Neuromuscular disease in the dialysis patient: an update for the nephrologist

Risk Factors and Frequency of Foot Ulceration in Patients Receiving Chronic Hemodialysis Treatment

OBJECTIVE

To determine the prevalence and risk factors of foot ulceration in patients receiving hemodialysis treatment.

METHODS

A total of 180 patients who received hemodialysis treatment in two state hospitals and a private health center between April 2017 and September 2017 were included in the study. The researchers collected data using a patient information form and by conducting physical evaluation of the lower extremities. They used the diabetic foot risk assessment algorithm to classify risk according to the data obtained.

RESULTS

Of the patients receiving hemodialysis treatment, 6.7% had foot ulceration, 19.4% had a history of foot ulceration, and 8.3% had a history of hospitalization associated with ulceration in a lower extremity. Infected foot ulceration was the most common (6.1%) cause of hospitalizations. In the group with current or past foot ulceration, diabetic nephropathy was the most common etiologic factor of end-stage kidney disease (48.6%); there was a significant between-group difference in diabetic nephropathy (P < .05). Etiologic factors had a significant effect on foot ulcerations: As determined by univariate logistic regression, diabetes (odds ratio [OR], 2.727; P < .05), presence of neuropathy (OR, 4.208; P < .05), low-density lipoprotein cholesterol (OR, 1.013; P < .05), and serum albumin (OR, 0.302; P < .036) all had a statistically significant effect on the presence of foot ulcerations.

CONCLUSIONS

Patients receiving hemodialysis treatment are at high risk for foot ulceration. Therefore, patient awareness strategies should be expanded to include individuals with end-stage renal disease regardless of diabetes status. Clinical and dialysis nurses should educate these patients about foot ulcerations and foot health to prevent ulcer development.

Exercise for patients with chronic kidney disease: from cells to systems to function

Chronic kidney disease (CKD) is among the leading causes of death and disability, affecting an estimated 800 million adults globally. The underlying pathophysiology of CKD is complex creating challenges to its management. Primary risk factors for the development and progression of CKD include diabetes mellitus, hypertension, age, obesity, diet, inflammation, and physical inactivity. The high prevalence of diabetes and hypertension in patients with CKD increases the risk for secondary consequences such as cardiovascular disease and peripheral neuropathy. Moreover, the increased prevalence of obesity and chronic levels of systemic inflammation in CKD have downstream effects on critical cellular functions regulating homeostasis. The combination of these factors results in the deterioration of health and functional capacity in those living with CKD. Exercise offers protective benefits for the maintenance of health and function with age, even in the presence of CKD. Despite accumulating data supporting the implementation of exercise for the promotion of health and function in patients with CKD, a thorough description of the responses and adaptations to exercise at the cellular, system, and whole body levels is currently lacking. Therefore, the purpose of this review is to provide an up-to-date comprehensive review of the effects of exercise training on vascular endothelial progenitor cells at the cellular level; cardiovascular, musculoskeletal, and neural factors at the system level; and physical function, frailty, and fatigability at the whole body level in patients with CKD.

High risk and low prevalence diseases: Guillain-Barré syndrome

INTRODUCTION

Guillain-Barré syndrome (GBS) is a rare but serious condition that carries with it a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of GBS, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

GBS is a rare immune-mediated neurologic disorder with peripheral nerve injury. It most commonly presents weeks after a bacterial or viral infection, though there are a variety of associated inciting events. The diagnosis is challenging and often subtle, as only 25-30% of patients are diagnosed on their initial healthcare visit. Clinicians should consider GBS in patients with progressive ascending weakness involving the lower extremities associated with hyporeflexia, but the cranial nerves, respiratory system, and autonomic system may be involved. While the ED diagnosis should be based on clinical assessment, further evaluation includes laboratory testing, cerebrospinal fluid (CSF) analysis, and potentially neuroimaging. Not all patients demonstrate albumino-cytological dissociation on CSF testing. Several criteria exist to assist with diagnosis, including the National Institute of Neurological Disorders and Stroke criteria and the Brighton criteria. Management focuses first on assessment of the patient's hemodynamic and respiratory status, which may require emergent intervention. Significant fluctuations in heart rate and blood pressure may occur, and respiratory muscle weakness may result in the need for airway protection. Neurology consultation is recommended, and definitive treatment includes PLEX or IVIG.

