EEG) findings in a pediatric cohort with renal disease. We retrospectively analyzed the records of 18 children with the diagnosis of PRES between January 2001 and June 2006 at the University of Miami/Holtz Children's Hospital, USA. There were 22 PRES episodes. The most common clinical presentation was generalized tonic-clonic seizures in 59% (13/22). The most common identified trigger of PRES was hypertensive crisis in 59% (13/22). Almost half of the children had no evidence of on-going uncontrolled hypertension; 44% (8/18) had normal funduscopic examination findings, and 50% (9/18) had no or mild left ventricular hypertrophy. Two of the 18 patients had recurrent PRES episodes, three episodes each. Diffuse slowing was the most common finding on the EEGs. Atypical magnetic resonance imaging (MRI) findings were more prevalent in the imaged cases (62% vs 25%, P < 0.05). All the computerized tomography (CT) scans were normal, despite the positive MRI findings in four cases when both types of imaging was used. All the episodes had total clinical resolution. In conclusion, despite the diverse initial trigger, acute hypertension seems to be the common pathogenic pathway for pediatric PRES. MRI seems superior to CT, with better sensitivity due to its high resolution and diffusion-weighted imaging. The lesions do not necessarily have to be in the posterior white matter and may not be totally reversible.

Aluminium intoxication in renal disease

Aluminium intoxication in renal failure occurred over weeks or months when dialysis fluid or parenteral solutions were heavily contaminated and over many years when the main source was oral administration of aluminium-containing phosphate binders. Encephalopathy was common during subacute intoxication but in slow aluminium poisoning the main brunt was borne by the bones. However, in both tempos of intoxication several organs or systems were involved. Encephalopathy was usually accompanied by bone disease, bone disease by parathyroid suppression and both by anaemia. The heart and the lymphocytes are probably damaged by aluminium overload. Among the many questions left unanswered 15 years after the incrimination of aluminium as the cause of this multi-system illness are: (1) does low level aluminium overload in renal failure cause gradual deterioration in cerebral function? And, if so, (2) does it resemble Alzheimer's disease or a slow-onset version of dialysis encephalopathy? The evidence we review suggests that the answer to (1) is 'yes' and to (2) 'probably the latter'.

Balancing organ quality, HLA-matching, and waiting times: impact of a pediatric priority allocation policy for deceased donor kidneys in Quebec

Deceased donor kidney allocation policy must balance the desire for high-quality organs, good human leukocyte antigen (HLA) matching, and minimal waiting times. We describe a 10-fold reduction in waiting times and an improvement in nonimmunologic indices of organ quality for child recipients after a change in organ allocation policy in Quebec, Canada. The new policy gives first priority to children (<18 yr) irrespective of HLA matching or waiting time. HLA matching after the policy change was predictably much worse. This study highlights the trade-offs that must be considered both in setting allocation policy and in decisions for individual recipients. We also consider potential unintended negative effects of such a policy change.

A randomized crossover trial comparing sevelamer with calcium acetate in children with CKD

BACKGROUND

A multicenter, randomized, open-label, crossover study was performed to compare the efficacy and safety of sevelamer, a calcium-free phosphate binder, with calcium acetate in pediatric patients with chronic kidney disease (CKD).

METHODS

Children (age, 0.9 to 18 years) with CKD undergoing hemodialysis or peritoneal dialysis or with a glomerular filtration rate of 20 or greater and less than 60 mL/min/1.73 m2 (> or = 0.33 and < 1.00 mL/s/1.73 m2) were randomly assigned to the following treatment scheme: 2 weeks of washout followed by 8 weeks of treatment with either sevelamer or calcium acetate in a crossover fashion. Phosphorus, calcium, and intact parathyroid hormone in serum were measured every 2 weeks, and phosphate binder dosages were adjusted, if needed. Serum lipid and vitamin concentrations were measured at the beginning and end of each treatment period. The primary end point was the decrease in serum phosphorus levels after 8 weeks of treatment.

