Sonographic assessment of carpal tunnel syndrome in diabetic patients with and without polyneuropathy

Ultrasound assessment of the brachial plexus nerve root cross-sectional areas in asymptomatic patients with type 2 diabetes

Type 2 diabetes mellitus (T2D) is one of the most common metabolic diseases and is often associated with cervical radiculoplexus neuropathies. Magnetic resonance imaging is the modality of choice for evaluating the brachial plexus, however, the use of ultrasound for its evaluation has increased and has been shown to be an additional reliable method. We aimed to compare the cross-sectional areas of the C5, C6, and C7 nerve roots of the brachial plexus, at the interscalene groove, in asymptomatic patients with T2D to that of an asymptomatic control cohort without T2D. A total of 25 asymptomatic patients with T2D were recruited from outpatient clinics. A total of 18 asymptomatic subjects without T2D were also recruited from hospital staff volunteers to form the control cohort. High-resolution ultrasound imaging of the bilateral C5, C6, and C7 nerve roots of the brachial plexus was performed in the short axis, at the level of the interscalene grooves. The nerve root cross-sectional areas were recorded and compared. In the patients with T2D, HbA1c and fasting blood glucose (FBG) levels were obtained as well as the duration of T2D in years and correlated with cross-sectional areas. The cross-sectional areas of C6 and C7 were significantly smaller in the T2D cohort. Additionally, HbA1c, and FBG levels as well as the duration of T2D were negatively correlated with the C5, C6, and C7 cross-sectional areas. Our study demonstrated smaller brachial plexus nerve root cross-sectional areas in asymptomatic patients with T2D which negatively correlated with HbA1c, and FBG levels as well as the duration of T2D.

The vagus nerve cross-sectional area on ultrasound in patients with type 2 diabetes

Diabetic neuropathy, including autonomic neuropathy is a serious complication related to type 2 diabetes mellitus (T2D). The vagus nerve (VN) is the longest nerve in the autonomic nervous system, and since diabetic neuropathy manifests first in longer nerves, the VN is commonly affected in early diabetic autonomic neuropathy. The use of high-resolution ultrasound for peripheral and cranial nerve imaging has significantly increased over the past 2 decades. The aim of the study is to compare the cross-sectional area of the VN in patients with T2D to that of a control cohort without T2D. A total of 52 VN cross-sectional areas were recorded from patients with T2D. A total of 56 VN cross-sectional areas were also recorded from asymptomatic subjects without T2D. In each subject, high-resolution ultrasound imaging of the bilateral VNs was performed in the short-axis between the common carotid artery and the internal jugular vein. The VN cross-sectional areas were recorded and compared. In the patients with T2D, HbA1c and fasting blood glucose levels were obtained as well as the duration of T2D in years and correlated with the cross-sectional areas. The bilateral VN cross-sectional areas were similar in both cohorts. Additionally, no correlation was seen between the VN cross-sectional areas, demographics, or clinical data of T2D. Our study demonstrated normal VN cross-sectional areas in patients with T2D without any significant relation with the patients' demographic or clinical data.

Characteristics of diabetic and non-diabetic carpal tunnel syndrome in terms of clinical, electrophysiological, and Sonographic features: a cross-sectional study

BACKGROUND

Although diabetes is considered a major risk factor for carpal tunnel syndrome (CTS), the characteristics of diabetic CTS have not been fully understood.

OBJECTIVE

This study is aimed at evaluation of the clinical, electrophysiological, and ultrasonographic findings of non-diabetic and diabetic CTS.

METHODS

This retrospective, cross-sectional study included patients diagnosed with CTS. Patient age, sex, involved side, body mass index, clinical and electrophysiological findings, and median nerve cross-sectional area (CSA) were identified. Diabetes was identified through patient or guardian interviews, medical records, and medication history. Linear and binary logistic regression models were established to confirm the associations between the electrophysiological findings, median nerve CSA, and clinical outcomes. Covariates, such as age, sex, body mass index, diabetes, symptom duration, and thenar muscle weakness were adjusted.

