Peripheral neuropathy in young-old and old-old patients

[Role and place of ipidacrine in the therapy of diseases of the peripheral nervous system. The resolution of the expert council]

The resolution of the expert council is devoted to discussing aspects of the use of ipidacrine for the treatment of mononeuropathies, polyneuropathies and radiculopathies of various etiologies. Specialists prepared recommendations for ipidacrine's application in treating peripheral nervous system disorders.

Toxic Neuropathies

OBJECTIVE

The purpose of this article is to provide an overview and update on the most clinically relevant toxic neuropathies.

LATEST DEVELOPMENTS

Broadly, toxic neuropathies were previously quite rare with the notable exception of neuropathy from alcohol or older chemotherapeutics. The development of newer therapies, particularly immunotherapy to treat malignancy, has resulted in a substantial increase in the occurrence of toxic neuropathies that require timely recognition and treatment. The understanding of other toxic neuropathies continues to evolve, such as statin-induced neuropathy, which new evidence suggests is much less common than previously suspected.

ESSENTIAL POINTS

Toxic neuropathies can be caused by medications, supplements, and recreational substances that injure peripheral nerves. Medications have evolved in the past 2 decades, as have the types of neuropathies that can be seen as related toxicities. In some areas of medicine, new classes and generations of drugs are associated with a lower incidence of toxic neuropathy.

Etiological profile of peripheral neuropathies in an academic hospital in southern Morocco

Background

Peripheral neuropathies constitute a common complaint in general and neurology practice, and are a source of handicap to patients. Epidemiological data in the Middle East and North Africa region as well as in the African continent are sparse. Nevertheless, regional etiological profiles are crucial in navigating the diagnostic maze of neuropathies. This study outlines the etiological profile of peripheral neuropathies in an academic hospital in southern Morocco.

Results

A total of 180 cases were recorded in a span of 8 years (22.5 cases per year). The mean age of patients was 42.35 years. Male gender was predominant (68.88%), with a sex ratio of 2.2. Motor symptoms were the most frequently reported (86.6%). The axonal form (40.56%) was the most frequently encountered electrophysiologic form. The most frequent etiologies in the study were diabetes (26.7%), acute polyradiculoneuropathy (26.1%) and amyotrophic lateral sclerosis (16.1%). Alcohol neuropathy was found in 2.2% of the cohort. No cause was found in 5% of cases. Outcome was mostly favorable under treatment, although 10 deaths due to acute polyradiculoneuropathy were recorded (mortality = 21.3%).

Conclusions

Knowledge of the etiological profile of peripheral neuropathies should guide clinicians to an early diagnosis and aid in an adapted management of patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41983-022-00531-4.

Patients with alcohol use disorder increase pain and analgesics use: A nationwide population-based cohort study

BACKGROUND

Alcohol has dual effects on many systems, including the pain system. We will test whether and how chronic alcohol consumption enhances pain sensation to develop pain disorder.

METHODS

We conducted a retrospective matched cohort study using data from the National Health Insurance Research Database (NHIRD) in Taiwan, in patients with and without alcohol use disorder (AUD). This study enrolled 19,174 individuals with AUD as study cohort and 19,174 propensity score-matched individuals without AUD as comparison cohort. The outcome was the incidence of pain disorders and the need for analgesics. The hazard ratios of pain disorders and the need for analgesics were evaluated using Cox proportional hazard regression analysis after adjusting for age, sex, index year, comorbidities, urbanization, areas of residence, and insurance premium.

RESULTS

The 14 years of follow-up showed that AUD patients had a higher adjusted hazard ratio (aHR) for developing pain disorders than in non-AUD controls [aHR= 1.290, 95% confidence interval (CI): 1.045-1.591]. Besides, AUD patients had a higher risk of analgesic use (aHR = 1.081, 95% CI: 1.064-1.312), including opioids and non-opioid analgesics. Most importantly, AUD patients required more days of analgesic use, increased dose of analgesics, and higher costs of analgesics. Moreover, AUD patients had more anemia (aHR=2.772, 95% CI: 2.581-2.872), which could be a mediating factor.

CONCLUSIONS

AUD patients had higher risks of developing pain disorders and subsequently increased analgesic demand. These results suggest that AUD worsened pain, and pain syndrome is correlated with the duration of chronic alcohol exposure.

Peripheral polyneuropathy from electrodiagnostic tests: a 10-year etiology and neurophysiology overview

BACKGROUND

Polyneuropathies are characterized by a symmetrical impairment of the peripheral nervous system, resulting in sensory, motor and/or autonomic deficits. Due to the heterogeneity of causes, an etiological diagnosis for polyneuropathy is challenging.

OBJECTIVE

The aim of this study was to determine the main causes of polyneuropathy confirmed by electrodiagnostic (EDX) tests in a tertiary service and its neurophysiological aspects.

METHODS

This observational cross-sectional study from a neuromuscular disorders center included individuals whose electrodiagnostic tests performed between 2008 and 2017 confirmed a diagnosis of polyneuropathy. Through analysis of medical records, polyneuropathies were classified according to etiology and neurophysiological aspect.

RESULTS

Of the 380 included patients, 59.5% were male, with a median age of 43 years. The main etiologies were: inflammatory (23.7%), hereditary (18.9%), idiopathic (13.7%), multifactorial (11.1%), and diabetes (10.8%). The main electrophysiological patterns were axonal sensorimotor polyneuropathy (36.1%) and "demyelinating and axonal" sensorimotor polyneuropathy (27.9%). Axonal patterns showed greater etiological heterogeneity, with a predominance of idiopathic and multifactorial polyneuropathy, while demyelinating and "demyelinating and axonal" polyneuropathies had a significantly fewer etiologies, with a predominance of hereditary and inflammatory polyneuropathies.

