Ulnar Nerve Cross-sectional Area Research Articles

Effect of Tourniquet-Related Nerve Ischemia on Response to Handheld Nerve Stimulation in Ulnar Nerve Transposition.

Tourniquet-related nerve ischemia has been well studied in several reconstructive procedures, but the time-course of impaired response to intraoperative stimulation is unclear. The present study evaluated ischemic effects on conduction during ulnar nerve transposition and examined the relationship between intra- and pre- operative diagnostics. We hypothesized that intraoperative ischemia would have minimal impact on conduction. Thirty patients scheduled for anterior transposition were enrolled after preoperative examination, electrodiagnostic testing, and ultrasound. Demographic and symptom severity data were recorded. A handheld biphasic nerve stimulator was used intraoperatively to assess minimum amplitude and pulse duration needed for muscle response. Measurements were taken at 15-minute intervals after placement. Changes in threshold amplitude and pulse duration were calculated between each 15-minute interval; no significant difference was found in the change of either value (p = 0.70 and 0.178). A weak negative correlation existed between preoperative CMAP amplitudes and average intraoperative pulse duration, which increased to a moderate correlation when compared to 45-minute pulse duration (r=-0.62, p<0.01). Preoperative ulnar nerve cross-sectional area (CSA) demonstrated no significant correlation with average pulse duration but a moderate correlation with pulse duration at 45 minutes (r=0.63, p=0.01). Tourniquet use did not prevent effective intraoperative stimulation of the ulnar nerve for at least 45 minutes. The window for meaningful stimulation with tourniquet usage appears to be greater than previously thought. Preoperative nerve CMAP amplitude and CSA does appear to influence pulse duration required after 45 minutes of ischemia, suggesting that injured nerves are more susceptible to ischemia. 1.

Ultrasound Measurements of the Ulnar Nerve at the Medial Epicondyle Correlate With Electrodiagnostic Studies.

Cubital tunnel syndrome is the second most common compressive neuropathy in the upper extremity and is commonly evaluated with electrodiagnostic studies (EDS). Ultrasound (US) has emerged as a potentially more efficient alternative to EDS. The purpose of this study is to evaluate whether measurements of the cross-sectional area (CSA) of the ulnar nerve at the elbow correlate with EDS results. This study was a prospective analysis of patients who presented with signs and symptoms consistent of cubital tunnel syndrome, who received USs of the ulnar nerve at the elbow and nerve conduction tests. Pearson correlation coefficients were used to evaluate the correlation between ulnar nerve CSA and electrodiagnostic data. t Tests were used to evaluate statistical differences between the mean ulnar nerve CSA of patients with positive or negative nerve conduction study results. Youden Index was used to calculate the optimal cut-off point for US CSA based on maximal sensitivity and specificity. Statistical significance was based on a two-sided P less than .05. The association between increasing US CSA at the medial epicondyle with slowing of the conduction velocity of the ulnar motor nerve across the elbow was statistically significant (r = -0.35, P = .02). Patients with positive EDS tests had significantly larger nerve size than those with negative tests (all Ps < .03). A cut-off point of greater than or equal to 11 mm2 had a sensitivity of 70.83% and specificity of 66.67%. Larger ulnar nerve CSAs correlate with slowing of the conduction velocity on EDSs, and those with positive EDSs have larger nerve sizes than those with negative tests.

Diagnostic efficiency of conventional ultrasound, shear wave elastography, and superb microvascular imaging in evaluating ulnar neuropathy at the elbow.

