Clinical Features and Electrodiagnosis of Ulnar Neuropathies

Endoscopic Versus Open In Situ Decompression for the Management of Cubital Tunnel Syndrome

This study compared the results of endoscopic cubital tunnel release (eCuTR) with those of open cubital tunnel release (oCuTR) for the management of cubital tunnel syndrome (CuTS). In this retrospective study, 35 patients underwent eCuTR or oCuTR. Group I and group II consisted of 16 patients undergoing eCuTR and 19 patients undergoing oCuTR, respectively. Patients were asked to report paresthesia and pain, and electromyography was performed. The Dellon and Bishop classifications were used. The Disabilities of the Arm, Shoulder and Hand (DASH) and visual analog scale (VAS) pain scores were recorded, as well as the key pinch strength and two-point discrimination. The incision length and operation duration were noted. The mean follow-up was 39 months. The mean operating time was longer in the endoscopy group (43 vs 22 minutes). Overall, 34.3% (n=12) of the cases were classified as Dellon grade II and 65.7% (n=23) were classified as Dellon grade III. According to the Bishop score, excellent or good results were obtained for 75% of the patients in the eCuTR group and 78.9% of the patients in the oCuTR group. In the eCuTR and oCuTR groups, all outcome measures improved after surgery: DASH score (preoperative, 37.7 vs 30.7; postoperative, 15.4 vs 20), VAS score (preoperative, 7.8 vs 7.3; postoperative, 4.3 vs 4.1), pinch strength (preoperative, 74 vs 66; postoperative, 93 vs 84), and two-point discrimination (preoperative, 5.6 vs 6.6; postoperative, 4.9 vs 4.5). No significant difference was apparent between the two techniques in outcomes. However, the endoscopic release had a higher reoperation rate and took twice as long to perform despite having a shorter incision. [Orthopedics. 2024;47(3):e119-e124.].

Do Socioeconomic Factors Affect Symptom Duration and Disease Severity at Presentation for Cubital Tunnel Syndrome?

BACKGROUND

Socioeconomic factors have been implicated in delayed presentation for compressive neuropathies of the upper extremity. Our article seeks to elucidate the effect of socioeconomic factors on self-reported symptom duration and objective disease severity at presentation for cubital tunnel syndrome.

METHODS

This retrospective cohort study included 207 patients with surgical management of cubital tunnel syndrome at 2 institutions between June 1, 2015, and March 1, 2020. Exclusion criteria included age under 18 years, revision surgery, lack of preoperative electrodiagnostic studies, and concurrent additional surgeries. Response variables were self-reported symptom duration, time from presentation to surgery, McGowan grade, and electrodiagnostic measures. Explanatory variables included age, sex, white race, diabetes mellitus, depression, anxiety, and the Distressed Communities Index.

RESULTS

Symptom duration was associated with nonwhite race, and time from presentation to surgery was associated with insurance provider. More clinically severe disease was associated with older age, male sex, and not having carpal tunnel syndrome. Nonrecordable sensory nerve action potential latency was associated with older age, higher body mass index, male sex, diabetes mellitus, and unemployment. Nonrecordable conduction velocities were associated with older age, and having fibrillations at presentation was associated with older age, male sex, and unemployment.

CONCLUSIONS

Economic distress is not associated with self-reported symptom duration, time from presentation to surgery, or presenting severity of cubital tunnel syndrome. White patients presented with shorter self-reported symptom duration. Insurance type was associated with delay from presentation to surgery. Older age and male sex were risk factors for more clinically severe disease at presentation.

