Diabetic Neuropathies

Bilateral Foot Drop Caused by Acute-onset Neuropathy after Diabetic Ketoacidosis: Successful Management and Long-term Follow-up for Employment

Background

Peripheral neuropathy is a common complication of diabetes, impacting many patients with type 1 or 2 diabetes. Acute-onset peripheral neuropathy after diabetic ketoacidosis (DKA) is rare yet serious, and reports on long-term functional outcomes and rehabilitation for this condition are limited. We present a case of bilateral foot drop caused by acute-onset peripheral neuropathy following DKA. The case was effectively managed through prompt and continuous intervention.

Case

A 21-year-old male university student with no notable medical history who was seeking employment presented with impaired consciousness. DKA associated with type 1 diabetes was diagnosed. As blood glucose and acidosis improved, he rapidly regained consciousness. On Day 3 post-onset, bilateral foot drop and lower leg sensory impairment emerged, with nerve conduction studies indicating lower extremity peripheral neuropathy on Day 8. Improvement during hospitalization was modest, so ankle-foot orthoses were prescribed on Day 10. He could walk independently with the orthoses on Day 12 and was discharged home on Day 15. Outpatient follow-up was continued to support the patient's efforts to gain employment. Needle electromyography in the tibialis anterior muscles bilaterally showed denervation at 2 months and polyphasic potentials at 8 months. In the 2 years post-onset, bilateral lower limb muscle strength progressively improved, and the patient successfully secured clerical employment.

Discussion

Successful rehabilitation for employment was achieved in the rare condition of acute-onset neuropathy after DKA through effective management based on early orthotic prescription, clinical and electrophysiological examinations, and continuous follow-up.

[Retrospective Long-Term Results After Dellon's Nerve Decompression In The Lower Leg For Polyneuropathy]

BACKGROUND

Patients affected by polyneuropathy often report pain, paraesthesia and numbness and are at risk of having an increased propensity to fall with the corresponding complications. In case of persistent symptoms after all conservative and medical treatment options have been exhausted, a nerve decompression in the lower leg as described by Dellon can lead to an improvement of the discomfort for many patients. This article presents our long-term results with Dellon's operation.

METHODS

In this retrospective study, we included 33 patients with diabetic or idiopathic polyneuropathy in whom we performed Dellon's nerve decompression in the lower leg in the years 2011-2013. In 29 out of the 33 patients, we investigated the level of pain (according to the numeric rating scale NRS 0-10), paraesthesia, numbness, Hoffman-Tinel sign, and Semmes-Weinstein monofilaments three months postoperatively. 88 months postoperatively (range 78-111 months), we were able to contact 20 of the 33 patients with a questionnaire asking about their present pain level (NRS 0-10), satisfaction with the postoperative result (NRS 0-10, 0=most satisfied, 10=not satisfied at all) and whether the patients would recommend the surgical procedure to their friends or family.

RESULTS

1. Significant pain reduction three months postoperatively, NRS 4.5 to 2.2, (p=0.000). 2. Significant reduction of paraesthesia three months postoperatively from 84.8 to 24.2% (p=0.000) 3. Significant reduction of numbness three months postoperatively from 97% to 39% (p=0.000). 4. Significant improvement of sensitivity three months postoperatively from 91% no sensitivity to 28% no sensitivity (p=0.000). 5. Significant improvement of Hoffmann-Tinel sign three months postoperatively from 76% to 13% (p=0.000). 88 months postoperatively, we saw a significant pain reduction from an average preoperative pain level of NRS 4.5 to a postoperative pain level of 2.7 (p=0.048). 88 months postoperatively, 65% of the patients would recommend the surgical procedure to their family and friends, and patient satisfaction was high (NRS 3,4).

CONCLUSION

Our long-term results show that Dellon's nerve decompression in the lower extremities leads to a marked, lasting pain reduction and a functional improvement.

Exploring the molecular mechanism of Xuebifang in the treatment of diabetic peripheral neuropathy based on bioinformatics and network pharmacology

Background

Xuebifang (XBF), a potent Chinese herbal formula, has been employed in managing diabetic peripheral neuropathy (DPN). Nevertheless, the precise mechanism of its action remains enigmatic.

Purpose

The primary objective of this investigation is to employ a bioinformatics-driven approach combined with network pharmacology to comprehensively explore the therapeutic mechanism of XBF in the context of DPN.

Study design and Methods

The active chemicals and their respective targets of XBF were sourced from the TCMSP and BATMAN databases. Differentially expressed genes (DEGs) related to DPN were obtained from the GEO database. The targets associated with DPN were compiled from the OMIM, GeneCards, and DrugBank databases. The analysis of GO, KEGG pathway enrichment, as well as immuno-infiltration analysis, was conducted using the R language. The investigation focused on the distribution of therapeutic targets of XBF within human organs or cells. Subsequently, molecular docking was employed to evaluate the interactions between potential targets and active compounds of XBF concerning the treatment of DPN.

Results

The study successfully identified a total of 122 active compounds and 272 targets associated with XBF. 5 core targets of XBF for DPN were discovered by building PPI network. According to GO and KEGG pathway enrichment analysis, the mechanisms of XBF for DPN could be related to inflammation, immune regulation, and pivotal signalling pathways such as the TNF, TLR, CLR, and NOD-like receptor signalling pathways. These findings were further supported by immune infiltration analysis and localization of immune organs and cells. Moreover, the molecular docking simulations demonstrated a strong binding affinity between the active chemicals and the carefully selected targets.

Conclusion

In summary, this study proposes a novel treatment model for XBF in DPN, and it also offers a new perspective for exploring the principles of traditional Chinese medicine (TCM) in the clinical management of DPN.

Nerve Decompression in the Lower Leg Results in an Improvement in Symptoms in Patients With Both Diabetic and Idiopathic Polyneuropathy

BACKGROUND

Patients suffering from polyneuropathy often complain of pain, tingling, and numbness sensations, as well as an increased risk of falling with the corresponding subsequent complications. If symptoms persist after conservative treatment options have been exhausted, nerve decompression in the lower extremity, as described by Dellon, can bring about an improvement in symptoms in many patients. Dellon originally reported that this surgery led to very successful outcomes in patients with diabetic polyneuropathy. In this study, we compare our postsurgical results in patients with diabetic versus idiopathic polyneuropathy.

METHODS

Thirty-three patients with idiopathic or diabetic polyneuropathy who had undergone Dellon nerve decompression in the lower extremity between 2011 and 2013 were included in the retrospective study. Pain (numeric rating scale [NRS] 0-10; 0, no pain; 10, worst imaginable pain), tingling, numbness, Hoffmann-Tinel sign, and Semes-Weinstein monofilament were assessed in 20 patients with diabetic polyneuropathy and in 13 patients with idiopathic polyneuropathy.

RESULTS

Three months after surgery, a significant reduction in pain was evident in patients with diabetic polyneuropathy, from a preoperative level of NRS 4.9 (minimum, 0; maximum, 10) to 2 (minimum, 0; maximum, 8; P = 0.005). Ninety percent of patients complained of tingling ( P = 0.000) before surgery and 18% after surgery, whereas 100% complained of numbness before surgery and 41% ( P = 0.000) after surgery. One hundred percent of patients had no measurable surface sensitivity before surgery (measured with the Semes-Weinstein monofilament), whereas 3 months after surgery, only 24% of patients still had no measurable surface sensitivity ( P = 0.000). A positive Hoffmann-Tinel sign was recorded in 85% of patients before surgery and only in 11% 3 months after surgery ( P = 0.000). In the case of patients with idiopathic polyneuropathy, a reduction in pain was evident 3 months after surgery, from a preoperative level of NRS 3.9 (minimum, 0; maximum, 9) to 2.2 (minimum, 0; maximum, 9; P = 0.058). Seventy-seven percent of patients complained of tingling before surgery and 42% after surgery ( P = 0.111), whereas 92% complained of numbness before surgery and 50% after surgery ( P = 0.030). Seventy-seven percent of patients had no measurable surface sensitivity before surgery (measured with the Semes-Weinstein monofilament), whereas 3 months after surgery, only 33% of patients still had no measurable surface sensitivity ( P = 0.047). A positive Hoffmann-Tinel sign was recorded in 62% of patients before surgery and only in 17% 3 months after surgery ( P = 0.041).