RESULTS

Out of the 920 hands, 126 and 794 belonged to the diabetic and non-diabetic CTS groups, respectively. The patients were significantly older in the diabetic CTS group (P < 0.001). The rate of thenar weakness in the diabetic CTS group was also significantly higher than that in the non-diabetic CTS group (P = 0.009). The diabetic CTS group had a more severe electrodiagnostic grade (P = 0.001). The prolonged onset latency of the compound motor nerve action potential (CMAP) and median nerve CSA were well associated with the degree of clinical symptoms. Increased median nerve CSA was significantly associated with prolonged CMAP onset latency (β = 0.64; P = 0.012), prolonged transcarpal latency (β = 0.95; P = 0.044), and decreased CMAP amplitude (β = -0.17; P = 0.002) in the non-diabetic CTS group.

CONCLUSION

Diabetic CTS had more profound electrophysiological abnormalities. Distal motor latency and median nerve CSA were not only associated with each other, but also with clinical symptoms. Further studies are needed to investigate the pathophysiological mechanisms underlying diabetic CTS.

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.

The role of ultrasound in determining the presence and severity of carpal tunnel syndrome in diabetic patients

Carpal tunnel syndrome (CTS) is seen in 5% of the population and 14%-30% in diabetics. Although electrophysiological tests are used as the gold standard method in the diagnosis, alternative methods are being studying. We aimed to investigate whether the measurement of median nerve cross-sectional area (CSA) by ultrasound is associated with the presence and severity of CTS. This prospective, cross-sectional observational study includes 128 randomly selected T2DM patients. Electrodiagnostic study was performed for all patients to diagnose CTS. Median nerve CSA were measured with ultrasound examination. The severity of the CTS was determined by Padua method. Among 128 diabetes mellitus (DM) patients, 54 (28%) had CTS and 53 (41%) had diabetic peripheral polyneuropathy. The mean duration of DM was 11.55 years. Median nerve CSAs of the patients were significantly higher in patients with CTS (CTS (-): 10.47 ± 2.67 vs CTS: (+) 12.37 ± 3.17; p < 0.001). Median nerve CSA cutoff value of >10 mm2 predicts the diagnosis of CTS. However, minimal, mild, and moderate CTS groups had similar CSA according to Padua classification (p > 0.05 for all). CSA measurement with ultrasonography can be used as an effective method in diagnosing severe CTS disease. However, median nerve CSA values should not be used to reveal the severity of CTS, in order not to miss the demonstration of minimal, mild, and moderate groups, as well as being an indicator of only the severe CTS group.

Potential Relationships between the Median Nerve Cross-Sectional Area and Physical Characteristics in Unilateral Symptomatic Carpal Tunnel Syndrome Patients

Background: The present study investigated the relationships between the median nerve cross-sectional area (CSA) and physical characteristics in patients with unilateral symptomatic carpal tunnel syndrome (CTS). Methods: Height, weight, body mass index (BMI), disease duration, results of electrodiagnostic testing (EDX), and median nerve CSA at the level of the wrist crease were recorded in 81 patients with CTS who presented with symptoms on only one side. Correlation coefficients between median nerve CSA and physical characteristics, disease duration, and results of EDX were analyzed. Results: Median nerve CSA at the wrist crease (mm2) was significantly larger on the symptomatic side (14.1 ± 3.8) than on the asymptomatic side (11.5 ± 2.9). Median nerve CSA correlated with body weight (correlation coefficient = 0.39) and BMI (correlation coefficient = 0.44) on the asymptomatic side, but not on the symptomatic side. These correlations were slightly stronger in females (correlation coefficient = 0.46) than in males (correlation coefficient = 0.40). No correlations between median nerve CSA and disease duration and the results of EDX were observed in both sides. Conclusions: In patients with unilateral symptomatic CTS, median nerve CSA correlated with BMI only on the asymptomatic side. The present results suggest that the relationship between median nerve CSA and BMI in CTS is significant until symptom onset but may be masked by edema and pseudoneuroma after its onset. A higher BMI is associated with a larger CSA of the median nerve, which may be a risk factor for the development of CTS.

The cross-sectional morphology of median nerve in carpal tunnel of healthy, adult population: A systematic review and meta-analysis

The cross-section area is a crucial parameter to assess peripheral neuropathy. The ultrasonographic evaluation of cross-section area of median nerve is a low-cost and readily available tool for diagnosis and assessment. However, the intra-nerve dimensional variability and its normative reference value in a healthy subject are missing. The current meta-analysis aims to capture the median nerve cross-section area for healthy subjects and generate a comprehensive ultrasonographic reference data set for each population.

