Nerve Cross-sectional Area Research Articles

Diagnostic accuracy of nerve ultrasonography for the detection of peripheral neuropathy in type 2 diabetes.

Nerve conduction studies (NCS) are the current objective measure for diagnosis of peripheral neuropathy in type 2 diabetes but do not assess nerve structure. This study investigated the utility of peripheral nerve ultrasound as a marker of the presence and severity of peripheral neuropathy in type 2 diabetes. A total of 156 patients were recruited, and nerve ultrasound was undertaken on distal tibial and distal median nerves. Neuropathy severity was graded using the modified Toronto Clinical Neuropathy Scale (mTCNS) and Total Neuropathy Score (TNS). Studies were undertaken by a single ultrasonographer blinded to nerve conduction results. A stepwise increase in tibial nerve cross-sectional area (CSA) was noted with increasing TNS grade (p< 0.001) and each mTCNS quartile (p< 0.001). Regression analysis demonstrated a correlation between tibial nerve CSA and neuropathy severity (p< 0.001). Using receiver operator curve analysis, tibial nerve CSA of >12.88 mm yielded a sensitivity of 70.5% and specificity of 85.7% for neuropathy detection. Binary logistic regression revealed that tibial nerve CSA was a predictor of abnormal sural sensory nerve action potential amplitude (odds ratio=1.239, 95% confidence interval [CI]=1.142-1.345) and abnormal neuropathy score (odds ratio=1.537, 95% confidence interval [CI]=1.286-1.838). Tibial nerve ultrasound has good specificity and sensitivity for neuropathy diagnosis in type 2 diabetes. The study demonstrates that tibial nerve CSA correlates with neuropathy severity. Future serial studies using both ultrasound and NCS may be useful in determining whether changes in ultrasound occur prior to development of nerve conduction abnormalities and neuropathic symptoms.

Morphological Changes of Medial Epicondyle-Olecranon Ligament and Ulnar Nerve in the Cubital Tunnel Syndrome: An Ultrasonic Study.

ObjectiveFew studies have performed detailed ultrasound measurements of medial epicondyle‐olecranon (MEO) ligament that cause the entrapment of ulnar nerve. This study aims to comprehensively evaluate dynamic ultrasonographic characteristics of MEO ligament and ulnar nerve for clinical diagnosis and accurate treatment of cubital tunnel syndrome (CuTS).MethodsThirty CuTS patients (CuTS group) and sixteen healthy volunteers (control group) who underwent ultrasound scanning from October 2016 to October 2020 were retrospectively collected, with 30 elbows in each group. Primary outcomes were thickness at six points, length and width of MEO ligament. Secondary outcomes were thickness of ulnar nerve under MEO ligament at seven parts and the cross‐sectional area (CSA) of ulnar nerve at proximal end of MEO ligament (P0 mm). The thickness of MEO ligament and ulnar nerve in different points of each group was compared by one‐way ANOVA analysis with Bonferroni post hoc test, other outcomes were compared between two elbow positions or two groups using independent‐samples t test.ResultsThickness of MEO ligament in CuTS group at epicondyle end, midpoint in transverse view, olecranon end, proximal end, midpoint in axial view, and distal end was 0.67 ± 0.31, 0.37 ± 0.18, 0.89 ± 0.35, 0.39 ± 0.21, 0.51 ± 0.38, 0.36 ± 0.25 at elbow extension, 0.68 ± 0.34, 0.38 ± 0.27, 0.77 ± 0.39, 0.32 ± 0.20, 0.48 ± 0.22, 0.32 ± 0.12 (mm) at elbow flexion, respectively. Compared with control group, they were significantly thickened except for proximal end at elbow flexion. MEO ligament thickness at epicondyle end and olecranon end was significantly larger than midpoint in two groups. No significant difference was found in length and width of MEO ligament among different comparisons. Ulnar nerve thickness at 5 mm proximal to MEO ligament (P5 mm, 3.25 ± 0.66 mm) was significantly increased than midpoint of MEO ligament (Mid), distal end of MEO ligament (D0 mm), 5 mm (D5 mm), 10 mm (D10 mm) distal to MEO ligament at extension in CuTS group. Compared with control group, ulnar nerve thickness at P5 mm in CuTS group was significantly increased at extension position, at D5 mm and D10 mm was significantly decreased at flexion position. CSA of ulnar nerve at extension position (14.44 ± 4.65 mm2) was significantly larger than flexion position (11.83 ± 3.66 mm2) in CuTS group, and CuTS group was significantly larger than control group at two positions.ConclusionsMEO ligament in CuTS patients was thickened, which compressed ulnar nerve and caused its proximal end swelling. Ultrasonic image of MEO ligament thickness was a significant indicator for CuTS and can guide surgeons in selecting the appropriate treatment.