CONCLUSIONS

An understanding of GBS can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Prevalence of diabetic foot at risk of ulcer development and its components stratification according to the international working group on the diabetic foot (IWGDF): A systematic review with metanalysis

AIMS

To determine the overall prevalence of diabetic foot at risk according to the International Working Group on the Diabetic Foot stratification.

MATERIALS AND METHODS

We searched PubMed/Medline, Scopus, Web of Science, and Embase. We included cross-sectional studies or cohorts from 1999 to March 2022. We performed a meta-analysis of proportions using a random-effects model. We assessed heterogeneity through subgroup analysis by continent and other characteristics.

RESULTS

We included 36 studies with a total population of 11,850 people from 23 countries. The estimated overall prevalence of diabetic foot at risk was 53.2% (95% CI: 45.1-61.3), I2 = 98.7%, p < 0.001. In the analysis by subgroups, South and Central America had the highest prevalence and Africa the lowest. The factors explaining the heterogeneity were the presence of chronic kidney disease, diagnostic method for peripheral arterial disease, and quality. The estimates presented very low certainty of evidence.

CONCLUSIONS

The overall prevalence of diabetic foot at risk is high. The high heterogeneity between continents can be explained by methodological aspects and the type of population. However, using the same classification is necessary for standardization of the way of measuring the components, as well as better designed general population-based studies.

Renal and Electrolyte Disorders and the Nervous System

OBJECTIVE

Neurologic complications are a major contributor to death and disability in patients with renal disease. Oxidative stress, endothelial dysfunction, accelerated arteriosclerosis, and uremic inflammatory milieu affect both the central and peripheral nervous systems. This article reviews the unique contributions of renal impairment to neurologic disorders and their common clinical manifestations as the prevalence of renal disease increases in a globally aging population.

LATEST DEVELOPMENT

Advances in the understanding of the pathophysiologic interplay between the kidneys and brain, also referred to as the kidney-brain axis, have led to more widespread recognition of associated changes in neurovascular dynamics, central nervous system acidification, and uremia-associated endothelial dysfunction and inflammation in the central and peripheral nervous systems. Acute kidney injury increases mortality in acute brain injury to nearly 5 times that seen in matched controls. Renal impairment and its associated increased risks of intracerebral hemorrhage and accelerated cognitive decline are developing fields. Dialysis-associated neurovascular injury is increasingly recognized in both continuous and intermittent forms of renal replacement therapy, and treatment strategies for its prevention are evolving.

ESSENTIAL POINTS

This article summarizes the effects of renal impairment on the central and peripheral nervous systems with special considerations in acute kidney injury, patients requiring dialysis, and conditions that affect both the renal and nervous systems.

Clinical and neurophysiological characterization of early neuromuscular involvement in children and adolescents with nephropathic cystinosis

BACKGROUND

Nephropathic cystinosis is a rare autosomal recessive lysosomal storage disorder characterized by kidney and extra-renal complications due to the accumulation of cystine crystals in various tissues and organs. Herein, we describe the early neuromuscular complications in a cohort of pediatric nephropathic cystinosis patients.

METHODS

We prospectively evaluated the clinical, biochemical, and neurophysiological data of 15 cystinosis patients. Neurophysiological evaluation was performed to confirm or exclude presence of neuropathy and/or myopathy.

RESULTS

Patients' age ranged between 20 and 216 months at time of examination. Nine patients were males. Three patients had early abnormal neurophysiological features consistent with neuromuscular involvement (clinically asymptomatic proximal myopathy with a patchy distribution in one patient and isolated asymptomatic sensory nerve conduction changes in two patients). A fourth patient had mixed abnormal motor and sensory axonal neuropathic changes associated with overt clinical features (predominantly motor symptoms). Patients with abnormal neuromuscular features were significantly older in age than the unaffected group (P = 0.005) and had a diagnosis of cystinosis with subsequent cysteamine therapy at a significantly older age than the unaffected group (P = 0.027 and 0.001, respectively).

CONCLUSIONS

We expanded the recognized phenotypes of cystinosis neuromuscular complications with early proximal skeletal myopathy and symptomatic motor and sensory axonal neuropathy. Early asymptomatic neuromuscular complications could develop in pediatric patients and would require neurophysiological studies for early detection prior to development of overt clinical manifestations. Prompt diagnosis and timely initiation of cysteamine therapy with recommended dose can delay the development of neuromuscular complications. A higher resolution version of the Graphical abstract is available as Supplementary information.