RESULTS

Forty-four patients were screened. Altogether, data for 18 patients (5 girls) aged 12.4 +/- 4.1 years were used for the crossover analysis. There was no significant difference in serum phosphorus levels at 8 weeks after the start of treatment in both groups. Total cholesterol (-27%) and low-density lipoprotein cholesterol (-34%) levels decreased significantly with sevelamer treatment (P < 0.02 and P < 0.005). An increased incidence of hypercalcemia (P < 0.0005) was observed with calcium acetate treatment, whereas metabolic acidosis was more frequent with sevelamer treatment (P < 0.005).

CONCLUSION

Treatment of children with CKD with sevelamer and calcium acetate provides similar phosphorus level control. The marked decrease in lipid levels and lower rate of hypercalcemia may augment the long-term benefit of sevelamer.

Special issues in pediatric kidney transplantation

Pediatric and adult kidney transplantation differ in many ways, but one of the most significant differences is the impact of kidney disease and kidney transplantation on growth and development in pediatric patients. Multiple facets of transplantation may have an impact on growth and development, including the timing of transplantation, choice of immunosuppressive agents, and the presence of hypertension. In addition, graft function has a significant impact on linear growth, and so preservation of function becomes important not only for general health and quality of life but also for optimizing growth. Other concerns in pediatric kidney transplantation include a heightened risk for posttransplantation infectious complications, including lymphoproliferative disease. In addition, the impact of immunosuppressive drugs on adherence to therapy is important. Although adherence is a complex and multifactorial process, immunosuppressive drugs that cause physical side effects may contribute to drug nonadherence because children, and particularly adolescents, may be inclined to stop taking medications associated with physical changes that differentiate them from their peers. Studies that further delineate factors that affect growth and development, risk for infectious complications, and nonadherence will be important to maximize outcomes in pediatric kidney transplantation.

Neurocognitive outcomes in children with chronic kidney disease: Current findings and contemporary endeavors

Given the rise in chronic kidney disease (CKD) in both children and adults, CKD has recently been targeted as a public health priority. Childhood onset kidney disease is generally a noncurable and progressive condition that leads to kidney failure by early adulthood. Fortunately, improved identification of kidney problems allows for early intervention, which is thought to slow progression toward end-stage renal disease. In addition, medical interventions for pediatric end-stage renal disease have also improved, allowing children to take advantage of lifesaving renal replacement treatments such as dialysis and kidney transplantation. In spite of improvements in identification and treatment, CKD causes both direct and indirect insults to a variety of organ systems. This paper reviews recently published studies pertaining to the neurocognitive and psychosocial impact of CKD on children of various ages and at various stages of kidney failure. Specific attention is focused on summarizing peer reviewed research that describes associations between kidney functioning and cognitive functioning, language acquisition, visual spatial abilities, memory, and executive functioning. In addition, peer reviewed research describing psychosocial outcomes associated with CKD related to academic achievement, social-behavioral functioning, and quality of life are summarized. The authors also identified disease-specific factors that likely mediate neurocognitive outcomes (e.g., anemia, hypertension, cardiovascular) and endorse the importance of continued interdisciplinary research collaborations that will provide a better understanding of the mechanisms responsible for improved neurocognitive functioning after transplantation. The authors conclude this review by describing a multicenter, prospective, longitudinal, National Institutes of Health funded study that is currently examining the developmental outcomes of children with mild to moderate CKD. The authors speculate that the Chronic Kidney Disease in Children Prospective Cohort Study (CKiD) findings will provide additional evidence-based guidance for clinicians and researchers working with children and adolescents with deteriorating kidney function to improve medical and developmental outcomes.

A study on visual evoked responses in children with chronic renal failure

AIMS OF THE STUDY

Nervous involvement is frequent in patients with renal failure. Early recognition of the condition by electrophysiological tests may provide means for protective measures before irreversible damage of nervous system (NS) structures takes place. This study has two objectives: (1) examining whether pattern-reversal visual evoked potential (PR-VEP) studies may provide information relating to possible subclinical NS involvement in pediatric patients with chronic renal failure (CRF) and (2) looking for a possible relationship between serum parathormone (PTH) and creatinine levels and PR-VEP parameters.

