Diagnostic value of high-resolution sonography in ulnar neuropathy at the elbow

Morphometry of the sural nerve in diabetic neuropathy: a systematic review

PURPOSE

The aim of this systematic review is to evaluate the usefulness of sural nerve ultrasonography in diagnosing diabetes mellitus (DM) and diabetic polyneuropathy (DPN), the latter of which is a common long-term complication for diabetic patients that frequently involves the sural nerve.

METHODOLOGY

A meta-analysis of the cross-sectional areas (CSAs) of sural nerves in healthy individuals and patients with diabetes mellitus based on a total of 32 ultrasonographic-based studies from 2015 to 2023 was performed. Sub-analyses were performed for factors such as geographical location and measurement site.

RESULTS

The meta-analysis showed that the mean CSA of the sural nerve was significantly larger in DM patients with DPN only compared to healthy individuals across all regions and when pooled together. An age-dependent increase in the CSA of healthy sural nerves is apparent when comparing the paediatric population with adults.

CONCLUSION

Sural nerve ultrasonography can distinguish diabetic adults with DPN from healthy adults based on cross-sectional area measurement. Future studies are needed to clarify the relationships between other parameters, such as body metrics and age, with sural nerve CSAs. Cut-offs for DPN likely need to be specific for different geographical regions.

Neuromuscular ultrasound: Impact on diagnosis and management

INTRODUCTION/AIM

High-resolution ultrasound (HRUS) is increasingly used in evaluating neuromuscular conditions. Its potential advantages include its ability to discern anatomic information and make specific etiological diagnoses. Although many studies have demonstrated HRUS effectiveness, especially in mononeuropathies, more information is needed to better determine how often and to what extent useful information is obtained; how it influences diagnosis, clinical decision-making, and patient management; and how it is used with electrodiagnostic (EDx) studies.

METHODS

A retrospective cohort study was performed on patients referred for HRUS at a university laboratory during 2021. Demographic information, referral diagnoses, clinical information, HRUS findings, and follow-up patient management were analyzed. For patients who had EDx, results were compared with HRUS. Determinations were made whether HRUS did or did not aid in the diagnosis. For patients in whom HRUS resulted in a diagnosis, determination was made whether it confirmed the diagnosis made clinically or by EDx but did not change management; added additional important information; and/or made a decisive impact on subsequent management.

RESULTS

Five hundred two patients were analyzed, most referred for mononeuropathy, brachial plexopathy, and polyneuropathy. HRUS was abnormal in 81.7% of patients. HRUS added additional useful information in 79.0% and was decisive in management in 62.7%. In patients who also had abnormal EDx, HRUS resulted in decisive management in 49.5%.

DISCUSSION

HRUS is an effective diagnostic tool that frequently adds localizing and structural information that is otherwise not obtainable by clinical and EDx evaluation. In a substantial number of patients selected for HRUS, it is decisive in guiding further management.

Ultra-high-definition (22 MHz) ultrasound of the ulnar nerve: additional value and normative data

We studied 30 healthy volunteers (60 arms), categorized into three age groups with equal numbers to verify if a 22 MHz compared with a 15 MHz ultrasound transducer has additional value for studying the intraneural architecture of the ulnar nerve throughout its course. At six sites, there were no differences in cross-sectional area measurements between the two transducers. With both, the cross-sectional area was significantly larger at the medial epicondyle compared with the other sites and smaller at the mid-forearm and Guyon's canal compared with the mid-upper arm. With higher age the cross-sectional area significantly increased. Significantly more fascicles were visible distal to the medial epicondyle compared with more proximal sites, as well as in men compared with women. Finally, higher body weight was related to a significantly smaller number of fascicles being seen. A 22 MHz transducer depicts more details of the intraneural architecture than a 15 MHz transducer. Our data can be used as normative data or reference values in analysing ulnar nerve pathology.Level of evidence: II.

Clinical Application of Ultrasound-guided Electrode Placement and Detection of Nerve Action Potential

BACKGROUND

 We explore a minimally invasive method (combined ultrasound detection, electrode placement and electrophysiologic nerve examination) to evaluate the early-stage quality of a nerve suture site.

METHODS

 Ten patients with median and/or ulnar nerve injuries who had undergone nerve suture were recruited. Postoperative ultrasound examination found that the nerve injury was sutured. Then, a stimulating electrode and recording electrode were located beside the nerve proximal and distal to the suture site guided by ultrasound. Measurement of nerve action potentials (NAP) were performed with these electrodes, followed by surgical exploration. The pre- and intraoperative electrophysiologic findings were compared, together with amplitude, latency, and wave shape of NAP.

RESULTS

 Of the 10 patients, 3 patients were diagnosed with median nerve injury, 2 with ulnar nerve injury, and 5 with the median nerve and ulnar nerve injury. NAP could not be detected pre- and intraoperatively in three median nerves from three patients and in two ulnar nerves from two patients. NAP was detected in 10 nerves from the remaining 5 patients. The pre- and intraoperative NAP results showed consistent results concerning the status of the nerve suture. Wilcoxon's signed-rank test indicated no significant difference in the amplitude and latency detected via sonographically placed electrodes and during surgical exploration. The number of negative-phase waves were equally distributed.

CONCLUSION

 Ultrasound-guided electrode placement and NAP detection can substitute surgery and serve as a minimally invasive approach to evaluate the regeneration of a sutured nerve.

Diagnostic Considerations in Compressive Neuropathies

Peripheral nerve compression of the upper extremity is a common pathology often necessitating surgical intervention, much is known, but much more is left to understand. For the more common pathologies, carpal tunnel syndrome, cubital tunnel syndrome, and ulnar tunnel syndrome, research and clinical efforts directed toward standardization and reduction of resource use have been attempted with varied success. Diagnosis of many of these syndromes is largely based on a proper history and physical examination. Electrodiagnostic studies continue to have value, but proportionally less than previous decades. In addition, emerging technologies, including magnetic resonance neurography, novel ultrasound evaluation techniques, and ultrasound-guided diagnostic injections, are beginning to demonstrate their ability to add value to the diagnostic algorithm, particularly when less common compressive neuropathies are present and/or the diagnosis is in question.

Ulnar nerve thickness at the elbow on longitudinal ultrasound view in control subjects

INTRODUCTION

Ulnar mononeuropathy at the elbow is the second most frequent neuropathy in humans. Diagnosis is based on clinical and electrophysiological criteria and, more recently, also on ultrasound. Cross-sectional ultrasound is currently the most valued, although longitudinal ultrasound allows assessment of the entire affected trajectory of the nerve in a single view, but always in a straight line with no changes in direction, as in the extended elbow. The main aim of this work is to propose normative values ​​for longitudinal ultrasound of the ulnar nerve at the elbow.

