Neuropathy in elderly: lessons learnt from nerve biopsy

Significant Impacts of the Body-Mass Index, Blood Pressure, Blood Glucose, and Ankle-Brachial Index on Peripheral Neuropathy Risk in Indonesian With Type 2 Diabetes: A Cross-Sectional Study

Background: Diabetic peripheral neuropathy is associated with morbidity and mortality in people with diabetes mellitus. Aims: In this study, we determined relationships of the body-mass index (BMI), systolic blood pressure, diastolic blood pressure, fasting blood glucose, HbA1c, and ankle-brachial index (ABI) with diabetic peripheral neuropathy risk. Methods: A cross-sectional study was conducted with 1088 Indonesians and data collected using self-reported questionnaires, laboratory examinations, and physical examinations. Instruments included a digital scale, height measurement device, digital sphygmomanometer, Doppler ultrasound, 10-g monofilament, and a 128-Hz tuning fork. Data analysis used the Chi-square test, Fisher Exact, and multiple logistic regression test with significance p < .05. Results: The BMI (p < .001), blood pressure (p < .001), ABI (p < .001), fasting blood glucose (p = .016), and HbA1c (p < .001) were significantly related to peripheral neuropathy risk. The conditions of obesity, hypertension, high ABI, high fasting blood glucose, and high HbA1c significantly increased the risk of peripheral neuropathy. Moreover, participants with ≥4 co-occurring abnormal levels of the BMI, systolic blood pressure, diastolic blood pressure, fasting blood glucose, HbA1c, and ABI had significantly synergistically increased risks of peripheral neuropathy, and the more abnormal conditions there were, the higher the risk of peripheral neuropathy. Conclusions: Abnormalities of the BMI, blood pressure, fasting blood glucose, HbA1c, and ABI significantly and synergistically increased the risk of peripheral neuropathy and can be considered predictors of peripheral neuropathy. Nurses are expected to be aware of these predictors so that they can immediately take appropriate steps if they encounter abnormal conditions by optimizing their role as educators.

The relationship between health literacy and successful aging in elderly individuals with type 2 diabetes

OBJECTIVE

In the study, it was aimed to evaluate the relationship between health literacy and successful aging in elderly individuals with type 2 diabetes.

METHODS

This descriptive study was conducted with the participation of 415 elderly patients with type 2 diabetes who presented to the diabetics outpatient clinic between April-September 2021. The study data were collected through Identifying Information Form, Health Literacy Scale, and Successful Aging Scale. In the analysis of the data, descriptive statistics, Pearson correlation analysis, One-Way ANOVA, and student's t test were used.

RESULTS

Health Literacy Scale total mean score of the elderly individuals was found as 55.50 ± 6.08, and their Successful Aging Scale total mean score was determined to be 38.91 ± 2.05. A positive correlation was found between Health Literacy Scale total mean score and Successful Aging Scale total mean score, while a negative relationship was determined between Successful Aging Scale mean score and HbA1c values (p < 0.001).

CONCLUSION

As a result of the study, it was concluded that elderly patients with type 2 diabetes who had high levels of health literacy had high levels of successful aging as well.

A retrospective study on side effects of first-line antiretroviral drugs on HIV patients based on 1A, 2A, and 5A regimen records at Zomba Central Hospital, Malawi

AIDS is an incurable disease that is common in Africa. Patients with HIV/AIDS having a CD4 count of less than 240 are put on life prolonging ARV drugs. The ARVs have serious side effects on some patients which may be handled by treating them or switching patient's drug to one with no or less serious side effects. However, before doing this, more understanding of the circumstances that lead to a side effect is vital. We use statistical analyses to link side effects of 1A, 2A, and 5A treatment regimens to the patient's social and demographic characteristics based on hospital data records. A retrospective review of patients' master cards (2011-2014) was done to assess adverse effects associated with different ARV regimens. Out of the 901 patients that showed side effects, 65.37% were females aged 31-40 and 34.63% were males. Comparatively, 1A regimen showed more side effects than 2A and 5A regimens. Age, gender and occupation correlated significantly with regimen symptoms (p< 0.05). Unlike men, women had the following extra side effects; cough, peripheral neuropathy and leg pains as compared to lipodystrophy. Our results show that old people (50years+) are less likely to get skin rash and other symptoms compared to lipodystrophy (RRR=0.973). Further, the probability of either having cough (0.0021, p< 0.05), or skin rash (0.0021, p< 0.05), as a side effect, on average, decreases as age increases with the same sex and weight. The probability of having peripheral neuropathy (0.0042, p< 0.01), however, increases with age. Knowledge of HIV patient's socio-demographics and the patient's regimen side effects can be utilised to appropriately manage severe ARV side effects. A therapy consideration that takes into account chemicals in ARV regimen responsible for specific side effects can be directed to patients with compatible socio-demographic characteristics.