Modern Treatment of Cubital Tunnel Syndrome: Evidence and Controversy

Cubital tunnel syndrome is the second most common peripheral mononeuropathy in the upper extremity. However, the diagnosis and treatment of cubital tunnel syndrome remains controversial without a standard algorithm. Although diagnosis can often be made from the patient's history and physical examination alone, electrodiagnostic studies, ultrasound, computed tomography (CT), and magnetic resonance image (MRI) can also be useful in diagnosing the disease and selecting the most appropriate treatment option. Treatment options include conservative nonoperative techniques as well as various surgical options, including in situ decompression with or without transposition, medial epicondylectomy, and nerve transfer in advanced disease. The purpose of this review is to summarize the most up-to-date literature regarding cubital tunnel syndrome and propose a treatment algorithm to provide clarity about the challenges of treating this complex patient population.

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.

Factors Associated With Severity of Cubital Tunnel Syndrome at Presentation

BACKGROUND

The outcomes of cubital tunnel syndrome surgery are affected by preoperative disease severity. The aim of this study was to identify factors associated with clinical and electrodiagnostic severity of cubital tunnel syndrome at presentation.

METHODS

We retrospectively identified 213 patients with electrodiagnostically confirmed cubital tunnel syndrome who underwent cubital tunnel surgery from July 2008 to June 2013. Our primary response variable was clinical cubital tunnel syndrome severity assessed by the McGowan grade. Our secondary response variables were sensory nerve action potential (SNAP) recordability, presence of fibrillations, and motor nerve conduction velocities (CVs) in the abductor digiti minimi (ADM) and first dorsal interosseous (FDI). Bivariate analysis was used to screen for factors associated with disease severity; significant variables were selected for multivariable regression analysis.

RESULTS

Older age was associated with higher McGowan grade and diabetes mellitus was associated with unrecordable SNAPs on bivariate analysis. No other variables met inclusion criteria for multivariable regression analysis for McGowan grade or unrecordable SNAPs. Multivariable regression analysis showed older age and higher Distressed Communities Index (DCI) to be associated with decreased motor nerve CVs in ADM. Multivariable regression analysis showed higher body mass index (BMI) and higher DCI to be associated with decreased motor nerve CVs in FDI. No variable was associated with the presence of fibrillations.

CONCLUSIONS

A subset of patients with cubital tunnel syndrome may benefit from earlier referral for hand surgery evaluation and earlier surgery. Older patients, with higher BMI, with diabetes mellitus, and with economic distress are at higher risk for presentation with more severe disease.

Influence of ergonomic factors on peripheral neuropathy under HAV exposure

BACKGROUND

Hand-arm vibration (HAV) is a risk factor for carpal tunnel syndrome (CTS) and ulnar neuropathy at the elbow (UNE). It is unclear how ergonomic factors influence the relationship between HAV exposure and CTS and UNE.

AIMS

We aimed to assess the relationship between cumulative HAV exposure and CTS and UNE in workers exposed to HAV from two tools with different ergonomic profiles.

METHODS

We performed nerve conduction studies (NCSs) of the sensory and motor median and ulnar nerves and recorded symptoms indicating CTS and UNE in workers exposed to HAV from impact wrenches or from rock drills. Exposure was measured as cumulative lifetime exposure. We used linear regression adjusted for age and body mass index to assess linear relationships.

RESULTS

Sixty-five workers participated (33 rock drill and 32 impact wrench operators). We found inverse linear associations between cumulative HAV exposure and median nerve sensory conduction velocity in impact wrench operators and ulnar nerve motor conduction velocity in rock drill operators (beta of 0.63 and 0.75). Based on NCS findings and symptoms, seven impact wrench operators had CTS and one UNE, and four rock drill operators had CTS and six UNE.

CONCLUSIONS

Our findings indicate that ergonomic factors influence the development of CTS and UNE under HAV exposure. The ergonomic profile seems to influence which type of neuropathy workers exposed to HAV will develop. Design of occupational exposure guidelines and future studies should be based on ergonomic profile and exposure characteristics for different tools and not merely HAV.

Electrodiagnostic Predictors of Outcomes After In Situ Decompression of the Ulnar Nerve

PURPOSE

Patients with severe ulnar neuropathy at the elbow frequently experience suboptimal surgical outcomes. Clinical symptoms alone may not accurately represent the severity of underlying nerve injury, calling for objective assessment tools, such as electrodiagnostic studies. The goal of our study was to determine whether specific electrodiagnostic parameters can be used to predict the outcomes after in situ decompression of the ulnar nerve.