METHODS

The neurological exploration of upper extremity, and electrophysiological and ultrasound parameters at the elbow of ulnar nerve were evaluated in 76 limbs from 38 asymptomatic subjects.

RESULTS

The diameters of the nerve as well as the distal and proximal areas were larger at the proximal region of the ulnar groove, and even more so in older individuals. In most of these elderly subjects, we found a small, non-significant slowdown in motor conduction velocity at the elbow with respect to the forearm (less than 5 m/s).

CONCLUSIONS

We observed a good correlation between the longitudinal and cross-sectional ultrasounds of the ulnar nerve at the elbow. Longitudinal ultrasound proved to be sensitive, reliable, simple and rapid, but its greatest contribution was allowing the visualization of the entire nerve trajectory in an integrated way, providing an image with good definition of the outline, proportions and intraneural characteristics of the nerve.

Percutaneous ultrasound-guided ulnar nerve release technique compared to open technique: A cadaveric study

Objectives: To evaluate the outcomes of a novel percutaneous ultrasound-guided technique for release of ulnar nerve entrapment at the elbow when compared to standard open release Methods: One single surgeon performed an ultrasound-guided percutaneous release of the cubital tunnel on a group of five cadaveric elbows and open release on five others. All procedures were timed, and incision lengths were recorded. Meticulous anatomic dissection was then performed to assess the complete release of the carpal tunnel and iatrogenic injuries. Results: No significant difference was found between the two groups in terms of complete release and iatrogenic injury, whereas Operative time was significantly shorter for the US-guided technique. Incomplete releases of the nerve were found only during the first two trials in each group, while the third, fourth, and fifth trials showed a complete ulnar nerve release in both series, highlighting a fast learning curve for both techniques. All of this through a significantly smaller incision in the US-guided technique. Conclusions: This study highlights the similar effects of these two techniques in terms of complete release of the ulnar nerve, with no clear superiority of one over the other in terms of morbidity rate. Both have a fast learning curve for an ultrasound-trained surgeon, with the US-guided technique being a less traumatic and quicker alternative procedure.

Diagnosing ulnar neuropathy at the elbow on MRI: importance of the longitudinal extent of the hyperintense ulnar nerve

OBJECTIVE

To evaluate the usefulness of the longitudinal extent (LE) of high ulnar nerve signal intensity (SI) for the diagnosis of ulnar neuropathy at the elbow (UNE).

MATERIALS AND METHODS

This retrospective study included 68 patients who underwent elbow MRI. Twenty-seven and 41 patients were enrolled in the UNE and control groups, respectively. Qualitative and quantitative analyses of the SI and size of the ulnar nerve at the cubital tunnel, proximal, and distal to the cubital tunnel were performed. Cross-sectional area (CSA) and nerve-to-muscle contrast ratio (NMCR) were measured at each level. The LE of the hyperintense ulnar nerve was evaluated using axial and coronal images. The presence of space-occupying lesions (SOLs), subluxation, and muscle denervation were recorded. Univariate and multivariate analyses were performed to identify independent predictive factors.

RESULTS

Ulnar nerve hyperintensity at and distal to the cubital tunnel, presence of compression, SOL, muscle denervation, LE of hyperintense ulnar nerve, NMCR, and CSA at and distal to the cubital tunnel significantly differed between the two groups. Multivariate logistic regression analysis showed that the LE of the hyperintense ulnar nerve and CSA at the cubital tunnel were independent predictive factors for UNE (p < 0.05).

CONCLUSION

LE of the hyperintense ulnar nerve could be a useful predictive factor for UNE.

Evidence-based guideline: Neuromuscular ultrasound for the diagnosis of ulnar neuropathy at the elbow

INTRODUCTION/AIMS

The purpose of this literature review is to develop an evidence-based guideline for the use of neuromuscular ultrasound in the diagnosis of ulnar neuropathy at the elbow (UNE). The proposed research question was: "In patients with suspected UNE, does ulnar nerve enlargement as measured with ultrasound accurately identify those patients with UNE?"

METHODS

A systematic review and meta-analysis was performed, and studies were classified according to American Academy of Neurology criteria for rating articles for diagnostic accuracy.

RESULTS

Based on Class I evidence in four studies, it is probable that neuromuscular ultrasound measurement of the ulnar nerve at the elbow, either of diameter or cross-sectional area (CSA), is accurate for the diagnosis of UNE.

RECOMMENDATION

For patients with symptoms and signs suggestive of ulnar neuropathy, clinicians should offer ultrasonographic measurement of ulnar nerve cross-sectional area or diameter to confirm the diagnosis and localize the site of compression (Level B).

High-Resolution Ultrasound in the Diagnosis and Surgical Management of Ulnar Neuropathy at the Elbow

High-resolution ultrasound (HRU) has recently demonstrated the potential to facilitate diagnosis and treatment of upper extremity compression neuropathy. The authors hypothesized that HRU can improve preoperative evaluation of ulnar neuropathy at the elbow (UNE) and that changes in ulnar nerve cross-sectional area (CSA) after cubital tunnel release may correlate with outcomes. Nineteen adult patients diagnosed with UNE who were scheduled for surgical decompression by a single hand surgeon were enrolled. Electrodiagnostic (EDX) testing, HRU of the ulnar nerve, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, and McGowan grade were obtained pre- and postoperatively. Fourteen patients completed the study. Statistically significant improvements were found in CSA measurements and QuickDASH scores. High-resolution ultra-sound was found to confirm UNE in all 7 patients with positive results on EDX, and additionally detected UNE in 3 of 6 patients with negative results on EDX and in 1 patient with equivocal (nonlocalized) EDX testing. All 4 of these additional HRU-detected cases improved clinically and by CSA measurements after surgery. In this series, HRU was superior to EDX testing in the diagnosis of UNE and demonstrated objective improvement in ulnar nerve CSA after successful cubital tunnel release. This modality, which is better tolerated, less costly, and less time-consuming than EDX testing or magnetic resonance imaging, should therefore be considered in the diagnosis and surgical management of UNE, particularly in cases with negative or equivocal results on EDX testing, or when outcomes are suboptimal. [Orthopedics. 2021;44(5):285-288.].