Diagnostic yield of nerve biopsy in the evaluation of peripheral neuropathies

BACKGROUND

With progress made in neurogenetics and neuroinflammation, the indications and value of nerve biopsies in the diagnostic evaluation of peripheral neuropathies are less clear. In this study, we aimed to evaluate the diagnostic yield of nerve biopsies in patients with peripheral neuropathies.

METHODS

We performed a retrospective review of nerve biopsy reports from April 1998 to June 2021 of patients with peripheral neuropathies presenting to the Department of Pathology, University of Malaya Medical Centre, Kuala Lumpur, Malaysia. The diagnostic value of the biopsies was determined based on the criteria by Midroni and Bilbao as follows: contributive (essential and helpful), non-contributive and inadequate.

RESULTS

A total of 107 nerve biopsies were analysed. Sixty-four (60 %) were males and the mean age was 52 years, ranging from 13 to 86 years. Ninety-four (88 %) were sural nerve biopsies; and only one patient (1 %) each had superficial peroneal and superficial radial nerve biopsy. The indications for the procedure were vasculitis (34 %), peripheral neuropathy of unknown aetiology (34 %), amyloidosis (14 %) and chronic inflammatory demyelinating polyneuropathy (10 %). In 68 (63 %) biopsies, the diagnostic value was contributive. Of these, 28 (26 %) were essential and 40 (37 %) were helpful. In contrast, 35 (33 %) biopsies were non-contributive and 4 (4 %) were inadequate. In 66 % (71/107) of cases, the nerve biopsy did not reveal a definite pathological diagnosis. However, in the remainder, a diagnosis of vasculitis (18 %, 19/107), followed by amyloidosis (10 %, 11/107) could be determined. For 32/71 biopsies with undetermined pathological diagnosis, neuropathy remained cryptogenic in 22 % (7/32) upon follow up.

CONCLUSIONS

With the exception of vasculitis and amyloidosis, there is limited value in performing nerve biopsies in the evaluation of patients with peripheral neuropathy. However, this should be interpreted with caution as the number of patients with a clinical diagnosis of vasculitis and amyloidosis were relatively larger than patients with other diagnosis. Refinement and careful selection of cases are required to increase the diagnostic yield of nerve biopsy.

Nerve biopsy: Current indications and decision tools

After initial investigation of patients presenting with symptoms suggestive of neuropathy, a clinical decision is made for a minority of patients to undergo further assessment with nerve biopsy. Many nerve biopsies do not demonstrate a definitive pathological diagnosis and there is considerable cost and morbidity associated with the procedure. This highlights the need for appropriate selection of patients, nerves and neuropathology techniques. Additionally, concomitant muscle and skin biopsies may improve the diagnostic yield in some cases. Several advances have been made in diagnostics in recent years, particularly in genomics. The indications for nerve biopsy have consequently changed over time. This review explores the current indications for nerve biopsies and some of the issues surrounding its use. Also included are comments on alternative diagnostic modalities that may help to supplant or reduce the use of nerve biopsy as a diagnostic test. These primarily include extraneural biopsy and neuroimaging techniques such as magnetic resonance neurography and nerve ultrasound. Finally, we propose an algorithm to assist in deciding when to perform nerve biopsies.

