Prevalence of diabetic neuropathy with somatic symptoms: a door-to-door survey in two Sicilian municipalities. Sicilian Neuro-Epidemiologic Study (SNES) Group

MRI-based Neuropathy Score Reporting And Data System (NS-RADS): multi-institutional wider-experience usability study of peripheral neuropathy conditions among 32 radiology readers

OBJECTIVE

To determine the inter-reader reliability and diagnostic performance of classification and severity scales of Neuropathy Score Reporting And Data System (NS-RADS) among readers of differing experience levels after limited teaching of the scoring system.

METHODS

This is a multi-institutional, cross-sectional, retrospective study of MRI cases of proven peripheral neuropathy (PN) conditions. Thirty-two radiology readers with varying experience levels were recruited from different institutions. Each reader attended and received a structured presentation that described the NS-RADS classification system containing examples and reviewed published articles on this subject. The readers were then asked to perform NS-RADS scoring with recording of category, subcategory, and most likely diagnosis. Inter-reader agreements were evaluated by Conger's kappa and diagnostic accuracy was calculated for each reader as percent correct diagnosis. A linear mixed model was used to estimate and compare accuracy between trainees and attendings.

RESULTS

Across all readers, agreement was good for NS-RADS category and moderate for subcategory. Inter-reader agreement of trainees was comparable to attendings (0.65 vs 0.65). Reader accuracy for attendings was 75% (95% CI 73%, 77%), slightly higher than for trainees (71% (69%, 72%), p = 0.0006) for nerves and comparable for muscles (attendings, 87.5% (95% CI 86.1-88.8%) and trainees, 86.6% (95% CI 85.2-87.9%), p = 0.4). NS-RADS accuracy was also higher than average accuracy for the most plausible diagnosis for attending radiologists at 67% (95% CI 63%, 71%) and for trainees at 65% (95% CI 60%, 69%) (p = 0.036).

CONCLUSION

Non-expert radiologists interpreted PN conditions with good accuracy and moderate-to-good inter-reader reliability using the NS-RADS scoring system.

CLINICAL RELEVANCE STATEMENT

The Neuropathy Score Reporting And Data System (NS-RADS) is an accurate and reliable MRI-based image scoring system for practical use for the diagnosis and grading of severity of peripheral neuromuscular disorders by both experienced and general radiologists.

KEY POINTS

• The Neuropathy Score Reporting And Data System (NS-RADS) can be used effectively by non-expert radiologists to categorize peripheral neuropathy. • Across 32 different experience-level readers, the agreement was good for NS-RADS category and moderate for NS-RADS subcategory. • NS-RADS accuracy was higher than the average accuracy for the most plausible diagnosis for both attending radiologists and trainees (at 75%, 71% and 65%, 65%, respectively).

Identifying new safety risk of human serum albumin: a retrospective study of real-world data

Objective: To mine and analyze the adverse reaction signals of human serum albumin (HSA) using the FDA adverse event reporting system (FAERS) database for the safe clinical use of this drug. Methods: Data cleaning and analysis of adverse event reports in the FAERS database for a total of 76 quarters from Q1 2004 to Q4 2022 were performed using the reporting odds ratio (ROR), Medicines and Healthcare Products Regulatory Agency (MHRA), and Bayesian confidence propagation neural network (BCPNN). Gender-differentiated signal detection was used to investigate the gender differences in the occurrence of HSA adverse events. Results: Through a combination of three methods, a total of 535 adverse event reports were identified. These reports involved 1,885 cases of adverse reactions, with respiratory, thoracic, and mediastinal disorders, as well as general disorders and administration site conditions, as the most common. One noteworthy new signal was the occurrence of transfusion-related acute lung injury. Additionally, gender-differentiated signals were present, with females experiencing paraesthesia, hypertension, pulmonary oedema, loss of consciousness, and vomiting. Conclusion: This study has revealed that HSA poses a risk of causing transfusion-related acute lung injury. It has also been observed that adverse reactions, including paraesthesia, hypertension, pulmonary oedema, loss of consciousness, and vomiting, are more prevalent in females. These findings should be taken into account when using HSA in a clinical setting.

Nrf2 signaling in diabetic nephropathy, cardiomyopathy and neuropathy: Therapeutic targeting, challenges and future prospective

Western lifestyle contributes to an overt increase in the prevalence of metabolic anomalies including diabetes mellitus (DM) and obesity. Prevalence of DM is rapidly growing worldwide, affecting many individuals in both developing and developed countries. DM is correlated with the onset and development of complications with diabetic nephropathy (DN), diabetic cardiomyopathy (DC) and diabetic neuropathy being the most devastating pathological events. On the other hand, Nrf2 is a regulator for redox balance in cells and accounts for activation of antioxidant enzymes. Dysregulation of Nrf2 signaling has been shown in various human diseases such as DM. This review focuses on the role Nrf2 signaling in major diabetic complications and targeting Nrf2 for treatment of this disease. These three complications share similarities including the presence of oxidative stress, inflammation and fibrosis. Onset and development of fibrosis impairs organ function, while oxidative stress and inflammation can evoke damage to cells. Activation of Nrf2 signaling significantly dampens inflammation and oxidative damage, and is beneficial in retarding interstitial fibrosis in diabetic complications. SIRT1 and AMPK are among the predominant pathways to upregulate Nrf2 expression in the amelioration of DN, DC and diabetic neuropathy. Moreover, certain therapeutic agents such as resveratrol and curcumin, among others, have been employed in promoting Nrf2 expression to upregulate HO-1 and other antioxidant enzymes in the combat of oxidative stress in the face of DM.