Cubital tunnel syndrome

Cubital tunnel syndrome (CuTS) is the second most common compression neuropathy of the upper limb, presenting with disturbance of ulnar nerve sensory and motor function.The ulnar nerve may be dynamically compressed during movement, statically compressed due to reduction in tunnel volume or compliance, and tension forces may cause ischaemia or render the nerve susceptible to subluxation, further causing local swelling, compression inflammation and fibrosis.Superiority of one surgical technique for the management of CuTS has not been demonstrated. Different techniques are selected for different clinical situations with simple decompression being the most common procedure due to its efficacy and low complication rate.Adjunctive distal nerve transfer for denervated muscles using an expendable motor nerve to restore the axon population in the distal nerve is in its infancy but may provide a solution for severe intrinsic weakness or paralysis. Cite this article: EFORT Open Rev 2021;6:743-750. DOI: 10.1302/2058-5241.6.200129.

Comparison of High Resolution Ultrasonography with Clinical Examination in the Assessment of Peripheral Nerve Involvement in Leprosy

Context:

Assessment of peripheral nerves in leprosy by clinical methods is subject to considerable inter-observer variability. High resolution ultrasonography (HRUS) can assess peripheral nerves more objectively.

Aims:

To compare the findings of peripheral nerve involvement in newly diagnosed cases of leprosy by clinical and sonological methods.

Settings and Design:

Cross sectional study in a tertiary care teaching hospital.

Subjects and Methods:

Four pairs of peripheral nerves of 40 newly diagnosed patients with leprosy were examined clinically and by HRUS.

Statistical Analysis Used:

Agreement between clinical examination and HRUS using kappa statistic; sensitivity; specificity; and predictive values.

Results:

Of the 320 nerves examined, 71 (22.18%) were abnormal clinically and 63 (19.7%) sonologically. Sonological abnormalities were increased cross sectional area (n = 63; 100%), hypoechogenicity with loss of fascicular architecture (n = 46; 73%) and increased vascularity (n = 35; 55.6%). There was moderate agreement (Cohen's Ḳ = 0.59) between clinical and sonological findings. HRUS findings were abnormal in 18 (7.2%) nerves that were clinically normal. HRUS was normal in 26 (36.6%) nerves which were clinically abnormal. Sensitivity of HRUS compared to clinical examination was 63%; specificity 92.7%; positive predictive value 71.4%; and negative predictive value 89.9%. Increased cross sectional area agreed with clinical findings the most.

Conclusions:

HRUS has low sensitivity (63%) and high specificity (92.7%) to identify abnormal peripheral nerves in leprosy, compared to clinical examination. It could detect abnormality of some (n = 18, 7.2%) clinically normal nerves, but showed normal findings of some nerves (n = 26, 36.6%), which were considered clinically abnormal.

Reference values for the cross-sectional area of normal radial nerve at two levels using high-resolution ultrasonography

Aim of the study

High-resolution ultrasound is less often used to evaluate the radial nerves. The radial nerve is often involved in entrapment syndromes. The aim of the study is to establish the reference values for the cross-sectional area of the normal radial nerve on high-resolution ultrasonography, and to identify relationships between the cross-sectional area and the subject’s age, gender, height, weight, body mass index, and hand dominance.

Material and methods

The study was conducted on 200 subjects of both sexes, between 18 and 75 years of age, who did not have history of peripheral neuropathy or trauma to the upper limb. High-resolution real-time sonographic examination of the radial nerves was performed in both arms at two different levels. Level 1 was taken just proximal to the nerve bifurcation, and level 2 just after the nerve exits the spiral grove.

Results

The mean cross-sectional area measured at level 2 (4.3 ± 0.4 mm²) was greater than that measured at level 1 (2.3 ± 0.3 mm²). No significant relationship was seen with age and hand dominance (p >0.05), but the cross-sectional area values at above mentioned levels were larger in males than in females (p <0.05). In addition, the cross-sectional areas of the radial nerves showed a positive correlation with height, weight, and body mass index (p <0.05).

Conclusion

The established ultrasonographic reference values along with basic clinical data will aid in the diagnosis, response to treatment, and prognostic evaluation of peripheral neuropathies.

Comparison of electrodiagnosis, neurosonography and MR neurography in localization of ulnar neuropathy at the elbow

INTRODUCTION

In patients with ulnar neuropathy at the elbow (UNE) the precise determination of the site of lesion is important for subsequent differential diagnostic considerations and therapeutic management. Due to a paucity of comparable data, to better define the role of different diagnostic tests, we performed the first prospective study comparing the diagnostic accuracy of short segment nerve stimulation, nerve ultrasonography, MR neurography (MRN), and diffusion tensor imaging (DTI) in patients with UNE.

METHODS

UNE was clinically diagnosed in 17 patients with 18 affected elbows. For all 18 affected elbows in patients and 20 elbows in 10 healthy volunteers, measurements of all different diagnostic tests were performed at six anatomical positions across the elbow with measuring points from distal (D4) to proximal (P6) in relation to the medial epicondyle (P0). Additional qualitative assessment regarding structural changes of surrounding nerve anatomy was conducted.

RESULTS

The difference between affected arms of patients and healthy control arms were most frequently the largest at measure intervals D2 to P0 and P0 to P2 for electrophysiological testing, or measure points P0 and P2 for all other devices, respectively. At both levels P0 and at P2, T2 contrast-to-noise ratio (CNR) of MRN and mean diffusivity (MD) of DTI-based MRN showed best accuracies.

DISCUSSION

This study revealed differences in diagnostic performance of tests concerning a specific location of UNE, with better results for T2 contrast to noise ratio (CNR) in MRN and mean diffusivity of DTI-based MRN. Additional testing with MRN and nerve ultrasonography is recommended to uncover anatomical changes.

Ultrasonographic Findings of the Ulnar Nerve Following Elbow Flexion in Patients with Cubital Tunnel Syndrome

OBJECTIVE

To evaluate the ultrasonographic findings obtained following various degrees of elbow flexion in patients with cubital tunnel syndrome (CuTS).

DESIGN

Retrospective, cross-sectional study.

SETTING

General teaching hospital, rehabilitation unit.

SUBJECTS

Electrophysiological and ultrasonographic assessments were performed on 11 elbows of healthy controls and 21 elbows of 17 patients with CuTS.

METHODS

Dynamic movement of the ulnar nerve during elbow motion was measured. To measure ulnar nerve dynamic movement during elbow motion, the distance from the medial epicondyle (ME) to the nearest surface of the ulnar nerve toward the ME was measured at the cubital tunnel inlet at elbow extension (0°), elbow flexion to 60°, and elbow flexion to 90°.