METHODS

This prospective study enrolled consecutive patients aged ≥18 years diagnosed with ulnar neuropathy at the elbow. Patients completed a baseline battery of motor, sensory, functional, and electrodiagnostic tests before undergoing in situ decompression of the ulnar nerve. They were reassessed at 6 weeks, 3 months, 6 months, and 12 months after surgery. Forty-two patients completed at least 2 follow-up assessments and were included in the study.

RESULTS

When controlling for other electrodiagnostic measurements and demographic factors, none of the electrodiagnostic parameters were predictive of outcomes at 12 months after surgery. Patients with decreased compound muscle action potential amplitudes demonstrated slower trends of recovery in grip strength, pinch strength, and overall scores on the Michigan Hand Outcomes Questionnaire as well as its function, work, and activities of daily living subscales, Disabilities of the Arm, Shoulder, and Hand questionnaire, and the Carpal Tunnel Questionnaire. Decreased motor nerve conduction velocity was predictive of slower recovery of 2-point discrimination and pinch strength.

CONCLUSIONS

Compound muscle action potential amplitude, but not other conventional electrodiagnostic parameters, was predictive of functional outcomes after in situ decompression of the ulnar nerve. This parameter should play a role in determining the timing and prognosis of treatment for ulnar neuropathy at the elbow.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Utility of carpal tunnel release and ulnar decompression in CMT1A and HNPP

INTRODUCTION/AIMS

Carpal and cubital tunnel syndrome (CTS, CuTS) are common among patients with hereditary neuropathy with liability to pressure-palsies (HNPP) and Charcot-Marie-Tooth-1A (CMT1A), and may impact quality of life. We aimed to evaluate the utility of nerve decompression surgeries in these patients.

METHODS

Medical records were reviewed for patients with PMP22 mutation confirmed in Mayo Clinic laboratories from January 1999 to December 2020, who had CTS and CuTS and underwent surgical decompression.

RESULTS

CTS occurred in 53.3% of HNPP and 11.5% of CMT1A, while CuTS was present in 43.3% of HNPP and 5.8% of CMT1A patients. CTS decompression occurred in 10-HNPP and 5-CMT1A patients, and CuTS decompression with/without transposition was performed in 5-HNPP and 1-CMT1A patients. In HNPP, electrodiagnostic studies identified median neuropathy at the wrist in 9/10 patients and ultrasound showed focal enlargements at carpal and cubital tunnels. In CMT1A, median and ulnar sensory responses were all absent, and the nerves were diffusely enlarged. After CTS surgery, pain, sensory loss, and strength improved in 4/5 CMT1A, and 6/10 HNPP patients. Of clinical, electrophysiologic and ultrasound findings, only activity-provoked features significantly correlated with CTS surgical benefit in HNPP patients (odds ratio=117.0:95% CI 1.94>999.99, p=0.01). One CMT1A and one HNPP patient improved with CuTS surgery while 2 HNPP patients worsened.

DISCUSSION

CTS symptom improvement post-surgery can be seen in CMT1A and (less frequent) in HNPP patients. CuTS surgery commonly worsened course in HNPP. Activity-provoked symptoms in HNPP best informed benefits from CTS surgery.

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.

Classifying the Severity of Cubital Tunnel Syndrome: A Preoperative Grading System Incorporating Electrodiagnostic Parameters

BACKGROUND

Current classifications for cubital tunnel syndrome have not been shown to reliably predict postoperative outcomes. In this article, the authors introduce a new classification that incorporates clinical and electrodiagnostic parameters, including compound muscle action potential amplitude, to classify the preoperative severity of cubital tunnel syndrome. The authors compare this to established classifications and evaluate its association with patient-rated improvement.