A systematic review and meta-analysis of the serum lipid profile in prediction of diabetic neuropathy

Whether the lipid profile in diabetic patients is associated with diabetic neuropathy (DN) development remains ambiguous, as does the predictive value of serum lipid levels in the risk of DN. Here, we performed the first meta-analysis designed to investigate the relationship between DN and the serum levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), and low-density lipoprotein cholesterol (LDL). Candidate studies were comprehensively identified by searching PubMed, Embase, Cochrane Library and Web of Science databases up to May 2020. Observational methodological meta-analysis was conducted to assess the relationships of TG, TC, HDL, and LDL levels with DN. Changes in blood lipids were used to estimate the effect size. The results were pooled using a random-effects or fixed-effects model. Potential sources of heterogeneity were explored by subgroup analysis. Various outcomes were included, and statistical analyses were performed using STATA (Version 12.0). Mean differences (MDs) and odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. The Newcastle–Ottawa Scale (NOS) was applied to assess the methodological quality. I2 statistics were calculated to evaluate statistical heterogeneity. Funnel plots were utilized to test for publication bias. A sensitivity analysis was performed by omitting each study one by one. Thirty-nine clinical trials containing 32,668 patients were included in the meta-analysis. The results demonstrated that DN patients showed higher TG and lower HDL levels (MD = 0.34, 95% CI: 0.20–0.48 for TG; MD = -0.05, 95% CI: -0.08–-0.02, I² = 81.3% for HDL) than controls. Subgroup analysis showed that patients with type 1 diabetes mellitus (T1DM) neuropathy had elevated TG levels in their serum (MD = 0.25, 95% CI: 0.16–0.35,I² = 64.4% for T1DM). However, only patients with T1DM neuropathy had reduced serum HDL levels, and there was no significant difference in serum HDL levels between patients with T2DM neuropathy and controls (MD = -0.07, 95% CI: -0.10–-0.03, I² = 12.4% for T1DM; MD = -0.02, 95% CI: -0.07–0.03, I² = 80.2% for T2DM). TC and LDL levels were not significantly different between DN patients and controls (MD = -0.03, 95% CI: -0.14–0.09, I² = 82.9% for TC; MD = -0.00, 95% CI: -0.08–0.08, I² = 78.9% for LDL). In addition, compared with mild or painless DN patients, those with moderate or severe pain DN pain had significantly reduced serum TC and LDL levels (MD = -0.31, 95% CI: -0.49–-0.13, I² = 0% for TC; MD = -0.19, 95% CI: -0.32–-0.08, I² = 0% for LDL). TG levels and HDL levels did not vary considerably between patients with mild or painless DN and those with moderate or severe DN pain patients (MD = 0.12, 95% CI: -0.28–0.51, I² = 83.2% for TG; MD = -0.07, 95% CI:-0.14–0.01, I² = 58.8% for HDL). Furthermore, people with higher TG and LDL levels had higher risk of DN (OR = 1.36, 95% CI: 1.20–1.54, I² = 86.1% for TG and OR = 1.10, 95% CI: 1.02–1.19, I² = 17.8% for LDL). Conversely, high serum HDL levels reduced the risk of DN (OR = 0.85, 95% CI: 0.75–0.96, I² = 72.6%), while TC levels made no significant difference with the risk of DN (OR = 1.02, 95% CI: 1.00–1.04, I² = 84.7%). This meta-analysis indicated that serum lipid profile changes are among the biological characteristics of DN. Lipid levels should be explored as routine laboratory markers for predicting the risk of DN, as they will help clinicians choose appropriate therapies, and thus optimize the use of available resources.

The metabolic drivers of neuropathy in India

AIMS

To determine the association between the metabolic syndrome (MetS) and neuropathy in Chennai, India.

METHODS

We recruited participants attending the M.V. Hospital for Diabetes. Neuropathy was defined using the Michigan Neuropathy Screening Instrument combined index and MetS was defined using the updated National Cholesterol Education Program criteria. Multivariable logistic regression models were used to assess the associations between individual metabolic components and neuropathy.

RESULTS

Of the 652 participants (42% female and mean (SD) age of 45.5 (9.7)) included in the study, the prevalence of neuropathy was 9.8%. Neuropathy prevalence increased with worsening glycemic status (p < 0.01), but not as the number of MetS components increased (p = 0.12). Among normoglycemic participants, an increasing neuropathy trend was observed as the number of MetS components increased (p = 0.04). Multivariable logistic regression found that diabetes (OR:3.41,1.28-9.11) was associated with neuropathy, but waist circumference was not (OR:1.002,0.88-1.14).

CONCLUSIONS

Similar to previous studies, diabetes was the most important metabolic risk factor for neuropathy in a population from Chennai, India. In contrast to other population-based studies, waist circumference was not associated with neuropathy. Whether the distribution of obesity affects nerves differently in Indian populations requires future studies with more precise anthropometric measures.

Prevalence of common causes of neuropathic pain in Korea: population-based observational study

OBJECTIVE

To investigate the prevalence of complex regional pain syndrome (CRPS), post-herpetic neuralgia (PHN), trigeminal neuralgia (TN), and diabetic neuropathy (DN), common causes of neuropathic pain encountered in pain clinics.

METHODS

We investigated the period prevalence rate of CRPS, PHN, TN, and DN using data from a Korean national electronic database from 2009 to 2013.