The current diagnosis of ulnar neuropathy at the elbow (UNE) relies mainly on the clinical presentation and nerve electrodiagnostic (EDX) testing, which can be uncomfortable and yield false negatives. The aim of this study was to investigate the diagnostic value of conventional ultrasound, shear wave elastography (SWE), and superb microvascular imaging (SMI) in diagnosing UNE. We enrolled 40 patients (48 elbows) with UNE and 48 healthy volunteers (48 elbows). The patients were categorized as having mild, moderate or severe UNE based on the findings of EDX testing. The cross-sectional area (CSA) was measured using conventional ultrasound. Ulnar nerve (UN) shear wave velocity (SWV) and SMI were performed in a longitudinal plane. Based on the EDX findings, UNE severity was graded as mild in 4, moderate in 10, and severe in 34. The patient group showed increased ulnar nerve CSA and stiffness at the site of maximal enlargement (CSA mean at the site of max enlargement [CSAmax] and SWV mean at the site of max enlargement [SWVmax]), ulnar nerve CSA ratio, and stiffness ratio (elbow-to-upper arm), compared with the control group (p < .001). Furthermore, the severe UNE group showed higher ulnar nerve CSAmax and SWVmax compared with the mild and moderate UNE groups (p < .001). The cutoff values for diagnosis of UNE were 9.5 mm2 for CSAmax, 3.06 m/s for SWVmax, 2.00 for CSA ratio, 1.36 for stiffness ratio, and grade 1 for SMI. Our findings suggest that SWE and SMI are valuable diagnostic tools for the diagnosis and assessment of severity of UNE.

The usefulness of ultrasonography for the early diagnosis of polyneuropathy in patients with type II diabetes mellitus

Background: Diabetic neuropathies, affecting over 50% of diabetes patients, present varied forms of polyneuropathy impacting somatic and autonomic nerves. Clinical assessments, laboratory findings, and nerve conduction studies (NCSs) aid in precise diagnosis, while recent technological advances highlight ultrasonography (US) as a promising, cost-effective diagnostic tool. Aims and Objectives: This study aims to assess the efficacy of US in early polyneuropathy diagnosis in type II diabetes, exploring its potential as an alternative to NCS. Materials and Methods: In this prospective observational study, we enrolled 30 adult patients with type II non-controlled diabetes and 30 age-matched controls, comprising 15 controlled diabetic patients and 15 normal individuals. The comprehensive assessments encompassed history-taking for diabetes duration, hypertension, and diabetic complications, along with clinical examinations and investigations involving nerve electrophysiology and US on one upper limb based on patient complaints. Results: Significant increases in the cross-sectional area (CSA) of the median nerve were observed in diabetic peripheral neuropathy groups compared to controls, with a P&lt;0.001. Similarly, at the level behind the medial epicondyle, the ulnar nerve CSA exhibited a significant increase in the diabetic peripheral neuropathy group (11.7 mm2) compared to controls (6.7 mm2) with a P&lt;0.002. In addition, a significant difference in cross-sectional values was found in the median nerve proximal to the carpal tunnel between the two groups (P&lt;0.05). In contrast, no significant differences were observed at other sites. Regarding the relationship between sonography and NCSs, NCSs showed higher sensitivity, but sonography demonstrated comparable specificity in evaluating diabetic peripheral neuropathy. Conclusion: Peripheral nerve US in the upper limb can be a valuable diagnostic tool for identifying and diagnosing diabetic peripheral neuropathy.

Diagnostic Utility of the Sonographic Median to Ulnar Nerve Cross-Sectional Area Ratio in Carpal Tunnel Syndrome

Diagnostic Utility of the Sonographic Median to Ulnar Nerve Cross-Sectional Area Ratio in Carpal Tunnel Syndrome

Elastography of nerves in the wrists of cyclists.

This study aimed to investigate changes in the elasticity of the median and ulnar nerves in cyclists. The study included 30 cyclists and 2 non-biking reference groups that included 32 healthy volunteers and 32 individuals with ulnar nerve entrapment neuropathies. All participants underwent physical, ultrasonographic, and elastographic examinations including assessment of nerve cross-sectional area (CSA) and stiffness (SWE). The cyclists' group was tested before and after a 2-hour workout. The values of ulnar nerve CSA and stiffness in Guyon's canal in resting cyclists were 5.30 ± 1.51 mm2 and 49.05 ± 11.18 kPa, respectively. These values were significantly higher than in the healthy volunteers, but not higher than in the nerve entrapment group. Median nerve CSA and stiffness at rest were 9.10 ± 2.61 mm2 and 38.54 ± 14.87 kPa, respectively. Both values were higher than respective values in the healthy group. Cycling induced an increase in all these parameters, although the increase in nerve stiffness was more noticeable than in CSA. The elasticity of the median and ulnar nerve in cyclists remains within normal limits, questioning the belief that cyclists are at risk of nerve palsy in Guyon's canal. However, cycling workout does exert compression, resulting in transient oedema of both nerves. The dynamics of changes was more noticeable in SWE examination than in conventional ultrasound, which may depend on SWE sensitivity.

Ultrasonographic evaluation of ulnar nerve morphology in patients with ulnar nerve instability.

Ulnar nerve instability (UNI) in the retroepicondylar groove is described as nerve subluxation or dislocation. In this study, considering that instability may cause chronic ulnar nerve damage by increasing the friction risk, we aimed to examine the effects of UNI on nerve morphology ultrasonographically. Asymptomatic patients with clinical suspicion of UNI were referred for further clinical and ultrasonographic examination. Based on ulnar nerve mobility on ultrasound, the patients were first divided into two groups: stable and unstable. The unstable group was further divided into two subgroups: subluxation and dislocation. The cross-sectional area (CSA) of the nerve was measured in three regions relative to the medial epicondyle (ME). In the ultrasonographic evaluation, UNI was identified in 59.1% (52) of the 88 elbows. UNI was bilateral in 50% (22) of the 44 patients. Mean CSA was not significantly different between groups. A statistically significant difference in ulnar nerve mobility was found between the group with CSA of <10 versus ≥10 mm2 (p = .027). Nerve instability was found in 85.7% of elbows with an ulnar nerve CSA value of ≥10 mm2 at the ME level. The probability of developing neuropathy in patients with UNI may be higher than in those with normal nerve mobility. Further prospective studies are required to elucidate whether asymptomatic individuals with UNI and increased CSA may be at risk for developing symptomatic ulnar neuropathy at the elbow.

Ultrasonic measurement for the diagnosis of cubital tunnel syndrome: A study in the Hong Kong Chinese population

Introduction: Ulnar nerve enlargement is observed in ultrasound (USG) in patients with cubital tunnel syndrome (CuTS). This study aims to compare the ultrasound size of the ulnar nerve between CuTS patients and control subjects, to find the cut off size for diagnosis, and to validate the use of USG as an adjunct in CuTS diagnosis. Materials and Methods: There were 23 elbows with clinical and nerve conduction test (NCT) confirmed CuTS, and 42 elbows in the control group. Cases with elbow deformities, old ulnar nerve injuries and postoperative cases were excluded. The ulnar nerve cross sectional area (CSA) was measured at 6 different levels and positions: over the medial epicondyle (ME) in elbow flexion/extension, 2 cm and 5 cm distal to the ME, 2 cm and 5 cm proximal to the ME. A cut off CSA value for CuTS diagnosis was derived. Correlation between ulnar nerve CSAs and NCT was analysed. Results: The age and gender distribution were similar in both groups (61.2 vs 56.6; M &gt; F, p &gt; 0.05). The mean CSA of the CuTS group vs control group was 19.2 mm2 vs 7.0 mm2, 19.5 mm2 vs 7.1 mm2, 20.8 mm2 vs 8.1 mm2 at ME flexion, ME extension and maximal CSA respectively. The derived CSA cut off value for CuTS at ME flexion, ME extension and maximal CSA were 10.5 mm2, 11.5 mm2, and 15 mm2 respectively. The CSA difference at different levels between the 2 groups were significant except at 5 cm proximal to ME. A strong negative correlation was seen between the CSA and the across elbow nerve conduction velocity, with correlation coefficient of −0.748 at ME flexion, −0.654 at ME extension and -0.676 at maximal CSA. Conclusion: USG can be used as an adjunct for the diagnosis of CuTS with high accuracy and patient safety. It can also be used to delineate possible anatomical etiologies at the cubital tunnel.

Does hot pack application change the morphology of the median and ulnar nerves?

This study aims to investigate the effect of the hot pack application on the morphology of healthy median and ulnar nerves. Between August 2021 and September 2022, a total of 54 healthy volunteers (17 males, 37 females; mean age: 31.9±9.4 years; range, 21 to 63 years) were included in the study. The cross-sectional area (CSA) and depth of the right median and ulnar nerve were measured using ultrasonography before and after 20-min hot pack application. The right median nerve CSA and depth from the level of the scaphoid bone (at the level of the carpal tunnel) and from the mid-forearm were also measured. The right ulnar nerve CSA and depth from the level of the hook of hamate and the mid-forearm were evaluated. The depth measurements between the skin and the outer hyperechoic border of the nerve were performed. After the hot pack application, there was an increase in both the median nerve CSA at the carpal tunnel (from 0.06±0.01 to 0.09±0.02 cm2 ) and forearm (from 0.06±0.02 to 0.09±0.02 cm2 ) levels (p<0.001) and the ulnar nerve CSA at the hook of hamate (from 0.04±0.03 to 0.06±0.01 cm2 ) and forearm (0.05±0.01 to 0.08±0.02 cm2 ) levels (p<0.001). No statistically significant difference was observed between the pre- and post-application depth measurements (p>0.05). Our study results show that the hot pack application leads to acute swelling of the median and ulnar nerves. In future studies, the relationship between morphological changes in healthy and pathological nerves and electrodiagnostic findings should be investigated.

Ultrasound Assessment of the Ulnar Nerve Around the Elbow and Diagnosis of Cubital Tunnel Syndrome, Clinical Outcomes.

There is increased interest in ultrasound (US) for the diagnosis of cubital tunnel syndrome (CuTS). We hypothesize that ulnar nerve cross-sectional area (CSA) correlates with disease severity and electrodiagnostic studies (EDX). ARetrospective review was performed at a tertiary medical center. One hundred seventeen patients (166 ulnar nerves) were evaluated. Maximum CSA at 3 points around the elbow (proximal, groove, and distal) and EDX results (American Board of Electrodiagnostic Medicine-certified physiatrist's interpretations) were collected. US was positive (CSA > 0.1 cm2) in 95/117 cases (81.20%) versus 84/117 (71.79%) positive for EDX. CuTS patients treated surgically had significantly greater (0.13 cm2, standard deviation [SD] 0.038) preoperative CSA than non-operative patients (0.10 cm2, SD 0.033) (p = .003). CSA increased as EDX increased in severity; mild (0.116 cm2, SD 0.031), moderate (0.121 cm2, SD 0.035), and severe (0.163 cm2, SD 0.047) with a significant difference between the mild and severe groups (P = .001) and between the moderate and severe groups (p = .01). Significant differences were seen between patients with positive US and EDX studies compared to those with negative US and EDX in the average physical function scores (57.26, SD 8.57 versus 43.18, SD 7.70; p < .001); average sleep scores (50.14, SD 9.53 versus 56.62, SD 7.31; p = .02); average physical function scores (43.04, SD 8.68 versus 57.08, SD 6.34; p < .001) and average depression scores (49.10, SD 10.88 versus 45.043, SD 7.06; p = .02). US is a reliable tool for diagnosis and surgical decision-making for CuTS. Diagnostic/III.

The incidence of ulnar nerve subluxation in patients with ulnar neuropathy at the elbow and healthy control: A clinical, electrodiagnostic, and ultrasonographic study

Abstract Background: Ulnar neuropathy at the elbow is a common presenting disorder in neuromuscular medicine. Patients suffer from paresthesia in the 4/5 finger, pain at the elbow, and weakness and atrophy in advanced cases. Objective: This study aimed to find the incidence of ulnar nerve subluxation in patients with ulnar neuropathy at the elbow. Materials and Methods: This is a case-control study conducted in Al-Sadiq teaching hospital at the period of January 2018–August 2022. It included 84 patients diagnosed with ulnar neuropathy at the elbow by history, clinical examination and electrodiagnostic testing. All patients and control undergo ultrasonographic examination by high-resolution ultrasound looking for ulnar nerve cross-sectional area at 3 points: (1) 7 cm proximal to medial epicondyle, (2) at the medial epicondyle, and (3) at the cubital tunnel 2-3 cm distal to medial epicondyle. Also, dynamic ultrasonographic examination were done looking for subluxation of ulnar nerve behind medial epicondyle during elbow flexion. If ulnar nerve move on the top of medial epicondyle it is considered partial and when it dislocates anteriorly beyond the tip of medial epicondyle it is considered complete subluxation.

Predictive value of ultrasonography in polyneuropathy diagnosis: electrophysiological and ultrasonographic analysis.

Peripheral neuropathy may cause serious complications such as foot ulcers and Charcot joint which can prevent by early diagnosis. We aimed to analyze the diagnostic value of ultrasonographic measurements of nerves and muscles in distal symmetric axonal polyneuropathy (DSAP). Study included 51 DSAP patients and 51 controls. Nerve conduction studies were performed. Median, ulnar, tibial, superficial peroneal, and sural nerves and the abductor pollicis brevis (APB), abductor digiti minimi (ADM), first dorsal interosseous (FDI), extensor digitorum brevis (EDB), abductor hallucis (AH) and tibialis anterior (TA) muscles were evaluated with ultrasound. The Toronto clinical scoring system (TCSS) was used to assess the severity of neuropathy. The median, ulnar, and tibial nerve cross-sectional areas (CSA) were higher in the DSAP group (p = 0.025, p = 0.011, p < 0.001 respectively) while superficial peroneal and sural nerve CSAs were not differed. Only AH and EDB ultrasonographic findings from the muscles differed between the two groups. Effect of diabetes and DSAP on sonographic findings were assessed with two-way ANOVA. Results indicated that only DSAP had a significant effect on sonographic nerve and muscle examination. The area under the ROC curve was 0.831 ± 0.042 for tibial nerve CSA (p < 0.001) with a cut-off value of 15.5 mm2 (sensitivity 74% and specificity 83%). Median, ulnar and tibial nerve CSAs were found to be larger in polyneuropathy patients and they were associated with the clinical and electrophysiological severity of polyneuropathy. ROC analysis showed that tibial nerve CSA may have a predictive value in the diagnosis of DSAP.

Morphological and electrophysiological evaluation of median and ulnar nerve in complex regional pain syndrome type 1.

Complex regional pain syndrome (CRPS) can be distinguished as type I without and type II with electrophysiological evidence of major nerve lesion. The pathophysiology of both subgroups is still under investigation. The aim of this research is to demonstrate the nerve morphology and electrophysiology in CRPS type I patients. Bilateral median and ulnar nerve cross-sectional areas were evaluated with ultrasound and also median and ulnar nerve conduction studies of both hands were performed. Cross-sectional areas of median and ulnar nerves and nerve conduction studies in healthy controls were also obtained and compared with the patients. Twenty-five male patients and 11 healthy male controls were enrolled in the study. The mean age of the patients was 24.08 ± 5.50 years and controls was 23.18 ± 5.09 (p> 0.05). Compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes of the diseased side were found significantly lower than the healthy side (p< 0.05). Both median and ulnar nerve distal motor latency values were significantly higher in the patient group (p< 0.05). There was no significant difference in the median and ulnar nerve cross-sectional area when compared with the opposite extremity and healthy volunteers. The lower SNAP and CMAP amplitudes of the median and ulnar nerves compared to the healthy side and the prolongation of the affected side median and ulnar nerve distal motor latencies of the affected individuals may indicate axonal involvement in patients with CRPS type 1. Decreased CMAP amplitudes may also indicate muscle atrophy due to a decrease in the number of functional motor units.

Characteristics of ulnar neuropathy in baseball players: Focusing on the entrapment point of the ulnar nerve and valgus instability.

The region where the ulnar nerve (UN) is swollen in baseball players with ulnar neuropathy is not apparent. This study investigated the UN's cross-sectional area (CSA) at each entrapment point in baseball players. We also aimed to clarify the relationship between valgus instability and the CSA of the UN. Forty baseball players were separated into healthy and ulnar neuropathy groups. The CSA and valgus instability were measured using ultrasonography (US). Relative to the medial epicondyle (MEC), the arcade of Struthers (SA) was 5 cm proximal, the cubital tunnel was the posterior part, and Osborne's ligament was defined as 3 cm distal. The ulnohumeral joint space was imaged as a low-echo space between the distal-medial corner of the trochlea and the proximal edge of the sublime tubercle. The UN in the ulnar neuropathy group had significant swelling in the cubital tunnel and Osborne's ligament. We found a weak positive correlation between the CSA and ulnohumeral joint space, and the ulnohumeral joint space at rest and valgus stress. Evaluation and treatment of UN, especially cubital tunnel and Osborne's ligament, are necessary for the rehabilitation of baseball players presenting with ulnar neuropathy and valgus instability.

Nerve enlargement differs among chronic inflammatory demyelinating polyradiculoneuropathy subtypes and multifocal motor neuropathy

ObjectiveWe aimed to evaluate differences in ultrasonographic nerve enlargement sites among typical chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), distal CIDP, multifocal CIDP and multifocal motor neuropathy (MMN) in a Japanese population. MethodsWe retrospectively reviewed medical records and selected 39 patients (14 with typical CIDP, 7 with multifocal CIDP, 4 with distal CIDP, and 14 with MMN) who underwent ultrasonography. Median and ulnar nerve cross-sectional areas (CSAs) were measured at the wrist, forearm, elbow, and upper arm. CSA ratios for each nerve were calculated as: wrist-to-forearm index (WFI) = wrist CSA/forearm CSA; elbow-to-upper arm index (EUI) = elbow CSA/upper arm CSA; and intranerve CSA variability (INCV) = maximal CSA/minimal CSA. ResultsSignificant differences were observed among typical CIDP, multifocal CIDP, distal CIDP, and MMN in CSA at the forearm and upper arm in the median nerves (p < 0.05). Patients with multifocal CIDP had lower WFI and EUI and higher INCV than the other groups (p < 0.05). ConclusionsRegardless of the untreated period, compared with other CIDP subtypes and MMN, multifocal CIDP showed a focal and marked nerve enlargement in the Japanese population. SignificanceDifferences in nerve enlargement site may be an underlying feature of multifocal CIDP.

Relationship between Clinical Severity and Cross-sectional Area of Ultrasonographic Examinations in Ulnar Neuropathy at the Elbow.

This study explored the relationship between clinical severity of ulnar neuropathy at the elbow (UNE) and ulnar nerve cross-sectional area (CSA) by ultrasound examination to identify appropriate measurement sites for UNE diagnosis and evaluation. In this retrospective analysis, we examined the arms of 37 patients diagnosed with UNE and those of 34 individuals as controls. The ulnar nerve CSAs were measured at 2 cm distal to the tip of the medial epicondyle (dME), the tip of the medial epicondyle (ME), 2 cm proximal to the tip of the medial epicondyle (pME), and any site showing the maximum CSA between the dME and pME (largest dpME). The modified McGowan classification (grades I, IIA, IIB, and III) was used to rate the clinical severity of UNE. For all sites, the CSAs were significantly correlated with clinical severity. The sites showing the maximum CSA were inconsistent between controls and grade IIA patients. Grade IIB patients showed the largest CSA at the ME in the majority of patients. In grade III patients, maximum CSA occurred only at the ME. Serial assessment to detect nerve enlargement at multiple sites was beneficial for mild UNE patients with weakness of the ulnar distal muscles with Medical Research Council (MRC) score of 4 or higher (grade IIA). For severe UNE patients with weakness of the ulnar distal muscles classified as MRC3 or less (grades IIB, III), the most efficient method for detecting enlarged nerves was to initially measure the CSA at the ME.

Changes in Ultrasound Measurements of the Ulnar Nerve at Different Elbow Joint Positions in Patients with Cubital Tunnel Syndrome.

Ultrasound imaging (US) is increasingly being used in the diagnosis of entrapment neuropathies. The aim of the current study was to evaluate changes in stiffness (shear modulus), cross-sectional area (CSA), and trace length (TRACE) of the ulnar nerve in patients with cubital tunnel syndrome (CuTS), with shear wave elastography (SWE). A total of 31 patients with CuTS were included. CSA, shear modulus, and TRACE examinations were performed in the SWE mode in four positions of the elbow: full extension, 45° flexion, 90° flexion, and maximum flexion. There were significant side-to-side differences in the ulnar nerve elasticity value at 45°, 90°, and maximal elbow flexion (all, p &lt; 0.001) but not at elbow extension (p = 0.36). There were significant side-to-side differences in the ulnar nerve CSA value at each elbow position (all, p &lt; 0.001). There were significant side-to-side differences in the ulnar nerve trace value at each elbow position (all, p &lt; 0.001). The symptomatic ulnar nerve in patients with CuTS exhibited greater stiffness (shear modulus), CSA, and TRACE values, compared with the asymptomatic side. US examinations (shear modulus, CSA, and TRACE evaluation) of the ulnar nerve can be helpful in supporting and supplementing the diagnosis in patients with CuTS.

Comparison of the median and ulnar nerves of rheumatoid arthritis patients and healthy subjects by ultrasound.

In this study, we aimed to investigate ulnar and median nerve cross-sectional areas (CSAs) by ultrasonography in RA patients who had no signs or symptoms of neurologic involvement. This case-control study was conducted with 76 participants (72 females, 4 males; mean age: 53.2+10.9 years; range, 18 to 65 years) between April 2011 and April 2013. Of the participants, 38 were RA patients without any signs or symptoms of ulnar or median nerve involvement, and 38 were healthy subjects. All participants were evaluated with ultrasound. The median and ulnar nerve CSAs were measured at the proximal inlet of the carpal tunnel using the pisiform bone as a landmark. There were no statistically significant differences between patients and controls in terms of median and ulnar CSAs (p>0.05). There were no correlations between median and ulnar CSAs of the dominant hand and age, height, weight, and disease duration. The median nerve CSA was >10 mm2 in 24% of the RA patients and 14% of controls, but the difference was not statistically significant (p=0.20). Similar median and ulnar CSAs were detected in RA patients and healthy controls. These findings cannot rule out a subclinical neurologic involvement.

Gray-Scale and Power Doppler Ultrasound Findings Predictive of Cubital Tunnel Syndrome Severity.

The use of ultrasound in the diagnosis of cubital tunnel syndrome (CuTS) is an attractive alternative to electrodiagnostic (EDX) studies, but its utility is binary with poor severity correlation. We hypothesize that increasing ulnar nerve cross-sectional area (CSA) and power Doppler measurement of intraneural vascularity may predict the extent of disease. We identified 20 elbows from patients with a history of CuTS and 20 elbows in 10 asymptomatic controls. Electrodiagnosis was performed for symptomatic patients. Gray-scale ultrasound and power Doppler ultrasound were performed to measure CSA and intraneural vascularity in all participants. Functional measures, Boston Carpal Tunnel Questionnaire (BCTQ), and Patient-Reported Outcomes Measurement Information System surveys were also completed. A strong positive correlation was found between CSA and motor nerve conduction velocity (MNCV) decrease between elbow and forearm, which increased when BCTQ >2 was used as a screening criterion. Increased CSA also demonstrated a high positive predictive value (PPV) in predicting MNCV changes, but poor ability to predict axonal loss. In contrast, power Doppler ultrasound demonstrated 100% PPV and 94% negative predictive value (NPV) in predicting severe CuTS (defined as compound motor action potential [CMAP] amplitude <6 mV and electromyography [EMG] findings). Cross-sectional area is a sensitive method for identifying changes in MNCV and amplitude but does not stratify disease severity, as defined by diminished CMAP amplitude and/or evidence of denervation on EMG. The presence of increased intraneural vascularity is relatively sensitive but highly specific for axonal loss. The combination of nerve CSA, BCTQ screening, and power Doppler ultrasound may provide an alternative means for CuTS assessment.

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.