CONCLUSIONS

Not only patients with diabetic polyneuropathy but also those with idiopathic polyneuropathy benefit from Dellon nerve decompression surgery in the lower extremities.

Features characterising cardiac autonomic neuropathy in diabetes using ensembled classification

OBJECTIVE

Using supervised machine learning to classify the severity of cardiovascular autonomic neuropathy (CAN). The aims were 1) to investigate which features contribute to characterising CAN 2) to generate an ensembled set of features that best describes the variation in CAN classification.

METHODS

Eighty-two features from demographic, beat-to-beat, biochemical, and inflammation were obtained from 204 people with diabetes and used in three machine-learning-classifiers, these are: support vector machine, decision tree, and random forest. All data were ensembled using a weighted mean of the features from each classifier.

RESULTS

The 10 most important features derived from the domains: Beat-to-beat, inflammation markers, disease-duration, and age.

CONCLUSIONS

Beat-to-beat measures associate with CAN as diagnosis is mainly based on cardiac reflex responses, disease-duration and age are also related to CAN development throughout disease progression. The inflammation markers may reflect the underlying disease process, and therefore, new treatment modalities targeting systemic low-grade inflammation should potentially be tested to prevent the development of CAN.

SIGNIFICANCE

Cardiac reflex responses should be monitored closely to diagnose and classify severity levels of CAN accurately. Standard clinical biochemical analytes, such as glycaemic level, lipidic level, or kidney function were not included in the ten most important features. Beat-to-beat measures accounted for approximately 60% of the features in the ensembled data.

Ameliorative Effects of Isoeugenol and Eugenol against Impaired Nerve Function and Inflammatory and Oxidative Mediators in Diabetic Neuropathic Rats

Diabetic polyneuropathy is characterized by structural abnormalities, oxidative stress, and neuroinflammation. The current study aimed to determine the antinociceptive effects of isoeugenol and eugenol and their combinations in neuropathic pain resulting from streptozotocin (STZ)-induced diabetes and neuroinflammation. Female SD rats were categorized into normal control, diabetic control, and treatment groups. On the 28th day and 45th day, behavioral studies (allodynia and hyperalgesia) were performed to analyze the development and protection of diabetic polyneuropathy. The levels of inflammatory and oxidative mediators, such as superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), catalase, reduced glutathione, and thiobarbituric acid reactive substances (TBARS), were estimated. In addition, the level of nerve growth factor (NGF) was estimated at the end of the study in different groups. The anti-NGF treatment decreased its upregulation in the dorsal root ganglion significantly. The results showed that isoeugenol, eugenol, and their combination have therapeutic potential against neuronal and oxidative damage induced by diabetes. In particular, both compounds significantly affected behavioral function in treated rats and showed neuroprotection against diabetic neuropathy, and their combination had synergistic effects.

Improving Effects of Peripheral Nerve Decompression Microsurgery of Lower Limbs in Patients with Diabetic Peripheral Neuropathy

Background: Peripheral nerve decompression microsurgery can relieve nerve entrapment and improve the symptoms of DPN. However, postoperative tissue adhesion will produce new pressure on the nerves, affecting the surgical efficacy. In this study, a nerve conduit was used in the peripheral nerve decompression microsurgery to prevent postoperative adhesions, and the role of the nerve conduit in surgical nerve decompression was explored. Methods: A total of 69 patients with DPN were recruited and randomly divided into three groups: the nerve conduit group, conventional surgery group, and control group. Two weeks before surgery and 6 months after surgery, patients in each group were clinically tested using the visual analog scale (VAS) score, neurophysiological test, Toronto clinical scoring system (TCSS) score, and two-point discrimination (2-PD) test. Results: The patients’ symptoms in the nerve conduit group were relieved to varying degrees, and the relief rate reached 90.9%; the treatment efficacy was higher than that in the other groups. The postoperative nerve conduction velocity (NCV) in the two surgical groups was significantly higher than that before the surgery, and the difference between the nerve conduit group and the conventional surgery group was statistically significant (p < 0.05). For the 2-PD test, there was a statistically significant difference between the two surgical groups (p < 0.05). The TCSS score in the two surgical groups was significantly higher than that in the control group (p < 0.01). There was a significant difference in the TCSS scores between the nerve conduit group and the conventional surgery group (p < 0.05). Conclusions: The nerve conduit could further improve the efficacy of peripheral nerve decompression microsurgery in the treatment of DPN.

Is diabetes the risk factor for poor neurological recovery after cervical spine surgery? A review of the literature

The poor prognosis of cervical spine surgery is mainly manifested as poor neurological recovery and the presence of new upper extremity dysfunction that promotes significant psychological and physiological burdens on patients. Many factors influence the prognosis of cervical spine surgery, including the age of patients, the time and mode of surgery, and the surgical technique used. However, in clinical studies, it has been observed that patients with diabetes have a higher probability of poor prognosis after surgery. Therefore, we review the pathophysiology of diabetic neuropathies and discuss its impact on cervical nerve system function, especially in cervical nerve roots and upper limb peripheral nerve conduction.

Exploration of meteorin-like peptide (metrnl) predictors in type 2 diabetic patients: the potential role of irisin, and other biochemical parameters

OBJECTIVES

Meteorin-like peptide (Metrnl), the newly discovered adipokines involves in glucose and lipid metabolism and energy homeostasis. The aim of the present study was to explore the potential predictors of Metrnl by emphasizing the Irisin, glycemic indices, and lipid profile biomarkers in type 2 diabetic patients.

METHODS

This cross-sectional study was carried out on 32 obese types 2 diabetic patients, 31 healthy obese, and 30 healthy normal weight people between August 2020 and March 2021. Serum Metrnl and Irisin, fasting blood glucose (FBS), fasting insulin (FI), fasting insulin (FI), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), HbA_1c and eAG levels were measured in a standard manner. To assay insulin resistance and insulin sensitivity, the homeostatic model assessment insulin resistance (HOMA-IR) and quantitative check index (QUICKI) model were used. Quantile regression analysis with the backward elimination method was used to explore predictors. The significant level was defined as p<0.05.

RESULTS

Between variables entered into the model, only the group item showed to be the main predictor of Metrnl in type 2 diabetic patients. Besides, the serum level of Irisin was lower in diabetic patients, and a significant difference was detected between obese diabetic patients and the normal weight group (p=0.024).

CONCLUSIONS

Given the multi-causality of diabetes and also the possible therapeutic role of Metrnl in the management of type 2 diabetic patients' abnormalities, designing future studies are needed to discover other predictors of Metrnl and the related mechanisms of Metrnl in the management of diabetes.