Ultrasonographic Evaluation of Ulnar Neuropathy at the Elbow: A Systematic Review and Meta-Analysis

Background: Several studies have aimed to discuss the Ultrasonographic (US) findings in the assessment of ulnar neuropathy at elbow; however, the current data are widely heterogeneous and it seems necessary to summarize the original studies to reach a consensus. The goal of this study was to conduct a systematic review on the ultrasound measurements of ulnar nerve cross-sectional area at the elbow among patients with definite diagnosis of ulnar neuropathy.
 Methods: The global databases including Medline, Web of Science, Cochrane Library, Google Scholar, and Scopus were deeply evaluated for all eligible English studies. Among the 343 initially retrieved articles, 31 studies met the eligibility criteria and were published from 2000 April to 2019 December. After excluding the non-eligible articles, 18 manuscripts were systematically reviewed with the goal of assessing Cross-Sectional Area (CSA) at different levels regarding the elbow using different techniques and by various types of transducer ranged from 4-18 MHZ. Data extraction was independently performed by two reviewers on some structured data-collection forms.
 Results: The summary of following details were systematically reviewed for the included studies: technique of US measurement and type of transducer, as well as cut-off value and diagnostic capability of the ultrasonography. The collected data were analyzed in STATA software using random or fixed-effect models, as effect size measures such as raw or standardized mean differences (MD or SMD).
 Conclusion: In the current meta-analysis, it was proved that ultrasound could be a suitable device to diagnose ulnar neuropathy at elbow, with acceptable sensitivity (72.0-76.1%) and specificity (76.1-81.8%) values.

Ultrasound Findings in Patients with Normal Nerve Conduction despite Clinical Signs and Symptoms Consistent with Carpal Tunnel Syndrome.

Confirmatory methods such as nerve conduction studies are often performed to support a clinical carpal tunnel syndrome diagnosis and to rule out other upper extremity pathologies. Ultrasonography provides another diagnostic option, especially when nerve conduction studies are discordant with history and physical examination. The authors explored the correlation of ultrasound findings with clinical carpal tunnel syndrome diagnosis in patients with normal nerve conduction study results. A database of 220 patients with carpal tunnel syndrome was analyzed retrospectively to reveal 24 patients (28 hands) with a clinical diagnosis and normal nerve conduction study results. Patient demographics and nerve conduction study and ultrasound findings were compared with those of a control group of patients without carpal tunnel syndrome (42 patients, 52 hands). Median nerve cross-sectional area was recorded; values of 10 mm 2 or greater were considered positive for carpal tunnel. Statistical and correlation analyses were performed between control and carpal tunnel groups comparing key measures of interest. Mean cross-sectional area was significantly increased in patients with carpal tunnel syndrome with normal nerve conduction study results compared with controls. The proportion of carpal tunnel-positive, nerve conduction study-negative patients with cross-sectional area measurements greater than 10 mm 2 was significantly greater than the proportion for control patients. Neither age nor body mass index correlated with cross-sectional area measurements. Nerve conduction study latencies and amplitudes did not correlate with ultrasound abnormalities. Patients diagnosed clinically with carpal tunnel syndrome with normal nerve conduction study results were found to have clinically significant median nerve cross-sectional area on ultrasound (10.1 ±2.1 mm 2 , p < 0.001). Cross-sectional area measurements on ultrasound did not correlate with nerve conduction study measures. These results suggest that ultrasound holds a unique diagnostic utility in the evaluation of carpal tunnel syndrome, especially when nerve conduction studies are negative. Diagnostic, II.