METHODS

The authors reviewed 44 patients who were treated surgically for cubital tunnel syndrome. Patients were retrospectively classified using their proposed classification and the Akahori, McGowan-Goldberg, Dellon, and Gu classifications. Correlation of grades was assessed by Spearman coefficients and agreement was assessed by weighted kappa coefficients. Patient-reported impairment was assessed using the Disabilities of the Arm, Shoulder, and Hand questionnaire before and after surgery.

RESULTS

The classifications tended to grade patients in a similar way, with Spearman coefficients of 0.60 to 0.85 ( p < 0.0001) and weighted kappa coefficients of 0.46 to 0.71 ( p < 0.0001). Preoperative Disabilities of the Arm, Shoulder, and Hand scores increased with severity grade for most classifications. In multivariable analysis, the authors' classification predicted postoperative Disabilities of the Arm, Shoulder, and Hand score improvement, whereas established classifications did not.

CONCLUSIONS

Established classifications are imperfect indicators of preoperative severity. The authors introduce a preoperative classification for cubital tunnel syndrome that incorporates electrodiagnostic findings in addition to classic signs and symptoms.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, III.

Nerve Imaging in the Wrist

Neuropathic symptoms involving the wrist are a common clinical presentation that can be due to a variety of causes. Imaging plays a key role in differentiating distal nerve lesions in the wrist from more proximal nerve abnormalities such as a cervical radiculopathy or brachial plexopathy. Imaging complements electrodiagnostic testing by helping define the specific lesion site and by providing anatomical information to guide surgical planning. This article reviews nerve anatomy, normal and abnormal findings on ultrasonography and magnetic resonance imaging, and common and uncommon causes of neuropathy.

A retrospective study of electrodiagnostically evaluated ulnar neuropathies with special guidelines for ulnar neuropathies at elbow

Background

The diagnosis of type, severity of ulnar neuropathy based on symptoms and clinical tests are unsatisfactory. This study aimed to retrospectively analyze ulnar neuropathies at different sites evaluated through electrodiagnostic studies (EDx), especially for ulnar neuropathy at elbow (UNE).

Results

Total 270 ulnar neuropathy patients’ data were recruited from laboratory record over a five-year period (2016–2021).Their demographic data, clinical history and EDx parameters were analyzed focusing on etiology, nerve lesion types, 5th-digit sensory, dorsal ulnar cutaneous nerve (DUCN) conduction, motor nerve conduction velocity (NCV) across elbow along with EMG of ADM, FDI, FCU, FDP muscles. The patients grouped into traumatic injuries—27.8% (T) and 72.2% non-traumatic (NT) had varied sensory-motor symptoms: pain—10%, altered sensation—28.1%, pain-paresthesia—14.8%, atrophy—25.2% and clawing—8.9%. UNE was the most prevalent (82.75%-NT, 66.67% -T) with < 50 m/s motor and sensory NCV across elbow. Compound muscle action potential (CMAP) amplitude > 50% drop across elbow was seen in 55.17%-NT and 54.16%-T groups. Abnormal DUCN and short-segment inching NCV were less frequently noted. In EMG, ADM (T-83.33% and NT-65.51%) and FDI (T-70.83% and NT-68.96%) muscles were evaluated the most and FDP the least.

Conclusion

UNE was the most common followed by forearm and wrist. NCV and CMAP across elbow are stronger EDx parameters for UNE. Neuropathy was irrespective of gender and prevalent at early of middle age. The EDx could be considered as one of the most valuable tests in confirming the localization, severity and type of ulnar nerve lesion, which favors management and prognosis of patient.

Influential factors of surgical decompression for ulnar nerve neuropathy in Guyon's canal

BACKGROUND

Guyon's canal syndrome is nerve compressive pathology which can lead to sensory and/or motor function deficits. This problem is usually difficult to distinguish from cubital tunnel syndrome and relatively less common than cubital tunnel syndrome. This study evaluated the functional results and patient-reported outcomes following decompression of the ulnar nerve in Guyon's canal.

