Sensory manifestations of diabetic neuropathies: anatomical and clinical correlations

Soft robotics-inspired sensing system for detecting downward movement and pistoning in prosthetic sockets: A proof-of-concept study

BACKGROUND

Vertical displacement of the residual limb within transtibial prosthetic socket, often known as "pistoning" or downward movement, may lead to skin breakdowns and ulcers. Downward movement is particularly difficult to self-manage for diabetic individuals living with amputation because of diminished sensation in the residual limb from peripheral neuropathy. Therefore, a customizable sensor at the distal end that can alert the users when high-risk downward movement and pistoning occurs is urgently needed.

OBJECTIVES

Presented herein for the first time is a lightweight, inexpensive sensing system inspired by soft robotics that can detect the occurrence and severity of downward movement at the distal end.

METHODS

The sensing system consists of a multilayered torus-shaped balloon, allowing easy integration with pin-lock socket systems. The design allows sensing of vertical displacement without imparting high reaction forces back onto the distal end. A benchtop compression tester was used to characterize system performance. Systematic and parametric benchtop tests were conducted to examine the sensor's physical characteristics. Long-term (24-h) stability of the sensor was also recorded.

RESULTS

Compared with water, air was determined to be a better medium with a higher linear full-scale span (FSS) because of its compressible nature. Repeatable 0.5-mm vertical displacements yielded a linear (>0.99 R2) FSS of 4.5 mm and a sensitivity of 0.8 kPa/mm. The sensing system is highly precise, with as low as 1% FSS total error band and average hysteresis of 2.84% of FSS. Over 24 h, a 4% FSS drift was observed.

CONCLUSION

Sensing system characteristics, coupled with low-cost, customizable fabrication, indicates promising performance for daily use to notify and alert transtibial prosthetic users of downward movement and/or pistoning.

Relationship between deep and superficial sensitivity assessments and gait analysis in diabetic foot patients

Peripheral neuropathy is a prevalent complication of diabetes that can lead to gait impairment and its adverse consequences. This study explored the potential utility of different parameters of gait analysis using a single sensor unit as a simple tool to detect peripheral neuropathy in 85 diabetic patients (DP) with diabetic foot in whom different somato-sensitivity tests in the feet were performed. Gait spatiotemporal parameters were examined by sensor inertial measurement placed in the lumbar area, while the superficial sensitivity pathway was assessed by nociception tests and deep sensitivity was examined by light touch-pressure and vibration sensitivity tests. Correlations between each sensory test and gait parameters were analysed in a logistic regression model in order to assess if gait parameters are associated with two different sensory pathways. Impaired deep sensory pathways were significantly (P < .05) correlated with lower gait speed, reduced cadence, smaller stride length, longer stance periods, and a higher risk of falling on the Tinetti Scale, while all gait parameters were significantly (P < .01) correlated with the superficial sensory pathway. Type 2 diabetics have significantly (P < .05) higher impairment in vibratory sensitivity than type 1 diabetics, and the years with diabetes mellitus (DM) diagnosis have a significant (P < .05) association with reduced vibration sensitivity. These findings indicate relationships between the deep sensory pathway and gait impairments in DP measured by inertial sensors, which could be a useful tool to diagnose gait alterations in DP and to evaluate the effect of treatments to improve gait and thus the risk of falls in diabetic patients.

Relationship between Cognitive Impairment and Depressive Symptoms with Somatosensory Functions in Diabetic and Non-Diabetic Older Adults and Its Impact on Quality of Life