CONCLUSION

The main causes of polyneuropathy confirmed by EDX test in this study were those that presented a severe, atypical and/or rapidly progressing pattern. Other causes were hereditary and those that defy clinical reasoning, such as multiple risk factors; some polyneuropathies did not have a specific etiology. EDX tests are useful for etiological diagnosis of rare polyneuropathies, because neurophysiological patterns are correlated with specific etiologies.

Neuropathy of the elderly

There is an aging of the peripheral nervous system characterized by a decrease in sensory and motor nerve conduction, amplitudes of motor and above all sensory potentials, an abolition of the ankle jerk reflexes and an alteration of proprioceptive sensitivity in almost two-thirds of individuals over 65 years old. These anomalies tend to increase beyond 80 years. However, these signs of aging do not affect the quality of life of the subjects. The causes of peripheral neuropathies in the elderly differ little from those observed before age 65. Of course, hereditary causes are much less frequent, except cases with a late onset, now easily detectable, such as familial amyloidosis. In our climates and in the most developed countries, diabetes remains the most common cause, the prevalence of neuropathy increasing with age. The so-called idiopathic causes are also frequent and despite extensive investigations, nearly 20% of cases remain without etiological diagnosis, but this type of neuropathy is generally mild and not very progressive. The presence of peripheral neuropathy in the elderly can cause real problems in daily life, including the frequency of falls that can be responsible for deleterious bone damage.

Diagnosis of peripheral neuropathy

Introduction

Peripheral neuropathy represents a spectrum of diseases with different etiologies. The most common causes are diabetes, exposure to toxic substances including alcohol and chemotherapeutics, immune-mediated conditions, and gene mutations. A thorough workup including clinical history and examination, nerve conduction studies, and comprehensive laboratory tests is warranted to identify treatable causes.

First steps

The variability of symptoms allows distinguishing characteristic clinical phenotypes of peripheral neuropathy that should be recognized in order to stratify the diagnostic workup accordingly. Nerve conduction studies are essential to determine the phenotype (axonal versus demyelinating) and severity. Laboratory tests, including genetic testing, CSF examination, nerve imaging, and nerve biopsy, represent additional clinical tests that can be useful in specific clinical scenarios.

Comments

We propose a flow chart based on five common basic clinical patterns of peripheral neuropathy. Based on these five clinical phenotypes, we suggest differential diagnostic pathways in order to establish the underlying cause.

Conclusions

The recognition of characteristic clinical phenotypes combined with nerve conduction studies allows pursuing subsequent diagnostic pathways that incorporate nerve conduction studies and additional diagnostic tests. This two-tiered approach promises higher yield and better cost-effectiveness in the diagnostic workup in patients with peripheral neuropathy.

Iatrogenesis and neurological manifestations in the elderly

Older people are often exposed to polypharmacy in a multimorbidity context. Inappropriate polypharmacy is often harmful, increasing the risk of inappropriate prescriptions and therefore adverse drug events (ADEs). Five to 20% of all hospital admissions are related to ADE in older people, among which 40 to 70% could be prevented. However, identifying ADEs and drug-related admissions in the elderly is challenging because ADEs often present as common geriatric problems such as falls, delirium, which might be due to the aging process, underlying diseases, and/or medications. In the pharmacovigilance database of the World Health Organization, drug-related neurological manifestations are the third reported cause of ADEs in the elderly, and neurological drugs are the third leading class of medications involved in ADEs. We must therefore be particularly vigilant, both in our prescriptions but also in our diagnoses to avoid prescribing inappropriate treatments and detect ADEs. Even though multiple pharmacologic changes occur in the elderly (absorption, distribution, drug metabolism and excretion), most of medications are still often prescribed at the same daily dosage as in young adults. When prescribing any drug for old patients, we should remember that daily intake should be adapted to these specificities, keeping in mind the old well-known aphorism "start low, go slow". In this review, we describe the main drug-related neurological manifestations (drug-induced movement disorders, falls, seizures, delirium, hypoglycemia, stroke, hyponatremia, peripheral neuropathy and myopathy, and serotonin syndrome) and the main drugs associated with neurological manifestations (dopamine receptor blocking agents, antithrombotics, anticholinergics, beta-lactams, antidepressants, benzodiazepines, mood stabilizers).

Alcohol-related peripheral neuropathy: a systematic review and meta-analysis

The primary aim of this systematic review was to establish the prevalence, character, and risk factors of peripheral neuropathy amongst chronic alcohol abusers and to identify the most appropriate management strategies. In this review, possible pathogenetic mechanisms are also discussed. A systematic, computer-based search was conducted using the PubMed database. Data regarding the above parameters were extracted. 87 articles were included in this review, 29 case–control studies, 52 prospective/retrospective cohort studies and 2 randomised control trials, 1 cross sectional study, and 3 population-based studies. The prevalence of peripheral neuropathy amongst chronic alcohol abusers is 46.3% (CI 35.7– 57.3%) when confirmed via nerve conduction studies. Alcohol-related peripheral neuropathy generally presents as a progressive, predominantly sensory axonal length-dependent neuropathy. The most important risk factor for alcohol-related peripheral neuropathy is the total lifetime dose of ethanol, although other risk factors have been identified including genetic, male gender, and type of alcohol consumed. At present, it is unclear what the pathogenetic mechanisms for the development of neuropathy amongst those who chronically abuse alcohol are, and therefore, it is unknown whether it is attributed to the direct toxic effects of ethanol or another currently unidentified factor. There is presently sparse data to support a particular management strategy in alcohol-related peripheral neuropathy, but the limited data available appears to support the use of vitamin supplementation, particularly of B-vitamin regimens inclusive of thiamine.