Machine Learning-Based Diabetic Neuropathy and Previous Foot Ulceration Patients Detection Using Electromyography and Ground Reaction Forces during Gait

Diabetic neuropathy (DN) is one of the prevalent forms of neuropathy that involves alterations in biomechanical changes in the human gait. Diabetic foot ulceration (DFU) is one of the pervasive types of complications that arise due to DN. In the literature, for the last 50 years, researchers have been trying to observe the biomechanical changes due to DN and DFU by studying muscle electromyography (EMG) and ground reaction forces (GRF). However, the literature is contradictory. In such a scenario, we propose using Machine learning techniques to identify DN and DFU patients by using EMG and GRF data. We collected a dataset from the literature which involves three patient groups: Control (n = 6), DN (n = 6), and previous history of DFU (n = 9) and collected three lower limb muscles EMG (tibialis anterior (TA), vastus lateralis (VL), gastrocnemius lateralis (GL)), and three GRF components (GRFx, GRFy, and GRFz). Raw EMG and GRF signals were preprocessed, and different feature extraction techniques were applied to extract the best features from the signals. The extracted feature list was ranked using four different feature ranking techniques, and highly correlated features were removed. In this study, we considered different combinations of muscles and GRF components to find the best performing feature list for the identification of DN and DFU. We trained eight different conventional ML models: Discriminant analysis classifier (DAC), Ensemble classification model (ECM), Kernel classification model (KCM), k-nearest neighbor model (KNN), Linear classification model (LCM), Naive Bayes classifier (NBC), Support vector machine classifier (SVM), and Binary decision classification tree (BDC), to find the best-performing algorithm and optimized that model. We trained the optimized the ML algorithm for different combinations of muscles and GRF component features, and the performance matrix was evaluated. Our study found the KNN algorithm performed well in identifying DN and DFU, and we optimized it before training. We found the best accuracy of 96.18% for EMG analysis using the top 22 features from the chi-square feature ranking technique for features from GL and VL muscles combined. In the GRF analysis, the model showed 98.68% accuracy using the top 7 features from the Feature selection using neighborhood component analysis for the feature combinations from the GRFx-GRFz signal. In conclusion, our study has shown a potential solution for ML application in DN and DFU patient identification using EMG and GRF parameters. With careful signal preprocessing with strategic feature extraction from the biomechanical parameters, optimization of the ML model can provide a potential solution in the diagnosis and stratification of DN and DFU patients from the EMG and GRF signals.

Peripheral Neuropathies Derived from COVID-19: New Perspectives for Treatment

Peripheral neuropathies constitute a group of disorders affecting the peripheral nervous system. Neuropathies have multiple causes such as infections (i.e., COVID-19), diabetes, and nutritional (low vitamin levels), among others. Many micronutrients, such as vitamins (A, C, D, E, B6, B12, and folate), certain minerals (Fe, Mg, Zn, Se, and Cu), and ω-3 fatty acids have immunomodulatory effects. Therefore, they may play an instrumental role in the treatment of COVID-19 infection. However, many COVID-19 patients can undergo neuropathy. In this context, there is a wealth of information on a variety of first-, second-, and third-line treatment options. This review focuses on the application of nutraceutical strategies in order to improve the symptomatology of neuropathy and neuropathic pain in patients that suffered from COVID-19. Our aim is to provide an alternative vision to traditional medical-pharmacological treatment through nutraceuticals.

Simple Quantitative Sensory Testing Reveals Paradoxical Co-existence of Hypoesthesia and Hyperalgesia in Diabetes

Background: Diabetic neuropathy is characterized by the paradoxical co-existence of hypo- and hyperalgesia to sensory stimuli. The literature shows consistently sensory differences between healthy and participants with diabetes. We hypothesized that due to differences in pathophysiology, advanced quantitative sensory testing (QST) might reveal sensory discrepancies between type 1 (T1D) and type 2 diabetes (T2D). Furthermore, we investigated whether vibration detection thresholds (VDT) were associated with sensory response.

Method: Fifty-six adults with T1D [43 years (28–58)], 99 adults with T2D [65 years (57–71)], and 122 healthy individuals [51 years (34–64)] were included. VDT, pressure pain detection thresholds (pPDT) and tolerance (pPTT), tonic cold pain (hand-immersion in iced water), and central pain mechanisms (temporal summation and conditioned pain modulation) were tested and compared between T1D and T2D. VDT was categorized into normal (< 18 V), intermediary (18–25 V), or high (> 25 V).

Results: In comparison to healthy, analysis adjusted for age, BMI, and gender revealed hypoalgesia to tibial (pPDT): p = 0.01, hyperalgesia to tonic cold pain: p < 0.01, and diminished temporal summation (arm: p < 0.01; abdomen: p < 0.01). In comparison to participants with T2D, participants with T1D were hypoalgesic to tibial pPDT: p < 0.01 and pPTT: p < 0.01, and lower VDT: p = 0.02. VDT was not associated with QST responses.

Conclusion: Participants with T1D were more hypoalgesic to bone pPDT and pPTT independent of lower VDT, indicating neuronal health toward normalization. Improved understanding of differentiated sensory profiles in T1D and T2D may identify improved clinical endpoints in future trials.

Development and characterisation of a rat model that exhibits both metabolic dysfunction and neurodegeneration seen in type 2 diabetes

Abstract

Accurate modelling type 2 diabetes and diabetic complications in rodents has proven a challenge, largely as a result of the long‐time course of disease development in humans. In the present study, we aimed to develop and comprehensively characterise a new rodent model of type 2 diabetes. To do this, we fed Sprague–Dawley rats a high fat/high sugar diet (HFD) to induce obesity and dyslipidaemia. After 3 weeks, we s.c. implanted osmotic mini pumps to enable a 14 day, slow infusion of streptozotocin (STZ; lower dose = 100 mg kg⁻¹; higher dose = 120 mg kg⁻¹) to dose‐dependently reduce pancreatic beta cell mass. After removing the mini pumps, we monitored animals for 4 months using a battery of tests to assess both metabolic and neurodegenerative changes across time. Our data demonstrate the combination of the HFD and lower dose STZ leads to induction of early‐stage type 2 diabetes defined by moderate hyperglycaemia, hyperinsulinaemia and impaired glucose tolerance, at the same time as the retention of an obese phenotype. By contrast, combining the HFD and higher dose STZ leads to induction of later‐stage type 2 diabetes defined by frank hyperglycaemia, hypoinsulinaemia (but not insulin depletion) and severely impaired glucose tolerance, at the same time as retaining an obese phenotype. Regardless of dose of STZ (and level of hyperglycaemia), all diabetic rats exhibited signs of peripheral neurodegeneration in the skin and muscle. Thus, this model recapitulates many of the complex metabolic disturbances seen in type 2 diabetes and provides an excellent platform for investigating the pathophysiological mechanisms that lead to diabetic complications such as peripheral neuropathy.

Key points

Type 2 diabetes is a major health concern and markedly increases risk cardiovascular and neurodegenerative diseases.

Accurate modelling of type 2 diabetes is a major challenge and has impeded our ability to understand the mechanisms that contribute to complications of type 2 diabetes.

We have developed a method of inducing different stages of type 2 diabetes using a high fat/high sugar diet and 14 day infusion of streptozotocin to dose‐dependently destroy pancreatic beta cell mass.

Over 4 months, we comprehensively characterised these animals and confirmed that they develop sustained metabolic dysfunction and progressive peripheral neurodegeneration as seen in type 2 diabetes.

This new model will improve our ability to investigate the pathophysiological mechanisms that link type 2 diabetes with complications such as neurodegeneration.

Focal Peripheral Neuropathies Observed in Patients Diagnosed With COVID-19: A Case Series

ABSTRACT

A growing number of studies have documented a wide variety of neurological manifestations associated with the novel SARS-CoV-2 (COVID-19). Of the available literature, cranial neuropathies and central nervous system disorders, such as encephalopathy and ischemic strokes, remain the predominant discussion. Limited investigations exist examining peripheral neuropathies of those with COVID-19. This case series discusses eight patients who tested positive for COVID-19 and presented with localized weakness after a prolonged course of mechanical ventilation (>21 days). We retrospectively reviewed all patients' charts who received electrodiagnostic evaluation between March and November 2020 in the outpatient clinic or in the acute care hospital at the JFK Medical Center/JFK Johnson Rehabilitation Institute and Saint Peter's University Hospital of New Jersey. A total of eight COVID-19-positive patients were identified to have a clinical presentation of localized weakness after a prolonged course of mechanical ventilation. All patients were subsequently found to have a focal peripheral neuropathy of varying severity that was confirmed by electrodiagnostic testing. Patient demographics, clinical, and electrodiagnostic findings were documented. The findings of local weakness and focal peripheral neuropathies after diagnosis of COVID-19 raise significant questions regarding underlying pathophysiology and overall prognosis associated with COVID-19.