RESULTS

The distance between the ME and ulnar nerve was lower in CuTS patients than in healthy patients at all elbow flexion angles. This difference was statistically significant at 0° and 60° elbow flexion (P < 0.05). When calculating the cutoff value, the distance between the ME and ulnar nerve at full elbow extension for CuTS diagnosis was 0.53 cm (sensitivity = 71.4%, specificity = 90.7%). The distance ratio between the ME and ulnar nerve for diagnosis of ulnar neuropathy at the elbow was 24.4% (sensitivity = 76.2%, specificity = 100%).

CONCLUSION

Measurement of the distance between the ME and ulnar nerve in full elbow extension may facilitate the diagnosis of patients with CuTS. These findings may be important for CuTS diagnosis, as they were also observed in patients with mild-stage CuTS.

Ultrasound Ulnar Nerve Measurement in a Healthy Population

Introduction

Ulnar tunnel syndrome at the elbow is a common pathology. The ultrasound cross-sectional area is a well-known metric widely accepted in radiology for the description of nerve entrapment. However, the pathological cut-off value remains challenging. The objectives of this study were to (1) describe the ultrasound cross-sectional area measurement of the ulnar nerve at three locations, and (2) to evaluate the inter-observer reliability by two independent ultrasonographers.

Methods

One-hundred ulnar nerves of 50 asymptomatic individuals were scanned using B-mode and power Doppler ultrasonography. The ultrasound cross-sectional area measurements of the ulnar nerve were performed at three different levels: 2 cm proximal to the epicondyle, at the level of the epicondyle, and 2 cm distal to the epicondyle.

Results

In our healthy population, we found 21, 24 and 7% of ultrasound cross-sectional area ulnar nerve > 8 mm², respectively, at three different levels of measurement and 4, 7, and 0% US-CSA ulnar nerve > 10 mm². The intraclass correlation coefficient measured at three different site levels were good (0.7943, 0.7509) to moderate (0.5701).

Conclusions

Almost one-quarter of our healthy population had an ultrasound cross-sectional area ulnar nerve more than 8 mm² and few more than 10 mm². A cut-off of ultrasound cross-sectional area ulnar nerve measurement more than 10 mm² could be considered as pathological. No abnormal elbow ulnar nerve vascularization has been seen. This is the first step towards normal B-mode ulnar nerve values at the elbow to further detect pathological US findings as ulnar nerve entrapment.

Ultrasound scanning in the diagnosis of peripheral neuropathies

Nerve ultrasound scanning has become a valuable diagnostic tool in the routine workup of peripheral nerve disorders, effectively complementing conventional electrodiagnostic studies. The most relevant sonographic features are nerve size and structural integrity. Several peripheral neuropathies show characteristic and distinct patterns of nerve enlargement, allowing their early and accurate identification, and reducing test-burden and diagnostic delay for patients. In mononeuropathies such as carpal tunnel syndrome and ulnar neuropathy at the elbow, nerve enlargement develops only at specific sites of entrapment, while in polyneuropathy the nerve enlargement may be multifocal, regional or even diffuse. Nerve ultrasound scanning can reliably identify chronic inflammatory neuropathies, even when extensive electrodiagnostic studies fail, and it should therefore be embedded in routine diagnostic workup of peripheral neuropathies. In this paper we describe a potential diagnostic strategy to achieve this.

Optimal Choice of Ultrasound-Based Measurements for the Diagnosis of Ulnar Neuropathy at the Elbow: A Meta-Analysis of 1961 Examinations

OBJECTIVE. The purpose of this study was to determine the optimal ultrasound (US) measurement technique and cutoff value for the diagnosis of ulnar neuropathy at the elbow. MATERIALS AND METHODS. A systematic literature search was conducted of the PubMed, Embase, Scopus, and Web of Science databases for studies evaluating the diagnostic accuracy of US of patients with ulnar neuropathy at the elbow before April 2019. Random-effects modeling was performed to compare the sensitivity, specificity, and diagnostic odds ratio (DOR) of different US measurements, including diameter and cross-sectional area (CSA) of the nerve at the medial epicondyle or proximal and distal levels, maximal diameter, maximal CSA, and nerve ratios. Sensitivity and metaregression analyses were performed to assess the impact of clinical and imaging-based variables on the DOR of US. RESULTS. Among 820 retrieved studies, 19 studies (1961 examinations) were included. Measuring the CSA of the ulnar nerve at the medial epicondyle with a cutoff value greater than 10-10.5 mm² had higher sensitivity (80.4%, 95% CI, 75.4-84.7%) than other techniques. Nerve ratios had higher specificity (89.1%, 95% CI, 85.8-91.8%) than other measurements; however, the definition of ratios and cutoff values varied across studies. ROC analysis showed higher diagnostic performance for measuring CSA at the medial epicondyle (AUC, 0.931). The mean CSA value was a significant predictor of the DOR of US (β coefficient, 0.307 ± 0.074; p < 0.001). Every 1-mm² larger CSA was associated with a 36% increase in DOR. The diagnostic performance of US was the same in any degree of elbow flexion. CONCLUSION. Measuring CSA of the ulnar nerve at the medial epicondyle has sensitivity and diagnostic performance superior to those of other techniques for the diagnosis of ulnar neuropathy at the elbow.

Current and future applications of ultrasound imaging in peripheral nerve disorders

Neuromuscular ultrasound (NMUS) is a rapidly evolving technique used in neuromuscular medicine to provide complimentary information to standard electrodiagnostic studies. NMUS provides a dynamic, real time assessment of anatomy which can alter both diagnostic and management pathways in peripheral nerve disorders. This review describes the current and future techniques used in NMUS and details the applications and developments in the diagnosis and monitoring of compressive, hereditary, immune-mediated and axonal peripheral nerve disorders, and motor neuron diseases. Technological advances have allowed the increased utilisation of ultrasound for management of peripheral nerve disorders; however, several practical considerations need to be taken into account to facilitate the widespread uptake of this technique.

Conditions and Injuries Affecting the Nerves Around the Elbow

Sports-related peripheral neuropathies account for 6% of all peripheral neuropathies and most commonly involve the upper extremity. The routes of the median, radial, and ulnar nerves are positioned in arrangements of pulleys and sheaths to glide smoothly around the elbow. However, this anatomic relationship exposes each nerve to risk of compression. The underlying mechanisms of the athletic nerve injury are compression, ischemia, traction, and friction. Chronic athletic nerve compression may cause damage with moderate or low pressure for long or intermittent periods of time.