Peripheral Nerve Involvement at First Diagnosis of Multiple Sclerosis: A Prospective MR Neurography Study.

The aim of this study was to assess peripheral nerve involvement in patients with multiple sclerosis (MS) at first clinical presentation using quantitative magnetic resonance (MR) neurography in correlation with clinical, laboratory, electrophysiological, and central nervous MR imaging data. In this prospective monocentric study, 30 patients first diagnosed with MS according to the McDonald criteria (19 women; mean age, 32.4 ± 8.8 years) and 30 age- and sex-matched healthy volunteers were examined with high-resolution 3 T MR neurography using a dual-echo T2-relaxometry sequence covering the tibial and peroneal nerves from proximal thigh to distal calf. Magnetic resonance biomarkers of T2 relaxation time (T2 app ), proton spin density (PSD), and nerve cross-sectional area (CSA) were correlated with clinical symptoms, intrathecal immunoglobulin (Ig) synthesis, nerve conduction study, and lesion load on brain and spine MR imaging. The diagnostic accuracy of MR biomarkers was assessed using receiver-operating characteristic curves. Diffuse nerve changes were detected along the tibial and peroneal nerves in MS patients, who showed decreased PSD ( P < 0.001), increased T2 app ( P < 0.001), and smaller tibial nerve CSA ( P < 0.001) compared with healthy subjects. Tibial PSD was identified as best parameter separating patients from controls (area under the curve = 0.876). Intrathecal IgG and IgM synthesis correlated with PSD values ( r = -0.44, P = 0.016, and r = -0.42, P = 0.022). Contrast-enhancement of brain or spine lesions was related to larger tibial and peroneal CSA ( P < 0.001, P = 0.033). Abnormal electrophysiology correlated with higher tibial and peroneal T2 app ( P < 0.001 and P = 0.033), lower tibial and peroneal PSD ( P = 0.018 and P = 0.002), and smaller peroneal CSA ( P < 0.001). Quantitative MR neurography reveals peripheral nerve changes in patients with initial diagnosis of MS. Correlation of imaging findings with intrathecal immunoglobulin synthesis may indicate a primary coaffection of the peripheral nervous system in MS.

Normative Value of the Cross-Sectional Area of the Median Nerve at the Carpal Tunnel Inlet and Distal Forearm in the Singapore Population.

Background: Ultrasonography is often used in the diagnosis of carpal tunnel syndrome (CTS). However, we were unable to find normative data regarding the cross-sectional area (CSA) of the median nerve in the Singapore population as measured by ultrasound. The aims of this study were to establish normative values of the CSA of the median nerve at the carpal tunnel inlet in a healthy population, 5 cm proximal to the carpal tunnel inlet, and to determine if the CSA correlated with side, age, gender or race. Methods: Sixty-nine wrists of 36 healthy subjects with no history of wrist injury or any signs and symptoms of CTS were examined. The CSA of the median nerve at the carpal tunnel inlet and 5 cm proximal to the carpal tunnel inlet was determined using ultrasound by a trained operator. Results: The mean CSA of the median nerve at the carpal tunnel inlet was 6.41 mm2 (SD 2.18 mm2). These were not significantly different from the values for mean CSA obtained 5 cm proximal to the carpal tunnel inlet. We did not find any correlation between the CSA of the median nerve and age, gender or race. Conclusions: The mean CSA of the median nerve at the carpal tunnel inlet in normal subjects in Singapore was found to be lower than other Asian populations. Wide variations of the median nerve CSA at the carpal tunnel inlet exists in the literature, and this is probably due to the heterogeneity of the study methodology and population. Level of Evidence: Level III (Diagnostic).