All-Atom Modeling of Complex Cellular Membranes

Cell membranes are composed of a variety of lipids and proteins where they interact with each other to fulfill their roles. The first step in modeling these interactions in molecular simulations is to have reliable mimetics of the membrane's lipid environment. This Feature Article presents our recent efforts to model complex cellular membranes using all-atom force fields. A short review of the CHARMM36 (C36) lipid force field and its recent update to incorporate the long-range dispersion is presented. Key examples of model membranes mimicking various species and organelles are given. These include single-celled organisms such as bacteria (E. coli., chlamydia, and P. aeruginosa) and yeast (plasma membrane, endoplasmic reticulum, and trans-Golgi network) and more advanced ones such as plants (soybean and Arabidopsis thaliana) and mammals (ocular lens, stratum corneum, and peripheral nerve myelin). Leaflet asymmetry in composition has also been applied to some of these models. With the increased lipid diversity in the C36 lipid FF, these complex models can better reflect the structural, mechanical, and dynamic properties of realistic membranes and open an opportunity to study biological processes involving other molecules.

A case of polyneuropathy associated with diabetic ketoacidosis in new-onset type 1 diabetes

Although diabetic peripheral neuropathy is the most common diabetic microangiopathic complication, several other neuropathy syndromes can occur in the context of diabetes. We describe a rare case of polyneuropathy associated with diabetic ketoacidosis in a patient with new‐onset type 1 diabetes. A 42‐year‐old man with diabetic ketoacidosis was admitted to our hospital with complications of respiratory and renal failure requiring mechanical ventilation and hemodialysis, respectively. After diabetic ketoacidosis improved from the critical state, he developed upper‐ and lower‐limb paralysis with sensory disturbances and pain, as well as right facial paralysis, left recurrent nerve paralysis, and left hypoglossal nerve paralysis. Autonomic nerve function was also impaired. As the pathophysiology, prevention, and treatment of polyneuropathy associated with diabetic ketoacidosis are unclear, the neurologic function of patients with diabetic ketoacidosis should be closely monitored.

High-Resolution Ultrasonography in the Assessment of Lumbar Radiculoplexus Neuropathy in Diabetics: Preliminary Results of a Case-Control Study

Background  The traditional diagnosis of lumbar radiculoplexus neuropathy (LRN) is based on a classical sequence of symptoms and targeted electrodiagnostic examination by means of electromyography. Ultrasonography reliably indicates the level of lumbar radiculopathy by assessing edema mesial to the site of compression. Materials and Methods  This case-control study was undertaken at a tertiary care hospital between July 2017 and June 2019 on 15 diabetic patients with symptoms of LRN. Fifteen healthy volunteers with no symptoms or clinical signs of LRN were included in the control group. The diameter (D) and transverse diameter (TD) of L1 nerve root (L1NR), L2NR, L3NR, and L4NR were measured, and their cross-sectional areas (CSAs) were calculated based on location in the lateral zone, where the NRs were visualized. On high-resolution ultrasonography, femoral nerve was localized lateral to the femoral artery in the femoral triangle beneath the inguinal ligament. Additionally, the CSA (calculated as CSA [mm ² ] = D × TD × π/4), the diameter (mm), and transverse diameter (mm) of bilateral femoral nerves at the level of L3-L4 were calculated. Results  The difference attributed to CSAs between affected NRs in LRN group and unaffected NRs in controls at levels L1-L4 was considered statistically significant ( p  < 0.05). Receiver operating characteristic analysis revealed mean values to be 8 mm ² (CSA) for L1NR, 11.2 mm ² (CSA) for L2NR, 13.6 mm2 (CSA) for L3NR, and 17.8 mm ² (CSA) for L4NR. There was significant difference between ΔCSA of LRN patients and controls at L1 to L4 levels ( p  < 0.05). CSA measurements of lateral femoral cutaneous nerve (8 mm ² ) and femoral nerve (58 mm ² ) performed on high-resolution ultrasonography were significantly larger on the affected side as compared with the unaffected side. Conclusion  Radiculoplexus neuropathy of the lumbar plexus can be reliably diagnosed on high-resolution ultrasonography that can reveal nerve thickening. The laterality of affected NRs was significantly greater in LRN group when compared with controls.

A Comprehensive Review of Neuronal Changes in Diabetics

There has been an exponential rise in diabetes mellitus (DM) cases on a global scale. Diabetes affects almost every system of the body, and the nervous system is no exception. Although the brain is dependent on glucose, providing it with the energy required for optimal functionality, glucose also plays a key role in the regulation of oxidative stress, cell death, among others, which furthermore contribute to the pathophysiology of neurological disorders. The variety of biochemical processes engaged in this process is only matched by the multitude of clinical consequences resulting from it. The wide-ranging effects on the central and peripheral nervous system include, but are not limited to axonopathies, neurodegenerative diseases, neurovascular diseases, and general cognitive impairment. All language search was conducted on MEDLINE, COCHRANE, EMBASE, and GOOGLE SCHOLAR till September 2021. The following search strings and Medical Subject Headings (MeSH terms) were used: "Diabetes Mellitus," "CNS," "Diabetic Neuropathy," and "Insulin." We explored the literature on diabetic neuropathy, covering its epidemiology, pathophysiology with the respective molecular pathways, clinical consequences with a special focus on the central nervous system and finally, measures to prevent and treat neuronal changes. Diabetes is slowly becoming an epidemic, rapidly increasing the clinical burden on account of its wide-ranging complications. This review focuses on the neuronal changes occurring in diabetes such as the impact of hyperglycemia on brain function and structure, its association with various neurological disorders, and a few diabetes-induced peripheral neuropathic changes. It is an attempt to summarize the relevant literature about neuronal consequences of DM as treatment options available today are mostly focused on achieving better glycemic control; further research on novel treatment options to prevent or delay the progression of neuronal changes is still needed.

Diabetes Ketoacidosis Complicating as Wrist Drop: A Case Report on Acute Motor Neuropathy

Diabetic ketoacidosis (DKA) is an acute and major complication of diabetes mellitus. Neurological complications can be seen at any time during the course of illness and range from decreased consciousness to ischemic or hemorrhagic stroke. Acute neuropathy is very rare in this milieu. Here, we report a case of a 40-year-old patient, who developed a left-sided wrist drop after being treated for DKA. The nerve conduction velocity studies demonstrated decreased action potential amplitude in only the motor component of the left radial nerve. Other possible causes of the complaint were ruled out and the patient was managed with cock-up splint, vitamin B1 and B6 supplementation, and physiotherapy. Despite all these measures, the patient had minimal improvement. Thus, close monitoring of patients is crucial to identify these infirmities, even after the acute condition has resolved.

Simulations of Diabetic and Non-Diabetic Peripheral Nerve Myelin Lipid Bilayers

The multilayered myelin sheath is a critical component of both central and peripheral nervous systems, forming a protective barrier against axonal damage and facilitating the movement of nervous impulses. It is primarily composed of cholesterol (CHL1), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), sphingomyelin (SM), and galactosylceramide (GalCer) lipids. For rat sciatic nerve myelin (part of the peripheral nervous system, PNS), it has been found that cholesterol and unsaturated fatty acid contents are significantly lower in diabetic than in non-diabetic conditions. In this study, lipid compositions from experimental data are used to create four model rat sciatic nerve myelin lipid bilayers: PI-containing (non-diabetic and diabetic) and PS-containing (non-diabetic and diabetic), which were then simulated using the all-atom CHARMM36 force field. Simulation results of diabetic membranes indicate less rigid, more laterally expansive, and thinner bilayers as well as potentially reduced interactions between GalCer on opposing myelin leaflets, supporting a direct role of the cholesterol content decrease in instigating myelin deterioration and diabetic peripheral neuropathy. Compared to PI-lipids, PS-lipids were found to cause higher inter-lipid spacing and decreased order within membranes as a result of their smaller headgroup size and higher inter-lipid hydrogen bonding potential, which allow them to more frequently reside deeper in the membrane plane and produce pushing effects on other lipids. GalCer deuterium order parameters and non-diabetic headgroup-to-headgroup bilayer thicknesses were compared to experimental data, exhibiting close alignment, supporting the future usage of these models to study the PNS myelin sheath.