Ultrasound Measurements and Assessments of the Ulnar Nerve at the Elbow and Cubital Tunnel: A Scoping Review

Ulnar neuropathy at the elbow (UNE) is the second most frequent peripheral nerve entrapment neuropathy in the upper extremity. The diagnosis is determined through a combination of history, physical examination, and electrodiagnostic testing. However, the use of high-resolution sonography is increasing, with sonographic measurements of ulnar nerve dimension established as a reliable diagnostic criterion for UNE. Sonographic imaging can describe anatomical features beyond ulnar nerve size, and therefore additional observations could potentially be used in UNE diagnosis and treatment follow-up. This review was a scoping of the literature on different sonographic measurements and assessments that have been reported to evaluate the ulnar nerve and cubital tunnel. This should provide a guide to scanning protocols for sonographers.

Clinical Findings and Electrodiagnostic Testing in Ulnar Neuropathy at the Elbow and Differences According to Site and Type of Nerve Damage

OBJECTIVE

The aim of the study was to evaluate the clinical and electrodiagnostic testing in ulnar neuropathy at the elbow and differences according to site (humeroulnar arcade vs. retroepicondylar groove) and injury physiopathology (axonal vs. demyelinating), through prospective multicenter case-control study.

DESIGN

Cases and controls were matched by age and sex. Ulnar neuropathy at the elbow diagnosis was made on symptoms. Statistical analysis was performed using Mann-Whitney, χ, and analysis of variance tests.

RESULTS

One hundred forty-four cases and 144 controls were enrolled. Sensory loss in the fifth finger had the highest sensitivity (70.8%) compared with clinical findings. Motor conduction velocity across elbow reached the highest sensitivity (84.7%) in localizing ulnar neuropathy at the elbow recording from at least one of the two hand muscles (first dorsal interosseous and abductor digiti minimi). Abnormal sensory action potential amplitude from the fifth finger occurred more frequently in axonal than in demyelinating forms. Differences between retroepicondylar groove and humeroulnar arcade regarded conduction block and job type.

CONCLUSIONS

Clinical findings have less usefulness than electrodiagnostic testing in ulnar neuropathy at the elbow diagnosis. Motor conduction velocity across elbow recorded from both abductor digiti minimi and first dorsal interosseous increases diagnostic accuracy. Axonal forms have greater clinical and electrodiagnostic testing severity than demyelinating forms, which are more frequent in retroepicondylar groove. Manual workers prevailed in humeroulnar arcade. These findings may be helpful in prognostic and therapeutic approaches.

Nerve ultrasound can identify treatment-responsive chronic neuropathies without electrodiagnostic features of demyelination

Introduction

We present a case series of six treatment‐naive patients with clinical phenotypes compatible with chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy without electrodiagnostic features of demyelination but with abnormal peripheral ultrasound findings who responded to treatment.

Methods

All six patients underwent a complete set of ancillary investigations, including extensive nerve conduction studies. We also performed standardized nerve ultrasound of median nerves and brachial plexus as part of a larger effort to evaluate diagnostic value of sonography.

Results

Nerve conduction studies did not show conduction block or other signs of demyelination in any of the six patients. Sonographic nerve enlargement was present in all patients and was most prominent in proximal segments of the median nerve and brachial plexus. Treatment with intravenous immunoglobulin resulted in objective clinical improvement.

Discussion

Our study provides evidence that nerve ultrasound represents a useful complementary diagnostic tool for the identification of treatment‐responsive inflammatory neuropathies.

Ultrasound in Multifocal Motor Neuropathy: Clinical and Electrophysiological Correlations

OBJECTIVES

Multifocal motor neuropathy (MMN) is a treatable autoimmune polyneuropathy, which may prove challenging diagnostically in the setting of absent conduction blocks or advanced axonal loss. Relatively few studies have examined the role of ultrasound (US) in MMN.

METHODS

Retrospective, cross-sectional study of patients with MMN who underwent peripheral nerve US. Charts were reviewed to extract clinical, sonographic, and electrophysiological data.

RESULTS

Eleven patients with MMN underwent US between 2013 and 2015; of these 11 patients, 7 had ≥3 abnormal nerve segments, and 6 had ≥5 sites of increased cross-sectional area (CSA). There was moderate correlation between the degree of amplitude drop observed in the median and ulnar motor nerves, and CSA. Significant correlation between CSA and limb strength was only observed for the median nerve.

CONCLUSIONS

Peripheral nerve US shows promise as a diagnostic tool in MMN and may be helpful to distinguish MMN from motor neuron disease.

Entrapment Neuropathies of the Upper Extremity

Upper extremity entrapment neuropathies are common and can cause pain, sensory loss, and muscle weakness that lead to functional disability. In this article, the authors review common entrapment neuropathies of the upper extremities, including median neuropathy at the wrist (carpal tunnel syndrome), ulnar neuropathy at the elbow, and radial neuropathy. The authors discuss the pathophysiology of nerve compression and typical etiologies, as well as strategies for differentiating between common mimics such as cervical radiculopathy and for selecting between various treatment modalities.

Diagnostic value of ultrasonography versus electrodiagnosis in ulnar neuropathy

Purpose

Ulnar neuropathy at elbow is the second-most common compression neuropathy. The main aim of this study was to assess the diagnostic value of ultrasonography (US) as an alternative method to electrodiagnosis (EDX), which had traditionally been used as the method of choice.

Methods

This diagnostic study was conducted on 66 participants (32 patients` elbows and 34 normal elbows) referred for EDX. Both groups were reassessed by US to evaluate the consistency of the two tests. The quantitative parameters of US, such as cross-sectional area (CSA) of the ulnar nerve at three different levels around the medial epicondyle (ME) were compared between groups.

Results

Our findings demonstrated that CSA at the ME and 2 cm distal to the ME were significantly larger in the patient group than normal participants. This higher nerve size was more prominent among those who had predominant axonal loss rather than demyelinating lesions (P<0.01). Finally, we evaluated US diagnostic value with the best singular feature (2 cm distal to ME) at a cutoff of 9 mm², which revealed specificity of 80% and sensitivity 84%.

Conclusion

Based on these results we can conclude that US is a sensitive and specific method in diagnosing ulnar neuropathy at the elbow and can be used as an acceptable complementary method, in particular when EDX is not available.

Nerve ultrasound: A reproducible diagnostic tool in peripheral neuropathy

OBJECTIVE

To determine interobserver variability of nerve ultrasound in peripheral neuropathy in a prospective, systematic, multicenter study.