Nerve Sonography in Charcot-Marie-Tooth Disease: A Systematic Review and Meta-analysis of 6061 Measured Nerves.

Because of the insidious character and variations in presenting symptoms, Charcot-Marie-Tooth (CMT) disease is challenging to diagnose in children. Diagnosis is based on clinical and nerve conduction studies, as well as genetic examination. Therefore, competent nerve imaging techniques and non-invasive alternatives to nerve conduction studies are a necessity, especially in children. We performed a systematic review and meta-analysis to evaluate the current evidence and effectiveness of ultrasound in investigating nerve cross-sectional area (CSA) in those with CMT compared with healthy controls and to pool the CSA measurements. We included studies published in international peer-reviewed journals that measured nerve CSA by ultrasound in patients with CMT. We implemented double-arm meta-analyses to compare the mean CSA of nerves between patients with CMT and healthy controls by calculating the pooled mean difference in CSA. Moreover, we performed subgroup analyses by stratifying the studies according to the site of CSA measurement and examined the difference in nerve CSA between CMT1A and other CMT types. The included studies provide measurements of 12 nerve roots and nerves (vagus, C3, C4, C5, C6, greater auricular, phrenic, median, ulnar, fibular, tibial and sural nerves) in 628 patients with CMT and 586 healthy controls with a total of 6061 measured nerves. Meta-analyses of sonographic nerve CSA are provided to express nerve ultrasonography in the diagnosis of CMT patient.

Efficacy of leupeptin in treating ischemia in a rat hind limb model.

Prolonged tourniquet use can lead to tissue ischemia and can cause progressive muscle and nerve injuries. Such injuries are accompanied by calpain activation and subsequent Wallerian‐like degeneration. Several known inhibitors, including leupeptin, are known to impede the activity of calpain and associated tissue damage. We hypothesize that employment of leupeptin in a rat model of prolonged hind limb ischemia can mitigate muscle and nerve injuries. Sprague–Dawley rats (n = 10) weighing between 300–400 g were employed in this study. Their left hind limbs were subjected to blood flow occlusion for a period of 2‐h using a neonatal blood pressure cuff. Five rats were given twice weekly intramuscular leupeptin injections, while the other five received saline. After 2 weeks, the animals were euthanized, their sciatic nerves and gastrocnemius muscles were harvested, fixed, stained, and analyzed using NIH Image J software. The administration of leupeptin resulted in larger gastrocnemius muscle fiber cross‐sectional areas for the right (non‐tourniquet applied) hindlimb as compared to that treated with the saline (p = 0.0110). However, no statistically significant differences were found between these two groups for the injured left hindlimb (p = 0.1440). With regards to the sciatic nerve cross‐sectional areas and sciatic functional index, no differences were detected between the leupeptin and control treated groups for both the healthy and injured hindlimbs. This research provides new insights on how to employ leupeptin to inhibit the degenerative effects of calpain and preserve tissues following ischemia resulting from orthopedic or plastic surgery procedures.

Reference Values for the Cross Sectional Area of Normal Tibial Nerve on High-resolution Ultrasonography.

The aim of the study was to establish reference values for the cross-sectional area of the tibial nerve on high-resolution ultrasonography and to investigate the relationship between the cross-sectional area of the tibial nerve and subject's age, gender, height (in cm), weight (in kg) and body mass index. Two hundred subjects of either gender and over 18 years of age with no history of peripheral neuropathy or trauma to the lower limb were evaluated with high-resolution ultrasonography. Mean cross-sectional areas of tibial nerves were measured at two different levels in both lower limbs, first at 1 cm below the bifurcation of the sciatic nerve into tibial and common peroneal nerves (level I) and the second at 1 cm superior and posterior to the medial malleolus (level II). The mean cross-sectional area measured at level I (0.196 + 0.014 cm2) was larger than the one measured at level II (0.111 ± 0.011 cm2). A positive correlation was found between the mean cross-sectional area and height, weight, and body mass index (p <0.05). Women had smaller cross-sectional areas of the tibial nerves than men at both sites. In addition, no significant relationship was found with the age of the subjects (p >0.05). The established reference values of the cross-sectional area of the tibial nerve will aid in early diagnosis of peripheral neuropathy.

Sonographic Changes in the Median Nerve Predict Conversion to Surgery after Corticosteroid Injection of the Carpal Tunnel.

Risk factors for conversion to surgical management of moderate severity carpal tunnel syndrome are poorly understood. The authors hypothesized that sonographic findings along the carpal tunnel could predict failure of conservative management for carpal tunnel syndrome. The authors report on 96 wrists with moderate clinical signs and symptoms of carpal tunnel syndrome. Sonographic evaluation with measurement of median nerve cross-sectional area was performed at three consistent anatomic locations. The authors recorded median nerve morphology, inlet and outlet dimensions of the carpal tunnel, and maximal thickness of the transverse carpal ligament. Steroid injection was performed. Patients were followed up for a minimum of 1 year after injection and progression to surgical management was recorded. A total of 54 percent ( n = 52) of patients converted to surgical management within 1 year after injection. Median nerve cross-sectional area decreased over the course of the carpal tunnel from proximal to distal in 81 of 96 wrists. A greater decrease in cross-sectional area of the median nerve between the pisiform and the hamate was associated with conversion to operative intervention for carpal tunnel syndrome, with the average decrease in median nerve cross-sectional area among those whose conservative treatment failed being 5.01 mm 2 compared with 2.97 mm 2 among those who did not progress to surgical treatment. This study demonstrates that ultrasound may be an additional tool used by clinicians to better counsel patients about the severity and progression of their disease. Patients who demonstrate a decrease in cross-sectional area of the median nerve along the carpal tunnel demonstrate a higher likelihood of progression to operative management. Risk, III.

Changes in tibial nerve stiffness during ankle dorsiflexion according to in-vivo analysis with shear wave elastography.

A more detailed assessment of pathological changes in the tibial nerve (TN) is needed to better assess how physical therapy influences TN pathologies. The cross-sectional nerve area can be used for TN assessment but may be influenced by individual differences in parameters, such as body height, body weight, and foot length. Therefore, there are no known reliable noninvasive quantitative methods for assessing TN neuropathy. Although recent ultrasonographic studies reported that TN stiffness changes could be used to assess TN neuropathies of the foot, these studies did not consider the joint position, and peripheral nerve tension can change with joint movement. Therefore, we considered that TN stiffness assessment could be improved by analyzing the relationship between ankle joint position and TN stiffness. This study aimed to investigate the relationship between TN stiffness and ankle angle changes using shear wave elastography. We hypothesized that the TN shear wave velocity significantly increases with ankle dorsiflexion and that the total ankle range or maximum dorsiflexion range correlates with the shear wave velocity.This cross-sectional study included 20 TNs of 20 healthy adults. Ultrasonography and shear wave elastography were used to evaluate the TN. TN stiffness was measured at 5 ankle positions as follows: maximum dorsiflexion (100% df), plantar flexion in the resting position (0% df), and 3 intermediate points (25% df, 50% df, and 75% df).TN shear wave velocity increased with an increase in ankle df angle. While total ankle range was significantly and negatively correlated with TN stiffness in all ankle positions, the maximum ankle df angle was significantly and negatively correlated only at 75% and 100% df.TN stiffness below 50% df may be affected by gliding or decreased nerve loosening, and TN stiffness above 75% df may be influenced by nerve tensioning. When measuring TN stiffness for diagnostic purposes, TN should be assessed at an ankle joint angle below 50% df.

The Correlation of Carpal Tunnel Pressure with Clinical Outcomes following Ultrasonographically-Guided Percutaneous Carpal Tunnel Release.

Background: To evaluate the correlation between carpal tunnel pressure (CTP) and the clinical presentations, and to explore the possible predictors for the postoperative recovery pattern in patients with carpal tunnel syndrome (CTS). Materials and Methods: Consecutive patients with idiopathic CTS following percutaneous ultrasound-guided carpal tunnel release (UCTR) were enrolled. CTP was measured preoperatively and immediately after operation. The Boston Carpal Tunnel Questionnaire (BCTQ) and the cross-sectional area (CSA) of median nerve were recorded preoperatively and at 1, 3, and 12 months postoperatively. Results: 37 patients (37 hands; 8 men and 29 females; median age, 59.0 years) were enrolled. CTP significantly decreased immediately from 40.0 (28.0–58.0) to 13.0 (8.0–20.0) mmHg after UCTR. BCTQ scores significantly improved at 1 month postoperatively, and the improvement trend persisted until 12 months postoperatively (p < 0.001). Preoperative CTP was positively correlated with preoperative CSA and preoperative BCTQ scores (p < 0.05, all). Using group-based trajectory modeling, all patients were categorized into the “gradual recovery” or “fast recovery” group. Higher preoperative CTP was significantly associated with a faster recovery pattern (odds ratio: 1.32). Conclusions: Preoperative CTP was well correlated with the clinical presentations and might be a useful predictor for the postoperative clinical recovery pattern.

Nerve Ultrasound Findings in Carpal Tunnel Syndrome and its Correlation with Clinical and Electrophysiological Data

Background: Sonologic evaluation of the median nerve has been shown to be a useful tool in carpal tunnel syndrome diagnosis. Neurosonology supplants clinical and electrodiagnostic work up. Objectives: To determine the median nerve ultrasound parameters in carpal tunnel syndrome (CTS) patients and find their correlation with patient reported clinical data and electrophysiology findings,to assess diagnostic accuracy of nerve ultrasound in CTS in comparison to clinical evaluation combined with electrodiagnosis as reference standard. Methods: 23 consecutive patients with carpal tunnel syndrome symptoms (46 wrists-35 with nerve conduction study confirmed CTS, 11 without CTS) underwent neurosonologic evaluation with high resolution ultrasound including median nerve cross sectional area(CSA) at carpal tunnel inlet, flattening ratio, Wrist/forearm CSA ratio measurements. Patient reported measures were recorded using Boston carpal tunnel syndrome questionnaire (BCTQ). Results: Statistically significant correlation was found between median nerve CSA at carpal tunnel inlet and disease severity assessed by electrodiagnosis (r=0.545, p value-0.002), hand function status had significant correlation with electrodiagnostic severity class (r=0.422, p value 0.012). Flattening ratio, Wrist/forearm CSA ratio did not show significant correlation with clinical and electrophysiology measures. Sensitivity and specificity for a cross sectional area cut off of 9 cm2 for diagnosis of CTS was found to be 85.7 percent and 64 percent respectively. Conclusion: Median nerve cross sectional area CSA measurement is the most useful neurosonologic parameter and correlates with electrodiagnostic severity. Ultrasound is a useful complementary tool for CTS diagnosis, assessment alongside electrodiagnosis. Keywords: Carpal Tunnel Syndrome, Neurosonology, Compression neuropathy

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.

Effect of Perineural Dextrose Injection on Ulnar Neuropathy at the Elbow: A Randomized, Controlled, Double-Blind Study