The Role of Protein Adduction in Toxic Neuropathies of Exogenous and Endogenous Origin

The peripheral (axonal) neuropathy associated with repeated exposure to aliphatic and aromatic solvents that form protein-reactive γ-diketones shares some clinical and neuropathological features with certain metabolic neuropathies, including type-II diabetic neuropathy and uremic neuropathy, and with the largely sub-clinical nerve damage associated with old age. These conditions may be linked by metabolites that adduct and cross-link neuroproteins required for the maintenance of axonal transport and nerve fiber integrity in the peripheral and central nervous system.

The time to develop treatments for diabetic neuropathy

BACKGROUND

Diabetic neuropathy is a multifaceted condition affecting up to 50% of individuals with long standing diabetes. The most common presentation is peripheral diabetic sensory neuropathy (DPN).

METHODS

We carried out a systematic review of papers dealing with diabetic neuropathy on Pubmed in addition to a targeted Google search.Search terms included small fiber neuropathy,diffuse peripheral neuropathy, quantitative sensory testing, nerve conduction testing, intra-epidermal nerve fiber density, corneal confocal reflectance microscopy, aldose reductase inhbitors, nerve growth factor, alpha-lipoic acid, ruboxistaurin, nerve growth factor antibody, and cibinetide.

RESULTS

Over the past half century, there have been a number of agents undergoing unsuccessful trials for treatment of DPN.There are several approved agents for relief of pain caused by diabetic neuropathy, but these do not affect the pathologic process.

EXPERT OPINION

The failure to find treatments for diabetic neuropathy can be ascribed to (1) the complexity of design of studies and (2) the slow progression of the condition, necessitating long duration trials to prove efficacy.We propose a modification of the regulatory process to permit early introduction of agents with demonstrated safety and suggestion of benefit as well as prolongation of marketing exclusivity while long term trials are in progress to prove efficacy.

Electrodiagnostic assessment of the autonomic nervous system: A consensus statement endorsed by the American Autonomic Society, American Academy of Neurology, and the International Federation of Clinical Neurophysiology

Evaluation of disorders of the autonomic nervous system is both an art and a science, calling upon the physician's most astute clinical skills as well as knowledge of autonomic neurology and physiology. Over the last three decades, the development of noninvasive clinical tests that assess the function of autonomic nerves, the validation and standardization of these tests, and the growth of a large body of literature characterizing test results in patients with autonomic disorders have equipped clinical practice further with a valuable set of objective tools to assist diagnosis and prognosis. This review, based on current evidence, outlines an international expert consensus set of recommendations to guide clinical electrodiagnostic autonomic testing. Grading and localization of autonomic deficits incorporates scores from sympathetic cardiovascular adrenergic, parasympathetic cardiovagal, and sudomotor testing, as no single test alone is sufficient to diagnose the degree or distribution of autonomic failure. The composite autonomic severity score (CASS) is a useful score of autonomic failure that is normalized for age and gender. Valid indications for autonomic testing include generalized autonomic failure, regional or selective system syndromes of autonomic impairment, peripheral autonomic neuropathy and ganglionopathy, small fiber neuropathy, orthostatic hypotension, orthostatic intolerance, syncope, neurodegenerative disorders, autonomic hyperactivity, and anhidrosis.

Performance analysis of noninvasive electrophysiological methods for the assessment of diabetic sensorimotor polyneuropathy in clinical research: a systematic review and meta-analysis with trial sequential analysis

Despite the availability of various clinical trials that used different diagnostic methods to identify diabetic sensorimotor polyneuropathy (DSPN), no reliable studies that prove the associations among diagnostic parameters from two different methods are available. Statistically significant diagnostic parameters from various methods can help determine if two different methods can be incorporated together for diagnosing DSPN. In this study, a systematic review, meta-analysis, and trial sequential analysis (TSA) were performed to determine the associations among the different parameters from the most commonly used electrophysiological screening methods in clinical research for DSPN, namely, nerve conduction study (NCS), corneal confocal microscopy (CCM), and electromyography (EMG), for different experimental groups. Electronic databases (e.g., Web of Science, PubMed, and Google Scholar) were searched systematically for articles reporting different screening tools for diabetic peripheral neuropathy. A total of 22 studies involving 2394 participants (801 patients with DSPN, 702 controls, and 891 non-DSPN patients) were reviewed systematically. Meta-analysis was performed to determine statistical significance of difference among four NCS parameters, i.e., peroneal motor nerve conduction velocity, peroneal motor nerve amplitude, sural sensory nerve conduction velocity, and sural sensory nerve amplitude (all p < 0.001); among three CCM parameters, including nerve fiber density, nerve branch density, and nerve fiber length (all p < 0.001); and among four EMG parameters, namely, time to peak occurrence (from 0 to 100% of the stance phase) of four lower limb muscles, including the vastus lateralis (p < 0.001), tibialis anterior (p = 0.63), lateral gastrocnemius (p = 0.01), and gastrocnemius medialis (p = 0.004), and the vibration perception threshold (p < 0.001). Moreover, TSA was conducted to estimate the robustness of the meta-analysis. Most of the parameters showed statistical significance between each other, whereas some were statistically nonsignificant. This meta-analysis and TSA concluded that studies including NCS and CCM parameters were conclusive and robust. However, the included studies on EMG were inconclusive, and additional clinical trials are required.

Correlates of diabetic polyneuropathy of the elderly in Sub-Saharan Africa

Background

Diabetic polyneuropathy is associated with significant physical disability among older adults. However, their frequency and correlates are not well known in the older adults in Sub-Saharan-Africa. The objectives were to evaluate the hospital-based prevalence of diabetic polyneuropathy and identify its correlates in older adults.

Methods

Over a period of 5 months, a cross-sectional survey was carried out at Douala Laquintinie Hospital (DLH), a main reference hospital in Douala, the economic capital of Cameroon. Participants in our study group comprised all patients with type 2 diabetes, whatever the reason for their reporting to the hospital. Diabetic Polyneuropathy was defined according to a Diabetic Neuropathy Examination score > 3/16.

Results

A total of 159 older adults with diabetes were examined during this recruitment period, among whom 106 (66.7%) were women. The mean age was 68.3 ± 6.5 years. Diabetes median duration was 108 months. For all patients assessed using the Diabetic Neuropathy Examination score, polyneuropathy was reported in 31.4%; among them, polyneuropathy proved symptomatic in 78% of them. Correlates of polyneuropathy were glycated hemoglobin (p = 0.049), HIV infection (p = 0.031) and albuminuria (p< 0.001), even after adjustment for age, gender and duration of diabetes.

Conclusion

A third of older adults with diabetes who visited our hospital were diagnosed with prevalent diabetes-related polyneuropathy. It shows that early detection is required through routine screening and regular follow-up examinations in order to reduce the risk of disability and improve the quality of life in elderly diabetics.

Emerging Roles of microRNAs as Biomarkers and Therapeutic Targets for Diabetic Neuropathy

Diabetic neuropathy (DN) is the most prevalent chronic complication of diabetes mellitus. The exact pathophysiological mechanisms of DN are unclear; however, communication network dysfunction among axons, Schwann cells, and the microvascular endothelium likely play an important role in the development of DN. Mounting evidence suggests that microRNAs (miRNAs) act as messengers that facilitate intercellular communication and may contribute to the pathogenesis of DN. Deregulation of miRNAs is among the initial molecular alterations observed in diabetics. As such, miRNAs hold promise as biomarkers and therapeutic targets. In preclinical studies, miRNA-based treatment of DN has shown evidence of therapeutic potential. But this therapy has been hampered by miRNA instability, targeting specificity, and potential toxicities. Recent findings reveal that when packaged within extracellular vesicles, miRNAs are resistant to degradation, and their delivery efficiency and therapeutic potential is markedly enhanced. Here, we review the latest research progress on the roles of miRNAs as biomarkers and as potential clinical therapeutic targets in DN. We also discuss the promise of exosomal miRNAs as therapeutics and provide recommendations for future research on miRNA-based medicine.