METHODS

We enrolled 20 patients with an acquired chronic demyelinating or axonal polyneuropathy and 10 healthy controls in 3 different centers. All participants underwent an extensive nerve ultrasound protocol, including cross-sectional area measurements of median, ulnar, fibular, tibial, and sural nerves, and brachial plexus. Real-time image acquisition was performed blind by a local and a visiting investigator (reference). Five patients were investigated using different types of sonographic devices. Intraclass correlation coefficients were calculated, and a random-effects model was fitted to identify factors with significant effect on interobserver variability.

RESULTS

Systematic differences between measurements made by different investigators were small (mean difference 0.11 mm2 [95% confidence interval 0.00-0.23 mm2]). Intraclass correlation coefficients were generally higher in arm nerves (0.48-0.96) than leg nerves (0.46-0.61). The hospital site and sonographic device did not contribute significantly to interobserver variability in the random-effects model.

CONCLUSIONS

Interobserver variability of nerve ultrasound in peripheral neuropathy is generally limited, especially in arm nerves. Different devices and a multicenter setting have no effect on interobserver variability. Therefore, nerve ultrasound is a reproducible tool for diagnostics in routine clinical practice and (multicenter) research.

The Use of Preoperative Dynamic Ultrasound to Predict Ulnar Nerve Stability Following In Situ Decompression for Cubital Tunnel Syndrome

PURPOSE

To assess the use of preoperative, dynamic ultrasound to predict ulnar nerve instability following in situ decompression for cubital tunnel syndrome.

METHODS

Prior to undergoing in situ decompression, 43 consecutive patients underwent dynamic ultrasound to assess the stability of the ulnar nerve during elbow flexion. The dynamic ultrasound findings were compared with the intraoperative assessment of nerve stability following in situ decompression.

RESULTS

The preoperative dynamic ultrasound agreed with intraoperative findings in 38 of 43 patients (88%). Physical examination of ulnar nerve stability agreed with the intraoperative findings in 5 of 43 patients (12%). For the 5 of 43 cases in which the dynamic ultrasound did not correlate with the degree of ulnar nerve stability after in situ decompression, dynamic ultrasound overestimated the degree of ulnar nerve stability in 4 cases.

CONCLUSIONS

Preoperative dynamic ultrasound can be used to accurately predict the degree of ulnar nerve instability following in situ decompression.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Indications for neuromuscular ultrasound: Expert opinion and review of the literature

Over the last two decades, dozens of applications have emerged for ultrasonography in neuromuscular disorders. We wanted to measure its impact on practice in laboratories where the technique is in frequent use. After identifying experts in neuromuscular ultrasound and electrodiagnosis, we assessed their use of ultrasonography for different indications and their expectations for its future evolution. We then identified the earliest papers to provide convincing evidence of the utility of ultrasound for particular indications and analyzed the relationship of their date of publication with expert usage. We found that experts use ultrasonography often for inflammatory, hereditary, traumatic, compressive and neoplastic neuropathies, and somewhat less often for neuronopathies and myopathies. Usage significantly correlated with the timing of key publications in the field. We review these findings and the extensive evidence supporting the value of neuromuscular ultrasound. Advancement of the field of clinical neurophysiology depends on widespread translation of these findings.

Neuromuscular ultrasound in electrically non-localizable ulnar neuropathy

INTRODUCTION

The aim of this study was to determine the value of high-resolution ultrasound (HRUS) in patients with ulnar neuropathy whose electrophysiology displayed an axonal, non-localizing pattern.

METHODS

A prospective study of patients referred to an electromyography laboratory for ulnar neuropathy was performed. Of the 56 patients with clinical and electrodiagnostic (EDx) evidence of ulnar neuropathy, 12 were identified with non-localizing electrophysiology who subsequently underwent HRUS of the ulnar nerve.

RESULTS

HRUS localized the ulnar neuropathy in all patients. In 2 patients, HRUS demonstrated structural lesions not at the elbow.

DISCUSSION

HRUS often adds complementary information to standard EDx studies, including ulnar neuropathy. Thus, HRUS should be employed in patients with a non-localizing ulnar neuropathy on EDx studies. Muscle Nerve 58: 655-659, 2018.

Ulnar neuropathy with abnormal non-localizing electrophysiology: Clinical, electrophysiological and ultrasound findings

OBJECTIVE

To systematically study demographic, clinical, electrophysiological and nerve ultrasound characteristics of ulnar neuropathy with abnormal non-localizing electrophysiology (NL-UN) and further define the utility of ultrasound over and above the conventional electro-diagnostic approach.

METHOD

NL-UNs were prospectively identified from 113 consecutive referrals with suspected ulnar neuropathy. All received electro-diagnostic tests and ulnar nerve ultrasound. NL-UN severity was graded using clinical and electrophysiological scales.

RESULTS

In 64 of 113 referrals, an ulnar mono- neuropathy was confirmed by electrophysiology. Sixteen of these 64 (25%) had NL-UN, predominantly males (14 out of 16 patients) with severe or moderate clinical and electrophysiological ratings. Ultrasound showed focal ulnar neuropathy at the elbow in 13 out of 16, and diffuse ulnar nerve abnormality in three, and identified a likely or possible causative mechanism in 11.

CONCLUSION

A significant proportion (a quarter) of ulnar neuropathies with abnormal electrophysiology were NL-UN, of heterogeneous etiology; the majority were males with significant disability and axonal loss. Ultrasound had a significant role in localization and classification that facilitated management.

SIGNIFICANCE

To our knowledge, this is the first systematic prospective study that analyzes the demographic, clinical, electrophysiological and ultrasound characteristics of NL-UN in a routine clinical neurophysiology setting.

Prevalence of carpal tunnel syndrome presenting with symptoms in an ulnar nerve distribution: A prospective study

INTRODUCTION

Patients presenting with symptoms of pain/paresthesias primarily in an ulnar nerve distribution may be noted to have exclusive median mononeuropathy at the wrist on subsequent electrodiagnostic testing. There has been limited research looking at the prevalence of this clinical presentation.

METHODS

A cohort of adults were surveyed to assess for severity and localization of hand symptoms using the Katz hand diagram and Boston Carpal Tunnel Questionnaire Symptoms Severity Scale. Thirty volunteers met our case definition for ulnar neuropathy and underwent a standardized physical examination, electrodiagnostic testing, and nerve ultrasound.

RESULTS

Eleven of 30 subjects (37%) were found to have exclusive median mononeuropathy at the wrist.