Aging is an inevitable process that impacts the peripheral and central nervous systems and is considered one of the strongest risk factors for neurodegenerative diseases. In addition, when it also presents with diabetes mellitus, the risk of neurological damage may be further increased. This current study aimed to explore the relationships between peripheral sensory system decline and cognitive functions, the symptoms of depression, and quality of life (QoL) as metrics of central nervous system impairment in institutionalized older adults. A total of 95 individuals participated in this case-control study, which included diabetics and non-diabetics. The superficial sensory pathway was assessed in terms of thermal sensation, nociception, and non-discriminative touch, and the deep sensory pathway was evaluated by assessing vibration and light touch-pressure sensations. To assess function at the intellectual level, the Mini-Mental State Examination (MMSE) and Trail Making Test (TMT) cognitive functional tests were used, while the symptoms of depression and QoL were explored by employing the Yesavage Geriatric Depression Scale and EuroQol 5D questionnaire (EQ-5D), respectively. In the overall population analyses, altered thermal sensation was significantly associated with cognitive impairment (CI; p < 0.05). In turn, bivariate analyses and a binary logistic regression showed that the symptoms of depression and QoL were significantly related to altered vibratory sensation when assessed using a medical tuning fork (p < 0.05). In the group of diabetic patients, those with CI also had significantly lower thermal sensation (p < 0.05) and non-discriminative touch sensation, although this was only a trend (p = 0.055). Diabetics with depression had a significantly worse non-discriminative touch (p < 0.05) and vibratory sensation when tested with a tuning fork (p < 0.05). In addition, poorer QoL was associated with reduced sensitivity to heat (p < 0.05), light touch pressure (p < 0.05), and vibrations when assessed either with a tuning fork (p < 0.05) or a biothesiometer (p < 0.05). In contrast, no relationships were found between sensory functions and cognitive assessments in non-diabetic patients. These findings indicate that superficial sensitivity damage was related to CI, while deep sensation alterations were related to depression and poor QoL, with diabetes apparently further strengthening these relationships.

Patterns of facial and blink reflex abnormalities in type 2 diabetes mellitus patients with short disease duration: a clue to subclinical cranial neuropathy

Background

Cranial neuropathies occur in 3 to 14% of diabetic patients. Motor conduction study of the facial nerve and blink reflex study are electrophysiologic techniques used to assess the facio-trigeminal pathway in diabetic patients. The patterns of facial and blink reflex abnormalities are inconsistent among studies. This study aimed to assess the subclinical facial nerve and blink reflex abnormalities patterns in short-duration type 2 diabetes mellitus patients. This cross-sectional study included 30 type 2 diabetic patients with disease duration ≤ 5 years. We included only patients with the Toronto clinical neuropathy score ≤ 5. We enrolled 30 age- and sex-matched healthy subjects as a control group. We performed facial nerve motor conduction and blink reflex studies. Patients with prior history of cranial nerve lesions, stroke, or any other disease-causing polyneuropathy or drug-induced neuropathy were excluded from the study.

Results

Thirty diabetic patients were included, 20 females (66.7%) and ten males (33.3%). Their mean age was 52.63 ± 8.94 years. None of the patients had clinical evidence of neuropathy. There were significant differences between patients and controls in the distal latencies and amplitudes of facial nerve compound muscle action potentials and contralateral R2 late response latencies of the blink reflex. We detected subclinical cranial abnormalities in 6 diabetic patients (20%). One of them (3.3%) had facial nerve conduction abnormalities, four of them (13.4%) had blink reflex abnormalities, and one of them (3.3%) had both facial nerve and blink reflex abnormalities.

Conclusion

Subclinical cranial neuropathy can occur in short-duration type 2 diabetes mellitus patients. We detected different blink reflex patterns and facial conduction study abnormalities. We recommend blink reflex and facial nerve conduction studies as simple tests for the early evaluation of neurological subclinical affection in patients with short disease duration of T2DM as they may appear in the absence of peripheral neuropathy.

Recognising the potential of large animals for modelling neuromuscular junction physiology and disease

The aetiology and pathophysiology of many diseases of the motor unit remain poorly understood and the role of the neuromuscular junction (NMJ) in this group of disorders is particularly overlooked, especially in humans, when these diseases are comparatively rare. However, elucidating the development, function and degeneration of the NMJ is essential to uncover its contribution to neuromuscular disorders, and to explore potential therapeutic avenues to treat these devastating diseases. Until now, an understanding of the role of the NMJ in disease pathogenesis has been hindered by inherent differences between rodent and human NMJs: stark contrasts in body size and corresponding differences in associated axon length underpin some of the translational issues in animal models of neuromuscular disease. Comparative studies in large mammalian models, including examination of naturally occurring, highly prevalent animal diseases and evaluation of their treatment, might provide more relevant insights into the pathogenesis and therapy of equivalent human diseases. This review argues that large animal models offer great potential to enhance our understanding of the neuromuscular system in health and disease, and in particular, when dealing with diseases for which nerve length dependency might underly the pathogenesis.