[Severe sensory-motor axonal neuropathy following diabetic ketoacidosis]

We report a case of severe sensory-motor axonal neuropathy on the lower extremities associated with diabetic ketoacidosis (DKA). A sixteen-year-old boy developed coma and admitted to our hospital. We diagnosed him with DKA based on remarkable hyperglycemia, severe acidosis with hyperketonemia. Intensive glycemic control with insulin was immediately started. He had complications of heart failure, rhabdomyolysis, and renal failure, which required intensive care including mechanical ventilation and hemodialysis. When recovered from the critical condition, he noticed severe weakness, numbness, and pain on the lower limbs, and urinary retention. On nerve conduction studies, both motor and sensory action potentials were absent. Serum anti-ganglioside antibodies were negative. Albuminocytologic dissociation was evident in the cerebrospinal fluid. MRI study revealed marked gadolinium enhancement of the cauda equina. After high-dose intravenous immunoglobulin treatment, he was relieved from leg pain, but the leg weakness and bladder bowel dysfunction did not show immediate improvement. It took approximately six months until he became able to stand and walk using ankle orthosis. Acute neuropathy is a rare complication of diabetes mellitus. Painful neuropathy is known to emerge in association with diabetic treatment, but it seldom causes severe motor disturbance. On the other hand, motor-dominant polyneuropathy has been reported to occur acutely along the treatment of DKA and hyperosmolar hyperglycemia syndrome (HHS). Present case and previous cases with DKA and HHS suggest that rapid correction of glucose level is one of the underlying factors of acute neuropathy related with diabetic treatment.

Treatment with Tang-luo-ning altered the microRNA expression profile in rats with diabetic peripheral neuropathy

Tang-luo-ning (TLN) is a traditional Chinese herbal recipe that has been used to treat diabetic peripheral neuropathy (DPN); nevertheless, the underlying mechanism remains unclear. This study was aimed to investigate the microRNA (miRNA) expression profile in diabetic rats treated with TLN, and the target genes were predicted. Male Sprague-Dawley rats were randomly divided into control, diabetes, and TLN-treated diabetes groups. Diabetes was induced with streptozotocin, and TLN (5 g/kg/day) was orally given for eight weeks. Then, the sciatic nerves were harvested for miRNA microarray analyses. The differentially expressed miRNAs and their target genes were analyzed. Compared with the control rats, 24 miRNAs were significantly upregulated, and 59 were downregulated in the sciatic nerves of the diabetic rats by more than two folds (all P < 0.05). In TLN-treated diabetes rats, 26 miRNAs were upregulated, and 14 were downregulated compared with diabetic rats without TLN treatment (all P < 0.05). DPN-induced alterations of the miRNA profile were reversed by the TLN treatment. A total of 1402 target genes were screened. In GO analysis, genes in localization, cytoplasm, and protein binding processes were enriched, and the most significantly enriched pathways included the neurotrophin, Fc epsilon RI, and Wnt signaling pathways. Further analyses revealed that DVL1 and NTF3 genes were involved in these pathways. Our findings indicate that TLN may affect the Wnt and neurotrophin pathways by acting on DVL1 and NTF3 genes.

Correlation Between Thioredoxin-Interacting Protein and Nerve Conduction Velocity in Patients With Type 2 Diabetes Mellitus

Aims: To investigate the correlation between thioredoxin-interacting protein (TXNIP) and peripheral nerve conduction velocity (NCV) in patients with type 2 diabetes mellitus.

Methods: In total, 338 patients with type 2 diabetes mellitus (T2DM) were included in this study. We collected the clinical data and measured the motor conduction velocities of the bilateral ulnar nerve, median nerve, tibial nerve, and common peroneal nerve, and the sensory conduction velocities of the ulnar nerve, median nerve, sural nerve, and superficial peroneal nerve. According to the results, the patients were divided into two groups: normal peripheral nerve conduction group (NCVN group) and abnormal peripheral nerve conduction group (NCVA group). The two groups were then compared in terms of the conventional biochemical index and the sugar metabolic index as well as the serum levels of TXNIP, reduced glutathione (GSH), total superoxide dismutase (SOD), malondialdehyde (MDA), and tumor necrosis factor alpha (TNF-α). The correlation between TXNIP and NCV was also analyzed.

Results: Compared with the NCVN group, the TXNIP and MDA values were significantly increased in the NCVA group (P < 0.05). Among the patients with T2DM, age, fasting glucose, SDBG, and TXNIP were risk factors for NCV abnormality, while vitamin D3 was a protective factor. After adjusting for related confounding factors, TXNIP was significantly correlated with NCV (P < 0.05). Among the patients with T2DM, TXNIP was an independent risk factor for left ulnar motor conduction velocity (MCV), right ulnar MCV, left median MCV, and right median MCV. TNF-α was identified as a positive influencing factor for serum TXNIP, while serum TXNIP was a positive factor for TNF-α and MDA (both P < 0.05).

Conclusion: Serum TXNIP is related to NCV in T2DM patients. In combination with oxidative stress and inflammation, TXNIP may affect diabetic peripheral neuropathy (DPN).

microRNA-9 and -29a regulate the progression of diabetic peripheral neuropathy via ISL1-mediated sonic hedgehog signaling pathway

In this study, we tested the hypothesis that overexpression of miR-9 and miR-29a may contribute to DPN development and progression. We performed a meta-analysis of miR expression profile studies in human diabetes mellitus (DM) and the data suggested that miR-9 and miR-29a were highly expressed in patients with DM, which was further verified in serum samples collected from 30 patients diagnosed as DM. Besides, ISL1 was confirmed to be a target gene of miR-9 and miR-29a. Lentivirus-mediated forced expression of insulin gene enhancer binding protein-1 (ISL1) activated the sonic hedgehog (SHH) signaling pathway, increased motor nerve conduction velocity and threshold of nociception, and modulated expression of neurotrophic factors in sciatic nerves in rats with DM developed by intraperitoneal injection of 0.45% streptozotocin, suggesting that ISL1 could delay DM progression and promote neural regeneration and repair after sciatic nerve damage. However, lentivirus-mediated forced expression of miR-9 or miR-29a exacerbated DM and antagonized the beneficial effect of ISL1 on DPN. Collectively, this study revealed potential roles of miR-9 and miR-29a as contributors to DPN development through the SHH signaling pathway by binding to ISL1. Additionally, the results provided an experimental basis for the targeted intervention treatment of miR-9 and miR-29a.

Spectrum of diabetic neuropathies

The diabetic state results in neuropathy. The main causative mechanism is hyperglycemia, although microvascular involvement, hypertriglyceridemia, as well as genetic and immune mechanisms may be contributory. There is a growing spectrum of types of diabetic neuropathies that differ based on the type of fibers involved (e.g. myelinated, unmyelinated, autonomic, somatic), distribution of nerves involved, and mechanisms of neuropathy. The most common type is distal sensory neuropathy (DSN), which affects the distal ends of large myelinated fibers, more often sensory than motor, and is often asymptomatic. The next-most common is distal small fiber neuropathy (DSFN), which largely affects the unmyelinated fibers and carries the phenotype of burning feet syndrome. Diabetic autonomic neuropathy (DAN) occurs when widespread involvement of autonomic unmyelinated fibers occurs, and patients can be incapacitated with orthostatic hypotension as well as neurogenic bladder and bowel involvement. Radiculoplexus diabetic neuropathy causes proximal weakness and pain, usually in the lower extremity, and has a combination of immune, inflammatory, and vascular mechanisms. The nerve roots and plexus are involved. These patients present with proximal weakness of a subacute onset, often with severe pain and some autonomic failure. Finally, rapid and sustained reduction of blood glucose can result in treatment-induced diabetic neuropathy (TIND), which largely affects the sensory and autonomic fibers. This occurs if HbA1c is rapidly reduced within 3 months, and the likelihood is proportional to the original A1c and the size of the reduction.

