Correlation between subclinical median neuropathy and the cross-sectional area of the median nerve at the wrist

Sonographic reference values for median nerve cross-sectional area: A meta-analysis of data from healthy individuals

Objective

Establish median nerve CSA reference values and identify patient-level factors impacting diagnostic thresholds.

Methods

Studies were identified through a robust search of multiple databases, and quality assessment was conducted using a modified version of the National Institute of Health Study Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. A meta-analysis was performed to identify normative values stratified by anatomic location. A meta-regression was conducted to examine heterogeneity effects of age, sex, and laterality.

Results

The meta-analysis included 73 studies; 41 (56.2%) were high quality. The median nerve CSA [95% CI] was 6.46mm2 [6.09-6.84], 8.68mm2 [8.22-9.13], and 8.60mm2 [8.23-8.97] at the proximal forearm, the carpal tunnel inlet, and the proximal carpal tunnel, respectively. Age was positively associated with CSA at the level of proximal carpal tunnel (β=0.03mm2, p=0.047). Men (9.42mm2, [8.06-10.78]) had statistically larger proximal tunnel CSA (p = 0.03) as compared to women (7.71mm2, [7.01-8.42]). No difference was noted in laterality.

Conclusion

A reference value for median nerve CSA in the carpal tunnel is 8.60mm2. Adjustments may be required in pediatrics or older adults. The diagnostic threshold of 10.0mm2 for male patients should be cautiously applied as the upper limit of normative averages surpasses this threshold.

Median Nerve Affection in Hypertensive Patients with and without Diabetes High-Resolution Ultrasound Assessment

PURPOSE

Diabetes is a documented risk factor for peripheral neuropathy. It was reported that associated hypertension could increase this risk. The present study aimed to assess the effect of hypertension and diabetes on median nerve using high-resolution ultrasound.

METHODS

The study includes 50 hypertensive patients (HTN group), 50 diabetic patients (DM group), 50 patients with coexisting diabetes and hypertension (HTN + DM group) and 50 healthy controls. Median nerve affection in the studied groups was studied by vibration perception thresholds (VPT). The median nerve cross-sectional area was determined at the nerve cross-sectional area of the median nerve at the carpal tunnel by high-resolution ultrasound. Clinical symptoms were assessed using Toronto Clinical Severity Score (TCSS).

RESULTS

There was significantly higher median nerve CSA in all patient groups in comparison to controls. HTN + DM group had significantly higher median nerve CSA when compared with DM group. Patients with peripheral neuropathy in HTN + DM and DM groups had significantly higher median nerve CSA than patients without. Using ROC curve analysis, it was shown that median CSA could successfully distinguish patients with peripheral neuropathy from patients without in HTN + DM group [AUC (95% CI): 0.71 (0.54-0.89)] and in DM group [AUC (95% CI): 0.86 (0.72-0.99)].

CONCLUSION

Hypertensive patients with and without diabetes have significantly higher median nerve CSA when compared with controls.

Measuring disease activity and predicting response to intravenous immunoglobulin in chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is characterised by significant clinical heterogeneity and as such reliable biomarkers are required to measure disease activity and assess treatment response. Recent advances in our understanding of disease pathogenesis and the discovery of novel serum-based, electrophysiologic and imaging biomarkers allow clinicians to make more informed decisions regarding individualised treatment regimes.

As a chronic immune-mediated process typified by relapse following withdrawal of immunomodulatory therapy, a substantial proportion of patients with CIDP require long term treatment with intravenous immunoglobulin (IVIg), a scarce and expensive donor-derived resource. The required duration and intensity of immunoglobulin treatment vary widely between individuals, highlighting both the heterogeneous nature of the underlying disease process as well as the variable pharmacologic properties of IVIg.

This review outlines the use of multimodal biomarkers in the longitudinal evaluation of nerve injury and how recent developments have impacted our ability to predict both response to immunoglobulin administration and its withdrawal.