METHODS

Patients who were diagnosed with Guyon's canal syndrome confirmed by electrodiagnostic studies and underwent nerve decompression surgery were included in this study. The functional improvement by examining the Froment's sign, Wartenberg's sign, static two-point discrimination, and Semmes Weinstein monofilament examination as physical examination scores was evaluated. The visual analogue scale of satisfaction and the disabilities of the arm, shoulder, and hand questionnaire were used for the postoperative patient-reported outcome evaluation.

RESULTS

From 2003 to 2019, 38 cases had been enrolled with a mean age of 53 years, ranging from 19 to 85 years. There were seven patients with comorbidity of diabetes mellitus and 28 patients who received additional neurolysis combined with the Guyon's release procedure. There were 19 patients with a good response to surgery and 10 patients with a poor surgical outcome due to persistent paresthesia or weakness. After statistical analysis, it was revealed that several influential factors could have been related to a compromised functional outcome, including a symptom duration of more than 3 months, combination with additional neurolysis of ipsilateral extremity, and/or comorbidity with diabetes mellitus.

CONCLUSION

It was concluded that promising functional outcomes after surgical release of ulnar neuropathy in Guyon's canal could be achieved if the patients did not need additional neurolysis or the symptom duration was within 3 months.

Differential Diagnosis for the Painful Tingling Arm

ABSTRACT

The painful tingling arm is a common presenting complaint for the musculoskeletal physician. The differential diagnosis for upper-extremity pain associated with paresthesias will be the focus of this review. Symptoms are often neurologic in etiology, originating from the spinal cord, nerve root(s), brachial plexus, or peripheral nerve(s). Localizing the pathology starts with a comprehensive understanding of neuromuscular anatomy. It also is imperative to understand the function of these respective structures. The differential diagnosis can be narrowed with a thorough history, including an assessment of sport-specific risk factors, along with a comprehensive physical examination and functional assessment. It is important to determine the sensory distribution of the patient's symptoms. If weakness also is present, the affected muscles must be identified. While the diagnosis can often be made clinically, electrodiagnostics, magnetic resonance imaging, and ultrasound can be used as needed for confirmation and more specific localization. Nonneurologic structures also may be causative or contributory to the patient's symptoms and also should be considered.

Nerve entrapment around elbow

Entrapment neuropathy around elbow is a common cause of disability across all age groups. The major nerves that traverse the elbow are ulnar, median and radial nerves and their branches. Cubital tunnel syndrome leading to ulnar nerve compression can often present with significant pain, paresthesia or weakness. Median and Radial nerve compression around the elbow, albeit less frequent, can also lead to significant morbidity and must be kept in the differential diagnosis when dealing with patients complaining of persistent pain around the elbow and weakness of forearm/hand muscles. Electrodiagnostic studies can be a useful adjunct to clinical examination, to help localize the site and quantify the grade of compression. Management should involve a trial of conservative treatment and failing that, surgical treatment should be considered. We hereby provide an overview of nerve entrapments around the elbow including their applied anatomy, etiology, clinical assessment and overview of the current concepts in surgical treatment.

Ultrasonography evaluation of the normal ulnar nerve in adult: Comparison of the cross-sectional area at elbow extension and flexion

Background

Cross-sectional area (CSA) measurement of the ulnar nerve in the adult population by using ultrasonography (US) at elbow extension and flexion has previously been reported, but not much evidence showed a significant difference between elbow extension and flexion position.

Purpose

To compare the ulnar nerve CSA between elbow extension and flexion position.

Methods

A comparative cross-sectional study was conducted by involving 36 healthy adults with normally functioning ulnar nerve proven by Nerve Conduction Study (NCS) or Electroneurography. The ulnar nerve CSA was measured on each elbow by using US at the level of the medial epicondyle, 2 cm distal and 2 cm proximal from the medial epicondyle.