Diabetic Amyotrophy: From the Basics to the Bedside

Diabetic amyotrophy is a rare complication of diabetes compared to distal symmetric polyneuropathy, but can occasionally be encountered in clinical practice, particularly as the incidence of diabetes increases. The distinctive history of unilateral neuropathic symptoms followed rapidly by atrophy and weakness is typical of the disorder. This complication most commonly occurs in cases of well-controlled Type 2 diabetes mellitus. While the underlying pathophysiology is known to be microvasculitic in nature, the diagnosis is often based on clinical and electrodiagnostic grounds and tissue biopsy is not typically performed. Attempts at corticosteroid administration during immunotherapy should be carefully considered on a patient-by-patient basis. Better recognition of this disorder is likely to result in more rapid diagnosis, counselling, and subspecialty referral.

Protective effects of losartan on some type 2 diabetes mellitus-induced complications in Wistar and spontaneously hypertensive rats

Diabetes mellitus type 2 (T2DM) is characterized by resistance of insulin receptors and/or inadequate insulin secretion resulting in metabolic and structural complications including vascular diseases, arterial hypertension and different behavioral alterations. We aimed to study the effects of the antihypertensive angiotensin AT1 receptor antagonist losartan on the T2DM-induced changes of exploratory behavior, anxiety, nociception and short term memory in normotensive Wistar and spontaneously hypertensive rats (SHRs). The experimental model of T2DM induced by a combination of high fat diet and streptozotocin, decreased exploratory activity and increased the level of carbonylated proteins in selected brain structures in both strains; as well it increased corticosterone level, pain threshold, anxiety-like behavior, and decline short term memory only in SHRs. Losartan treatment alleviated some of the T2DM- induced metabolic complications, abolished the T2DM-induced hypo activity, and normalized the corticosterone level, carbonylated proteins in brain, nociception and memory. Losartan did not exert effect on the anxiety behavior in both strains. We showed that T2DM exerted more pronounced negative effects on the rats with comorbid hypertension as compared to normotensive rats. Overall effects on the studied behavioral parameters are related to decreased exploration of the new environment, increased anxiety-like behavior, and decline in short-term memory. The systemic sub-chronic treatment with an angiotensin AT1 receptor antagonist losartan ameliorated most of these complications.

Is it possible to substitute the monofilament test for the Ipswich Touch Test in screening for peripheral diabetic neuropathy?

BACKGROUND

This study aimed to assess the agreement and efficacy of the Ipswich Touch Test compared to the monofilament test in individuals with type 2 diabetes.

MATERIALS AND METHODS

A cross-sectional and analytical study was conducted. The inclusion criteria were patients with type II diabetes (n = 250) who did not present ulcers or amputation in either foot. The exclusion criteria were as follows: patients who presented sequelae of cerebrovascular disease or other neurological pathologies, as well as diagnoses of malignancy, alcohol abuse, liver cirrhosis, hepatitis B, AIDS, hypothyroidism, chronic kidney disease or lupus erythaematosus, as these clinical conditions could influence or bias the results (Won and Park in Endocrinol Metab 31:230-238, 2016). Sensitivity, specificity, predictive values, likelihood ratios, and Kappa index were calculated. Other factors assessed were glycated haemoglobin and body mass index.

RESULTS

Most of the participants were female (71.2%), and glycated haemoglobin (HbA1c) was greater than 7% in 54.4% of the patients. The mean age was 59.43 years, and the mean time since diagnosis was 12.38 years. The Kappa index was 0.819 (p < 0.001), and the Ipswich Touch Test had a sensitivity of 83.33%, a specificity of 97.66%, a positive predictive value of 85.71%, a negative predictive value of 97.21%, a positive likelihood ratio of 30.19%, and a negative likelihood ratio of 0.17%. The level of significance was 5% in this study.

CONCLUSION

The Ipswich Touch Test resented good agreement and efficacy compared to the gold standard-the 10 g monofilament test.

Neuropathy May Be an Independent Risk Factor for Amputation After Lower-Extremity Burn in Adults With Diabetes

IN BRIEF Treatment of lower-extremity burn injuries in adults with diabetes can be complex, and some diabetes-related factors can lead to impaired healing of such wounds, putting patients at risk of amputation. In this retrospective review of adult patients with lower-extremity burns, patients with pre-injury neuropathy and higher A1C levels were more likely to require amputations after their burn injury. The authors conclude that lower-extremity burn injuries in patients with diabetes require close follow-up and possibly referral to a burn specialist for interventions and treatment strategies to offset more serious complications.

Taurine protects against myelin damage of sciatic nerve in diabetic peripheral neuropathy rats by controlling apoptosis of schwann cells via NGF/Akt/GSK3β pathway

Diabetic peripheral neuropathy is a common complications of Type 2 Diabetes and its main pathological feature is myelin sheath damage of peripheral nerve that was induced by Schwann cells (SCs) apoptosis. Increasing evidence suggested that taurine might play a role in improving DPN because of its ability to prevent SCs apoptosis. In this study, we explore the effect of taurine on preventing SCs apoptosis and its underlying mechanism. Sprague Dawley rats were treated with streptozotocin to establish the diabetes model. Rats were randomly divided into control, diabetes, taurine treatment (as giving 0.5%, 1% and 2% taurine in drinking water) groups. RSC96 cell (a rat SCs line) was used for intervention experiments in vitro. Results showed that taurine significantly corrected morphology of damaged myelin sheath and inhibited SCs apoptosis in sciatic nerve of diabetic rats. Moreover, taurine prevented apoptosis of RSC96 cells exposed to high glucose. Mechanistically, taurine up-regulated NGF expression and phosphorylation levels of Akt and GSK3β, while, blocking activation of NGF and phosphorylation of Akt and GSK3β increased apoptosis of high glucose-exposed RSC96 cells with taurine supplement. These results revealed taurine improved the myelin sheath damage of sciatic nerve in diabetic rats by controlling SCs apoptosis via NGF/Akt/GSK3β signaling pathways, which provides some clues that taurine might be effective and feasible candidate for the treatment of DPN.

Does a Rehabilitation Program of Aerobic and Progressive Resisted Exercises Influence HIV-Induced Distal Neuropathic Pain?

OBJECTIVE

Distal symmetrical polyneuropathy is a common neurological sequela after HIV, which leads to neuropathic pain and functional limitations. Rehabilitation programs with exercises are used to augment pharmacological therapy to relieve pain but appropriate and effective exercises are unknown. This study explored the safety and effect of moderate-intensity aerobic exercises and progressive resisted exercises for HIV-induced distal symmetrical polyneuropathy neuropathic pain.

DESIGN

A randomized pretest, posttest of 12 wks of aerobic exercise or progressive resisted exercise compared with a control. Outcome measures were assessed using the subjective periphery neuropathy, brief peripheral neuropathy screening, and numeric pain rating scale. Pain was assessed at baseline, 6 and 12 wks. Data between groups were compared using Kruskal-Wallis, Mann-Whitney U test, and within-groups Friedman and Wilcoxon signed rank tests.

RESULTS

There were 136 participants (mean [SD] age = 36.79 [8.23] yrs) and the exercise groups completed the protocols without any adverse effects. Pain scores within and between aerobic exercise and progressive resisted exercise groups showed significant improvement (P < 0.05) from baseline to 6 and 12 wks compared with the control (P > 0.05).

CONCLUSIONS

This study supports a rehabilitation program of moderate-intensity aerobic exercise and progressive resisted exercise being safe and effective for reducing neuropathic pain and is beneficial with analgesics for HIV-induced distal symmetrical polyneuropathy.