Neuropathy and neural plasticity in the subcutaneous white adipose depot

The difficulty in obtaining as well as maintaining weight loss, together with the impairment of metabolic control in conditions like diabetes and cardiovascular disease, may represent pathological situations of inadequate neural communication between the brain and peripheral organs and tissues. Innervation of adipose tissues by peripheral nerves provides a means of communication between the master metabolic regulator in the brain (chiefly the hypothalamus), and energy-expending and energy-storing cells in the body (primarily adipocytes). Although chemical and surgical denervation studies have clearly demonstrated how crucial adipose tissue neural innervation is for maintaining proper metabolic health, we have uncovered that adipose tissue becomes neuropathic (ie: reduction in neurites) in various conditions of metabolic dysregulation. Here, utilizing both human and mouse adipose tissues, we present evidence of adipose tissue neuropathy, or loss of proper innervation, under pathophysiological conditions such as obesity, diabetes, and aging, all of which are concomitant with insult to the adipose organ as well as metabolic dysfunction. Neuropathy is indicated by loss of nerve fiber protein expression, reduction in synaptic markers, and lower neurotrophic factor expression in adipose tissue. Aging-related adipose neuropathy particularly results in loss of innervation around the tissue vasculature, which cannot be reversed by exercise. Together with indications of neuropathy in muscle and bone, these findings underscore that peripheral neuropathy is not restricted to classic tissues like the skin of distal extremities, and that loss of innervation to adipose may trigger or exacerbate metabolic diseases. In addition, we have demonstrated stimulation of adipose tissue neural plasticity with cold exposure, which may ameliorate adipose neuropathy and be a potential therapeutic option to re-innervate adipose and restore metabolic health.

Macrophage Depletion Ameliorates Peripheral Neuropathy in Aging Mice

Aging is known as a major risk factor for the structure and function of the nervous system. There is urgent need to overcome such deleterious effects of age-related neurodegeneration. Here we show that peripheral nerves of 24-month-old aging C57BL/6 mice of either sex show similar pathological alterations as nerves from aging human individuals, whereas 12-month-old adult mice lack such alterations. Specifically, nerve fibers showed demyelination, remyelination and axonal lesion. Moreover, in the aging mice, neuromuscular junctions showed features typical for dying-back neuropathies, as revealed by a decline of presynaptic markers, associated with α-bungarotoxin-positive postsynapses. In line with these observations were reduced muscle strengths. These alterations were accompanied by elevated numbers of endoneurial macrophages, partially comprising the features of phagocytosing macrophages. Comparable profiles of macrophages could be identified in peripheral nerve biopsies of aging persons. To determine the pathological impact of macrophages in aging mice, we selectively targeted the cells by applying an orally administered CSF-1R specific kinase (c-FMS) inhibitor. The 6-month-lasting treatment started before development of degenerative changes at 18 months and reduced macrophage numbers in mice by ∼70%, without side effects. Strikingly, nerve structure was ameliorated and muscle strength preserved. We show, for the first time, that age-related degenerative changes in peripheral nerves are driven by macrophages. These findings may pave the way for treating degeneration in the aging peripheral nervous system by targeting macrophages, leading to reduced weakness, improved mobility, and eventually increased quality of life in the elderly.SIGNIFICANCE STATEMENT Aging is a major risk factor for the structure and function of the nervous system. Here we show that peripheral nerves of 24-month-old aging mice show similar degenerative alterations as nerves from aging human individuals. Both in mice and humans, these alterations were accompanied by endoneurial macrophages. To determine the pathological impact of macrophages in aging mice, we selectively targeted the cells by blocking a cytokine receptor, essential for macrophage survival. The treatment strongly reduced macrophage numbers and substantially improved nerve structure and muscle strength. We show, for the first time, that age-related degenerative changes in peripheral nerves are driven by macrophages. These findings may be helpful for treatment weakness and reduced mobility in the elderly.

Long-term Peripheral Neuropathy in Breast Cancer Patients Treated With Adjuvant Chemotherapy: NRG Oncology/NSABP B-30

Background

The long-term effects of chemotherapy are sparsely reported. Peripheral neuropathy (PN) is one of the most frequent toxicities associated with taxane use for the treatment of early-stage breast cancer. We investigated the impact of the three different docetaxel-based regimens and patient characteristics on long-term, patient-reported outcomes of PN and the impact of PN on long-term quality of life (QOL).

Methods

The National Surgical Adjuvant Breast and Bowel Project Protocol B-30 was a randomized trial comparing sequential doxorubicin (A) and cyclophosphamide (C) followed by docetaxel (T) (AC→T), concurrent ACT, or AT in women with node-positive, early-stage breast cancer. The AC→T group had a higher cumulative dose of T. PN was one of the symptoms assessed in a QOL substudy. Statistical methods included simple and mixed ordinal logistic regression and general linear models. All statistical tests were two-sided.