ObjectiveTo compare perineural dextrose injection efficacy in the treatment of ulnar neuropathy at the elbow with a control group. DesignProspective double-blind randomized control study. SettingTraining and research hospital. ParticipantsThe study was completed with 40 patients with ulnar neuropathy at the elbow. InterventionNormal saline (0.9% sodium chloride) was injected in patients in the control group (n=20; mean age=38.1±10.7 years; median duration of symptoms=4.5 months), and 5% dextrose was injected in patients in the dextrose group (n=20; mean age=43.6±13.5 years; median duration of symptoms=5 months), perineurally under ultrasound guidance twice at 2-week intervals. Ultrasound-guided perineural injection of 1 cc each was administered into the ulnar nerve, 2 cm and 4 cm distal to the medial epicondyle, at the level of the medial epicondyle, and 2 cm and 4 cm proximal to the medial epicondyle. The amount of total fluid injected was 5 cc. Main Outcome Measure(s)At baseline and weeks 2, 4, and 12, the patients were evaluated with the Visual Analog Scale for pain and the Disabilities of the Arm Shoulder and Hand questionnaire for disability. Electrophysiological evaluation was performed with ulnar nerve conduction studies, and the ulnar nerve cross-sectional area was measured on ultrasonography. ResultsThe improvements in pain, disability, ulnar motor nerve velocity, and ulnar nerve cross-sectional area in the dextrose group were superior to those in the control group, especially at weeks 4 and 12 (P<.001, using independent samples t tests). ConclusionPerineural 5% dextrose may be an effective alternative therapy for those with ulnar neuropathy at the elbow for up to the 12th week.

A systematic review: normative reference values of the median nerve cross-sectional area using ultrasonography in healthy individuals

Median nerve cross-sectional area (CSA) was used for screening and diagnosis of neuropathy, but few studies have suggested reference range. Hence, this systematic review was performed to evaluate a normative values of median nerve CSA at various landmarks of upper limb based on ultrasonography. PubMed and Web of science were used to search relevant articles from 2000 to 2020. Forty-one eligible articles (2504 nerves) were included to access median nerve CSA at different landmarks (mid-arm, elbow, mid-forearm, carpal tunnel (CT) inlet and CT outlet). Data was also stratified based on age, sex, ethnicity, geographical location, and method of measurement. Random effects model was used to calculate pooled weighted mean (95% confidence interval (CI), [upper bound, lower bound]) at mid-arm, elbow, mid-forearm, CT inlet and outlet which found to be 8.81 mm2, CI [8.10, 9.52]; 8.57 mm2 [8.00, 9.14]; 7.07 mm2 [6.41, 7.73]; 8.74 mm2 [8.45, 9.03] and 9.02 mm2 [8.08, 9.95] respectively. Median nerve CSA varies with age, geographical location, and sex at all landmarks. A low (I2 < 25%) to considerable heterogeneity (I2 > 75%) was observed, indicating the variation among the included studies. These findings show that median nerve CSA is varying not only along its course but also in other sub-variables.

Nerve high-resolution ultrasound in a 2-year follow-up of radial nerve palsy related to humeral shaft fractures.

High-resolution nerve ultrasonography (HRUS) could have an emerging importance in diagnosis and follow-up of axonopathic radial palsy associated with humeral shaft fractures due to closed trauma. The aim of our study was to establish the role of HURS in this context through a longitudinal multimodal analysis. Clinical, electrodiagnostic (EDX) and HRUS evaluations were prospectively performed at month 1, 3, 6, 12 and 24 from injury, in a continuous series of 19 patients collected in a 5-year study. Clinical severity was scored on MRC of involved muscles, EDX on presence/absence of functional continuity; anatomical continuity and nerve cross sectional area (NCSA) of radial (RN) and posterior interosseus (PIN) nerves were evaluated through HRUS. All patients showed clinical improvement during follow-up; EDX functional continuity was reached by all patients within 12 months; HRUS revealed RN anatomical continuity in all patients and PIN involvement in 74%. RN NCSA progressively reduced during FU, but it was still significantly higher than contralateral at month 24; PIN NCSA became normal within 24 months. When anatomical RN continuity is confirmed by HRUS, good functional outcome is reached even in patients with EDX loss of functional continuity. Together with clinical and EDX evaluations, HRUS may provide useful data in the follow-up of radial palsy due to humeral shaft fractures.

Ultrasound Cross-Sectional Area of the Median Nerve Is Not a Predictor of Patient Reported Outcomes After Carpal Tunnel Release.