Sonographic reference values of median nerve cross-sectional area: a protocol for a systematic review and meta-analysis

BACKGROUND

Median nerve cross-sectional area (CSA) is the primary sonographic parameter for assessing and diagnosing median nerve pathology, such as carpal tunnel syndrome. However, variability in the sensitivity of diagnostic thresholds exists, which may be due to a lack of standardized normative reference values. Current estimates of normal median nerve CSA stem largely from small studies using a local pool of healthy controls. A systematic review and meta-analysis will be conducted to identify all available data for median nerve CSA in healthy, asymptomatic individuals to create a comprehensive set of normative reference values.

METHODS

Articles that include sonographic measures of median nerve CSA will be identified through a rigorous search of published evidence, a hand search through tables of contents of key journals, and the gray literature, including ClinicalTrials.gov and conference abstracts. Each abstract and full text will be reviewed by multiple raters to identify studies from 2000 to present that include original data. Any study that provides median nerve CSA values from healthy individuals will be included (e.g., reference value study, control participants in a diagnostic study). Studies will be assessed for quality using a modified version of the National Institute of Health Study Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies, with primary focus on the use of a detailed and acceptable image acquisition and analysis protocol. Using data from included studies, reference values will be calculated for median nerve CSA by anatomical regions, including the distal forearm, wrist, and carpal tunnel at the level of the pisiform. Reference values will be stratified by gender, ethnicity, and age based upon the specificity of the data provided by the included articles.

DISCUSSION

A comprehensive set of normative reference values of median nerve CSA will reduce variability across studies, allowing future research to more accurately evaluate and establish diagnostic thresholds. Additionally, normative values can serve as a reference for evaluating treatment outcomes and provide a means to investigate and understand minor nuances in CSA changes that may be indicative of preclinical stages of median nerve pathology.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2016 CRD42016037286.

Detection of Intraneural Median Nerve Microvascularity Using Contrast-Enhanced Sonography: A Pilot Study

OBJECTIVES

Demonstrating vascularity within the human median nerve may be difficult using power Doppler sonography. To this end, a pilot study documenting contrast-enhanced vascularity of the median nerve was conducted.

METHODS

Patients undergoing contrast-enhanced transthoracic echocardiography were recruited for this study (n = 24). During echocardiography, a simultaneous contrast-enhanced sonographic examination of the median nerve was conducted. The study and study protocol were built from preclinical evidence. Image analysis was based on the power Doppler pixel intensity within a defined region of interest to obtain quantitative data representing the average pixel intensity, maximum pixel intensity, and power Doppler pixel dot count. Semiquantitative data representing the power Doppler dot count grading were also obtained.

RESULTS

Spearman correlations between analytical methods showed strong positive, statistically significant (P< .05) correlations between the average pixel intensity and maximum pixel intensity and between the power Doppler dot count and dot count grading. Statistically significant increases in the average pixel intensity and power Doppler dot count were seen at all but 1 time point throughout the contrast-enhanced sonographic examination when compared to precontrast administration. Statistically significant increases in the maximum pixel intensity were seen at all but 4 time points.

CONCLUSIONS

These pilot results represent early evidence that contrast-enhanced sonography can be used to image median nerve vascularity. In this convenience sample, median nerve contrast-enhanced sonographic data collection was feasible, safe, and consistent.

Ultrasound of the hand and wrist

There have been immense technical innovations and broadened clinical applications of ultrasound in the musculoskeletal system over the past 20 years. Specifically with regard to the hand and wrist, the advent of higher resolution transducers and postprocessing software applications have resulted in overall enhanced visualization of soft tissue structures (tendons/ligaments) as well as surface osseous lesions such as subclinical erosions in rheumatoid arthritis. Quantitative ultrasound, using either power Doppler or contrast-enhanced imaging, has become a central outcomes measure used to evaluate and document patient response to treatment in inflammatory arthropathies such as rheumatoid arthritis. This review will summarize the current state of clinical applications of ultrasound in the evaluation of the hand and wrist, with a summary of technical advances and specific applications in rheumatologic conditions.This review was exempt from institutional review board approval.