Results

Of 1512 patients, 41.9% reported PN two years after treatment initiation. Treatment with AT and ACT was associated with less severe long-term PN compared with AC→T (odds ratio [OR] = 0.45, 95% confidence interval [CI] = 0.35 to 0.58; OR = 0.59, 95% CI = 0.46 to 0.75). Preexisting PN, older age, obesity, mastectomy, and greater number of positive nodes were also associated with higher risk of long-term PN. Patients who reported worse PN symptoms at 24 months had statistically significantly worse QOL (Ptrend < .001).

Conclusions

The administration of docetaxel is associated with long-term PN. The lower rate of long-term PN in AT and ACT patients might be an important consideration in supporting choosing these therapies for individuals with preexisting neuropathic symptoms or other risk factors for neuropathy.

Hepatitis C virus and human T-cell lymphotropic virus type 1 co-infection: impact on liver disease, virological markers, and neurological outcomes

OBJECTIVES

Human T-cell lymphotropic virus type 1 (HTLV-1) infection is associated with neurological abnormalities, such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and peripheral neuropathy (PN). Hepatitis C virus (HCV) infection is the leading cause of chronic liver disease worldwide, and causes PN in approximately 9% of patients. Because the interplay between these potentially neuropathogenic viruses in the same individual is still poorly understood, the clinical and laboratory outcomes of co-infected patients were evaluated and compared with those of controls.

METHODS

The prevalence rates of neurological and laboratory abnormalities were evaluated in HCV/HTLV-1 co-infected patients (n=50), and in subjects with single HCV (n=46) or HTLV-1 (n=150) infection.

RESULTS

A higher frequency of isolated PN was present in HCV-infected patients; this was not associated with cryoglobulinemia. No difference was found in the frequency of PN or HAM/TSP when co-infected subjects were compared to singly infected subjects. Hepatic involvement was present in HCV-infected subjects, as shown by increased levels of serum alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and bilirubin, in addition to thrombocytopenia. On the other hand, HCV/HTLV-1 co-infected individuals presented a better prognosis for hepatic involvement when compared with singly HCV-infected subjects.

CONCLUSIONS

These data suggest that HCV/HTLV-1 co-infection does not mutualistically alter the outcome with regard to neurological manifestations. Nonetheless, changes in the immunological environment induced by HTLV-1 infection could lead to a reduction in hepatic damage, even without significant HCV clearance.

Balance and mobility assessment for ruling-out the peripheral neuropathy of the lower limbs in older adults

The peripheral neuropathy of the lower limbs (PNLL) is an important cause of balance and mobility impairment in older adults. The nerve conduction study (NCS) is the gold standard for PNLL diagnosis. Aim of this work is to establish the sensitivity (Sn) and the specificity (Sp) of the balance and mobility examination for the PNLL in older adults. This study consecutively recruited 72 participants (>65years) who accessed to the clinical neurophysiology outpatient clinic for suspected PNLL. Participants were given the NCS and four clinical tests. Mobility was evaluated by the Timed Up and Go (TUG) test, the Performance Oriented Mobility Assessment (POMA) and the de Morton Mobility Index (DEMMI). In addition the Clinical Evaluation of Static Upright Stance (CELSIUS) scale was developed for a selective evaluation of static balance. Based on the NCS, 36% of participants had PNLL. The CELSIUS scale (cutoff: 19.5/24), the TUG test (cutoff: 9.6s) and the DEMMI scale (cutoff: 17.5/19) have high Sn (0.92÷0.96), but low Sp (0.28÷0.43) for the PNLL in the older adult. POMA scale (cutoff: 14.5/16) has low Sn (0.73), but acceptable Sp (0.85). In addition, CELSIUS, DEMMI and TUG negative likelihood ratios are 0.13, 0.17 and 0.12, respectively. Balance and mobility examination have high sensitivity for PNLL. CELSIUS score>19/24, DEMMI score>17/19 or TUG time≤9.6s substantially reduce PNLL likelihood. These clinical measures are thus recommended for ruling-out PNLL in the older adult.