D3T acts as a pro-oxidant in a cell culture model of diabetes-induced peripheral neuropathy

Diabetes mellitus is one of the most common chronic diseases in the United States and peripheral neuropathy (PN) affects at least 50% of diabetic patients. Medications available for patients ameliorate symptoms (pain), but do not protect against cellular damage and come with severe side effects, leading to discontinued use. Our research group uses differentiated SH-SY5Y cells treated with advanced glycation end products (AGE) as a model to mimic diabetic conditions and to study the mechanisms of oxidative stress mediated cell damage and antioxidant protection. N-acetylcysteine (NAC), a common antioxidant supplement, was previously shown by our group to fully protect against AGE-induced damage. We have also shown that 3H-1,2-dithiole-3-thione (D3T), a cruciferous vegetable constituent and potent inducer of nuclear factor (erythroid-derived 2)- like 2 (Nrf2), can significantly increase cellular GSH concentrations and protect against oxidant species-induced cell death. Paradoxically, D3T conferred no protection against AGE-induced cell death or neurite degeneration. In the present study we establish a mechanism for this paradox by showing that D3T in combination with AGE increased oxidant species generation and depleted GSH via inhibition of glutathione reductase (GR) activity and increased expression of the NADPH generating enzyme glucose-6-phosphate dehydrogenase (G6PD). Blocking NADPH generation with the G6PD inhibitor dehydroepiandrosterone was found to protect against AGE-induced oxidant species generation, loss of viability, and neurite degeneration. It further reversed the D3T potentiation effect under AGE-treated conditions. Collectively, these results suggest that strategies aimed at combating oxidative stress that rely on upregulation of the endogenous antioxidant defense system via Nrf2 may backfire and promote further damage in diabetic PN.

The aetiologies of the unilateral oculomotor nerve palsy: a review of the literature

Oculomotor nerve palsy (ONP) is an important and common clinical diagnosis. Its main features are diplopia and ptosis. Its aetiologies are various and complex. A number of different conditions have been reported to cause ONP, such as diabetes mellitus, aneurysm, tumours, painful ophthalmoplegia, pituitary lesions, cavernous sinus lesions, central nervous system infections, and subarachnoid haemorrhage. A patients needs to undergo several tests in order to establish the correct underlying pathology. In this review, we have summarized the aetiologies of the unilateral ONP, and discussed their relative clinical features, pathogenesis, diagnostic criteria, treatment options, and prognosis. We searched PubMed for papers related to ONP and its aetiologies, and selected the publications, which seemed appropriate.

Administration of CORM-2 inhibits diabetic neuropathy but does not reduce dyslipidemia in diabetic mice

The antinociceptive effects of the carbon monoxide-releasing molecule tricarbonyldichlororuthenium (II) dimer (CORM-2) during chronic pain are well documented, but most of its possible side-effects remain poorly understood. In this work, we examine the impact of CORM-2 treatment on the lipoprotein profile and two main atheroprotective functions attributed to high-density lipoprotein (HDL) in a mouse model of type 1 diabetes while analyzing the effect of this drug on diabetic neuropathy. Streptozotocin (Stz)-induced diabetic mice treated with CORM-2 (Stz-CORM-2) or vehicle (Stz-vehicle) were used to evaluate the effect of this drug on the modulation of painful diabetic neuropathy using nociceptive behavioral tests. Plasma and tissue samples were used for chemical and functional analyses, as appropriate. Two main antiatherogenic properties of HDL, i.e., the ability of HDL to protect low-density lipoprotein (LDL) from oxidation and to promote reverse cholesterol transport from macrophages to the liver and feces in vivo (m-RCT), were also assessed. Stz-induced diabetic mice displayed hyperglycemia, dyslipidemia and pain hypersensitivity. The administration of 10 mg/kg CORM-2 during five consecutive days inhibited allodynia and hyperalgesia and significantly ameliorated spinal cord markers (Cybb and Bdkrb1expression) of neuropathic pain in Stz mice, but it did not reduce the combined dyslipidemia shown in Stz-treated mice. Its administration to Stz-treated mice led to a significant increase in the plasma levels of cholesterol (∼ 1.4-fold vs. Ctrl, ∼ 1.3- fold vs. Stz-vehicle; p < 0.05) and was attributed to significant elevations in both non-HDL (∼ 1.8-fold vs. Ctrl; ∼ 1.6-fold vs. Stz-vehicle; p < 0.05) and HDL cholesterol (∼ 1.3-fold vs. Ctrl, ∼ 1.2-fold vs. Stz-vehicle; p < 0.05). The increased HDL in plasma was not accompanied by a commensurate elevation in m-RCT in Stz-CORM-2 compared to Stz-vehicle mice; instead, it was worsened as revealed by decreased [³H]-tracer trafficking into the feces in vivo. Furthermore, the HDL-mediated protection against LDL oxidation ex vivo shown by the HDL isolated from Stz-CORM-2 mice did not differ from that obtained in Stz-vehicle mice. In conclusion, the antinociceptive effects produced by a high dose of CORM-2 were accompanied by antioxidative effects but were without favorable effects on the dyslipidemia manifested in diabetic mice.

Insulin-induced upregulation of lipoprotein lipase in Schwann cells during diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is one of the major complications associated with diabetes. It is characterized by the degeneration of the myelin sheath around axons, referred to as demyelination. Such demyelinations are often caused by reduced lipid component of the myelin sheath. Since, lipoprotein lipase (LPL) provides the lipid for myelin sheath by hydrolysing the triglyceride rich lipoproteins, and also helps in the uptake of lipids by the Schwann cells (SCs) for its utilization, LPL is considered as the important factor in the regeneration of myelin sheath during diabetic neuropathy. Earlier reports from our laboratory have provided the insights of insulin and its receptor in SCs during diabetic neuropathy. In order to evaluate the long term effect of insulin on lipid metabolism during diabetic neuropathy, in this study, we analyzed the expression of LPL in SCs under normal, high glucose and insulin treated conditions. A decrease in the expression of LPL was observed in SCs of high glucose condition and it was reversed upon insulin treatment. Histochemical observations of sciatic nerve of insulin treated neuropathy subjects showed the improved nerve morphology, signifying the importance of insulin in restoring the pathophysiology of diabetic neuropathy.

Diabetic Microvascular Disease: An Endocrine Society Scientific Statement

Both type 1 and type 2 diabetes adversely affect the microvasculature in multiple organs. Our understanding of the genesis of this injury and of potential interventions to prevent, limit, or reverse injury/dysfunction is continuously evolving. This statement reviews biochemical/cellular pathways involved in facilitating and abrogating microvascular injury. The statement summarizes the types of injury/dysfunction that occur in the three classical diabetes microvascular target tissues, the eye, the kidney, and the peripheral nervous system; the statement also reviews information on the effects of diabetes and insulin resistance on the microvasculature of skin, brain, adipose tissue, and cardiac and skeletal muscle. Despite extensive and intensive research, it is disappointing that microvascular complications of diabetes continue to compromise the quantity and quality of life for patients with diabetes. Hopefully, by understanding and building on current research findings, we will discover new approaches for prevention and treatment that will be effective for future generations.

Multitasking in older adults with type 2 diabetes: A cross-sectional analysis

Background and purpose

Deficits in the ability to multitask contribute to gait abnormalities and falls in many at-risk populations. However, it is unclear whether older adults with type 2 diabetes mellitus (DM) also demonstrate impairments in multitasking. The purpose of this study was to compare multitasking performance in cognitively intact older adults with and without DM and explore its relationship to measures of gait and functional ability.

Methods

We performed a cross-sectional analysis of 40 individuals aged 60 and older with type 2 DM and a matched group of 40 cognitively intact older adults without DM. Multitasking was examined via the ambulatory Walking and Remembering Test (WART) and seated Pursuit Rotor Test (PRT). Self-selected normal and fast walking speed and stride length variability were quantitatively measured, and self-reported functional ability was assessed via the Late Life Function and Disability Index (LLFDI).

Results

Participants with DM walked slower and took more steps off path when multitasking during the WART. No between-group differences in multitasking performance were observed on the PRT. Multitasking performance demonstrated little correlation with gait and functional ability in either group.

Discussion and conclusions

Older adults with DM appear to perform poorly on an ambulatory measure of multitasking. However, we analyzed a relatively small, homogenous sample of older adults with and without type 2 DM and factors such as peripheral neuropathy and the use of multiple comparisons complicate interpretation of the data. Future research should explore the interactions between multitasking and safety, fall risk, and function in this vulnerable population. Clinicians should recognize that an array of factors may contribute to gait and physical dysfunction in older adults with type 2 diabetes, and be prepared to assess and intervene appropriately.