The purpose of this study was to evaluate the relationship between cross sectional area (CSA) of the median nerve on ultrasound (US) with pre- and postoperative Boston Carpal Tunnel Questionnaire (BCTQ) scores. We hypothesize that there is a positive correlation between CSA and the ΔBCTQ after carpal tunnel release (CTR). This was a single center study. During a 6-year period (2014-2020), CSA of the median nerve on US and BCTQ scores were collected prospectively for patients presenting with the chief complaint of numbness and tingling in the upper extremity. Patients who underwent CTR and presented for their 6-week follow-up had repeat measurements of the CSA and BCTQ. These patients were included in this study. Patients were then divided into ultrasound positive (CSA ≥ 10) and ultrasound negative (CSA < 10) groups. These groups were compared on the basis of demographics, preoperative BCTQ scores, postoperative BCTQ scores, and 6-week ΔBCTQ score. US-positive and-negative groups did not differ significantly in their preoperative BCTQ, postoperative BCTQ, or ΔBCTQ scores. Both groups did, however, experience significant improvement when comparing preoperative to postoperative BCTQ scores within their respective US group. Regardless of the preoperative CSA of the median nerve, patients who underwent CTR experienced a significant improvement in their BCTQ results. US-positive patients experienced no greater improvement than US-negative patients. These results would suggest that US is not a good predictor of subjective surgical outcome measures such as the BCTQ.

A paired comparison of nerve dimensions using B-Mode ultrasound and shear wave elastography during regional anaesthesia.

Shear wave elastography (SWE) presents nerves in colour, but the dimensions of its colour maps have not been validated with paired B-Mode nerve images. Our primary objective was to define the bias and limits of agreement of SWE with B-Mode nerve diameter. Our secondary objectives were to compare nerve area and shape, and provide a clinical standard for future application of new colour imaging technologies such as artificial intelligence. Eleven combined ultrasound-guided regional nerve blocks were conducted using a dual-mode transducer. Two raters outlined nerve margins on 110 paired B-Mode and SWE images every second for 20 s before and during injection. Bias and limits of agreement were plotted on Bland-Altman plots. We hypothesized that the bias of nerve diameter would be <2.5% and that the percent limits of agreement would lie ±0.67% (2 SD) of the bias. There was no difference in the bias (95% confidence interval (CI) limits of agreement) of nerve diameter measurement, 0.01 (-0.14 to 0.16) cm, P = 0.85, equivalent to a 1.4% (-56.6% to 59.5) % difference. The bias and limits of agreement were 0.03 (-0.08 to 0.15) cm2, P = 0.54 for cross-sectional nerve area; and 0.02 (-0.03 to 0.07), P = 0.45 for shape. Reliability (ICC) between raters was 0.96 (0.94-0.98) for B-Mode nerve area and 0.91 (0.83-0.95) for SWE nerve area. Nerve diameter measurement from B-Mode and SWE images fell within a priori measures of bias and limits of agreement.

The cross-sectional area of the vagus nerve is not reduced in Parkinson's disease patients.

BackgroundRecent studies have revealed the importance of the gut brain axis in the development of Parkinson's disease (PD). It has also been suggested that the cross-sectional area (CSA) of the vagus nerve can be used in the diagnosis of PD. Here, we hypothesize that the CSA of the vagus nerve is decreased in PD patients compared to control participants.MethodsIn this study we measured the CSA of the vagus nerve on both sides in 31 patients with PD and 51 healthy controls at the level of the common carotid artery using high-resolution ultrasound.ResultsThe mean CSA of the left vagus nerve in the PD and the control group was respectively 2.10 and 1.90 and of the right respectively 2.54 and 2.24 mm2. There is no difference in CSA of the vagus nerve in PD patients compared to controls (p = .079). The mean CSA of the right vagus nerve was significantly larger than the left (p < .001). Age, sex and autonomic symptoms were no significant predictors of the CSA of the vagus nerve.ConclusionThese findings show that the CSA of the vagus nerve using ultrasonography is not a reliable diagnostic tool in the diagnosis of PD.