Clinical spectrum and quality of life in patients with chronic polyneuropathy: A cross-sectional study

Chronic polyneuropathy is a disabling condition of the peripheral nerves, characterized by symmetrical sensory motor symptoms and signs. There is paucity of studies on the etiological spectrum of polyneuropathy and its impact on quality of life (QoL). The present cross-sectional study in a referral based tertiary care center in North India found diabetic neuropathy as the commonest cause (25.5%) amongst 212 patients with chronic polyneuropathy. Idiopathic axonal polyneuropathy was present in 14.2% patients. Leprosy presenting as confluent mononeuritis multiplex constituted 11.3% of the patients. Additionally, it revealed a significantly worse QoL in these patients in all domains measured by short form (SF-36). This is the first study conducted in India to determine the QoL in chronic neuropathy patients. The current study demonstrates the clinical feasibility and applicability of the SF-36 generic health status in patients with polyneuropathies.

The Influence of Clinically Diagnosed Neuropathy on Respiratory Muscle Strength in Type 2 Diabetes Mellitus

OBJECTIVES

This cross-sectional study investigated the influence of clinically diagnosed neuropathy (cdNP) on respiratory muscle strength in patients with type 2 diabetes mellitus (T2DM).

METHODS

110 T2DM patients and 35 nondiabetic healthy controls (≥60 years) were allocated to one of three groups depending on the presence of cdNP: T2DM without cdNP (D-; n = 28), T2DM with cdNP (D+; n = 82), and controls without cdNP (C; n = 35). Clinical neurological diagnostic examination consisted of Vibration Perception Threshold and Diabetic Neuropathy Symptom score. Respiratory muscle strength was registered by maximal Inspiratory and Expiratory Pressures (PI_max and PE_max), and respiratory function by Peak Expiratory Flow (PEF). Isometric Handgrip Strength and Short Physical Performance Battery were used to evaluate peripheral skeletal muscle strength and physical performance. Univariate analysis of covariance was used with age, level of physical activity, and body mass index as covariates.

RESULTS

PI_max, PE_max, and PEF were higher in C compared to D- and D+. Exploring more in detail, PI_max, PE_max, and PEF were significantly lower in D+ compared to C. PE_max and PEF were also significantly lower in D- versus C. Measures of peripheral muscle strength and physical performance showed less associations with cdNP and T2DM.

CONCLUSIONS

The presence of cdNP affects respiratory muscle strength in T2DM patients compared to healthy controls. Both cdNP and diabetes in themselves showed a distinctive impact on respiratory muscle strength and function; however, an accumulating effect could not be ascertained in this study. As commonly used measures of peripheral muscle strength and physical performance seemed to be less affected at the given time, the integration of PI_max, PE_max, and PEF measurements in the assessment of respiratory muscle weakness could be of added value in the (early) screening for neuropathy in patients with T2DM.

Drug therapy for chronic idiopathic axonal polyneuropathy

BACKGROUND

Chronic idiopathic axonal polyneuropathy (CIAP) is an insidiously progressive sensory or sensorimotor polyneuropathy that affects elderly people. Although severe disability or handicap does not occur, CIAP reduces quality of life. CIAP is diagnosed in 10% to 25% of people referred for evaluation of polyneuropathy. There is a need to gather and review emerging evidence on treatments, as the number of people affected is likely to increase in ageing populations. This is an update of a review first published in 2004 and previously updated in 2006, 2008, 2011 and 2013.

OBJECTIVES

To assess the effects of drug therapy for chronic idiopathic axonal polyneuropathy for reducing disability and ameliorating neurological symptoms and associated impairments, and to assess any adverse effects of treatment.

SEARCH METHODS

In July 2016, we searched Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews in the Cochrane Library, MEDLINE, Embase, and the Web of Science. We searched two trials registries for ongoing trials. We also handsearched the reference lists of relevant articles, reviews and textbooks identified electronically, and we would have contacted authors and other experts in the field to identify additional studies if this seemed useful.

SELECTION CRITERIA

We sought all randomised or quasi-randomised (alternate or other systematic treatment allocation) trials that examined the effects of any drug therapy in people with CIAP at least one year after the onset of treatment. People with CIAP had to fulfil the following criteria: age 40 years or older, distal sensory or sensorimotor polyneuropathy, absence of systemic or other neurological disease, chronic clinical course not reaching a nadir in less than two months, exclusion of any recognised cause of the polyneuropathy by medical history taking, clinical or laboratory investigations, and electrophysiological studies in agreement with axonal polyneuropathy, without evidence of demyelinating features. The primary outcome was the proportion of participants with a significant improvement in disability. Secondary outcomes were change in the mean disability score, change in the proportion of participants who make use of walking aids, change in the mean Medical Research Council sum score, degree of pain relief and/or reduction of other positive sensory symptoms, change in the proportion of participants with pain or other positive sensory symptoms, and frequency of adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed the results of the literature search and extracted details of trial methodology and outcome data of all potentially relevant trials.

MAIN RESULTS

We identified 39 studies and assessed them for possible inclusion in the review, but we excluded all of them because of insufficient quality or lack of relevance. We summarised evidence from non-randomised studies in the Discussion.

AUTHORS' CONCLUSIONS

Even though CIAP has been clearly described and delineated, no adequate randomised or quasi-randomised controlled clinical treatment trials have been performed. In their absence there is no proven efficacious drug therapy.

Vasculitic neuropathy in elderly: A study from a tertiary care university hospital in South India

Objective:

To describe clinical, electrophysiological, and histopathological profile of vasculitic neuropathy in elderly subjects aged 65 years or more.

Design:

Retrospective chart review.

Setting:

Departments of Neurology and Neuropathology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.

Patients and Methods:

Elderly subjects, diagnosed vasculitic neuropathy by nerve biopsy over one decade, were studied.

Results:

The cohort consisted of 46 subjects. Symptom duration was 21.54 ± 33.53 months. Onset was chronic in majority (82.6%). Key features included paresthesias (89%), weakness (80%), sensory loss (70%), wasting (63%), and relapsing-remitting course (6.5%). Most Common clinico-electrophysiological patterns were distal symmetrical sensorimotor polyneuropathy - 19, mononeuritis multiplex - 9, and asymmetric sensorimotor neuropathy - 10. Diagnosis of vasculitis was not suspected before biopsy in 31 (67.3%). Nerve biopsy revealed definite vasculitis - 12, probable - 10, and possible - 24. Treatment included immunomodulatory agents (41), symptomatic medications only (9), and antiretroviral therapy (1). Twenty-four patients were followed up for mean period of 6.5 months. Outcome at last follow-up was improved (13), unchanged (8), and worsened (3).

Conclusion:

Vasculitis is an important, treatable cause of neuropathy in elderly. Nerve biopsy should be used judiciously for early diagnosis and appropriate treatment.

Who is healthy? Aspects to consider when including healthy volunteers in QST--based studies-a consensus statement by the EUROPAIN and NEUROPAIN consortia

Clinical and human experimental pain studies often include so-called "healthy" controls in investigations of sensory abnormalities, using quantitative sensory testing (QST) as an outcome measure. However, the criteria for what is considered "healthy" vary among the different studies and between study centers and investigators, partly explaining the high variability of the results. Therefore, several aspects should be considered during inclusion of healthy volunteers in QST-based trials to have homogenous groups of healthy controls with less variability between human experimental studies, so that results are less likely to be false negative or false positive because of subject-related factors. The EUROPAIN and NEUROPAIN consortia aimed to define factors influencing the variability in selection of healthy subjects in QST-based studies before the start of both projects and to give recommendations how to minimize it based on the current literature and expertise of the participants. The present suggestions for inclusion criteria of healthy volunteers into QST-based trials describe a 2-level approach including standardized questionnaires enabling the collection of relevant information on sociodemographic data, medical history, current health status, coping strategies in dealing with pain, and the motivation of the volunteer to participate in the study. These suggestions are believed to help researchers interpret their results in comparison with others and improve the quality of clinical studies including healthy volunteers as controls or in human experimental pain studies. They aim to reduce any confounding factors. Furthermore, the acquired information will allow post hoc analyses of variance for different potential influencing factors.

Frequent laboratory abnormalities in CIDP patients

INTRODUCTION

The role of screening laboratory tests in chronic inflammatory demyelinating polyneuropathy (CIDP) is currently unknown. The objectives of this study are to explore common laboratory test abnormalities in CIDP patients.

METHODS

CIDP subjects attending the Neuromuscular Clinic between 01/2013 and 12/2014 were evaluated. Demographic data, clinical history, physical examination, and laboratory test results were extracted from their charts.

RESULTS

Seventy-nine charts were reviewed. Mean age was 61 ± 11 years. Most (84%) CIDP patients had laboratory test abnormalities; the most frequent were paraproteinemia (29%) and elevated HbA1C (28%) and creatine kinase (27%). Additional abnormalities included anemia in 19%, and elevated anti-neutrophil cytoplasmic antibody, erythrocyte sedimentation rate, and urate in 17%, elevated antinuclear antibodies, rheumatoid factor, and thyroid-stimulating hormone in 11%, and abnormal C3 in 10%.

CONCLUSIONS

Laboratory test abnormalities were found in most CIDP patients. The most common were paraproteinemia, higher than expected frequency of diabetes, and unexpected CK elevation. Additional abnormalities included anemia, high urate levels, and common biomarkers for vasculitic neuropathies. Muscle Nerve 53: 862-865, 2016.

Peripheral neuropathies

Peripheral neuropathies are diseases of the peripheral nervous system that can be divided into mononeuropathies, multifocal neuropathies, and polyneuropathies. Symptoms usually include numbness and paresthesia. These symptoms are often accompanied by weakness and can be painful. Polyneuropathies can be divided into axonal and demyelinating forms, which is important for diagnostic reasons. Most peripheral neuropathies develop over months or years, but some are rapidly progressive. Some patients only suffer from mild, unilateral, slowly progressive tingling in the fingers due to median nerve compression in the wrist (carpal tunnel syndrome), while other patients can be tetraplegic, with respiratory insufficiency within 1-2 days due to Guillain-Barré syndrome. Carpal tunnel syndrome, with a prevalence of 5% and incidence of 1-2 per 1000 person-years, is the most common mononeuropathy. Population-based data for chronic polyneuropathy are relatively scarce. Prevalence is estimated at 1% and increases to 7% in persons over 65 years of age. Incidence is approximately 1 per 1000 person-years. Immune-mediated polyneuropathies like Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy are rare diseases, with an annual incidence of approximately 1-2 and 0.2-0.5 per 100 000 persons respectively. Most peripheral neuropathies are more prevalent in older adults and in men, except for carpal tunnel syndrome, which is more common in women. Diabetes is a common cause of peripheral neuropathy and is associated with both mono- and polyneuropathies. Among the group of chronic polyneuropathies, in about 20-25% no direct cause can be found. These are slowly progressive axonal polyneuropathies.

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.

Neuropathy in elderly: lessons learnt from nerve biopsy

OBJECTIVE

To study the utility of nerve biopsy in providing diagnostic, therapeutic or prognostic information that aid in clinical management in elderly subjects with peripheral neuropathy.