DISCUSSION

Carpal tunnel syndrome should remain high on the differential for patients presenting with symptoms of pain/paresthesias primarily in an ulnar nerve distribution. Muscle Nerve 59:60-63, 2019.

A Novel Diagnostic and Prognostic Tool for Simple Decompression of Ulnar Nerve in Cubital Tunnel Syndrome

BACKGROUND

Surgical decompression of the ulnar nerve (UN) is effective for treating cubital tunnel syndrome (CubTS). Nevertheless, the outcome is not always satisfying. Different surgical, clinical, and imaging findings have been claimed as outcome predictors, but there is no consensus in the literature. We analyzed the outcome-predicting role of ultrasonography (US) of the UN in patients with CubTS and its possible role for diagnosis and follow-up.

METHODS

Patients with CubTS treated by simple UN decompression underwent US and electrodiagnotic (ED) studies of the UN at the elbow before and after surgery. Outcome was evaluated through the Bishop scale. A correlation analysis between pre- and postoperative clinical, US, and ED findings was performed.

RESULTS

Thirty-six patients were enrolled. Preoperatively, we observed a negative correlation between the motor conduction velocity (MCV) and the transverse (TD) and anteroposterior diameters and cross-sectional area (CSA) of the UN at the precubital (P = 0.001, P = 0.001, P = 0.005) and cubital level (P = 0.02, P = 0.002, P = 0.001). Preoperative precubital TD and CSA were associated with outcome (P = 0.01, P = 0.006) and postoperative MCV (P = 0.004, P = 0.008). The cut-off values TD >6 mm and CSA >23.91 mm² were predictors of poor outcome. Finally, postoperative cubital TD and CSA values were inversely correlated with outcome (P = 0.0002, P = 0.0007) and postoperative MCV (P = 0.0002, P = 0.0004).

CONCLUSIONS

The US examination of the UN is useful for the management of patients with CubTS as an adjunct to clinical and ED evaluations. US measurements are correlated with pre- and postoperative ED findings and thus are useful for diagnosis and follow-up. Interestingly, specific precubital US measurements are good predictors of outcome.

Investigation of the Effect of Cervical Radiculopathy on Peripheral Nerves of the Upper Extremity With High-Resolution Ultrasonography

STUDY DESIGN

Prospective, cross-sectional observational study.

OBJECTIVE

We aimed to investigate the effects of chronic cervical radiculopathy (CR) on the cross-sectional area (CSA) values of the cervical nerve roots (CNRs), median, ulnar, and radial nerves with high-resolution ultrasonography.

SUMMARY OF BACKGROUND DATA

Symptomatic nerve roots are wider than asymptomatic nerve roots due to the presence of edema. Peripheral nerves have also been shown to develop edema, fibrosis, and changes distal to the affected nerve as a result of mechanical compression. In addition according to "double-crush syndrome" hypothesis, the peripheral nerves are more sensitive to pressure, and a proximal nerve lesion makes the distal segment of the nerve more susceptible to anatomic deterioration by causing interruption in the axoplasmic conduction due to compression.

METHODS

Forty patients with chronic CR were included to the study. Both affected CNRs and the contralateral nerve roots (control group) were evaluated with high-resolution ultrasonography. Ulnar and median nerve CSA measurements were performed at four measurement points and radial nerve measurements at a single measurement point.

RESULTS

CSA measurements were statistically significantly higher at the CNR of the affected side compared to the unaffected side. There was no statistically significant difference when affected and unaffected sides were compared in terms of measurements performed from median, ulnar, and radial nerves at all measurement points.

CONCLUSION

The results of the present study indicate that the changes in the CNR caused by CR do not have any effect on the peripheral nerves. We did not find any affection in peripheral nerve CSA that might have been suggestive of double-crush syndrome in CR.

LEVEL OF EVIDENCE

2.

[Diagnostic nerve ultrasonography]

CLINICAL/METHODICAL ISSUE

For the diagnostics of nerve lesions an imaging method is necessary to visualize peripheral nerves and their surrounding structures for an etiological classification.

STANDARD RADIOLOGICAL METHODS

Clinical neurological and electrophysiological investigations provide functional information about nerve lesions. The information provided by a standard magnetic resonance imaging (MRI) examination is inadequate for peripheral nerve diagnostics; however, MRI neurography is suitable but on the other hand a resource and time-consuming method.

METHODICAL INNOVATIONS

Using ultrasonography for peripheral nerve diagnostics.

PERFORMANCE

With ultrasonography reliable diagnostics of entrapment neuropathies and traumatic nerve lesions are possible. The use of ultrasonography for neuropathies shows that a differentiation between different forms is possible.

ACHIEVEMENTS

Nerve ultrasonography is an established diagnostic tool. In addition to the clinical examination and clinical electrophysiology, structural information can be obtained, which results in a clear improvement in the diagnostics. Ultrasonography has become an integral part of the diagnostic work-up of peripheral nerve lesions in neurophysiological departments.

PRACTICAL RECOMMENDATIONS

Nerve ultrasonography is recommended for the diagnostic work-up of peripheral nerve lesions in addition to clinical and electrophysiological investigations. It should be used in the clinical work-up of entrapment neuropathies, traumatic nerve lesions and spacy-occupying lesions of nerves.

Electrophysiological examination and high frequency ultrasonography for diagnosis of radial nerve torsion and compression

This study aims to evaluate the value of electrophysiological examination and high frequency ultrasonography in the differential diagnosis of radial nerve torsion and radial nerve compression.Patients with radial nerve torsion (n = 14) and radial nerve compression (n = 14) were enrolled. The results of neurophysiological and high frequency ultrasonography were compared.Electrophysiological examination and high-frequency ultrasonography had a high diagnostic rate for both diseases with consistent results. Of the 28 patients, 23 were positive for electrophysiological examination, showing decreased amplitude and decreased conduction velocity of radial nerve; however, electrophysiological examination cannot distinguish torsion from compression. A total of 27 cases showed positive in ultrasound examinations among all 28 cases. On ultrasound images, the nerve was thinned at torsion site whereas thickened at the distal ends of torsion. The diameter and cross-sectional area of torsion or compression determined the nerve damage, and ultrasound could locate the nerve injury site and measure the length of the nerve.Electrophysiological examination and high-frequency ultrasonography can diagnose radial neuropathy, with electrophysiological examination reflecting the neurological function, and high-frequency ultrasound differentiating nerve torsion from compression.

Ultrasonographic Evaluation of the Radial Nerves in Patients with Unilateral Refractory Lateral Epicondylitis

Objective

To evaluate the possible radial nerve entrapment of patients with unilateral refractory lateral epicondylitis (LE) by using ultrasound (US) and electroneuromyography.