Effect of Erythropoietin-stimulating agent on uremic neuropathy in hemodialysis patients: a single-center open-label prospective study

Background

Uremic neuropathy is a distal sensorimotor polyneuropathy caused by uremic toxins; its severity is correlated with the degree of renal insufficiency. Erythropoietin (EPO) and erythropoietin receptors (EpoR) are produced in the peripheral nervous system. This is a single-center open-label prospective study was designed to investigate the possible effect of erythropoietin-stimulating agents (ESAs) on uremic neuropathy. Twenty-four newly diagnosed end-stage kidney disease (ESKD) patients were selected, clinical assessment, laboratory, and neurophysiological study were done at 1 and follow-up after 3 months. Patients were divided into two groups (group A received ESA and group B did not receive ESA).

Results

Eighteen patients completed the study, eight patients (44.4%) did not have symptoms but had electrophysiological findings of neuropathy (subclinical neuropathy). After 3 months of hemodialysis, patients in group A showed improvement of some electrophysiological features (ulnar MNCV; P = 0.016).

Conclusions

The use of ESA may improve uremic neuropathy in patients with newly diagnosed ESKD who have been started on hemodialysis.

Development and validation of the dialysis dementia risk score: A retrospective, population-based, nested case-control study

Background

Dementia is prevalent and underdiagnosed in the dialysis population. We aimed to develop and validate a simple dialysis dementia scoring system to facilitate identification of individuals who are at high risk for dementia.

Methods

We applied a retrospective, nested case‐control study design using a national dialysis cohort derived from the National Health Insurance Research Database in Taiwan. Patients aged between 40 and 80 years were included and 2940 patients with incident dementia were matched to 29,248 non‐dementia controls. All subjects were randomly divided into the derivation and validation sets with a ratio of 4:1. Conditional logistic regression models were used to identify factors contributing to the risk score. The cutoff value of the risk score was determined by Youden's J statistic and the graphic method.

Results

The dialysis dementia risk score (DDRS) finally included age and 10 comorbidities as risk predictors. The C‐statistic of the model was 0.71 (95% confidence interval [CI] 0.70–0.72). Calibration revealed a strong linear relationship between predicted and observed dementia risk (R² = 0.99). At a cutoff value of 50 points, the high‐risk patients had an approximately three‐fold increased risk of having dementia compared to those with low risk (odds ratio [OR] 3.03, 95% CI 2.78–3.31). The DDRS performance, including discrimination (C‐statistic 0.71, 95% CI 0.69–0.73) and calibration (p value of Hosmer−Lemeshow test for goodness of fit = 0.18), was acceptable during validation. The OR value (2.82, 95% CI 2.37–3.35) was similar to those in the derivation set.

Conclusion

The DDRS system has the potential to serve as an easily accessible screening tool to determine the high‐risk groups who deserve subsequent neurological evaluation in daily clinical practice.

Associations of Small Fiber Neuropathy with Geriatric Nutritional Risk Index and Arterial Stiffness in Hemodialysis

BACKGROUND

Peripheral neuropathy is a common neurological complication in uremic patients, and quantitative sensory testing (QST) is effective for diagnosis of small fiber neuropathy. Malnutrition and arterial stiffness are prevalent in patients undergoing hemodialysis (HD). The associations of small fiber neuropathy with nutritional status and arterial stiffness remain uncertain in maintenance HD patients.

METHODS

A total of 152 HD patients were included. Geriatric nutritional risk index (GNRI), an indicator of nutritional status, was calculated by serum albumin and actual and ideal body weight. Arterial stiffness was defined as brachial-ankle pulse wave velocity (baPWV) > 1400 cm/s. Small fiber neuropathy was assessed by an abnormal QST threshold of cold and warm sensation in patients' hands or feet. Multivariate forward logistic regression analysis was performed to examine the associations among abnormal QST threshold, GNRI, and arterial stiffness.