The relation between serum uric acid levels and diabetic peripheral neuropathy in type 2 diabetes in Guilan, north of Iran

BACKGROUND

Diabetic peripheral neuropathy (DPN) is one of the most common chronic microvascular complications in type 2 diabetes mellitus (T2DM). Hence, the present study aimed to investigate the association between Serum Uric Acid (SUA) levels and diabetic peripheral polyneuropathy in patients with type 2 diabetes.

METHODS

We performed this case-control study during 2019-2020 on individuals with diabetes referring to the Razi clinic of Rasht, in the north of Iran. Polyneuropathy in patients was assessed based on the Neuropathy Disability Score (NDS), Diabetic neuropathy symptom score (DNS) scoring system, and electromyography (EMG)/nerve conduction velocity (NCV). The inclusion criterion for the control group was normal EMG/NCV. Then, the patients were assessed for SUA level and also laboratory results.

RESULTS

In total, 230 patients with type 2 diabetes were examined. The mean SUA level in the DPN group was significantly higher compared to the control group (6.72 ± 1.75 vs. 4.57 ± 1.49 mg/dL). With increasing the SUA, the odds of developing neuropathy increased by 2.2 times (OR = 2.2). The risk factors for diabetic polyneuropathy included gender (male) (OR = 0.347), SBP (OR = 1.1), retinopathy (OR = 3.29), and microalbuminuria (OR = 4.44). The chance of developing polyneuropathy in patients with retinopathy was 3.3 times higher than in the control group, it was 4.4 times in microalbuminuria patients.

CONCLUSION

Elevated SUA level increased the chance of developing peripheral polyneuropathy in a person with type 2 diabetes. SUA levels higher than 5.25 mg / dL expose a person with type 2 diabetes to developing peripheral polyneuropathy.

Relationship between symptoms during a gastric emptying study, daily symptoms and quality of life in patients with diabetes mellitus

AIMS

Gastric emptying is of limited utility for predicting the severity of symptoms in patients with diabetes mellitus and gastrointestinal symptoms. We evaluated the extent to which symptoms recorded during a ¹³ C-spirulina-based gastric emptying breath test (GEBT) or scintigraphy predicting the severity of daily symptoms in diabetes mellitus.

METHODS

Gastric emptying, symptoms during a gastric emptying study, either scintigraphy (n = 38) or GEBT (n = 111), and daily gastrointestinal symptoms were evaluated in 149 patients with diabetes mellitus and variably severe gastrointestinal symptoms.

KEY RESULTS

Gastric emptying was normal, delayed, and rapid in 37%, 52%, and 9% measured with the GEBT and 55%, 34%, and 11% of patients measured with scintigraphy; differences between GEBT and scintigraphy were not significant. Daily symptoms were moderately severe or more intense in 58% and 21% of patients undergoing scintigraphy and GEBT (P < 0.0001). Symptoms during the GEBT (46%) and emptying t_half (3%) explained 50% of the variance in daily symptoms in the GEBT group. In the scintigraphy group, symptoms explained 29% of this variance; the t_half was insignificant. Patients who reported that one or more symptoms were more severe than the others during the GE study were more likely (OR 3.98, 95% CI 2.16, 7.33) to report the same symptom(s) as being the most severe in the daily diary.

CONCLUSIONS

Symptoms during a GEBT and to a lesser extent during scintigraphy, but not gastric emptying predict the severity of daily symptoms and may serve as a biomarker in patients with diabetes mellitus.

Cutaneous innervation in impaired diabetic wound healing

Type 2 diabetes is associated with several potential comorbidities, among them impaired wound healing, chronic ulcerations, and the requirement for lower extremity amputation. Disease-associated abnormal cellular responses, infection, immunological and microvascular dysfunction, and peripheral neuropathy are implicated in the pathogenesis of the wound healing impairment and the diabetic foot ulcer. The skin houses a dense network of sensory nerve afferents and nerve-derived modulators, which communicate with epidermal keratinocytes and dermal fibroblasts bidirectionally to effect normal wound healing after trauma. However, the mechanisms through which cutaneous innervation modulates wound healing are poorly understood, especially in humans. Better understanding of these mechanisms may provide the basis for targeted treatments for chronic diabetic wounds. This review provides an overview of wound healing pathophysiology with a focus on neural involvement in normal and diabetic wound healing, as well as future therapeutic perspectives to address the unmet needs of diabetic patients with chronic wounds.

Chronic venous disease and diabetic microangiopathy: pathophysiology and commonalities

Chronic venous disease and diabetes mellitus are highly prevalent and debilitating conditions affecting millions of individuals globally. Although these conditions are typically considered as separate entities, they often co-exist which may be important in both understanding their pathophysiology and determining the best treatment strategy. Diabetes mellitus is twice as common in patients with chronic venous disease compared with the general population. Notably, a large proportion of patients with diabetes mellitus present with venous disorders, although this is often overlooked. The etiology of chronic venous disease is multifactorial, involving hemodynamic, genetic, and environmental factors which result in changes to the venous endothelium and structural wall as well as inflammation. Inflammation, endothelial dysfunction and hyperfiltration or leakage, are commonly observed in diabetes mellitus and cause various diabetic microvascular complications. Both diseases are also influenced by the increased expression of adhesion molecules, chemokines, and cytokines, and are characterized by the presence of vessel hypertension. Consequently, despite differences in etiology, the pathophysiology of both chronic venous disease and diabetic microangiopathy appears to be driven by endothelial dysfunction and inflammation. Treatment strategies should take the co-existence of chronic venous disease and diabetic microangiopathy into account. Compression therapy is recommended in inflammatory conditions that have an edema component as seen in both chronic venous disease and diabetes mellitus. Lifestyle changes like weight loss and exercise, will improve metabolic state and lower inflammation and should be promoted in these patients. Additionally, both patient populations may benefit from venoactive drugs.

Assessing pathological changes within the nucleus ambiguus of horses with recurrent laryngeal neuropathy: An extreme, length-dependent axonopathy

INTRODUCTION

Equine recurrent laryngeal neuropathy (RLN) is a naturally occurring model of length-dependent axonopathy characterized by asymmetrical degeneration of recurrent laryngeal nerve axons (RLn). Distal RLn degeneration is marked, but it is unclear whether degeneration extends to include cell bodies (consistent with a neuronopathy).

METHODS

With examiners blinded to RLN severity, brainstem location, and side, we examined correlations between RLN severity (assessed using left distal RLn myelinated axon count) and histopathological features (including chromatolysis and glial responses) in the nucleus ambiguus cell bodies, and myelinated axon count of the right distal RLn of 16 horses.

RESULTS

RLN severity was not associated with RLn cell body number (P > .05), or degeneration. A positive correlation between the left and right distal RLn myelinated axon counts was identified (R² = 0.57, P < .05).

DISCUSSION

We confirm that RLN, a length-dependent distal axonopathy, occurs in the absence of detectable neuronopathy.

Diabetic Gastroparesis

This review covers the epidemiology, pathophysiology, clinical features, diagnosis, and management of diabetic gastroparesis, and more broadly diabetic gastroenteropathy, which encompasses all the gastrointestinal manifestations of diabetes mellitus. Up to 50% of patients with type 1 and type 2 DM and suboptimal glycemic control have delayed gastric emptying (GE), which can be documented with scintigraphy, 13C breath tests, or a wireless motility capsule; the remainder have normal or rapid GE. Many patients with delayed GE are asymptomatic; others have dyspepsia (i.e., mild to moderate indigestion, with or without a mild delay in GE) or gastroparesis, which is a syndrome characterized by moderate to severe upper gastrointestinal symptoms and delayed GE that suggest, but are not accompanied by, gastric outlet obstruction. Gastroparesis can markedly impair quality of life, and up to 50% of patients have significant anxiety and/or depression. Often the distinction between dyspepsia and gastroparesis is based on clinical judgement rather than established criteria. Hyperglycemia, autonomic neuropathy, and enteric neuromuscular inflammation and injury are implicated in the pathogenesis of delayed GE. Alternatively, there are limited data to suggest that delayed GE may affect glycemic control. The management of diabetic gastroparesis is guided by the severity of symptoms, the magnitude of delayed GE, and the nutritional status. Initial options include dietary modifications, supplemental oral nutrition, and antiemetic and prokinetic medications. Patients with more severe symptoms may require a venting gastrostomy or jejunostomy and/or gastric electrical stimulation. Promising newer therapeutic approaches include ghrelin receptor agonists and selective 5-hydroxytryptamine receptor agonists.

GI Dysfunctions in Diabetic Gastroenteropathy, Their Relationships With Symptoms, and Effects of a GLP-1 Antagonist

CONTEXT

Delayed gastric emptying (GE) is common but often asymptomatic in diabetes. The relationship between symptoms, glycemia, and neurohormonal functions, including glucagonlike peptide 1 (GLP-1), are unclear.

OBJECTIVES

To assess whether GE disturbances, symptoms during a GE study, and symptoms during enteral lipid infusion explain daily symptoms and whether GLP-1 mediates symptoms during enteral lipid infusion.

DESIGN

In this randomized controlled trial, GE, enteral lipid infusion, gastrointestinal (GI) symptoms during these assessments, autonomic functions, glycosylated hemoglobin (HbA1c), and daily GI symptoms (2-week Gastroparesis Cardinal Symptom Index diary) were evaluated. During enteral lipid infusion, participants received the GLP-1 antagonist exendin 9-39 or placebo.

SETTING

Single tertiary referral center.

PARTICIPANTS

24 healthy controls and 40 patients with diabetic gastroenteropathy.

MAIN OUTCOME MEASURES

GE, symptoms during enteral lipid infusion, and the effect of exendin 9-39 on the latter.

RESULTS

In patients, GE was normal (55%), delayed (33%), or rapid (12%). During lipid infusion, GI symptoms tended to be greater (P = 0.06) in patients with diabetes mellitus (DM) than controls; exendin 9-39 did not affect symptoms. The HbA1c was inversely correlated with the mean symptom score during the GE study (r = -0.46, P = 0.003) and lipid infusion (r = -0.47, P < 0.01). GE and symptoms during GE study accounted for 40% and 32%, respectively, of the variance in daily symptom severity and quality of life.

CONCLUSIONS

In DM gastroenteropathy, GE and symptoms during a GE study explain daily symptoms. Symptoms during enteral lipid infusion were borderline increased but not reduced by a GLP-1 antagonist.

The Clinical Features of Painful Small-Fiber Neuropathy Suggesting an Origin Linked to Primary Sjögren's Syndrome

OBJECTIVE

We attempted to determine whether clinical features could differentiate painful small-fiber neuropathy related to primary Sj€ogren's syndrome (pSS-SFN) from idiopathic SFN (idio-SFN).

METHODS

Validated clinical questionnaires and neurophysiological investigations specific for pain and SFN assessment were performed in 25 patients with pSS-SFN and 25 patients with idio-SFN.

RESULTS

Patients with idio-SFN had more frequent severe burning sensations and higher mean anxiety scores and daily pain intensity compared to patients with pSSSFN. Conversely, patients with pSS-SFN had reduced electrochemical skin conductance measured by Sudoscan_, and almost half of them had the sensation of walking on cotton wool.