METHODS

Clinico-pathological data of 100 elderly subjects aged 65 and above with peripheral neuropathy who underwent nerve biopsy in the last decade (2002-2011) was reviewed.

RESULTS

The study included 100 subjects (M:F 78:22). Mean age at biopsy and symptom duration was 69.62±4.8 years and 24.17±40.4 months, respectively. The most common pattern of was distal symmetric sensorimotor polyneuropathy (35%), followed by multiple mononeuropathy (29%) and asymmetric sensorimotor neuropathy (15%). The nerve biopsy was 'diagnostic' in 24%, (definite vasculitis in 12, leprosy in 10 and acute inflammatory demyelinating polyradiculoneuropathy in 2) and proved 'essential' or 'helpful' in therapeutic management in 81% subjects. In 60 (60%) patients, where a pre-biopsy aetiological diagnosis could be arrived at based on the available data, nerve biopsy confirmed the diagnosis in 29 of 60 (48.3%), and offered a new diagnosis in 25 (41.7%). A higher yield of biopsy was noted in subjects with asymmetric/multiple mononeuropathy compared with symmetric neuropathies (32.7% versus 17.7%). In 40 (40%) patients without a pre-biopsy aetiological diagnosis, nerve biopsy was 'essential' in 7 of 40 (17.5%) as it provided a definitive diagnosis (definite vasculitis: 5, leprosy: 2), and 'helpful' in 21 of 40 (52.5%) (ischaemic neuropathy: 10, possible vasculitis: 9, probable vasculitis: 2).

CONCLUSION

Nerve biopsy aided in the detection of potentially treatable disorders and influenced patient management in a significant proportion of elderly subjects with peripheral neuropathy (81%), particularly in subset with undiagnosed neuropathies confirming that it's a useful tool in diagnosis of neuropathy in the elderly. With minor differences, the aetiological profile in our biopsied neuropathic elderly subjects may reflect the findings in other similar cohorts.

Peripheral neuropathy in the elderly

Peripheral neuropathy is an important factor of disability in the elderly, which is significant now that up to 20% of the population is older than 60 years in industrialized countries. Potentially treatable neuropathies including primary inflammatory polyneuropathies and systemic disorders, especially vasculitic neuropathies, are as common in this age group as in younger patients. Neuropathies associated with diabetes, malignancy, and monoclonal gammopathies are even more common in these patients. It is thus essential to identify the causes of these neuropathies in this group of patients and treat them whenever feasible.

A rational diagnostic approach to peripheral neuropathy

Peripheral neuropathies are among the most common disorders encountered by neuromuscular specialists and their evaluation can be challenging. The first part of this review outlined an algorithm based on anatomy, pathology, electrodiagnosis, and clinical localization that leads to a full characterization of the peripheral neuropathy. In the second part, we apply this approach, emphasizing recognition of atypical features and formulation of a focused differential diagnosis, thus reducing the number of uninformative tests. We review evidence supporting the routine use of commonly ordered laboratory tests and recommend a panel of tests that should be performed in patients with symmetric, distal, sensory-predominant peripheral neuropathy. Using this diagnostic approach, a diagnosis could be made in two thirds of patients.

Reproducibility of peroneal motor nerve conduction measurement in older adults

OBJECTIVE

While neuropathy is common in the elderly, nerve conduction (NC) reproducibility in older adults is not well-established. We sought to evaluate intraobserver reproducibility of peroneal motor NC measures in a diverse sample of older adults.

METHODS

We measured peroneal motor NC amplitude and velocity in a subset of participants (mean age=82.9±2.7, n=62, 50% female, 51.6% black, 35.5% DM) in the Health, Aging, and Body Composition Study. Using coefficients of variation (CVs), intraclass correlation coefficients (ICCs), and Bland Altman Plots, we compared two sets of measurements taken by the same examiner hours apart on the same day.

RESULTS

Low CVs (2.15-4.24%) and moderate to high ICCs (0.75-0.99) were observed. No systematic variation was found across measures. Despite small numbers in some subgroups, we found no differences in reproducibility by diabetes, race or study site.

CONCLUSION

NC measures have moderate to high intraobsever reproducibility in older adults and are not affected by diabetes, race, or gender.

SIGNIFICANCE

These data provide evidence to support use of these measures in aging research.

Factors affecting test results and standardized method in quiet standing balance evaluation

Objective

To identify factors affecting test results of the quiet standing balance evaluation conducted by posturography and to investigate the standardized method by comparing results according to feet width.

Method

The study cohort consisted of 100 healthy individuals. We assessed the quiet standing balance of subjects by using 3 different methods: standing on a force plate with feet width the same as shoulder width (test 1); with feet width the same as half the shoulder width (test 2); with feet width determined by the subject's comfort (test 3). Subjects underwent each test with their eyes open and closed for 30 seconds each time. Parameters for measuring standing balance included the mean mediolateral and anteroposterior extent, speed, and the velocity moment of center of pressure (COP) movement.

Results

All parameters showed better results when the subject's eyes were open rather than closed, and the mean AP extent and speed increased as the age of the subjects increased (p<0.01). However, there was no significant correlation between height and the study parameters, and no differences between men and women. Mean mediolateral extent and speed were significantly longer and faster in test 1 compared with tests 2 and 3 (p<0.01). The results of test 2 were better than the results of test 3, but the difference was not statistically significant.

Conclusion

COP movements increased with age and when subjects closed their eyes in an evaluation of quiet standing balance conducted by posturography. Gender and height did not affect results of the test. We suggest that an appropriate method for conducting posturography is to have the subject stand on a force plate with their feet width the same as half the shoulder width, because this posture provided relatively accurate balance capacity.