RESULTS

The prevalence of CRPS decreased slightly throughout the study period, while the prevalence of PHN increased from 2009 to 2013. The prevalence of TN was reduced over the same period. The prevalence of DN increased from 2009 to 2012 but decreased in 2013. All four neuropathic diseases were more prevalent in individuals aged over 70 years. The prevalence of CRPS, PHN, and TN were more common in women than in men, but DN showed no gender difference.

CONCLUSION

While the prevalence of CRPS and TN has decreased in Korea, that of PHN and DN has increased. With the exception of DN, the neuropathic diseases were more prevalent in women. Further studies are necessary to investigate the risk factors and socioeconomic burden for each disease, and national efforts are essential to limit the development of these preventable neuropathic diseases.

Randomized controlled trial of a clinical decision support system for painful polyneuropathy

INTRODUCTION

Despite the existence of guidelines, painful neuropathy is often inappropriately treated. We sought to determine the effectiveness of a clinical decision support system on guideline-recommended medication use.

METHODS

We randomized neurology providers, stratified by subspecialty, to a best practice alert (BPA) linked to a Smartset or a BPA alone when seeing patients with neuropathy. The primary outcome was the proportion of patients with uncontrolled nerve pain prescribed a guideline-recommended medication. Generalized estimating equations were used to assess effectiveness.

RESULTS

Seventy-five neurology providers (intervention 38, control 37) treated 2697 patients with neuropathy (intervention 1026, control 671). Providers did not acknowledge the BPA in 1928 (71.5%) visits. Only four of eight intervention arm neurologists who treated patients with uncontrolled nerve pain opened the Smartset. The intervention was not associated with guideline-recommended medication use (odds ratio 0.52, 0.18-1.48; intervention 52%, control 54.8%).

DISCUSSION

Our intervention did not improve prescribing practices for painful neuropathy. Physicians typically ignored the BPAs/Smartset; therefore, future studies should mandate their use or employ alternate strategies.

Denoising of diffusion MRI improves peripheral nerve conspicuity and reproducibility

BACKGROUND

Quantitative diffusion MRI is a promising technique for evaluating peripheral nerve integrity but low signal-to-noise ratio (SNR) can impede measurement accuracy.

PURPOSE

To evaluate principal component analysis (PCA) and generalized spherical deconvolution (genSD) denoising techniques to improve within-subject reproducibility and peripheral nerve conspicuity.

STUDY TYPE

Prospective.

SUBJECTS

Seven healthy volunteers and three peripheral neuropathy patients.

FIELD STRENGTH/SEQUENCE

3T/multiband single-shot echo planar diffusion sequence using multishell 55-direction scheme.

ASSESSMENT

Images were processed using four methods: "original" (no denoising), "average" (10 repetitions), "PCA-only," and "PCA + genSD." Tibial and common peroneal nerve segmentations and masks were generated from volunteer diffusion data. Quantitative (SNR and contrast-to-noise ratio [CNR]) values were calculated. Three radiologists qualitatively evaluated nerve conspicuity for each method. The two denoising methods were also performed in three patients with peripheral neuropathies.

STATISTICAL TESTS

For healthy volunteers, calculations included SNR and CNR_FA (computed using FA values). Coefficient of variation (CV%) of CNR_FA quantified within-subject reproducibility. Groups were compared with two-sample t-tests (significance P < 0.05; two-tailed, Bonferroni-corrected). Odds ratios (ORs) quantified the relative rates of each of three radiologists confidently identifying a nerve, per slice, for the four methods.

RESULTS

"PCA + genSD" yielded the highest SNR (mean_overall = 14.83 ± 1.99) and tibial and common peroneal nerve CNR_FA (mean_tibial = 3.45, mean_peroneal = 2.34) compared to "original" (P _SNR < 0.001; P _CNR = 0.011) and "PCA-only" (P _SNR < 0.001, P _CNR < 0.001). "PCA + genSD" had higher within-subject reproducibility (low CV%) for tibial (6.04 ± 1.98) and common peroneal nerves (8.27 ± 2.75) compared to "original" and "PCA-only." The mean FA was higher for "original" than "average" (P < 0.001), but did not differ significantly between "average" and "PCA + genSD" (P = 0.14). "PCA + genSD" had higher tibial and common peroneal nerve conspicuity than "PCA-only" (OR_tibial = 2.50, P < 0.001; OR_peroneal = 1.86, P < 0.001) and "original" (OR_tibial = 2.73, P < 0.001; OR_peroneal = 2.43, P < 0.001).

DATA CONCLUSION

PCA + genSD denoising method improved SNR, CNR_FA , and within-subject reproducibility (CV%) without biasing FA and nerve conspicuity. This technique holds promise for facilitating more reliable, unbiased diffusion measurements of peripheral nerves.

LEVEL OF EVIDENCE

2 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2020;51:1128-1137.

SVM-CART for Disease Classification

Classification and regression trees (CART) and support vector machines (SVM) have become very popular statistical learning tools for analyzing complex data that often arise in biomedical research. While both CART and SVM serve as powerful classifiers in many clinical settings, there are some common scenarios in which each fails to meet the performance and interpretability needed for use as a clinical decision-making tool. In this paper, we propose a new classification method, SVM-CART, that combines features of SVM and CART to produce a more flexible classifier that has the potential to outperform either method in terms of interpretability and prediction accuracy. Further-more, to enhance prediction accuracy we provide extensions of a single SVM-CART to an ensemble, and methods to extract a representative classifier from the SVM-CART ensemble. The goal is to produce a decision-making tool that can be used in the clinical setting, while still harnessing the stability and predictive improvements gained through developing the SVM-CART ensemble. An extensive simulation study is conducted to asses the performance of the methods in various settings. Finally, we illustrate our methods using a clinical neuropathy dataset.