RESULTS

baPWV and prevalence of abnormal QST threshold were significantly higher in diabetic patients. Multivariate logistic analyses revealed that older age (OR, 1.081; 95% CI, 1.026-1.139, p = 0.003) and male gender (OR, 4.450; 95% CI, 1.250-15.836, p = 0.021) were associated with abnormal warm threshold of hands. Furthermore, diabetes (OR, 3.966; 95% CI, 1.351-11.819, p = 0.012) and lower GNRI (per 1 unit increase, OR, 0.935, 95% CI, 0.887-0.985, p = 0.012) were associated with abnormal cold threshold of feet. Arterial stiffness (OR, 5.479, 95% CI, 1.132-22.870, p = 0.020) and higher calcium-phosphorus product (OR, 1.071, 95% CI, 1.013-1.132, p = 0.015) were associated with abnormal warm threshold of feet.

CONCLUSIONS

Lower GNRI and arterial stiffness were significantly associated with small fiber neuropathy in patients undergoing HD. Malnutrition risk and vascular factors might play important roles in small fiber neuropathy among patients undergoing HD.

Neurophysiological and Neuroradiological Changes in Children With Chronic Kidney Disease

Background: Patients with chronic kidney disease (CKD) on maintenance hemodialysis frequently present with neurological complications. These complications include peripheral neuropathy, encephalopathy, and stroke. Objectives: To detect the prevalence of neurological manifestations and complications in children with CKD through neurophysiological and neuro-radiological findings. Methods: The study included 50 patients with CKD admitted to a pediatric nephrology unit. Their history and complete physical and neurological examination findings had been recorded. All patients underwent nerve conduction, electromyography, electroencephalography, and magnetic resonance imaging of the brain. Results: Fifty children of both sexes (23 males and 27 females) with a mean age of (12.08 ± 3.46 year) were studied. Eleven (22%) patients with CKD developed polyneuropathy, mostly of an axonal polyneuropathy pattern, while 39 (78%) of them showed normal electrophysiological studies. No myopathy was detected. Abnormal electroencephalography findings were detected in 18% of patients, mostly generalized and focal (temporal, occipital, and frontal) epileptogenic activity. Abnormal MRI brain findings were detected in 16% of patients, mostly of encephalomalacia. Conclusion: Uremic neuropathy was highly prevalent in children with CKD on maintenance hemodialysis. They developed polyneuropathy, mostly of an axonal polyneuropathy pattern. EEG is a useful method for early recognition of subclinical uremic encephalopathy and/or epileptogenic activity. Early demonstration and management of uremic neurological conditions may decrease the physical disability of CKD patients.

Arm and hand function in hemodialysis patients. A cross sectional analytical study

Aims: To investigate the arm and hand function in hemodialysis patients.Methods: Upper limb function using validated questionnaires such as Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH), Cochin and Boston were applied to 57 chronic renal failure patients on hemodialysis and 60 healthy controls. Epidemiological data, data on pain and paresthesia in the upper limb and handgrip strength were obtained.Results: The three questionnaires showed worse performance of upper limb function in chronic renal failure patients than controls: DASH questionnaire with P = 0.05; Cochin questionnaire with P = 0.0004 and Boston questionnaire with P = 0.03. The questionnaire scores were affected by presence of pain (P = 0.05 for DASH and < 0.0001 for Boston questionnaires) and paresthesia (DASH with P = 0.003; Cochin with P = 0.01 and Boston questionnaire with P < 0.0001). Handgripstrength was lower in hemodialysis patients when compared with controls (P = 0.02) but did not affect the performance of any of the studied questionnaires.Conclusions: Upper limb function is impaired in hemodialysis patients and the main associations found were with pain and paresthesia.

Risk of dementia in patients with end-stage renal disease under maintenance dialysis-a nationwide population-based study with consideration of competing risk of mortality

Background

Dementia is prevalent in the end-stage renal disease (ESRD) population. However, it is still not clarified whether ESRD is one of the etiology of dementia or its attributable effect on the cumulative risk of dementia. Meanwhile, the effect of competing risk of mortality should be taken into consideration when performing epidemiologic analyses among populations with high risk of mortality.

Methods

By using the National Health Insurance Research Database (1998–2010), we identified 927,142 non-ESRD individuals and 99,158 ESRD patients to investigate the effect of ESRD on the risk of dementia. Age- and sex-specific incidence rates (IRs) and cumulative incidence rates (CIRs) were first compared between these two cohorts. Competing risk analyses including cause-specific and subdistribution proportional hazards models were then constructed with adjustments for potential confounders.