Dyslipidaemia in chronic acquired distal axonal polyneuropathy

The link between hypertriglyceridaemia (HTG) and/or hypercholesterolaemia (HCL) and neuropathy is uncertain. We retrospectively reviewed records of 100 consecutive patients investigated for acquired chronic axonal distal polyneuropathy of unknown cause. Findings were compared with those of 102 consecutive controls. Patients with idiopathic neuropathy were subsequently compared with age- and gender-matched controls. There were more neuropathy patients than controls with HCL, defined as cholesterol levels >5 mmol/L (63 vs. 45.1%; p = 0.011). Neuropathy patients also had higher cholesterol levels than controls (p = 0.04). Cholesterol-lowering drug usage was similar in both groups. HTG (defined as >2 mmol/L) and triglyceride levels were comparable in both groups. HTG ranged from 2.1-4.2 mmol/L in neuropathy patients. A cause for neuropathy was identified in 59 patients. Thirty-one had impaired glucose metabolism. Forty-one had idiopathic neuropathy. No link was demonstrated between idiopathic neuropathy or painful idiopathic neuropathy, and HTG/HCL. Mean triglyceride and cholesterol levels in patients with idiopathic neuropathy were comparable to those of controls. HTG was significantly more common (p = 0.027), and triglyceride levels significantly higher (p = 0.005) in patients with neuropathy due to diabetes/impaired glucose tolerance (IGT)/alcoholism, than in patients with neuropathy of any other cause. These results suggest HCL >5 mmol/L may represent a cofactor contributing to presence of neuropathy irrespective of the underlying cause. They on the other hand do not support mild/moderate HTG as an independent cause of neuropathy. HTG is common in patients with neuropathy associated with diabetes/IGT/chronic alcoholism, where it may play a role in peripheral nerve damage. As previously reported, IGT was in our cohort frequent, present in one case in three, in the absence of another identifiable aetiology.

Peripheral nerve conduction abnormalities in nonparetic side of ischemic stroke patients

Cardiovascular diseases manifest similar age and sex distribution in the general population and have some commons risk factors with some neuropathies. The aim of this study is to verify whether standard nerve conduction studies show significant differences in a group of poststroke hemiplegic patients, when compared with a control group, in the hypothesis that stroke, as a primary cardiovascular event, could be strongly associated with peripheral nervous system disease. Nerve conduction studies were performed in 15 hemiplegic patients and 10 aged matched control subjects. Percentage of patients showing slowed ulnar and common peroneal motor nerve conduction and lower ulnar sensory nerve action potential was significantly higher in hemiplegic patients. These findings suggest that an overall increased risk of neuropathies could be detected among stroke patients.

Is there a need for long-term follow-up in chronic idiopathic polyneuropathy?

OBJECTIVE

To evaluate the long-term functional status and well-being in patients with chronic idiopathic polyneuropathy (CIP) in comparison to Guillain-Barré syndrome (GBS) and healthy controls.

MATERIALS AND METHODS

Forty-two CIP and 42 GBS-patients were examined at median 5 and 6 years after disease onset and were compared with 50 healthy controls. The Fatigue Severity Scale (FSS), Visual Analogue Scale for pain (VAS), Disability Rating Index (DRI) and Medical Outcome Study 36-item short-form health status scale (SF-36) were used. Variables at onset and symptoms at follow-up were correlated with outcome measurements in GBS.

RESULTS

Patients with CIP and GBS had more pain and disability than healthy controls. Additionally, CIP-patients were more fatigued than healthy controls. Patients with CIP were more fatigued [FSS 4.9 (SD 1.6) vs 3.8 (SD 1.8); P < 0.01] and disabled [DRI 4.1 (SD 2.3) vs 2.5 (SD 2.1); P = 0.05] than those with GBS. Physical functioning on the SF-36 was more impaired in CIP than GBS, compared with healthy controls.

CONCLUSIONS

Patients with CIP and GBS seem to develop persistent impairment on long-term functional status and well-being, more clearly in CIP, reflecting the importance of long-term follow-up in further disease management.

A semi-automated analysis method of small sensory nerve fibers in human skin-biopsies

Computerized detection method (CDM) software programs have been extensively developed in the field of astronomy to process and analyze images from nearby bright stars to tiny galaxies at the edge of the Universe. These object-recognition algorithms have potentially broader applications, including the detection and quantification of cutaneous small sensory nerve fibers (SSNFs) found in the dermal and epidermal layers, and in the intervening basement membrane of a skin punch biopsy. Here, we report the use of astronomical software adapted as a semi-automated method to perform density measurements of SSNFs in skin-biopsies imaged by Laser Scanning Confocal Microscopy (LSCM). In the first half of the paper, we present a detailed description of how the CDM is applied to analyze the images of skin punch biopsies. We compare the CDM results to the visual classification results in the second half of the paper. Abbreviations used in the paper, description of each astronomical tools, and their basic settings and how-tos are described in the appendices. Comparison between the normalized CDM and the visual classification results on identical images demonstrates that the two density measurements are comparable. The CDM therefore can be used - at a relatively low cost - as a quick (a few hours for entire processing of a single biopsy with 8-10 scans) and reliable (high-repeatability with minimum user-dependence) method to determine the densities of SSNFs.

POLYNEUROPATHIES IN THE ELDERLY: A CLINICO PATHOLOGICAL STUDY OF 74 CASES

In elderly patients, peripheral neuropathies are common and may lead to disability. In order to investigate the relative incidence of different polyneuropathies in the elderly focusing on the contribution of nerve biopsy to their diagnosis, the authors studied 74 patients over 65 years of age with clinical, laboratory, electrophysiological, and sural nerve biopsy findings of different types of polyneuropathy. Vasculitic polyneuropathy seemed to be the most common cause of disabling neuropathy in the elderly, followed by paraneoplasia and diabetes. The possible diagnosis of idiopathic axonal neuropathy in the nine cases with neuropathy of unknown origin is discussed.