Time to Onset of Paresthesia Among Community Members Exposed to the World Trade Center Disaster

We examined whether time to onset of paresthesia was associated with indicators of severity of World Trade Center (WTC) exposure. We analyzed data from 3411 patients from the Bellevue Hospital—WTC Environmental Health Center. Paresthesia was defined as present if the symptom occurred in the lower extremities with frequency “often” or “almost continuous.” We plotted hazard functions and used the log-rank test to compare time to onset of paresthesia between different exposure groups. We also used Cox regression analysis to examine risk factors for time-to-paresthesia after 9/11/2001 and calculate hazard ratios adjusted for potential confounders. We found significantly elevated hazard ratios for paresthesia for (a) working in a job that required cleaning of WTC dust in the workplace; and (b) being heavily exposed to WTC dust on September 11, 2001, after adjusting for age, race/ethnicity, depression, anxiety, post-traumatic stress disorder, and body mass index. These observational data are consistent with the hypothesis that exposure to WTC dust or some other aspect of cleaning WTC dust in the workplace, is associated with neuropathy and paresthesia. Further neurological evaluations of this and other WTC-exposed populations is warranted.

Association Between Metabolic Syndrome Components and Polyneuropathy in an Obese Population

Importance

Past studies have shown an association between metabolic syndrome and polyneuropathy, but the precise components that drive this association remain unclear.

Objectives

To determine the prevalence of polyneuropathy stratified by glycemic status in well-characterized obese and lean participants and investigate the association of specific components of metabolic syndrome with polyneuropathy.

Design, Setting, and Participants

We performed a cross-sectional, observational study from November 1, 2010, to December 31, 2014, in obese participants (body mass index [calculated as weight in kilograms divided by height in meters squared] of 35 or more with no comorbid conditions or 32 or more with at least 1 comorbid condition) from a weight management program and lean controls from a research website. The prevalence of neuropathy, stratified by glycemic status, was determined, and a Mantel-Haenszel χ2 test was used to investigate for a trend. Logistic regression was used to model the primary outcome of polyneuropathy as a function of the components of metabolic syndrome after adjusting for demographic factors. Participants also completed quantitative sudomotor axon reflex testing, quantitative sensory testing, the neuropathy-specific Quality of Life in Neurological Disorders instrument, and the short-form McGill Pain Questionnaire.

Exposures

Components of metabolic syndrome (as defined by the National Cholesterol Education Program Adult Treatment Panel III), including glycemic status (as defined by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus).

Main Outcomes and Measures

Toronto consensus definition of probable polyneuropathy. Secondary outcomes included intraepidermal nerve fiber density and nerve conduction study parameters.

Results

We enrolled 102 obese participants (mean [SD] age, 52.9 [10.2] years; 48 men and 54 women; 45 with normoglycemia [44.1%], 31 with prediabetes [30.4%], and 26 with type 2 diabetes [25.5%]) and 53 lean controls (mean [SD] age, 48.5 [9.9] years; 16 men and 37 women). The prevalence of polyneuropathy was 3.8% in lean controls (n = 2), 11.1% in the obese participants with normoglycemia (n = 5), 29% in the obese participants with prediabetes (n = 9), and 34.6% in the obese participants with diabetes (n = 9) (P < .01 for trend). Age (odds ratio, 1.09; 95% CI, 1.02-1.16), diabetes (odds ratio, 4.90; 95% CI, 1.06-22.63), and waist circumference (odds ratio, 1.24; 95% CI, 1.00-1.55) were significantly associated with neuropathy in multivariable models. Prediabetes (odds ratio, 3.82; 95% CI, 0.95-15.41) was not significantly associated with neuropathy.

Conclusions and Relevance

The prevalence of polyneuropathy is high in obese individuals, even those with normoglycemia. Diabetes, prediabetes, and obesity are the likely metabolic drivers of this neuropathy.

Trial Registration

clinicaltrials.gov Identifier: NCT02689661.

The epidemiology and risk factors of chronic polyneuropathy

Polyneuropathy is a disabling condition of the peripheral nerves, characterized by symmetrical distal numbness and paresthesia, often accompanied with pain and weakness. Although the disease is often encountered in neurological clinics and is well known by physicians, incidence and prevalence rates are not well known. We searched EMBASE, Medline, Web-of-science, Cochrane, PubMed Publisher, and Google Scholar, for population-based studies investigating the prevalence of polyneuropathy and its risk factors. Out of 5119 papers, we identified 29 eligible studies, consisting of 11 door-to-door survey studies, 7 case-control studies and 11 cohort/database studies. Prevalence of polyneuropathy across these studies varies substantially. This can partly be explained by differences in assessment protocols and study populations. The overall prevalence of polyneuropathy in the general population seems around 1% and rises to up to 7% in the elderly. Polyneuropathy seemed more common in Western countries than in developing countries and there are indications that females are more often affected than males. Risk factor profiles differ across countries. In developing countries communicable diseases, like leprosy, are more common causes of neuropathy, whereas in Western countries especially diabetes, alcohol overconsumption, cytostatic drugs and cardiovascular disease are more commonly associated with polyneuropathy. In all studies a substantial proportion of polyneuropathy cases (20-30%) remains idiopathic. Most of these studies have been performed over 15 years ago. More recent evidence suggests that the prevalence of polyneuropathy in the general population has increased over the years. Future research is necessary to confirm this increase in prevalence and to identify new and potentially modifiable risk factors.