METHODS

The full text of manuscripts were collected after short-listing the abstracts collected from search strategy. A quality assurance tool was used to capture the risk of bias of each study after reviewing the included manuscripts. The pooled estimate of cross-section area was stratified according to anatomical landmarks, sex, and ancestry.

RESULTS

A total of 97 observational studies dealt with 6679 wrists of healthy subjects were included. The pooled estimate of the cross-section area of median nerve at carpal tunnel inlet was 8.54mm² [95% CI: 8.34-8.74mm²]. The same pooled estimate at carpal tunnel outlet was 8.03mm² [95% CI: 7.46-8.60mm²]. Both these pooled estimates have significant correlation with mean age of population. Age and sex were two primary predictors of the cross-section of median nerve. The flattening ratio, circularity, and wrist-forearm ratio of median nerve were also computed.

CONCLUSION

These normative data could serve as a reference for assessing median nerve pathologies, including carpal tunnel syndrome. The ethnic variation of pooled estimate and heterogeneity will guide clinician set up the reference value for diagnostic criteria.

The Interaction of Diabetic Peripheral Neuropathy and Carpal Tunnel Syndrome

BACKGROUND

Diabetes mellitus (DM) increases the risk for carpal tunnel syndrome (CTS) and is associated with its own neuropathic complications. Diabetic peripheral neuropathy (DPN) is a common complication seen in diabetic patients. In this study, we examine the relationship between the severity of DPN and CTS.

METHODS

Type 2 diabetic and control patients (n = 292) were recruited at a clinic visit. The Michigan Neuropathy Screening Instrument (MNSI) questionnaire was used to collect data related to peripheral neuropathy. The MNSI scores were compared for patients with CTS with and without DM in univariable and multivariable analyses. χ2 analyses were performed to quantitatively measure the associations between peripheral neuropathy and the presence of CTS.

RESULTS

Of the 292 patients, 41 had CTS, and 19 of these had both CTS and DM. Of the 138 diabetic patients, 85 had peripheral neuropathy. There was no association between a diagnosis of CTS and an MNSI score indicative of peripheral neuropathy. In the diabetic population, CTS was inversely associated with DPN (P = .017). The MNSI scores between diabetic and control patients with CTS were comparable.

CONCLUSION

The severity of peripheral neuropathy in diabetic patients with and without CTS is comparable. Diabetic patients without peripheral neuropathy have an association with higher incidence of CTS in this study, suggesting that there are disparate mechanisms causing DPN and CTS. Nevertheless, diabetes and CTS are risk factors for developing the other, and future studies should further explore how DPN and CTS differ to tailor patient interventions based on their comorbidities.

Mega Nerves: Factors Associated with Large Median Nerves on Ultrasound of the Carpal Tunnel

Although increased cross-sectional area of the median nerve on ultrasound has been associated with carpal tunnel syndrome, there has been little research examining outlier cases with exceedingly large nerves. The purpose of this study was to identify factors associated with these "mega" nerves, and to determine whether these nerves carry with them increased severity of disease.

Methods

Patients who presented to clinic with upper extremity paresthesias over a 4-year period were included in this study. Two groups were created: mega nerves (cross-sectional area >2 SD above average), and nonmega nerves. Statistical analysis was performed to compare demographics, symptom scores, and nerve conduction studies (NCS). Significant variables were then compared between patients with mega nerves and those with ultrasound positive nerves (≥10 mm²), which did not reach mega size (normal nerves were excluded).

Results

The cohort included 425 median nerves with 25 mega nerves. The groups differed significantly in diabetes status, body mass index (BMI), Boston Carpal Tunnel Questionnaire (BCTQ) Symptom Severity Scale scores, and NCS results. When compared only with ultrasound positive but nonmega nerves, mega nerves were still associated with diabetes, higher BMI, and worse NCS results.

Conclusions

Diabetes, BMI, NCS results, and BCTQ Symptom Severity Scale scores are associated with mega nerves. However, BCTQ scores do not differ between mega nerves and other ultrasound positive nerves. In patients with obesity or diabetes, outlier ultrasound measurements may not correlate with worsened clinical symptoms, even in the setting of more significantly altered NCS results.