Results

The overall IR and CIR of dementia were much higher in the ESRD group than in the non-ESRD group (10.73 vs. 1.40 per 1000 person-years and 0.061 vs. 0.017, respectively, both P < 0.0001). Results from the multivariable cause-specific hazard models suggested that ESRD was one of the etiological factors for dementia (cause-specific hazard ratio [csHR] : 2.06 [95% CI : 1.95–2.17]). However, the subdistribution HR (sdHR) of ESRD was 0.51 (95% Cl : 0.49–0.54), which indicated the lower cumulative incidence risk of dementia in ESRD patients. The inverse relationship between csHR and sdHR could be explained by the high mortality rate in the ESRD population. These findings were also essentially consistent across various subgroup analyses according to selected confounders, as well as in the analyses that limited dementia diagnoses made by neurologists or psychologists.

Conclusions

Although ESRD appears directly associated with the risk of dementia, the high competing mortality means that primary prevention of comorbidity associated with dementia may be more effective in reducing overall dementia in the general population, which may also potentially reduce the incidence of ESRD and prevent death from multimorbidity when affected by ESRD.

Electronic supplementary material

The online version of this article (10.1186/s13195-019-0486-z) contains supplementary material, which is available to authorized users.

Neurological sequel of chronic kidney disease: From diminished Acetylcholinesterase activity to mitochondrial dysfunctions, oxidative stress and inflammation in mice brain

With increasing prevalence, chronic kidney disease (CKD) has become a global health problem. Due to the retention of uremic toxins, electrolytes and water, and the resultant metabolic disturbances, CKD affects several organs, including the nervous system. Thus, CKD patients suffer from several neurological complications, including dementia, cognitive impairment, motor abnormalities, depression, and mood and sleep disturbances. However, the mechanisms underlying the neurological complications are least elucidated. We have recently reported a highly reproducible mice model of CKD induced by high adenine diet, which exhibited psychomotor behavioral abnormalities and blood-brain barrier disruption. In the present study, using the mice model, we have investigated psycho-motor and cognitive behaviour, and the neurochemical and histopathological alterations in brain relevant to the observed behavioural abnormalities. The results demonstrate global loss of Acetylcholinesterase activity, and decrease in neuronal arborisation and dendritic spine density in discrete brain regions, of the CKD mice. Oxidative stress, inflammation, and mitochondrial dysfunctions were found in specific brain regions of the mice, which have been regarded as the underlying causes of the observed neurochemical and histopathological alterations. Thus, the present study is of immense importance, and has therapeutic implications in the management of CKD-associated neurological complications.

Axonal Sensorimotor Polyneuropathies

PURPOSE OF REVIEW

This article describes clinical features of axonal sensorimotor polyneuropathies based on selected etiologies.

RECENT FINDINGS

Axonal sensorimotor polyneuropathies have been well described for some time. Recent advances include the assessment of the incidence of peripheral neuropathy in the elderly, the recognition of the limited influence of electrodiagnostic testing on the clinical management of uncomplicated axonal sensorimotor polyneuropathy, the development of guidelines for treatment of painful neuropathy, the identification of risk factors predisposing patients for chemotherapy-induced neuropathy, a report on the association of metabolic syndrome and idiopathic axonal sensorimotor neuropathy, and the availability of more cost-effective genetic testing for identifying inherited polyneuropathies.

SUMMARY

Axonal sensorimotor polyneuropathies carry an extensive list of differential diagnoses. Diagnosis is based on detailed history, physical examination, recognition of associated neurologic and non-neurologic features, and appropriate testing. Disease-modifying treatments are lacking in many cases. Management focuses on modification of predisposing lifestyle and medical factors, rehabilitation, and pain relief.

Frequency of Polyneuropathy in Patients on Long Term Peritoneal Dialysis Treatment

INTRODUCTION

Uremic polyneuropathy is very common among patients with Chronic Kidney Disease (CKD). The patients have electrophysiologic signs of impaired nerve function, although a lower percentage of patients are symptomatic. Electrophysiological parameters are quantitative indices of Polyneuropathy (PNP) severity.

AIM

To assess the frequency of PNP in patients on long term Peritoneal Dialysis (PD) treatment.

MATERIALS AND METHODS

Twenty three PD patients were analysed, who were receiving dialysis for at least five years and the study population divided into two groups according to duration of PD treatment. Group 1 consisted of the patients who were dialysed for at least 10 years and Group 2 consisted of patients who were dialysed for five to nine years. Patients who switched from Haemodialysis (HD) to PD and patients with coexisting diseases that could lead to disturbances in nerve conduction were excluded from the study. PNP was diagnosed when slowing of Nerve Conduction Velocity (NCV) and/or lengthening of distal latencies and/or decrease in amplitude of muscle action potential were present in two or more nerves and longer F wave response was present in one or two nerves. Carpal Tunnel Syndrome (CTS) was diagnosed if slowing of NCV and/or decrease in amplitude of muscle action potential and/or lenghening of distal latency of either sensory or motor median nerve present.

RESULTS

PNP was observed in 17 of the patients {73.9%; Group 1 (n=10) and Group 2 (n=7)}. Mixed type sensory motor neuropathy was diagnosed in nine patients from Group 1 and five patients from Group 2; one patient from Group 1 had demyelinating PNP affecting motor and sensory nerves; one patient from Group 2 had axonal PNP affecting motor and sensory nerves. From Group 1, two patients had CTS related to PNP and one patient had CTS without PNP. The results of motor conductivity testing showed lower conduction velocity for left popliteal nerve in Group 1 and Group 2 patients (13.85±2.17 ms, 4.80±1.11 ms, p=0.01). In both groups, mean motor and sensory latency, amplitude and velocity of other nerves were not found to be significantly different (p>0.05).

CONCLUSION

PNP is a common complication in long term PD patients. Over five years of treatment, frequency of PNP and CTS do not increase with duration of dialysis.

Effects of hemodialysis on intraneural blood flow in end-stage kidney disease

INTRODUCTION

We quantified intraneural blood flow (INBF) in 18 patients with end-stage kidney disease (ESKD) and examined its relationship with nerve size, neuropathy severity, and nerve excitability parameters.

METHODS

Sonographic measurements of the median nerve were performed at the same site before and after hemodialysis. INBF was quantified by analyzing power Doppler sonograms to obtain the vessel score (VSc) and maximum perfusion intensity (MPI). Corresponding median motor nerve excitability studies were performed. Neuropathy severity was assessed using Total Neuropathy Score.

RESULTS

A total of 39% of ESKD patients had detectable INBF compared with none in the control group (P < 0.0001). Patients with detectable INBF had larger nerves and more severe neuropathy (P < 0.01). INBF parameters were significantly reduced after a session of dialysis (VSc: P < 0.01; MPI: P < 0.01). A significant relationship was found between interdialytic change in INBF and changes in nerve excitability.

CONCLUSIONS

Increased INBF is a potential marker for neuropathy severity in ESKD patients. Muscle Nerve 57: 287-293, 2018.

Neurological complications in chronic kidney disease

Patients with chronic kidney disease (CKD) are frequently afflicted with neurological complications. These complications can potentially affect both the central and peripheral nervous systems. Common neurological complications in CKD include stroke, cognitive dysfunction, encephalopathy, peripheral and autonomic neuropathies. These conditions have significant impact not only on patient morbidity but also on mortality risk through a variety of mechanisms. Understanding the pathophysiological mechanisms of these conditions can provide insights into effective management strategies for neurological complications. This review describes clinical management of neurological complications in CKD with reference to the contributing physiological and pathological derangements. Stroke, cognitive dysfunction and dementia share several pathological mechanisms that may contribute to vascular impairment and neurodegeneration. Cognitive dysfunction and dementia may be differentiated from encephalopathy which has similar contributing factors but presents in an acute and rapidly progressive manner and may be accompanied by tremor and asterixis. Recent evidence suggests that dietary potassium restriction may be a useful preventative measure for peripheral neuropathy. Management of painful neuropathic symptoms can be achieved by pharmacological means with careful dosing and side effect considerations for reduced renal function. Patients with autonomic neuropathy may respond to sildenafil for impotence. Neurological complications often become clinically apparent at end-stage disease, however early detection and management of these conditions in mild CKD may reduce their impact at later stages.

Exercise limitation following transplantation

Organ transplantation is one of the medical miracles or the 20th century. It has the capacity to substantially improve exercise performance and quality of life in patients who are severely limited with chronic organ failure. We focus on the most commonly performed solid-organ transplants and describe peak exercise performance following recovery from transplantation. Across all of the common transplants, evaluated significant reduction in VO2peak is seen (typically renal and liver 65%-80% with heart and/or lung 50%-60% of predicted). Those with the lowest VO2peak pretransplant have the lowest VO2peak posttransplant. Overall very few patients have a VO2peak in the normal range. Investigation of the cause of the reduction of VO2peak has identified many factors pre- and posttransplant that may contribute. These include organ-specific factors in the otherwise well-functioning allograft (e.g., chronotropic incompetence in heart transplantation) as well as allograft dysfunction itself (e.g., chronic lung allograft dysfunction). However, looking across all transplants, a pattern emerges. A low muscle mass with qualitative change in large exercising skeletal muscle groups is seen pretransplant. Many factor posttransplant aggravate these changes or prevent them recovering, especially calcineurin antagonist drugs which are key immunosuppressing agents. This results in the reduction of VO2peak despite restoration of near normal function of the initially failing organ system. As such organ transplantation has provided an experiment of nature that has focused our attention on an important confounder of chronic organ failure-skeletal muscle dysfunction.

Evaluation of spectrum of peripheral neuropathy in predialysis patients with chronic kidney disease

INTRODUCTION

Neurological complications secondary to the uremic state, contribute largely to the morbidity and mortality in patients with renal failure. The prevalence of peripheral neuropathy remains high in advanced renal dysfunction.

MATERIALS AND METHODS

The present cross-sectional study was conducted on 100 adult patients of chronic kidney disease between 18 and 75 years of age with serum creatinine greater than 2 mg/dL. Apart from routine examination and baseline investigations, detailed history was elicited pertaining to patients' neurological symptoms, and scored according to the Neurological Symptom Score. Motor nerve conduction velocity was measured from right median, ulnar, peroneal, and tibial nerves.

RESULTS

It was observed that neurological symptoms increased steadily with raise in serum creatinine. The mean nerve conduction velocities (NCVs) of right median nerve, ulnar nerve, peroneal nerve, and tibial nerve were 51.34 ± 6.07, 53.04 ± 5.91, 44.72 ± 6.14, and 44.20 ± 5.17, respectively. The NCVs of all the tested nerves decreased significantly with increase in serum creatinine levels (p < 0.01): 70% of the patients had uremic polyneuropathy; 6% had asymptomatic neuropathy, 51% had symptomatic non-disabling neuropathy, while disabling neuropathy was seen in 13% of the patients.

CONCLUSION

Our data suggests that NCV testing when complimented with meticulous neurological assessment can provide invaluable input. These tests apart from helping us detect neuropathy in advanced renal dysfunction; can also detect the disease in largely asymptomatic patients which avoids the necessity to order for detailed neurophysiological investigation.

Falls in elderly hemodialysis patients

The elderly, (age ≥ 65 years) hemodialysis (HD) patient population is growing rapidly across the world. The risk of accidental falls is very high in this patient population due to multiple factors which include aging, underlying renal disease and adverse events associated with HD treatments. Falls, the most common cause of fatal injury among elderly, not only increase morbidity and mortality, but also increase costs to the health system. Prediction of falls and interventions to prevent or minimize fall risk and associated complications will be a major step in helping these patients as well as decreasing financial and social burdens. Thus, it is vital to learn how to approach this important problem. In this review, we will summarize the epidemiology, risk factors, pathophysiology and complications of falls in elderly HD patients. We will also focus on available methods to assess and predict the patients at higher risk of falling and will provide recommendations for interventions to reduce the occurrence of falls in this population.

Neurological complications of chronic kidney disease

Chronic kidney disease (CKD) is a critical and rapidly growing global health problem. Neurological complications occur in almost all patients with severe CKD, potentially affecting all levels of the nervous system, from the CNS through to the PNS. Cognitive impairment, manifesting typically as a vascular dementia, develops in a considerable proportion of patients on dialysis, and improves with renal transplantation. Patients on dialysis are generally weaker, less active and have reduced exercise capacity compared with healthy individuals. Peripheral neuropathy manifests in almost all such patients, leading to weakness and disability. Better dialysis strategies and dietary modification could improve outcomes of transplantation if implemented before surgery. For patients with autonomic neuropathy, specific treatments, including sildenafil for impotence and midodrine for intradialytic hypotension, are effective and well tolerated. Exercise training programs and carnitine supplementation might be beneficial for neuromuscular complications, and restless legs syndrome in CKD responds to dopaminergic agonists and levodopa treatment. The present Review dissects the pathophysiology of neurological complications related to CKD and highlights the spectrum of therapies currently available.