METHODS

PR-VEP recordings at low spatial frequencies were performed and peak-to-peak amplitudes and latencies of the P100 component were measured in 19 neurologically asymptomatic children with CRF, 15 of whom were on continuous ambulatory peritoneal dialysis (CAPD) and four on hemodialysis (HD). A similar procedure was applied to 29 healthy, age- and sex-matched, subjects. Patients were sub-grouped according to the serum PTH and creatinine levels. Student's-t and one-way ANOVA tests were used for comparisons within patient and control groups and sub-groups relating to serum PTH and creatinine levels.

RESULTS

We did not demonstrate any statistically significant differences in PR-VEP parameters in patients vs. controls. PR-VEP amplitudes were higher in patients with low serum creatinine levels as compared to group with high creatinine values and to controls. No other relationship was found between PR-VEP parameters and serum PTH and creatinine levels in this pediatric population.

CONCLUSION

Young patients with CRF and under dialysis do not necessarily show pathologic alterations in PR-VEPs when they are neurologically intact. This fact suggests that either PR-VEPs are not sensitive enough to detect clinically silent NS involvements in such patients, or it could be related to positive effects of the currently improving standards in the management of dialysis and supportive nutrition. Additional factors such as the age of the patient during examination, the latency between dialysis and visual evoked potential (VEP) assessment, or the selected check size may have some impact on the results and justify further studies.

Neuropsychological functioning in end-stage renal disease

AIMS

To compare the neuropsychological functioning and behaviour of children with non-syndromic end-stage renal disease (ESRD) and sibling controls.

METHODS

The study was carried out at two tertiary care paediatric teaching hospitals, in Halifax and Vancouver, Canada. Children with ESRD were on a renal transplant waiting list and either pending dialysis or on dialysis therapy. Twenty two patient-sibling pairs were evaluated. Neuropsychological assessments consisting of measures of intelligence, academic achievement, memory, and motor abilities were carried out. Maternal ratings of behaviour and self-report rating of self-esteem were collected.

RESULTS

The Verbal, Performance, and Full Scale IQs of patients with ESRD were significantly lower than the IQs of the sibling controls. The mean differences were 8.6, 11.7, and 10.9 points, respectively. ESRD patients also had significantly more difficulty on measures of fine motor coordination and ability to copy geometric designs than sibling controls. There were no differences between groups on measures of academic achievement, memory, behaviour, or self-esteem.

CONCLUSIONS

Although children with ESRD exhibited mild deficits on measures of intelligence and some measures of motor abilities, their neuropsychological outcome was more favourable than earlier reports indicated.

Current status of kidney transplant: update 2003

Pediatric transplantation has seen remarkable advances over the past two decades with reduced morbidity and mortality, reduced rejection rates, and improved long-term patient and allograft survival. Infants currently have short-term patient and allograft survival rates better than any other age group; short-term allograft survival rates in CD recipients are equal to those in LD recipients. With decreased rejection, long-term allograft survival is improving dramatically. Transplantation allows for much reduced risks and improved metabolic status, growth and development, and more normal social interactions. The future of transplantation continues to be exciting, with opportunities for reduced immunosuppressive medications and their side effects, and the elusive goal of transplantation tolerance seems within reach.

Psychosocial adaptation after solid organ transplantation in children

The possibility of extending life with advanced medical procedures such as organ transplantation in childhood has made it possible to focus on patients' well-being in a wider perspective. They still experience a high prevalence of medical and physical disabilities, which definitively have an impact on a child's psychosocial adjustment after transplantation. Many disabilities originate before transplantation, and much effort should be taken to diminish possible complications and ameliorate growth and neurodevelopment, which have an impact for later adjustment regardless of a successful transplantation. Well-being and QOL are not necessarily always correlated to the degree of physical disability. Different social, financial, and demographic factors also have an impact, as do children's and families' ability to cope with a chronic disorder. Nonadherence and noncompliance are a great problem, particularly in adolescents. They are the result and a possible cause of inferior psychosocial adjustment. Continuous multidisciplinary support, follow-up, and education are needed to cope with this problem. Validated and reliable health status measures in pediatric transplant recipients are scarce in the literature, and few assessments can be completed by the children themselves. A continuing effort must be made to improve psychosocial adjustment and QOL after transplantation to achieve the ultimate goal in medicine: the overall well-being of our patients.