[Polyneuropathies in the elderly. Classification and thematic review]

The term polyneuropathy (PNP) is used to describe a group of entities affecting the peripheral nerves, due to external trauma or internal pathology. The prevalence of PNP in the elderly is between 5 and 10%. Despite the multiplicity of causes, the most common etiological factor is diabetes. PNP is characterized by a wide variety of symptoms, due to the multiple functions of nerves. Clinical manifestations range from sensory or motor deficit to inability to maintain gait and stability. Diagnosis is difficult in the elderly, and can be a challenge to the geriatrician in patients with functional impairment. The gold standard for diagnosis is electrophysiology testing. The present article describes the main PNP in the elderly based on the physiopathology of these diseases and provides a practical proposal for clinical classification.

The effects of aerobic exercise training on the age-related lipid peroxidation, Schwann cell apoptosis and ultrastructural changes in the sciatic nerve of rats

The potential role of exercise in preventing the age-related spontaneous peripheral neuropathy has not been studied. We examined the effects of long-term aerobic exercise training on lipid peroxidation, Schwann cell (SC) apoptosis and ultrastructural changes in the sciatic nerve of rats during aging. Three groups of 12-week old Wistar rats ran on a treadmill for 6, 9 and 12 months (exercise trained (ET) group, n=10 each) according to an exercise training program targeted at a speed of 22 m/min (at 7 degrees incline), 60 min/day, 6 days/week. Three corresponding groups of untrained rats were used as the controls (sedentary (SED) group). At the end of each period, sciatic nerve biopsies were performed, and processed for biochemical, immunohistochemical and ultrastructural analyses. The results showed that aging was associated with an increased level of nerve malondialdehyde (MDA, marker of lipid peroxidation) and a higher number of SC apoptosis in SED group. The SED group showed irregular nerve fibers with thin myelin sheaths and areas of myelin-axon detachment. However, the ET group had significantly diminished nerve lipid peroxidation and SC apoptosis. In the ET group, nerve fibers had a thick myelin sheath with frequent folding. These findings suggest that aerobic exercise training protects peripheral nerves by attenuating oxidative reactions, and preserving SCs and myelin sheath from pathologic changes, which occur during normal aging.

Hospital-referred polyneuropathies-causes, prevalences, clinical- and neurophysiological findings

The aim of this study was to evaluate the causes, prevalences, clinical manifestations of hospital-referred polyneuropathies, and evaluate neurophysiological findings in idiopathic polyneuropathy. From 2000 to 2005, 226 patients with polyneuropathy were examined. Polyneuropathy was diagnosed when symptoms, clinical- and neurophysiological findings were compatible with affection of at least two peripheral nerves. They were classified in symptomatic and idiopathic polyneuropathy after investigation. Clinical manifestations were evaluated for diabetes- (DPN), inflammatory- (INPN), hereditary- (HPN) and idiopathic polyneuropathy (IDPN). Neurophysiological findings were investigated in IDPN. 72% had a symptomatic polyneuropathy. Most frequent causes were diabetes mellitus (18%), inflammation, (16%) and hereditary (14%). Most common prevalences per 100,000 were as follows: IDPN, 21; DPN, 13 and HPN, 11. Predominating clinical manifestations were: sensory and motor in INPN, HPN and IPN; sensory in DPN. Pain was more present in IDPN and DPN than in others. In IDPN axonal demyelinating affection was present in 20%. Symptomatic polyneuropathy was common and diabetes mellitus, inflammation and hereditary were frequent causes. In IDPN, DPN, HPN and INPN different clinical patterns were found. Additionally, in IDPN axonal demyelinating affection was more frequent than previously reported.

Expression of the antioxidant enzyme peroxiredoxin 5 in the human peripheral nervous system

Peroxiredoxins (PRDXs) belong to a family of peroxidases that are highly expressed in mammalian tissues. Comparatively, little is known about their expression in the nervous system. In this study, we examined in human sural nerve, the expression of PRDX5, the most recently defined peroxiredoxin family member. Immunohistochemical staining of paraffin sections showed that PRDX5 expression was mainly localised to the axon and, to a lesser extent, to the Schwann cells. Immunogold labelling electron microscopy further revealed that PRDX5 is widely distributed in multiple cellular compartments, most importantly in mitochondria but also in axoplasm, Schwann cell cytosol, nucleus, and myelin. A progressive decline in PRDX5 expression with advancing age was identified in human nerves at different ages. The wide distribution of PRDX5 in cellular and sub-cellular structures indicates that it may play important roles in a wide range of tissue components in normal peripheral nerves.

Perceived Control is a Concurrent Predictor of Activity Limitations in Patients With Chronic Idiopathic Axonal Polyneuropathy

OBJECTIVES

To investigate (1) whether control perceptions (person's perception of ease or difficulty of performing behavior) and emotions contribute to activity limitations and if so (2) whether these variables mediate the relation between impairment and activity limitations in patients with chronic idiopathic axonal polyneuropathy (CIAP).

DESIGN

Cross-sectional study.

SETTING

Outpatient clinics of a university medical center.

PARTICIPANTS

Fifty-six patients diagnosed with CIAP.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Control perceptions about performing activities (questionnaire based on the theory of planned behavior), emotions (Hospital Anxiety and Depression Scale), activity limitations (performance: Shuttle Walk Test [SWT]; self-report: Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36] physical functioning subscale, self-reported ability to walk), and physical impairments (muscle strength, sensory function).