Impacts of elevated glycaemic haemoglobin and disease duration on the sensorimotor control of hands in diabetes patients

BACKGROUND

To understand the impacts of disease chronicity and hyperglycaemia on sensorimotor control of hands of diabetic patients, this study investigated the differences in hand sensation, strength and motor control by applying the pinch-holding-up activity test for patients with diabetes mellitus (DM) with different levels of glycaemic control and disease chronicity.

METHODS

One hundred and fifty-nine patients with clinically defined DM were included. Semmes-Weinstein monofilament, static two-point discrimination and moving two-point discrimination, maximal pinch strength precision pinch performance tests and nerve conduction studies (NCS) of the subjects were carried out. Forty-seven (29.6%) patients were in the HbA(1c) < 7% category, and 112 (70.4%) patients were in the >7% group. There were 87 (54.7%) patients with the disease duration <10 years, and 72 (45.3%) patients with disease duration ≧10 years.

RESULTS

The severity of hyperglycaemia significantly impacts the results for Semmes-Weinstein monofilament, precision pinch force control, sensory and motor NCS tests (p < 0.05). In addition, the chronicity of disease influences the motor control of precision pinch performance and the amplitude of motor NCS (p < 0.05) for the diabetes patients.

CONCLUSIONS

The evidence suggests that disease chronicity and hyperglycaemia have impacts on sensorimotor control in the hands of DM patients. In addition, the efficiency of prehensile forces of hand-to-object interactions in the pinch-holding-up activity test could be significant for identifying hand function, as well as pathologic changes in median nerve function, for patients with DM.

Carpal tunnel syndrome severity staging using sonographic and clinical measures

INTRODUCTION

Ultrasonography may be valuable in staging carpal tunnel syndrome severity, especially by combining multiple measures. This study aimed to develop a preliminary severity staging model using multiple sonographic and clinical measures.

METHODS

Measures were obtained in 104 participants. Multiple categorization structures for each variable were correlated to diagnostic severity based on nerve conduction. Goodness-of-fit was evaluated for models using iterative combinations of highly correlated variables. Using the best-fit model, a preliminary scoring system was developed, and frequency of misclassification was calculated.

RESULTS

The severity staging model with best fit (rho 0.90) included patient-reported symptoms, functional deficits, provocative testing, nerve cross-sectional area, and nerve longitudinal appearance. An 8-point scoring scale classified severity accurately for 79.8% of participants.

CONCLUSIONS

This severity staging model is a novel approach to carpal tunnel syndrome evaluation. Including more sensitive measures of nerve vascularity, nerve excursion, or other emerging techniques may refine this preliminary model.

How the impact of median neuropathy on sensorimotor control capability of hands for diabetes: an achievable assessment from functional perspectives

To comprehend the sensorimotor control ability in diabetic hands, this study investigated the sensation, motor function and precision pinch performances derived from a pinch-holding-up activity (PHUA) test of the hands of diabetic patients and healthy subjects. The precision, sensitivity and specificity of the PHUA test in the measurements of diabetic patients were also analyzed. We hypothesized that the diabetic hands would have impacts on the sensorimotor functions of the hand performances under functionally quantitative measurements. One hundred and fifty-nine patients with clinically defined diabetes mellitus (DM) and 95 age- and gender-matched healthy controls were included. Semmes-Weinstein monofilament (SWM), static and moving two-point discrimination (S2PD and M2PD), maximal pinch strength and precision pinch performance tests were conducted to evaluate the sensation, motor and sensorimotor status of the recruited hands. The results showed that there were significant differences (all p<0.05) in SWM, S2PD, M2PD and maximum pinch strength between the DM and control groups. A higher force ratio in the DM patients than in the controls (p<0.001) revealed a poor ability of pinch force adjustment in the DM patients. The percentage of maximal pinch strength was also significantly different (p<0.001) between the DM and control groups. The sensitivity, specificity and area under the receiver operating characteristic curve were 0.85, 0.51, and 0.724, respectively, for the PHUA test. Statistically significant degradations in sensory and motor functions and sensorimotor control ability were observed in the hands of the diabetic patients. The PHUA test could be feasibly used as a clinical tool to determine the sensorimotor function of the hands of diabetic patients from a functional perspective.