Kidney transplants for children under 1 year of age - a single-center experience

From September 20, 1970 to October 24, 2001, we performed 46 kidney transplants in infants under 1 yr old at the University of Minnesota. This article reviews the preoperative care, surgical technique, and immunosuppression. Recipients included 16 females and 30 males; the youngest recipient was 6 wk old. The mean pretransplant height was 62.8 cm, which increased to 77 cm at 1 yr post-transplant and to 104 cm at 5 yr. We used 40 living donors (all but 1 were related to the recipient) and 6 cadaver donors. The overall actuarial graft survival was 85% at 1 yr and 70% at 5 yr. In the cyclosporine era, graft survival improved to 91% at 1 yr and 80% at 5 yr. Death with function was the most common cause of graft loss (n = 5), followed by biopsy-proven chronic rejection (n = 4), biopsy-proven recurrent disease (n = 3), and graft thrombosis (n = 2). Patient survival was 91% at 1 yr and 86% at 5 yr. In the cyclosporine era, patient survival was 100% at 5 yr and 85% at 10 yr. We concluded that an early transplant is the best treatment option for infants under 1 yr old with chronic renal failure. Whenever possible, adult living kidney donors should be used.

Involvement of voltage- and ligand-gated Ca2+ channels in the neuroexcitatory and synergistic effects of putative uremic neurotoxins

BACKGROUND

Renal failure has been viewed as a state of cellular calcium toxicity due to the retention of small fast-acting molecules. We have tested this hypothesis and identified potentially neuroexcitatory compounds among a number of putative uremic neurotoxins by examining the acute in vitro effects of these compounds on cultured central neurons. The in vitro neuroexcitatory and synergistic effects of guanidinosuccinate and spermine were also examined in vivo.

METHODS

The acute effects of 17 candidate uremic neurotoxins on murine spinal cord neurons in primary dissociated cell culture were investigated using the tight-seal whole-cell recording technique. The compounds studied comprised low-molecular-weight solutes like urea, indoles, guanidino compounds, polyamines, purines and phenoles, homocysteine, orotate, and myoinositol. Currents evoked by these compounds were further examined using various ligand- and voltage-gated ion channel blockers. The acute in vivo effects of guanidinosuccinate and spermine were behaviorally assessed following their injection in mice.

RESULTS

It was shown that 3-indoxyl sulfate, guanidinosuccinate, spermine, and phenol evoked significant whole-cell currents. Inward whole-cell current evoked by 3-indoxyl sulfate was not blocked by any of the applied ligand- or voltage-gated ion channel blockers, and the compound appeared to influence miscellaneous membrane ionic conductances, probably involving voltage-gated Ca2+ channels as well. Phenol-evoked outward whole-cell currents were at least partly due to the activation of voltage-gated K+ channels, but may also involve a variety of other ionic conductances. On the other hand, inward whole-cell currents evoked by guanidinosuccinate and spermine were shown to be due to specific interaction with voltage- and ligand-gated Ca2+ channels. Guanidinosuccinate-evoked current was caused by activation of N-methyl-d-aspartate (NMDA) receptor-associated ion channels. Low (micromol/L) concentrations of spermine potentiated guanidinosuccinate-evoked current through the action of spermine on the polyamine binding site of the NMDA receptor complex, whereas current evoked by high (mmol/L) concentrations of spermine alone involved direct activation of voltage-gated Ca2+ channels. Finally, intracerebroventricular administration of 0.25 micromol/L spermine potentiated clonic convulsions induced by guanidinosuccinate. These neuroexcitatory and synergistic effects of guanidinosuccinate and spermine could take place at pathophysiologic concentrations.