RESULTS

Control perceptions significantly (P<.01) correlated with all measures of activity limitations (r range, .58-.69). Hierarchical multiple regression analyses showed that perceived control explained 9% of the variance in the SWT (beta=.34, P<.01), 12% in the SF-36 (beta=.40, P<.01), and 24% in ability to walk (beta=.54, P<.01). In all measures of activity limitations, perceived control significantly mediated the effect of impairment.

CONCLUSIONS

Perceived control explained and mediated variance in activity limitations, whereas emotions did not. This suggests that increasing patients' perceptions of control might enhance performance of activities, even without changes in impairment.

Balance in the elderly

Balance dysfunction remains a significant contributing factor for disability in the elderly. A wide variety of surgical, pharmaceutical, medical, and rehabilitation treatment options exists for these patients. The complexity of the balance system, however, often requires a thorough, multidisciplinary approach to the evaluation and successful treatment of balance impairment.

The neurology of cobalamin deficiency in an elderly population in Israel

OBJECTIVES

To evaluate the neurological status in elderly subjects with cobalamin deficiency (CblD) compared with matched non-deficient subjects before and after cobalamin (Cbl) supplementation.

METHODS

Participants completed a questionnaire on activities of daily living, level of education, medical history, alcohol, nicotine, caffeine, and medication usage and prior consumption of vitamins. They underwent a detailed programmed neurological evaluation which was repeated after 6-9 months of Cbl therapy.

RESULTS

There were 113 subjects with blood Cbl < or =147 pmol/L, methylmalonic acid > or =0.24 mumol/L, and 212 nondeficient subjects (controls). The mean age of the patients and controls was 79.5 +/- 6.9 and 79.5 +/- 5.9 years, respectively. Fifty patients (44.4 %) and 56 controls (26.4%) were found to have mild sensory neuropathy (SN).When subjects with diabetes mellitus (DM) were excluded, however, only 30 (26.5%) patients and 23 (10.8 %) controls had SN. A history of confusional state was more common among the patients than among the controls (12.4 % and 3.3%, respectively) as was a low mini-mental state examination (MMSE) score (20.2% and 15.2%, respectively). No patient had clinical signs compatible with subacute combined degeneration (SCD). Supplementation of Cbl for 6-9 months did not alter the neurological findings,while the biochemical deficiency was corrected.

CONCLUSIONS

Mild SN rather than SCD is the main neurological impairment in elderly people with CblD. Short-term supplementation of CbL can correct the biochemical deficiency without affecting the neurological impairment.

Characterization of neuropathies associated with elevated IgM serum levels

BACKGROUND

In contrast to the IgM monoclonal gammopathies the neuropathy associated with polyclonal IgM gammopathy has not been well characterized.

OBJECTIVE

To characterize the neuropathy in patients with elevated serum IgM.

DESIGN

Retrospective review.

SETTING

Academically based neuropathy center.

PATIENTS

45 patients with elevated quantitative immunoglobulin M were identified.

MAIN OUTCOME MEASURES

Patients are described with regard to clinical phenotype, electrodiagnostic features of demyelination or focality, presence of IgM monoclonal gammopathy, and presence of autoantibody activity.

RESULTS

Elevated IgM levels occurred in 45 (11.5%) of 391 patients. Of these, 24 (53%) had polyclonal gammopathy and 21 (47%) had an IgM monoclonal gammopathy. Anti-nerve antibodies occurred in 14/21 (67%) of patients with monoclonal gammopathy, as compared to 1/24 (4%) with polyclonal gammopathy. Clinically, most patients in all groups had a predominantly large fiber sensory neuropathy. Thirty patients underwent electrodiagnostic testing. Of these, 22/30 (73%) fulfilled at least one published criteria for CIDP, including 92% of the monoclonal gammopathy patients and 59% of the polyclonal gammopathy patients. Fifteen of the 30 patients had evidence of focality or multifocality, with 14 of these 15 showing evidence of demyelination.

CONCLUSIONS

Monoclonal and polyclonal IgM patients have similar distributions of neuropathy phenotypes. Neuropathy in association with elevated serum IgM, with or without monoclonal gammopathy or autoantibody activity, is more likely to be demyelinating or multifocal. Serum quantitative IgM level and immunofixation in neuropathy patients may aid in identification of an immune mediated or a demyelinating component.

Nerve conduction studies in selected peripheral nerve disorders

PURPOSE OF REVIEW

The physiological properties of nerve and muscle are influenced by pathological changes and the aim of this review is to discuss recent contributions of electrophysiological studies to the understanding and diagnosis of selected peripheral nerve disorders. The relationships between pathology and physiology emphasize the close interdependence between electrophysiological studies, clinical deficits and other laboratory information. Attention should be paid to the strengths and limitations of electrophysiological methods, considering their impact on diagnosis and treatment of patients.

RECENT FINDINGS

Several studies have shown particular pathophysiological profiles associated with different antibody subtypes in autoimmune peripheral neuropathies and this association further supports the suggestion of pathological specificity in both acute and chronic neuropathy. The sensitivity and specificity of physiological profiles therefore become increasingly important since some of these neuropathies are accessible to treatment. On the other hand, the pathophysiological and clinical profiles may be heterogeneous in patients with some disorders. This could be related to a more indistinct division between different types of pathology with increased understanding of pathogenetic mechanisms. Moreover, new insights into disturbed axonal function have stimulated attempts to develop methods to explore normal and diseased human nerve function.

SUMMARY

The exploration of axonal membrane and ion-channel function has become accessible using studies of excitability and are of potential value where conventional studies only provide nonspecific evidence of the number of fibers and the integrity of myelin. These studies will presumably become increasingly important in the years ahead considering the lack of understanding of the functional disturbances in axonal neuropathies.