Electrodiagnostic Testing and Nerve Ultrasound of the Carpal Tunnel in Patients with Type 2 Diabetes

In diabetic patients, controversies still exist about the validity of electrodiagnostic and nerve ultrasound diagnosis for carpal tunnel syndrome (CTS). We analyzed 69 patients with type 2 diabetes. Nerve conduction studies and peripheral nerve ultrasound of the median nerve over the carpal tunnel were performed. CTS symptoms were assessed using the Boston Carpal Tunnel Questionnaire. Polyneuropathy was assessed using the Neuropathy Symptom Score and the Neuropathy Disability Score. Although 19 patients reported predominantly mild CTS symptoms, 37 patients met the electrophysiological diagnosis criteria for CTS, and six patients were classified as severe or extremely severe. The sonographic cross-sectional area (CSA) of the median nerve at the wrist was larger than 12 mm² in 45 patients (65.2%), and the wrist-to-forearm-ratio was larger than 1.4 in 61 patients (88.4%). Receiver operating characteristic analysis showed that neither the distal motor latency, the median nerve CSA, nor the wrist-to-forearm-ratio could distinguish between patients with and without CTS symptoms. Diagnosis of CTS in diabetic patients should primarily be based upon typical clinical symptoms and signs. Results of electrodiagnostic testing and nerve ultrasound have to be interpreted with caution and additional factors have to be considered especially polyneuropathy, but also body mass index and hyperglycemia.

High-resolution neuromuscular ultrasound-based diagnosis of carpal tunnel syndrome in a sample of Egyptian population

Background

Carpal tunnel syndrome is the commonest entrapment neuropathy. The cut-off point of cross-sectional area to diagnose carpal tunnel syndrome may vary among populations. The objective of this study was to determine the best cut-off point of median nerve cross-sectional area to diagnose carpal tunnel syndrome among Egyptian population and to compare the difference of median nerve cross-sectional area in diabetic patients versus healthy individuals.

Results

Mean cross-sectional area was 7.78 ± 1.260 mm2 among healthy individuals and 8 ± 1.018 mm2 among diabetics. Cut-off cross-sectional area of median nerve above which compression is anticipated is 9.5 mm2.

Conclusion

Ultrasound can be used to diagnose carpal tunnel syndrome by measuring the median nerve cross-sectional area.

Quantitative assessment of intraneural vascular alterations in peripheral nerve trauma using high-resolution neurosonography: technical note

High-resolution neurosonography (HRNS) has become a major imaging modality in assessment of peripheral nerve trauma in the recent years. However, the vascular changes of traumatic lesions have not been quantitatively assessed in HRNS. Here, we describe the vascular-ratio, a novel HRNS-based quantitative parameter for the assessment of intraneural vascular alterations in patients with nerve lesions. N = 9 patients suffering from peripheral nerve trauma were examined clinically, electrophysiologically and with HRNS (SonoSite Exporte, Fuji). Image analyses using Fiji included determination of the established fascicular ratio (FR), the cross-section ratio (CSR), and as an extension, the calculation of a vascular ratio (VR) of the healthy versus damaged nerve and a muscle perfusion ratio (MPR) in comparison to a healthy control group. The mean VR in the healthy part of the affected nerve (14.14%) differed significantly (p < 0.0001) from the damaged part (VR of 43.26%). This coincides with significant differences in the FR and CSR calculated for the damaged part versus the healthy part and the controls. In comparison, there was no difference between VRs determined for the healthy part of the affected nerve and the healthy controls (14.14% / 17.72%). However, the MPR of denervated muscles was significantly decreased compared to the non-affected contralateral controls. VR and MPR serve as additional tools in assessing peripheral nerve trauma. Image analysis and calculation are feasible. Combined with the more morphologic FR and CSR, the VR and MPR provide a more detailed insight into alterations accompanying nerve trauma.

STUDY OF EFFICIENCY OF SURGICAL TREATMENT OF TUNNEL NEUROPATHY OF THE UPPER EXTREMITY AT ELDERLY PATIENTS

The research objective are the assessment and increase in efficiency of treatment of tunnel neuropathy of the upper extremities at patients aged from 60 years and also more senior.Material and methods - the examination and the subsequent treatment of 115 patients of age category 60 years and more senior with compression pathology of nerves of the upper extremity. Diagnostic process included clinical examination, an ultrasonography, an electroneuromyography (EMG).Results - total number of cases of neuropathy is 140 at 115 patients due to the multiple combined compression of nerves in several channels in 25 cases. All patients included in a research had performed open decompression of a nerve . The excellent result was received at 32 (27.8%) patients, good - in 68 (59.1%) cases, satisfactory - at 13 (11.3%) patients, unsatisfactory - at 2 (1.7%) patients.The conclusion - expeditious treatment of tunnel neuropathy at elderly patients allows to improve quality of life of patients and gives low level of complications.