Results

The average ulnar nerve CSA at the medial epicondyle, 2 cm distal and proximal to the medial epicondyle at elbow extension respectively were 5.95 ± 0.74 mm2, 6.27 ± 0.92 mm2, and 5.92 ± 0.73 mm2. At elbow flexion, the average ulnar nerve CSA at the positions was 5.70 ± 0.83 mm2, 5.23 ± 0.87 mm2, dan 5.73 ± 0.71 mm2 respectively. The CSA of the ulnar nerve at elbow extension was significantly larger compared to the flexion position in the three areas observed in this study (p < 0.001).

Conclusion

The CSA of the ulnar nerve at elbow extension position was larger compared to the flexion position. Elbow position should be considered in measuring CSA of the ulnar nerve.

Nerve Conduction Studies in Surgical Cubital Tunnel Syndrome Patients

Background: Electrodiagnostic studies (EDX) serve a prominent role in the diagnostic workup of cubital tunnel syndrome (CBTS), but their reported sensitivity varies widely. The goals of our study were to determine the sensitivity of EDX in a cohort of patients who responded well to surgical cubital tunnel release (CBTR), and whether the implementation of the Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) criteria improves the sensitivity. Methods: We identified 118 elbows with clinical CBTS who had preoperative EDX and underwent CBTR. The EDX diagnoses were CBTS, ulnar neuropathy (UN), and normal ulnar nerves. We divided the 118 elbows into those that received above-elbow stimulation (XE group) and those that did not (non-XE group). We calculated the sensitivities for all groups and reinterpreted the results according to the AANEM guidelines. Results: Cubital tunnel release provided significant relief in 93.6% of the elbows. Based on the EDX reports, 11% patients had clear CBTS, 23% had UN, and 66% showed no UN. The sensitivities were 11.7% for CBTS and 34.2% for any UN. In the XE group, the sensitivity of the EDX reports for CBTS and UN climbed to 33.3% and 58.3%, respectively. When we calculated the across-elbow motor nerve conduction velocity, the sensitivity for CBTS and UN was 87.5% and 100%, respectively. The XE and non-XE groups showed no difference except for sex, bilaterality, concomitant carpal tunnel release, and obesity (P < .05). Conclusion: Implementing AANEM guidelines results in significant improvement in correlation of clinical and electrodiagnostic findings of CBTS.

Differentiation of ulnar neuropathy at the wrist due to ganglion cyst from ulnar neuropathy at the elbow

OBJECTIVE

Here, we aimed to describe the clinical, electrodiagnostic (EDx) and ultrasonographic (US) findings in a series of patients with ulnar neuropathy at the wrist (UNW) due to compression by a ganglion cyst. We also sought features that differentiate UNW from ulnar neuropathy at the elbow (UNE).

METHODS

We reviewed electronic medical records of consecutive patients with UNW caused by ganglion cysts. We compared their clinical, EDx and US findings to findings in our previously reported prospective series of UNE patients.

RESULTS

We identified 10 patients with UNW caused by ganglion cyst compression, who all presented with intrinsic hand muscle weakness and atrophy. Compared to 175 UNE patients they less often complained of paresthesia (60% vs. 98%) and presented less sensory loss in the palm (30% vs. 96%) and little finger (50% vs. 95%). They more often had distal ulnar motor latency recorded from the abductor digiti minimi (ADM)>3.6ms (80% vs. 30%), and denervation activity on needle EMG in the first dorsal interosseous (FDI) compared to ADM (100% vs. 60%). Only 20% of our UNW patients had ulnar nerve swelling at the site of compression on US.

CONCLUSION

UNW potentially caused by ganglion cyst should be suspected in patients presenting with intrinsic hand muscle atrophy and weakness, particularly in cases with normal sensation, increased distal ulnar motor latency recorded from ADM and more severe neuropathic changes in FDI compared to ADM muscle.

An electrodiagnostic grading system for ulnar neuropathy at the elbow

INTRODUCTION

Ulnar neuropathy at the elbow (UNE) is the second most common entrapment neuropathy. