Turkish version of the Michigan Neuropathy Screening Instrument in the assessment of diabetic peripheral neuropathy: a validity and reliability study

F-wave motor unit numbers do not change in diabetic polyneuropathy: does it indicate a pathophysiologic mechanism for generating F-waves?

OBJECTIVES

Motor unit number estimation (MUNE) methods including the one using F-waves (F-MUNE) are used to detect axonal loss in polyneuropathies. The aim of this study is to evaluate the amount of axonal loss by repeater F-wave parameters and F-MUNE in patients with type 2 diabetes mellitus (DM).

METHODS

In 24 controls and 49 patients with diabetic polyneuropathy, 90 F-waves elicited with supramaximal and 300 F-waves with submaximal stimulation of the ulnar nerve were recorded from the abductor digiti minimi muscle. F-MUNE values were calculated using the automated software with the repeater F-waves elicited using submaximal stimulation.

RESULTS

Ulnar repeater F-wave index and repeater neuron index were found to be significantly higher in patients with DM compared with the control group. The amplitudes of F-waves elicited using both sub- and supramaximal stimulus intensities were reduced in patients with polyneuropathy when compared with controls. The F-MUNE values were found to be similar between the two groups.

DISCUSSION

Repeater F-wave parameters recorded from the upper extremity might indicate the presence of axon loss in DM-related polyneuropathy. However, F-MUNE failed to reveal axonal loss in diabetic polyneuropathy probably because of its length-dependent nature and the dominance of low-amplitude F-waves, which might be secondary to several yet unknown mechanisms, mainly related to sensory fiber dysfunction.

Barriers and new opportunities in developing effective therapies for diabetic neuropathy: International expert consensus recommendations

BACKGROUND

Diabetic neuropathy (DN) affects up to half of individuals with type 1 and type 2 diabetes. Despite evidence that improving metabolic and cardiovascular health can slow its progression, DN remains a significant clinical challenge due to the lack of disease-modifying therapies and effective pain management strategies. This consensus aimed to identify gaps and recommend strategies to address these challenges.

METHOD

A workshop, initiated by Steno Diabetes Centre Copenhagen and the Danish Diabetes and Endocrinology Academy, conducted a gap analysis based on insights from clinical studies, observational cohorts, and clinical practice. Online invitations targeted experienced clinicians, researchers, and drug developers committed to improving DN treatment through innovative clinical trials. Thirty-five participants from six countries reached consensus via a Delphi process on key steps to advance DN therapy.

RESULT

Four critical barriers and needs were addressed: (1) Translating bench research to clinical practice, (2) Enhancing clinical trial design, (3) Improving outcome measures, and (4) Identifying effective treatments for painful DN.

CONCLUSION

Successful interventional trials require robust outcome measures to capture clinically meaningful changes in DN phenotypes, providing the basis for developing effective, disease-modifying treatments.

Promising predictors of diabetic peripheral neuropathy in children and adolescents with type 1 diabetes mellitus

BACKGROUND

Diabetic peripheral neuropathy (DPN) in children and adolescents with type 1 diabetes mellitus (T1DM) is a growing issue, with controversial data in the terms of prevalence and evaluation timelines. Currently, there are no clear standards for its early detection. Therefore, our aim was to assess the contribution of the Michigan neuropathy screening instrument (MNSI), lipid profile, serum neuron specific enolase (NSE), and serum heat shock protein 27 (HSP 27) to the prediction of DPN in children and adolescents with T1DM.

METHODS

In this case-control study, fifty children diagnosed with T1DM for at least five years were enrolled and evaluated through complete neurological examination, MNSI, and nerve conduction study (NCS). Additionally, HbA1c, lipid profile, serum NSE, and serum HSP 27 levels were measured for patients and controls.

RESULTS

The prevalence of DPN in our study was 24% by NCS, and electrophysiological changes showed a statistically significant lower conduction velocity for the posterior tibial and sural nerves, as well as a prolonged latency period for the common peroneal and sural nerves in neuropathic patients. In these patients, older age, earlier age of diabetes onset, longer disease duration, higher total cholesterol, triglycerides, low density lipoprotein cholesterol, HbA1c, serum NSE, and HSP27 levels were observed. The MNSI examination score ≥ 1.5 cutoff point had an area under the curve (AUC) of 0.955, with 75% sensitivity and 94.74% specificity, according to receiver operating characteristic curve analysis. However, the questionnaire's cutoff point of ≥ 5 had an AUC of 0.720, 75% sensitivity, and 63% specificity, with improved overall instrument performance when combining both scores. Regarding blood biomarkers, serum NSE had greater sensitivity and specificity in discriminating neuropathic patients than HSP27 (92% and 74% versus 75% and 71%, respectively). Regression analysis revealed a substantial dependency for MNSI and serum NSE in predicting DPN in patients.

CONCLUSIONS

Despite limited research in pediatrics, MNSI and serum NSE are promising predictive tools for DPN in children and adolescents with T1DM, even when they are asymptomatic. Poor glycemic control and lipid profile changes may play a critical role in the development of DPN in these patients, despite conflicting results in various studies.

Early detection of diabetic neuropathy based on health belief model: a scoping review

Introduction

Uncontrolled blood sugar levels may result in complications, namely diabetic neuropathy. Diabetic neuropathy is a nerve disorder that causes symptoms of numbness, foot deformity, dry skin, and thickening of the feet. The severity of diabetic neuropathy carries the risk of developing diabetic ulcers and amputation. Early detection of diabetic neuropathy can prevent the risk of diabetic ulcers. The purpose: to identify early detection of diabetic neuropathy based on the health belief model.

Method

This research searched for articles in 6 databases via Scopus, Ebsco, Pubmed, Sage journal, Science Direct, and SpringerLink with the keywords "screening Neuropathy" AND "Detection Neuropathy" AND "Scoring Neuropathy" AND "Diabetic" published in 2019-2023. In this study, articles were identified based on PICO analysis. Researchers used rayyan.AI in the literature selection process and PRISMA Flow-Chart 2020 to record the article filtering process. To identify the risk of bias, researchers used the JBI checklist for diagnostic test accuracy.

Results

This research identified articles through PRISMA Flow-Chart 2020, obtaining 20 articles that discussed early detection of diabetic neuropathy.

Conclusion

This review reports on the importance of early detection of neuropathy for diagnosing neuropathy and determining appropriate management. Neuropathy patients who receive appropriate treatment can prevent the occurrence of diabetic ulcers. The most frequently used neuropathy instruments are the vibration perception threshold (VPT) and questionnaire Michigan Neuropathy Screening Instrument (MNSI). Health workers can combine neuropathy instruments to accurately diagnose neuropathy.

Plantar fascia stiffness in patients with type 2 diabetes mellitus: Stiffness effect on fall risk and gait speed

AIMS

The primary objective was to compare patients with type 2 diabetes mellitus (T2DM) and healthy peers in terms of plantar fascia (PF) stiffness, fall risk, and gait speed. The second objective was to examine the relationship between stiffness of PF and fall risk, gait speed.

METHODS

Fifty patients diagnosed with T2DM (mean duration = 10.74 ± 7.07 years) were included. Myotonometer was used to evaluate the stiffness of PF. To assess the risk of falling, and gait speed, the International Fall Efficiency Scale (FES-I) and the 4-Meter Gait Speed Test (4mGST) were used, respectively.

RESULTS

Compared to healthy controls, PF stiffness (right foot mean difference = 148.99 N/m, left foot mean difference = 113.13 N/m p < .001) was higher in the T2DM group. The FES-I and 4mGST scores were worse in the group with T2DM (p < .05). 12.8 % of FES-I and 23.4 % of 4mGST variance were explained by stiffness of PF.

CONCLUSIONS

The results of the study showed that the stiffness of PF changed in patients with T2DM. There was a decrease in gait speed and an increase in the risk of falling as PF stiffness increased.

Efficacy and safety of high-dose intramuscular vitamin D2 injection in type 2 diabetes mellitus with distal symmetric polyneuropathy combined with vitamin D insufficiency: study protocol for a multicenter, randomized, double-blinded, and placebo-controlled trial

Background

Distal symmetric polyneuropathy (DSPN) is the most common chronic complication of type 2 diabetes mellitus (T2DM). DSPN may lead to more serious complications, such as diabetic foot ulcer, amputation, and reduced life expectancy. Observational studies have suggested that vitamin D deficiency may be associated with the development of DSPN in T2DM. However, interventional studies have found that low-dose vitamin D supplementation does not significantly improve neuropathy in DSPN. This study aims to evaluate the efficacy and safety of intramuscular injection of high-dose vitamin D (HDVD) in T2DM with DSPN combined with vitamin D insufficiency.

Methods and analysis

We will conduct a multicenter, randomized, double-blinded, and placebo-controlled trial in four large hospitals. All eligible participants will be randomly assigned to either the vitamin D₂ supplement or placebo control group and injected intramuscularly monthly for 3 months. Additionally, anthropometric measurements and clinical data will be collected at baseline and 3 months. Adverse events will be collected at 1, 2, and 3 months. The primary outcome measure is the change in the mean Michigan Neuropathy Screening Instrument (MNSI) score at baseline and 3 months post-intervention. We will use the gold-standard liquid chromatography-tandem mass spectrometry method to distinguish between 25(OH)D₂ and 25(OH)D₃ levels. The MNSN score before the intervention will be used as a covariate to compare the changes between both groups before and after the intervention, and the analysis of covariance will be used to analyze the change in the MNSI score after HDVD supplementation.

Discussion

Glycemic control alone does not prevent the progression of DSPN in T2DM. Some studies have suggested that vitamin D may improve DSPN; however, the exact dose, method, and duration of vitamin D supplementation are unknown. Additionally, neuropathy repair requires HDVD supplementation to sustain adequate vitamin D levels. This once-a-month intramuscular method avoids daily medication; therefore, compliance is high. This study will be the first randomized controlled trial in China to analyze the efficacy and safety of HDVD supplementation for patients with T2DM and DSPN and will provide new ideas for pharmacological research and clinical treatment of diabetic neuropathy.

Clinical trial registration

https://www.chictr.org.cn/, identifier ChiCTR2200062266.

Validity and reliability of the Polish version of the Michigan Neuropathy Screening Instrument

BACKGROUND

Diabetic sensorimotor polyneuropathy is an important risk factor for foot ulceration and amputation. Thus, patients with diabetes should be screened for this disorder according to local guidelines. An obstacle to the diagnosis of this disease may be the lack of unified diagnostic criteria due to the lack of properly validated scales used for assessment.

AIM

To validate both sections (A and B) of the Michigan Neuropathy Screening Instrument (MNSI) in Polish (PL) patients with diabetes.

METHODS

A cross-sectional study using a test (A1, B1) and re-test (A2, B2) formula was performed in 80 patients with diabetes. The gold standard used for neuropathy detection was a nerve conduction study (NCS) which was performed in all participants. Reliability of the MNSI-PL was assessed using the Cronbach’s alpha, Kuder-Richardson formula 20 (KR-20), split-half reliability, the Gottman split-half tests, and correlation between first and second half was accessed. Stability was assessed using an intraclass correlation coefficient (ICC). For external validation, we used simple linear correlation, binomial regression, and agreement between two different tools using a Bland-Altman plot analysis.

RESULTS

The scale was internally consistent (Cronbach’s alpha for the full scale: 0.81 for A and 0.87 for B). MNSI-PL scores in test/retest showed high stability (ICC = 0.73 for A and ICC = 0.97 for B). The statistically important correlations between MNSI-PL and NCS were found for B1, B2, and A1 (P < 0.005). The cut-off points of ≥ 3 for section A (sensitivity of 90%-100%; specificity of 33%-40%) and ≥ 2 for section B (sensitivity of 81%-84%; specificity of 60%-70%) were obtained during neuropathy detection.

CONCLUSION

The MNSI-PL is a reliable and valid instrument in screening for diabetic neuropathy.

Precision of Michigan Neuropathy Screening Instrument (MNSI) Tool for the Diagnosis of Diabetic Peripheral Neuropathy Among People with Type 2 Diabetes-A Study from South India

Diabetic peripheral neuropathy (DPN) is one of the risk factors for foot-related complications among people with type 2 diabetes mellitus (T2DM). Hence, we aimed to validate the Michigan Neuropathy Screening Instrument (MNSI) tool against biothesiometer with a cut-off value of ≥25 V and also to determine the cut-off point of MNSI score for the diagnosis of diabetic neuropathy among people with T2DM in India. A cross-sectional study was conducted among 357 people with T2DM in a tertiary care centre for diabetes in Chennai, South India. The eligible study participants underwent testing with a biothesiometer and the MNSI tool was administered. The patient version tool of MNSI was translated to the local language, Tamil. The MNSI scores (1, 1.5, 2, and 2.5) were compared with biothesiometer value. For the MNSI scores of less than 1, 1.5, 2, and 2.5, sensitivities were 97.6%, 97.6%, 96.8%, and 77.8% and specificities were 76.6%, 77.9%, 85.7%, and 88.3% respectively. The cut-off value of MNSI score was derived as two with AUC of 0.934. The sensitivity was 96.8% and the specificity was 85.7% with 89.6% accuracy. The high sensitivity indicates the positive cases are diagnosed correctly. There is no validated tool available for detection of DPN in Indian population. The Indian version of MNSI tool was found to be effective for screening diabetic neuropathy among people with T2DM. The MNSI tool was found to be reliable, convenient, and non-invasive for diagnosis of DPN and can be used in routine clinical settings.

Translation, validation, and diagnostic accuracy of the Arabic version of the Michigan neuropathy screening instrument

The Michigan Neuropathy Screening Instrument (MNSI) is used to screen patients for diabetic neuropathy (DNP). We aimed to translate the MNSI questionnaire into Arabic (MNSIq-Ar) and to assess the validity and diagnostic performance of the MNSI Arabic version (MNSI-Ar).Cronbach alpha α and the interclass correlation coefficient were used to measure the reliability and reproducibility of the MNSIq-Ar. The instrument's validity was assessed by Spearman correlation with the Utah Early Neuropathy Scale (UENS), the Modified Toronto Neuropathy Score (mTCNS), diabetic neuropathy symptoms (DNS), and sural nerve amplitude (SNA). The construct validity of the MNSI-Ar was assessed by its ability to differentiate the severity of DNP (using the Kruskal-Wallis test). The diagnostic performance was assessed through the receiver operator curve area.We recruited 89 participants (mean [SD] age, 50.8 [12.3] years; 48% men). The MNSIq-Ar showed an α of 0.81 and intraclass correlation coefficient = 0.94, and the correlation coefficients with UENS, mTCNS, DNS, and sural nerve amplitude were 0.67, 0.83, 0.73, and -0.49, respectively (all P < .0001). The MNSI-Ar was able to differentiate the different severities of DNP. The receiver operator curve area was 0.93 with a high sensitivity of 95.9% and 100% for probable and confirmed DNP, respectively.MNSI-Ar is a reliable and valid tool to screen for diabetic neuropathy in the Arabic language with a good diagnostic performance and high sensitivity.