Optimal Ultrasonographic Measurements for Diagnosing Carpal Tunnel Syndrome in Patients With Diabetic Sensorimotor Polyneuropathy: A Case-Control Study

Objective

To investigate the optimal sonographic method for diagnosing carpal tunnel syndrome (CTS) in patients with diabetic sensorimotor polyneuropathy (DSP).

Methods

A total of 190 participants were divided into four groups based on DSP history and electrodiagnostic results of CTS. The absolute parameters were measured at baseline and the relative values were calculated: maximal cross-sectional area (CSA) of the median nerve throughout the carpal tunnel (Mmax), median nerve CSA at the forearm level (Mf), ulnar nerve CSA at the pisiform level (Upi), difference between Mmax and Mf (∆MM), and difference between Mmax and Upi (∆MU). Then, the optimal ultrasonographic parameters for diagnosing CTS, according to the presence of DSP, using absolute and relative cutoff values were analyzed.

Results

Median and ulnar nerve CSAs were significantly larger in the DSP group than in the control group. In the DSP participants, the mean Mmax, ∆MM, and ∆MU values were significantly larger in patients with both DSP and CTS than in patients with DSP only. The Mmax thresholds of 9.5 mm² in the control group and 11.5 mm² in the DSP group showed the greatest sensitivity and specificity for diagnosing CTS. The ∆MM thresholds of 2.5 mm² and ∆MU thresholds of 4.5 mm² had the greatest sensitivity and specificity in both the DSP and control groups.

Conclusion

Measurement of Mmax, ∆MM and ∆MU is an optimal ultrasonographic evaluation method for diagnosing CTS in patients with DSP.

Can ultrasound imaging be used for the diagnosis of carpal tunnel syndrome in diabetic patients? A systemic review and network meta-analysis

BACKGROUND

High-resolution ultrasound (US) becomes a reliable tool for diagnosing carpal tunnel syndrome (CTS), but whether it can be applied to patients with preexisting diabetes mellitus (DM) remains unclear.

METHODS

We searched PubMed and Embase and systemically reviewed studies exploring the median nerve CSAs at the wrist level by US imaging. Nine studies enrolling at least one subgroup comprising patients with both DM and CTS were included for network meta-analysis. The primary outcome was the inter-group difference of the wrist-level median nerve CSA.

RESULTS

The median nerve size at the wrist level was larger in patients with only CTS than in patients with only DM [CSA difference = 3.14 mm², 95% confidence interval (CI) 1.92-4.35]. Patients with DM and CTS had a slightly enlarged median nerve CSA than did patients with only CTS, but the difference was not statistically significant (0.52 mm², 95% CI - 0.54 to 1.59). According to rank probabilities, median nerve CSAs in patients with DM and CTS were likely to be ranked as the largest, followed by patients with only CTS, patients with only DM, and healthy controls. Furthermore, median nerve CSAs seemed smaller in patients with than without diabetic polyneuropathy.

CONCLUSIONS

Although DM causes swelling of the median nerve at the wrist level, patients with CTS have a larger CSA regardless of preexisting DM. The add-on effect of DM on median nerve CSAs in patients with CTS is limited. Diabetic polyneuropathy tends to result in less swollen median nerves in the CTS population.

Medical Ultrasound in the Evaluation of the Carpal Tunnel: A Critical Review

The use of medical ultrasound as an imaging modality in the evaluation of the carpal tunnel syndrome has been growing. Technical progress and the introduction of new, high-quality devices and ultra-high frequency transducers with smaller dimensions have led to a better quality of acquired images and the development of new examination methodologies. The sonographic method has a number of advantages: available, non-invasive, cheaper, and allows an easier and faster evaluation and diagnosis of carpal tunnel syndrome, along with the possibility to assess various parameters of the median nerve, including its size, blood flow, and mobility. In addition, medical ultrasound may be used to detect anatomical variations and space-occupying lesions in the carpal tunnel to monitor the therapeutic response in patients suffering from carpal tunnel syndrome and to evaluate median nerve injuries. Herein, we present a review of the pertinent literature with regard to the diagnostic potential of medical ultrasound in the evaluation of pathological changes in the carpal tunnel.