CONCLUSION

The observed in vitro and in vivo effects of uremic retention solutes suggest that the identified compounds could play a significant role in uremic pathophysiology. Some of the compounds tested displayed in vitro and in vivo neuroexcitatory effects that were mediated by ligand- and voltage-gated Ca2+ channels. The findings suggest a mechanism for the involvement of calcium toxicity in the central nervous system complications in renal failure with particular reference to guanidinosuccinate and spermine.

Neurodevelopmental outcome in high-risk patients after renal transplantation in early childhood

Patient and graft survival rates of pediatric renal transplant recipients are currently excellent, but there are few reports regarding the long-term neurodevelopmental outcome after renal transplantation (Tx) in early childhood. Children with renal failure from infancy would be expected to have a less favorable developmental prognosis. We report the neurodevelopmental outcome in 33 school-age children transplanted between 1987 and 1995 when < 5 yr of age. We prospectively performed a neurological examination, magnetic resonance imaging (MRI) of the brain, electroencephalograms (EEGs), audiometry, and neuropsychological tests (NEPSY), and measured cognitive performance (WISC-R); we related these results to school performance and to retrospective risk factors prior to Tx. Twenty-six (79%) children attended normal school and 76% had normal motor performance. Six of the seven children attending a special school had brain infarcts on MRI. The EEG was abnormal in 11 (35%), and five (15%) received anti-convulsive treatment after Tx. Sensorineural hearing loss was documented in six patients. The mean intelligence quotient (IQ) was 87, and 6-24% showed impairment in neuropsychological tests. The children attending a special school had been more premature, but had not had a greater number of pre- or neonatal complications. They had experienced a greater number of hypertensive crises (p = 0.002) and seizures (p = 0.03), mainly during dialysis, but the number of septic infections and the mean serum aluminum levels were not significantly greater than in the children with normal school performance. In these previously lethal diseases, the overall neurodevelopmental outcome is reassuring. However, it is of crucial importance to further minimize the risk factors prior to Tx.

Pediatric kidney transplantation: historic hallmarks and a personal perspective

Over the last five decades, pediatric kidney transplantation (Tx) has proved to be a viable therapeutic alternative for children with end-stage renal disease. Patient and graft survival rates, as well as long-term quality of life, have improved dramatically during this time, as a result of advances in surgical techniques, immunosuppression, and pre- and post-operative care. The inspired, hard work of multi-disciplinary clinical teams, combined with the determination and courage of the young patients and their families, have fueled the success of pediatric kidney Tx. It is with similar optimism and drive that we face the great challenges of the future, such as maximizing the donor pool and inducing tolerance.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.

Optimal care of the pediatric end-stage renal disease patient on dialysis

This manuscript is an effort on behalf of the American Society of Pediatric Nephrology to provide recommendations designed to optimize the clinical care of pediatric patients with end-stage renal disease (ESRD). Although many of the recommendations are evidenced-based with the supporting data being derived from a variety of sources, including patient registries, others are opinion-based and derived from the combined clinical experience of the authors. In all cases, it is recommended that the decision to initiate dialysis should be made only after an assessment of a combination of biochemical and clinical characteristics. Irrespective of the choice of dialysis modality (hemodialysis v peritoneal dialysis), dialysis efficacy should be measured regularly, and the dialysis prescription should be designed to achieve target clearances. Attention to dialysis adequacy, control of osteodystrophy, nutrition, and correction of anemia is mandatory, because all may influence patient outcome in terms of growth, cognitive development, and school performance. Finally, the availability of a multidisciplinary team of pediatric specialists is desirable to provide all facets of pediatric ESRD care, including renal transplantation, in an optimal manner. Future clinical research efforts intended to address topics such as dialysis adequacy, anemia management, and growth should be encouraged.