Distal Symmetric Polyneuropathy: A Review

IMPORTANCE

Peripheral neuropathy is a highly prevalent and morbid condition affecting 2% to 7% of the population. Patients frequently experience pain and are at risk of falls, ulcerations, and amputations. We aimed to review recent diagnostic and therapeutic advances in distal symmetric polyneuropathy, the most common subtype of peripheral neuropathy.

OBSERVATIONS

Current evidence supports limited routine laboratory testing in patients with distal symmetric polyneuropathy. Patients without a known cause should undergo a complete blood cell count, comprehensive metabolic panel, vitamin B12 measurement, serum protein electrophoresis with immunofixation, fasting glucose measurement, and glucose tolerance test. The presence of atypical features such as asymmetry, non-length dependence, motor predominance, acute or subacute onset, and prominent autonomic involvement should prompt a consultation with a neurologist or neuromuscular specialist. Electrodiagnostic tests and magnetic resonance imaging of the neuroaxis contribute substantial cost to the diagnostic evaluation, but evidence supporting their use is lacking. Strong evidence supports the use of tricyclic antidepressants, serotonin norepinephrine reuptake inhibitors, and voltage-gated calcium channel ligands in the treatment of neuropathic pain. More intensive glucose control substantially reduces the incidence of distal symmetric polyneuropathy in patients with type 1 diabetes but not in those with type 2 diabetes.

CONCLUSIONS AND RELEVANCE

The opportunity exists to improve guideline-concordant testing in patients with distal symmetric polyneuropathy. Moreover, the role of electrodiagnostic tests needs to be further defined, and interventions to reduce magnetic resonance imaging use in this population are needed. Even though several efficacious medications exist for neuropathic pain treatment, pain is still underrecognized and undertreated. New disease-modifying medications are needed to prevent and treat peripheral neuropathy, particularly in type 2 diabetes.

Impairments and comorbidities of polyneuropathy revealed by population-based analyses

OBJECTIVE

To quantify polyneuropathy impairments and comorbidities utilizing the Rochester Epidemiology Project (2010 census = 148,201).

METHODS

ICD-9-CM coding identified polyneuropathy cases (2006-2010) and their 5:1 age- and sex-matched controls. Mortality and impairments were evaluated while identifying and adjusting for Charlson Index comorbidities.

RESULTS

Overall prevalence of polyneuropathy was 1.66%, and markedly rose to 6.6% in persons older than 60 years. Cases (n = 2,892) had more comorbidities than controls (n = 14,435) with higher median Charlson Index (6 vs 3, p < 0.001). Diabetes with end-organ disease represented the largest increased comorbidity in cases compared with controls (46.8% vs 6.5%). Diabetic polyneuropathy was the most common specific subtype (38.2%). Miscoded idiopathic cases and false-negative controls also commonly had diabetic polyneuropathy. Median modified Rankin Scale score was considerably higher for cases than controls (4 vs 1, p < 0.001). Multiple comorbidities were found associated with polyneuropathy after adjusting for diabetes co-occurrence, including pulmonary disease, dementia, and others. Polyneuropathy was an independent contributor to multiple functional impairments including difficulty walking (odds ratio [OR] = 1.9), climbing stairs (OR = 2.0), using an assistive device (OR = 2.0), fall tendency (OR = 2.4), work disability (OR = 4.2), lower limb amputations (OR = 3.9), and opioid use (OR = 2.7). Prevalent cases had a younger median age at death than controls (80 vs 86 years, p < 0.001), and incident cases had a 6-month shorter survival.

CONCLUSIONS

Polyneuropathies have notable neurologic impairments beyond their identified multiple comorbidities. Life expectancy is shortened. Diabetic polyneuropathy is underidentified. The quantified extent of the disease burden and refined comorbidity associations emphasize that greater research efforts and health care initiatives are needed.

Role of neurologists and diagnostic tests on the management of distal symmetric polyneuropathy

IMPORTANCE

Distal symmetric polyneuropathy (DSP) is a prevalent condition that results in high costs from diagnostic testing. However, the role of neurologists and diagnostic tests in patient care is unknown.

OBJECTIVE

To determine how often neurologists and diagnostic tests influence the diagnosis and management of DSP in a community setting.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective cohort study, we used a validated case-capture method (International Classification of Diseases, Ninth Revision screening technique with subsequent medical record abstraction) to identify all patients with a new DSP diagnosis treated by community neurologists in Nueces County, Texas, who met the Toronto Diabetic Neuropathy Expert Group consensus criteria for probable DSP. Using a structured data abstraction process, we recorded diagnostic test results, diagnoses rendered (before and after testing), and subsequent management from April 1, 2010, through March 31, 2011.

MAIN OUTCOMES AND MEASURES

Changes in DSP cause and management after diagnostic testing by neurologists.

RESULTS

We identified 458 patients with DSP followed up for a mean (SD) of 435.3 (44.1) days. Neurologists identified a cause of DSP in 291 patients (63.5%) before their diagnostic testing. Seventy-one patients (15.5%) had a new DSP cause discovered after testing by neurologists. The most common new diagnoses were prediabetes (28 [6.1%]), vitamin B12 deficiency (20 [4.4%]), diabetes mellitus (8 [1.7%]), and thyroid disease (8 [1.7%]). Management changes were common (289 [63.1%]) and usually related to neuropathic pain management (224 [48.9%]). A potential disease-modifying management change was made in 113 patients (24.7%), with the most common changes being diabetes management in 45 (9.8%), treatment with vitamins in 39 (8.5%), diet and exercise in 33 (7.2%), and adjustment of thyroid medications in 10 (2.2%). Electrodiagnostic testing and magnetic resonance imaging of the neuroaxis rarely led to management changes.