CONCLUSION

Our results suggest that idio-SFN more specifically involved small sensory fibers than pSS-SFN, in which subtle dysfunction of larger sensory fibers and damage of distal autonomic sudomotor innervation may occur. A practical algorithm is proposed to help to differentiate SFN associated with pSS from idio-SFN, based on information very easy to obtain by clinical interview.

Netrin-1 improves adipose-derived stem cell proliferation, migration, and treatment effect in type 2 diabetic mice with sciatic denervation

BACKGROUND

Diabetic peripheral neurovascular diseases (DPNVs) are complex, lacking effective treatment. Autologous/allogeneic transplantation of adipose-derived stem cells (ADSCs) is a promising strategy for DPNVs. Nonetheless, the transplanted ADSCs demonstrate unsatisfying viability, migration, adhesion, and differentiation in vivo, which reduce the treatment efficiency. Netrin-1 secreted as an axon guidance molecule and served as an angiogenic factor, demonstrating its ability in enhancing cell proliferation, migration, adhesion, and neovascularization.

METHODS

ADSCs acquired from adipose tissue were modified by Netrin-1 gene (NTN-1) using the adenovirus method (N-ADSCs) and proliferation, migration, adhesion, and apoptosis examined under high-glucose condition. The sciatic denervated mice (db/db) with type 2 diabetes mellitus (T2DM) were transplanted with N-ADSCs and treatment efficiency assessed based on the laser Doppler perfusion index, immunofluorescence, and histopathological assay. Also, the molecular mechanisms underlying Netrin-1-mediated proliferation, migration, adhesion, differentiation, proangiogenic capacity, and apoptosis of ADSCs were explored.

RESULTS

N-ADSCs improved the proliferation, migration, and adhesion and inhibited the apoptosis of ADSCs in vitro in the condition of high glucose. The N-ADSCs group demonstrated an elevated laser Doppler perfusion index in the ADSCs and control groups. N-ADSCs analyzed by immunofluorescence and histopathological staining demonstrated the distribution of the cells in the injected limb muscles, indicating chronic ischemia; capillaries and endothelium were formed by differentiation of N-ADSCs. The N-ADSCs group showed a significantly high density of the microvessels than the ADSCs group. The upregulation of AKT/PI3K/eNOS/P-38/NF-κB signaling pathways and secretion of multiple growth factors might explain the positive effects of Netrin-1 on ADSCs.

CONCLUSION

The overexpression of Netrin-1 in ADSCs improves proliferation, migration, and treatment effect in type 2 diabetic mice with sciatic denervation, which directs the clinical treatment of patients with DPNVs.

Pathological classification of equine recurrent laryngeal neuropathy

Recurrent Laryngeal Neuropathy (RLN) is a highly prevalent and predominantly left-sided, degenerative disorder of the recurrent laryngeal nerves (RLn) of tall horses, that causes inspiratory stridor at exercise because of intrinsic laryngeal muscle paresis. The associated laryngeal dysfunction and exercise intolerance in athletic horses commonly leads to surgical intervention, retirement or euthanasia with associated financial and welfare implications. Despite speculation, there is a lack of consensus and conflicting evidence supporting the primary classification of RLN, as either a distal ("dying back") axonopathy or as a primary myelinopathy and as either a (bilateral) mononeuropathy or a polyneuropathy; this uncertainty hinders etiological and pathophysiological research. In this review, we discuss the neuropathological changes and electrophysiological deficits reported in the RLn of affected horses, and the evidence for correct classification of the disorder. In so doing, we summarize and reveal the limitations of much historical research on RLN and propose future directions that might best help identify the etiology and pathophysiology of this enigmatic disorder.

TNF-Alpha in Peripheral Neuropathy Patients with Impaired Glucose Regulation

Impaired glucose regulation (IGR) is the prestate of diabetes; about 1/3 of IGR patients will develop to diabetes finally. In this study, we investigated the serum tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels in peripheral neuropathy impaired patients with impaired glucose regulation (IGR). A total of 70 IGR patients received the conventional nerve conduction test, including 30 patients with peripheral neuropathy (PN) and 40 patients without peripheral neuropathy (NPN). The other 40 healthy individuals were recruited as controls. The serum TNF-α and IL-6 in IGR patients were higher than in control group, and serum TNF-α and IL-6 levels in IGR-PN group were higher than in IGR-NPN group (27.7 ± 17.8 versus 13.1 ± 6.7 pg/mL and 18.1 ± 17.7 versus 6.4 ± 3.7 pg/mL, resp., both p < 0.05). Multifactors logistic regression analysis showed that TNF-α (OR = 0.893; p = 0.009) was an independent factor affecting whether IGR could combine with peripheral neuropathy. TNF-α and IL-6 could aggregate peripheral neuropathy in impaired glucose regulation patients; TNF-α might be independent risk factor for peripheral neuropathy in glucose regulation impaired patients.

Antihyperalgesic Activity of Rhodiola rosea in a Diabetic Rat Model

Preclinical Research Rhodiola rosea L. (Crassulaceae) is used for enhancing physical and mental performance. Recent studies demonstrated that R. rosea had anti-inflammatory activity in animal models, for example, carrageenan- and nystatin-induced edema in rats, possibly by inhibiting phospholipase A2 and cyclooxygenases-1 and -2. In addition, R. rosea had antinociceptive activity in thermal and chemical pain tests as well as mechanical hyperalgesia. The purpose of the present study was to assess the antihyperalgesic effect of an ethanol extract of Rhodiola rosea (R. rosea) in a diabetic rat model. Rats were administered a single dose of streptozotocin (STZ; 50 mg/kg, i.p.) and hyperalgesia was evaluated four weeks later. Formalin-evoked (0.5%) flinching was increased in diabetic rats compared with nondiabetic controls Systemic (1-100 mg/kg, i.p.) and local (0.1-10 mg/paw into the dorsal surface of the right hind paw) administration of R. rosea ethanol extract dose-dependently reduced formalin-induced hyperalgesia in diabetic rats. The antihyperalgesic effect of R. rosea was compared with gabapentin. These results suggest that R. rosea ethanol extract may have potential as a treatment for diabetic hyperalgesia.

Offloading treatment is linked to activation of proinflammatory cytokines and start of bone repair and remodeling in Charcot arthropathy patients

BACKGROUND

Proinflammatory cytokines are an integral part of the osteolytic activity of Charcot arthropathy but are also central to normal bone healing. As there are no previous longitudinal studies investigating their role during the recovery phase of Charcot, we set out to monitor systemic levels of proinflammatory cytokines from Charcot presentation until a clinically and radiographically documented chronic state has been reached.

METHODS

Twenty-eight consecutive Charcot patients were monitored during 2 years by repeated foot radiographs, MRI and plasma levels of interleukin [IL]-6, IL-8, IL-1β, Tumor Necrosis Factor [TNF]-α, and IL-1 receptor antibody (IL-1RA). Charcot patients were treated with total contact cast (TCC) on the first day of inclusion. Neuropathic diabetic controls (n = 20) and Healthy subjects (n = 20) served as reference.

RESULTS

Plasma IL-6, IL-8, IL-1β and TNF-α in the acute and chronic phase of Charcot were below or at the level of diabetic controls and healthy, whereas IL-1RA/IL-1β ratio was continuously higher in Charcot patients. IL-6, TNF-α and IL-1RA began to increase one week after offloading to reach a peak after 4 months before gradually receding.

CONCLUSIONS

A sustained increase of IL-6 and TNF-α starting shortly after offloading and paralleled by accelerated bone healing on radiographs, suggest that offloading, by activating the inflammatory stage, has a key role to play in the onset of coupled bone remodeling. High IL-1RA/IL-1β ratio in Charcot patients at presentation supports a counter-balancing anti-inflammatory role for IL-1RA in the acute phase whereas a high ratio after two years, possibly due to renewed weight-bearing on a deformed foot, signal need for continued anti-inflammatory activity and contradicts a "cold" biological state in the chronic phase.