Dialysis and renal transplantation in infants with irreversible renal failure

Historically, infants with irreversible renal failure fared poorly, and aggressive medical intervention was considered futile. Although the care of this population clearly remains a challenge, technical advances and clinical experience have now made dialysis and transplantation reasonable and successful therapeutic options. This report provides a discussion of practical guidelines and patient care issues particular to the infant with end-stage renal disease. Topics addressed include nutritional requirements, neurodevelopmental abnormalities, and the possible contribution of alterations of the immune system to patient morbidity. Specific technical considerations for the performance of peritoneal dialysis, hemodialysis, and transplantation in the very small infant are also presented.

Growth, development and nutritional status in Japanese children under 2 years on continuous ambulatory peritoneal dialysis

We examined the growth, development and nutritional status over a period of 10 years of 15 young children (< 2 years old) on continuous ambulatory peritoneal dialysis (CAPD). There were 6 males and 9 females with a mean age of 12.5 months, mean weight of 6.3 kg, mean height of 66.2 cm at the start of CAPD and a mean duration of therapy of 2.6 years. Height, weight, head circumference, development quotient (DQ), blood chemistry and dietary intake were assessed over a period of 10 years. The patients' mean height standard deviation score (SDS) did not change significantly (from -2.51 to -2.74) during CAPD therapy. The mean growth velocity index (GVI) during CAPD was 76.5% and correlated positively with energy intake but not with protein intake. The mean DQ was low (67.0%) at the start of CAPD and 69.3% at the end of CAPD. DQ did not correlate with energy intake, GVI, head circumference SDS or with the weight/height ratio; however, 2 patients with low DQ (< 60%) had a low energy intakes. Although most patients had a low DQ, the IQ at 5-6 years of age was normal in all patients except 1 without cerebral disease. Our study showed minimal growth (delta SDS) and mental developmental (IQ) delays during CAPD therapy, but an adequate nutritional intake must be assured to obtain the above results.

Aluminum content of infant formulas used in Turkey

In the past few years, there has been an upsurge of interest in aluminum (Al) and human health. The well-recognized manifestations of systemic Al toxicity include fracturing osteomalacia, dialysis encephalopathy, and microcytic hypochromic anemia. The role of Al in causing childhood diseases is also becoming clearer, but the safe plasma level still remains to be determined in newborns, especially in premature newborns, implying that it should be kept low. Premature infants receiving iv fluid therapy show evidence of Al loading. Additionally, the infant-feeding mixtures, especially the soy-based infant formulas, tested may be a significant additional source of Al in the diet of infants with low birthweights, and in infants and in young children with impaired renal function. Careful clinical and biochemical monitoring is warranted to determine whether it will be necessary to eliminate Al contamination of both oral and parenteral preparations used in infants and children who may be at risk for Al intoxication. In this present study, the Al content of infant feeds was measured by electrothermal atomic absorption spectrophotometry, and also compared with those of breast milk, cow's milk, milk powder, and some starches that are commonly used for preparation of infant feed in Turkey. Our results show that Al content of commercially available powdered infant formulas, most of which are imported from Europe, ranged from 1.211 to 10.925 micrograms/g. The mean value was higher than that of breast milk. It was also found that the Al content of cow's milk in various containers was higher than that of breast milk. The highest Al level among cow's milk samples was in the aluminized carton box.

The cognitive development of pre-school children treated for chronic renal failure