CONCLUSIONS AND RELEVANCE

Neurologists diagnosed the cause of DSP in nearly two-thirds of patients before their diagnostic testing. Inexpensive blood tests for diabetes, thyroid dysfunction, and vitamin B12 deficiency allowed neurologists to identify a new cause of DSP in 71 patients (15.5%). In contrast, expensive electrodiagnostic tests and magnetic resonance imaging rarely changed patient care.

The metabolic syndrome and neuropathy: therapeutic challenges and opportunities

The metabolic syndrome and neuropathy are common conditions, especially in the elderly, that are associated with significant morbidity. Furthermore, the metabolic syndrome is reaching epidemic proportions across the world. Current evidence supports the association of the metabolic syndrome and its individual components with neuropathy. Several clinical trials have demonstrated that treating hyperglycemia, a component of the metabolic syndrome, has a significant effect on reducing the incidence of neuropathy in those with type 1 diabetes. However, glucose control has only a marginal effect on preventing neuropathy in those with type 2 diabetes, suggesting that other factors may be driving nerve injury in these patients. Emerging evidence supports the metabolic syndrome as including risk factors for neuropathy. Interventions exist for treatment of all of the metabolic syndrome components, but only glucose control has strong evidence to support its use and is widely employed. Our understanding of the biology of metabolic nerve injury has rapidly expanded over the past several years. Mechanisms of injury include fatty deposition in nerves, extracellular protein glycation, mitochondrial dysfunction, and oxidative stress. Additionally, the activation of counter-regulatory signaling pathways leads to chronic metabolic inflammation. Medications that target these signaling pathways are being used for a variety of diseases and are intriguing therapeutic agents for future neuropathy clinical trials. As we move forward, we need to expand our understanding of the association between the metabolic syndrome and neuropathy by addressing limitations of previous studies. Just as importantly, we must continue to investigate the pathophysiology of metabolically induced nerve injury.

Expenditures in the elderly with peripheral neuropathy: Where should we focus cost-control efforts?

To optimize care in the evaluation of peripheral neuropathy, we sought to define which tests drive expenditures and the role of the provider type. We investigated test utilization and expenditures by provider type in those with incident neuropathy in a nationally representative elderly, Medicare population. Multivariable logistic regression was used to determine predictors of MRI and electrodiagnostic utilization. MRIs of the neuroaxis and electrodiagnostic tests accounted for 88% of total expenditures. Mean and aggregate diagnostic expenditures were higher in those who saw a neurologist. Patients who saw a neurologist were more likely to receive an MRI and an electrodiagnostic test. MRIs and electrodiagnostic tests are the main contributors to expenditures in the evaluation of peripheral neuropathy, and should be the focus of future efficiency efforts.

A community-based epidemiological study of peripheral neuropathies in Assiut, Egypt

BACKGROUND

There is very little published information about the prevalence, patterns, and predictors of peripheral neuropathies. The current study is a community-based survey was conducted in the Assiut Governorate to estimate their prevalence and clinical profile.

MATERIAL AND METHODS

A door-to-door study was carried out on 42,223 persons from rural and urban communities in the Assiut Governorate, Egypt. There were 13,288 (31.5%) subjects from the urban and 28,935 (68·5%) from the rural area. All subjects filled in a questionnaire designed specifically for diagnosis of peripheral neuropathy. Positive cases were then given a complete medical and neurological examination, routine laboratory tests, neurophysiology, and neuroimaging (magnetic resonance).

RESULTS

The crude prevalence rate (CPR) of peripheral neuropathy was 3181/100,000 inhabitants. There was a significantly higher prevalence in the rural compared with the urban population (3795 versus 1844/100,000) and in females than males (4473 versus 1943/100,000; P<0.001 for both). The most common type reported was entrapment neuropathy (736 cases with CPR of 1743/100,000), particularly carpal tunnel syndrome (1686/100,000). Diabetic neuropathy was the most common non-compressive neuropathy with a CPR of 649/100,000. Type II diabetes was recorded in 241 patients with a CPR of 571/100,000. Compressive radiculopathy had a crude prevalence of 358/100,000; traumatic and iatrogenic radiculopathy had a prevalence rate of 149/100,000. Less common conditions were: uremic neuropathy (21/100,000) hepatic neuropathy (14/100,000), Bell's palsy (28/100,000), Guillian-Barre' syndrome (12/100,000), chronic inflammatory demyelinating polyneuropathy (12/100,000), hereditary sensory motor neuropathy (12/100,000), and idiopathic neuropathy (92/100,000).

CONCLUSION

The overall prevalence of peripheral neuropathies was high in comparison to other studies. Entrapment neuropathy, diabetic neuropathy, and spondylotic radiculopathy were the most common. Overall, the prevalence of peripheral neuropathy was higher in the rural than in the urban population.

Peripheral neuropathic symptoms in celiac disease and inflammatory bowel disease

OBJECTIVES

An association between celiac disease (CD) and peripheral neuropathy (PN) has been reported.

METHODS

Patients with CD and/or inflammatory bowel disease (IBD) were recruited from the gastroenterology clinics at a medical center and local support groups. Control subjects without CD or IBD were recruited from the staff of the medical center as well as relatives and attendees at support groups. Each participant completed a survey that used two validated PN instruments to define and characterize PN.

RESULTS

In the CD group, 38.9% met criteria for PN compared with 38.7% in the IBD group (P = 0.97) and 20.5% in the control group (P < 0.001). On multiple logistic regression, the odds of PN after adjusting for age, gender, diabetes, vitamin B12 deficiency, and cancer history were increased for CD (odds ratio, 2.51; 95% confidence interval, 1.82-3.47) and IBD (odds ratio, 2.78; 95% confidence interval, 1.85-4.18).

CONCLUSIONS

PN is more often found in patients with CD and/or IBD than in the general population.

Diabetic neuropathy: clinical manifestations and current treatments

Diabetic peripheral neuropathy is a prevalent, disabling disorder. The most common manifestation is distal symmetrical polyneuropathy (DSP), but many patterns of nerve injury can occur. Currently, the only effective treatments are glucose control and pain management. While glucose control substantially decreases the development of neuropathy in those with type 1 diabetes, the effect is probably much smaller in those with type 2 diabetes. Evidence supports the use of specific anticonvulsants and antidepressants for pain management in patients with diabetic peripheral neuropathy. However, the lack of disease-modifying therapies for diabetic DSP makes the identification of new modifiable risk factors essential. Growing evidence supports an association between components of the metabolic syndrome, including prediabetes, and neuropathy. Studies are needed to further explore this association, which has implications for the development of new treatments for this common disorder.

Tests and expenditures in the initial evaluation of peripheral neuropathy

BACKGROUND

Peripheral neuropathy is a common disorder in which an extensive evaluation is often unrevealing.

METHODS

We sought to define diagnostic practice patterns as an early step in identifying opportunities to improve efficiency of care. The 1996-2007 Health and Retirement Study Medicare claims-linked database was used to identify individuals with an incident diagnosis of peripheral neuropathy using International Classification of Diseases, Ninth Revision, codes and required no previous neuropathy diagnosis during the preceding 30 months. Focusing on 15 relevant tests, we examined the number and patterns of tests and specific test utilization 6 months before and after the incident neuropathy diagnosis. Medicare expenditures were assessed during the baseline, diagnostic, and follow-up periods.

RESULTS

Of the 12, 673 patients, 1031 (8.1%) received a new International Classification of Diseases, Ninth Revision, diagnosis of neuropathy and met the study inclusion criteria. Of the 15 tests considered, a median of 4 (interquartile range, 2-5) tests were performed, with more than 400 patterns of testing. Magnetic resonance imaging of the brain or spine was ordered in 23.2% of patients, whereas a glucose tolerance test was rarely obtained (1.0%). Mean Medicare expenditures were significantly higher in the diagnostic period than in the baseline period ($14,362 vs $8067, P < .001).

CONCLUSIONS

Patients diagnosed as having peripheral neuropathy typically undergo many tests, but testing patterns are highly variable. Almost one-quarter of patients receiving neuropathy diagnoses undergo high-cost, low-yield magnetic resonance imaging, whereas few receive low-cost, high-yield glucose tolerance tests. Expenditures increase substantially in the diagnostic period. More research is needed to define effective and efficient strategies for the diagnostic evaluation of peripheral neuropathy.

The evaluation of distal symmetric polyneuropathy: a physician survey of clinical practice

OBJECTIVE

To define current clinical practice for evaluating distal symmetric polyneuropathy.

DESIGN

Using a modified Dillman method, we sent surveys to 600 internists, 600 neurologists, and 45 neuromuscular specialists selected from the American Medical Association Physician Masterfile. Survey questions pertained to which tests providers would order in the following 3 scenarios: (1) the initial evaluation of distal symmetric polyneuropathy, (2) the use of additional tests if the initial evaluation was unrevealing, and (3) patients with diabetes. The t test was used to compare the number of tests ordered by physician type, and the χ(2) test was used to compare proportions of tests ordered.

SETTING

National survey of physicians.

PARTICIPANTS

Internists, neurologists, and neuromuscular specialists.

RESULTS

The response rate was 35%. Overall, many tests were ordered for the full evaluation of distal symmetric polyneuropathy (mean [SD], 16.5 [7.2] tests), and there was substantial variation within and between provider types. Internists ordered fewer tests (mean [SD], 14.5 [6.1] tests) than did neurologists (mean [SD], 17.5 [7.9] tests) (P < .001). Regarding the glucose tolerance test, substantial differences were found between physician types, with neurologists and neuromuscular specialists ordering this test more frequently (28.6% and 72.3%, respectively) and internists ordering it less frequently (4.1%). A brain and/or spine magnetic resonance imaging scan was ordered by 19.8% of internists and 12.9% of neurologists.

CONCLUSIONS

From the supporting evidence, current practice intent on evaluating distal symmetric polyneuropathy is highly variable and differs widely. For this disorder of the peripheral nerves, a high-yield test such as the glucose tolerance test is rarely used, whereas magnetic resonance imaging is likely overused. Research that defines the optimal evaluation of distal symmetric polyneuropathy has the potential to result in more efficient care.

An Overview of Neurological Disorders in Wales

This pragmatic work was undertaken to assist commissioners of health services in Wales in their planning for future provision of services for neurological and neurosurgical patients. A literature search, which was carried out to ascertain the epidemiology of neurological and neurosurgical disorders in Wales, revealed limited epidemiological surveys of patients in Wales, while other literatures although outdated were still relevant. More recent national reports, published by professional bodies and patients' organisations, were also identified. These disorders were also grouped according to their aetiology and symptoms into 13 groups. Using all the available literature, total estimates of annual incidence and point prevalence of these disorders were arrived at. We can conclude that approximately 5.8% of the population in Wales are affected by neurological and neurosurgical disorders that include headaches, traumatic and infectious diseases of the nervous system.

Two-Stage Community-Based Screening Model for Estimating Prevalence of Diabetic Polyneuropathy (KCIS No. 6)

The aim of this study was to apply a calibrated two-stage community-based design to estimate the prevalence of diabetic distal sensorimotor polyneuropathy (DPN) in Taiwan. Type 2 diabetics were identified from a population-based screening program in Keelung, Taiwan. Administration of the Neurological Symptom Score (NSS) questionnaire identified 210 DPN-positive cases of the 587 diabetic subjects tested. The accuracy of this NSS screening was tested with sensitive electrophysiological DPN diagnosis. A smaller validation study was also conducted to estimate the sensitivity and specificity of the NSS questionnaire. In the validation study, the overall prevalence rate for DPN among type 2 diabetics was 26.79%. The sensitivity, specificity, positive predictive value and negative predictive values were 73.33, 30.49, 24.72 and 75.76%, respectively. The estimates of sensitivity, specificity and positive predictive values were 75.00, 33.33 and 42.86% for old cases of diabetes, and 72.22, 29.69 and 22.41% for newly diagnosed cases. The range of prevalence rate in the main study was adjusted to 28.46-36.30% after calibration for sensitivity and specificity with the validation study data. A two-stage community-based screening model with calibration of prevalence rate was developed and enabled a cost-effective DPN prevalence rate estimate in a study with a large number of subjects.

Peripheral Neuropathy

This chapter focuses on peripheral neuropathy, which is the third or fourth most common neurologic disorder, even among the elderly. It begins with a description of the classification system for peripheral neuropathies. Because the underlying etiology or precipitating events of peripheral neuropathy are identifiable for the majority of affected individuals, epidemiologic research has largely focused on descriptive studies of disease frequency or on identifying the factors that modify the influence of the already existing risk factors. Three of the most common neuropathies are covered in detail: diabetic neuropathy, carpal tunnel syndrome, and Guillain–Barré syndrome. Each of these conditions is discussed in terms of distribution and risk factors, and is concluded with a discussion of future research directions to address unanswered questions. The chapter emphasizes methodologic approaches that that could be employed to improve the rigor of studies of these conditions.

Prevalence of cervical spondylotic radiculopathy: a door-to-door survey in a Sicilian municipality

INTRODUCTION

Because of the limited information on cervical spondylotic radiculopathy, we conducted a door-to-door two-phase survey in a Sicilian municipality.

MATERIAL AND METHODS

We first screened for cervical spondylotic radiculopathy among the inhabitants of the municipality: (N = 7653, as of the prevalence day, November 1, 1987). Study neurologists then investigated those subjects suspected to have had a cervical spondylotic radiculopathy. Diagnoses were bases on specified criteria.

RESULTS

We found 27 subjects affected by CSR (17 definite, 10 possible). Prevalence (cases per 1000 population) was 3.5 in the total population; it increased to a peak at age 50-59 years, and decreased thereafter. The age-specific prevalence was consistently higher in women.

CONCLUSIONS

Comparison with other prevalence studies shows similar age-specific patterns, but different magnitudes, which may partly reflect methodologic differences across studies.

The efficacy of aldose reductase inhibitors in the management of diabetic complications. Comparison with intensive insulin treatment and pancreatic transplantation

Recently, aldose reductase inhibitors (ARIs) have been registered in several countries for the improvement of glycaemic control. However, their efficacy is still controversial. ARIs inhibit the enhanced flux of glucose through the polyol pathway. As such, they can never be more effective than normoglycaemia, and so their potential benefits and limitations should be considered relative to the effects of prolonged euglycaemia. The clinical effects of ARIs can be put into perspective by assessing the effects of improved glycaemic control attained in randomised trials of intensive insulin treatment [such as the Diabetes Control and Complications Trial (DCCT)] and after pancreatic transplantation. Although direct comparison of these 3 interventions is hampered by differences in patient populations, duration and methods of follow-up and in the potency of ARIs, the effects of these 3 metabolic interventions and their course in time appear remarkably similar. For neuropathy, all 3 interventions induce an increase in average motor nerve conduction velocity of approximately 1 m/sec during the first months of treatment. At the same time, improvement of painful symptoms may occur. These changes probably largely represent a metabolic amelioration of the condition of the nerves. Around the second year of treatment with all 3 forms of metabolic improvement, an acceleration of nerve conduction of a similar magnitude occurs, with signs of structural nerve regeneration and some sensory recuperation. Experience with ARIs in nephropathy is still limited, but similar improvements in glomerular filtration rate and, less consistently, in urinary albumin excretion were found during short term normoglycaemia produced by all 3 forms of treatment. Comparison of a small number of studies, however, shows differences between intensive insulin regimens, pancreatic transplantation and ARIs in effects on retinopathy. Retinopathy often temporarily deteriorates in the early phases of improved glycaemic control, but this is not noted with ARIs. New microaneurysm formation was slightly reduced in a single long term study with the ARI sorbinil, but the preventive effects on the overall levels of retinopathy seemed less strong than in normoglycaemia trials of similar duration. However, the pharmacodynamic effects on inhibiting the polyol pathway differ among ARIs, and the half-life of the inhibiting effect of sorbinil may have been too short for a complete reduction of polyol pathway activity. The trials of prolonged intensive insulin therapy and pancreatic transplantation have demonstrated that very strict metabolic control must be maintained continuously for many years before a significant reduction of complications can be demonstrated.(ABSTRACT TRUNCATED AT 400 WORDS)