Design

Cross-sectional study.

Setting

Three physical medicine and rehabilitation departments.

Subjects

Consecutive 44 patients (15 M, 29 F) with unilateral refractory LE.

Methods

All patients underwent detailed clinical, electrophysiological and ultrasonographic evaluations. Ultrasound imaging was used to evaluate thickness and presence of abnormal findings of the common extensor tendon (CET) and cross-sectional area (CSA) of the radial nerve (at spiral groove and before bifurcation) bilaterally. Unaffected sides of the patients were taken as controls.

Results

When compared with the unaffected sides, CET thickness and radial nerve CSAs (at both levels) were higher, and abnormal US findings regarding LE (47.7% vs. 6.8%) were more common on the affected sides than nonaffected sides (all P  < 0.001). Grip strength values were lower on the affected sides ( P  < 0.001). Electrophysiological studies were all normal, and similar between the two sides (all P  > 0.05). When subgroup analyses were performed after taking into account the hand dominance, affected and dominant sides were found to be the same in 31 and different in 13 patients. In subgroups, CETs and radial nerve CSAs at both levels were higher on the affected sides (all P  < 0.01).

Conclusions

Radial nerves and the CETs seem to be swollen on the affected sides, independent from the hand dominance of the patients with refractory LE. These results morphologically support the previous literature that attributes some of the chronic complaints of these patients actually to radial nerve entrapment.

Ulnar Nerve Cross-Sectional Area for the Diagnosis of Cubital Tunnel Syndrome: A Meta-Analysis of Ultrasonographic Measurements

OBJECTIVE

To examine the performance of sonographic cross-sectional area (CSA) measurements in the diagnosis of cubital tunnel syndrome (CuTS).

DATA SOURCES

Electronic databases, comprising PubMed and EMBASE, were searched for the pertinent literature before July 1, 2017.

STUDY SELECTION

Fourteen trials comparing the ulnar nerve CSA measurements between participants with and without CuTS were included.

DATA EXTRACTION

Study design, participants' demographic characteristics, diagnostic reference of CuTS, and methods of CSA measurement.

DATA SYNTHESIS

Among different elbow levels, the between-group difference in CSA was the largest at the medial epicondyle (6.0mm²; 95% confidence interval [CI], 4.5-7.4mm²). The pooled mean CSA in participants without CuTS was 5.5mm² (95% CI, 4.4-6.6mm²) at the arm level, 7.4mm² (95% CI, 6.7-8.1mm²) at the cubital tunnel inlet, 6.6mm² (95% CI, 5.9-7.2mm²) at the medial epicondyle, 7.3mm² (95% CI, 5.6-9.0mm²) at the cubital tunnel outlet, and 5.5mm² (95% CI, 4.7-6.3mm²) at the forearm level. The sensitivities, specificities, and diagnostic odds ratios pooled from 5 studies, using 10mm² as the cutoff point, were .85 (95% CI, .78-.90), .91 (95% CI, .86-.94), and 53.96 (95% CI, 14.84-196.14), respectively.

CONCLUSIONS

The ulnar nerve CSA measured by ultrasound imaging is useful for the diagnosis of CuTS and is most significantly different between patients and participants without CuTS at the medial epicondyle. Because the ulnar nerve CSA in healthy participants, at various locations, rarely exceeds 10mm², this value can be considered as a cutoff point for diagnosing ulnar nerve entrapment at the elbow region.

Diagnosing carpal tunnel syndrome with Doppler ultrasonography: a comparison of ultrasonographic measurements and electrophysiological severity

INTRODUCTION

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. Diagnosis is based on clinical history, physical examination, and electrophysiological studies. Imaging techniques are performed for difficult-to-diagnose cases because they provide information about the morphology of the median nerve. More recently, it has been shown that Doppler ultrasonography can detect increased intraneural blood flow in CTS. The aim of our study is to evaluate the relationship between the severity of CTS, hypervascularization, and cross-sectional area (CSA) to determine the diagnostic value of Doppler ultrasonography.

PATIENTS AND METHODS

The study group comprised 125 wrists of 75 patients who had been diagnosed with CTS, both clinically and electrophysiologically. The control group comprised 100 wrists of 50 healthy volunteers. Wrists were classified into five stages of CTS severity based on electrophysiologic studies. A radiologist examined the wrists blindly with grayscale images and Doppler ultrasonography to assess CSA and hypervascularization.

RESULTS

A total of 121 wrists were included. There were 28 wrists with minimal CTS severity stage, 36 with mild, 36 with moderate, and 21 with severe. The sensitivity and specificity of CSA and hypervascularization in detecting CTS was 90.9, 94.0, 93.4, and 90.0%, respectively. There was a significant correlation between CTS severity and hypervascularization (p < 0.005) for all stages.

CONCLUSION

Our study shows that Doppler ultrasonography results strongly correlate with CTS severity. Hence, this is a useful method for diagnosing CTS and estimating its severity.

Ultrasonography has a diagnostic value in the assessment of cervical radiculopathy: A prospective pilot study

OBJECTIVE

This study investigated the diagnostic accuracy of the difference in the cross-sectional areas (CSAs) of affected cervical nerve roots (NRs) for diagnosing cervical radiculopathy (CR).

METHODS

In total, 102 CR patients and 219 healthy volunteers were examined with ultrasound. The CSA of the cervical NR at each level was measured on the affected side and the contralateral side in CR patients by blinded ultrasonographic technicians. The difference between the CSAs of CR patients and normal volunteers and the difference in the laterality of CSA at the same affected level (ΔCSA) were calculated for each cervical level.

RESULTS

The CSAs of the affected NRs in CR patients were significantly larger than those of the unaffected NRs in CR patients and those of the control group at the C5, C6 and C7 levels (P<0.005). ΔCSA was also significantly larger in the CR group at all levels (P<0.001). A receiver operating characteristic analysis demonstrated that the threshold values were 9.6 mm² (CSA) for C5NR and 15 mm² for both C6NR and C7NR.

CONCLUSIONS

This study revealed that the CSAs of affected NRs were enlarged and that the laterality of the CSA (ΔCSA) was greater in CR patients than in control patients.

KEY POINTS

• Cervical radiculopathy is diagnosed through ultrasonographic measurement of the CSAs. • The CSAs of affected nerve roots were significantly enlarged. • The ΔCSA in the CR group was significantly higher than in the control group. • Diagnostic CSA and ΔCSA thresholds were identified.