Chronic renal failure in young children is associated with impaired cognitive development, but recent studies present a more optimistic perspective. An important question is whether the earlier initiation of renal replacement therapy (RRT) might prevent the reported developmental retardation. The cognitive development of 31 patients (age < 5 years with a serum creatinine clearance of < 20% of normal) undergoing different treatment modalities was monitored by repeated measurements during a prospective 3-year study. Fifteen patients received conservative treatment and 16 patients were on dialysis treatment at the start of the project. We were able to evaluate the effect of the onset of RRT on 12 patients who were transferred from conservative treatment to dialysis. At the beginning of the study, the cognitive development of the total group was significantly delayed (mean developmental index = 78.5, SD = 19.5) compared with a normal population. Patients undergoing conservative treatment scored significantly higher (P < 0.01) than those on dialysis. The effect of starting dialysis treatment appeared to be positive, but only a significant short-term improvement was observed. Follow-up evaluation of 7 patients on conservative treatment and of 9 dialysis patients over a 2-year period did not show any significant change in a positive or negative direction. The present study revealed that pre-school dialysis patients are at risk with respect to their cognitive development. This is particularly true for the group with concomitant disorders. Less severe disease in the group on conservative treatment may be assumed to be a positive contributing factor to the more normal performance of these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Evoked potentials in children with chronic renal failure, treated conservatively or by continuous ambulatory peritoneal dialysis

Children with chronic renal failure (CRF) show developmental, intellectual and motor disturbances. It is questionable if an early start of renal replacement therapy may prevent or delay these disturbances. We studied the neurological and intellectual development of children < 5 years suffering from CRF (creatinine clearance < 20% of normal) prospectively, over a period of 3 years. As part of the neurological study, brainstem auditory evoked potentials (BAEP) and somatosensory evoked potentials (SSEP) were recorded. Measurements were performed in a group of 22 children every 6 months. In 18 of these children CRF was present from birth. Sufficient data were available for analysis in 19 (BAEP) and 22 (SSEP), respectively. A delay of peak I of BAEP gave indications for peripheral conduction disturbances, possibly due to cochlear dysfunction. Brainstem conduction was normal. There were no differences between the children treated conservatively (n = 9) and those treated with continuous ambulatory peritoneal dialysis (CAPD) (n = 10). In children < 2.5 years SSEP showed a delayed thalamocortical conduction, which was not observed in older children. This might indicate a delayed myelination in young children with CRF. No differences were found between the children treated conservatively (n = 10) and those treated with CAPD (n = 12).

Improved neurological outcome in children with chronic renal disease from infancy

Progressive encephalopathy, developmental delay, microcephaly, electroencephalogram (EEG) and computed tomographic (CT) scan abnormalities have been reported in 80% of children with chronic renal failure (CRF) in infancy. Malnutrition, aluminium intoxication and psychosocial deprivation are proposed as causes. In 15 children with CRF from infancy we evaluated the effect of no aluminium salts and early vigorous nutritional and psychosocial support, in addition to the standard therapy, on neurological development. Six patients underwent dialysis (2 at birth) and 3 received transplants. None of our patients were given aluminium therapy. The nutritional status of the patients in the first 2 years of life was assessed with the waterlow classification. At the end of the follow-up period (mean 50 months range 14-148 months), patients underwent neurodevelopmental assessment, head CT scan, EEG, nerve conduction velocity (NCV) and auditory brain stem evoked response (ABER). None of our patients developed progressive encephalopathy or recurrent seizures. All have a normal neurological examination apart from hypotonia. Microcephaly was present in 5 patients. There was a good correlation between malnutrition in the first 2 years of life and microcephaly. Developmental delay was present in 3 patients; all 3 were microcephalic. There was evidence of brain atrophy on CT scan in only 3 patients. EEG was abnormal in 6 patients, but only severe in 1 patient. Only 1 patient had diminished NCV; all patients had a normal ABER. We conclude that a policy of no oral aluminium therapy and early nutritional support leads to better neurological outcome in children with CRF from infancy.

Cognitive development and learning in the pediatric organ transplant recipient

Although organ transplantation is considered a viable treatment approach for end-stage organ disease, few empirical investigations have assessed the effects of transplantation on the cognitive development and learning of pediatric organ transplant recipients. This article reviews studies evaluating neurocognitive changes following organ transplantation in pediatric end-stage renal and liver disease. Despite numerous methodological problems inherent in the investigations examined, the findings of some studies are suggestive of potential neurocognitive benefits associated with organ transplantation. Recommendations are made regarding methodological improvements for future investigations assessing neurocognitive outcomes of organ transplantation.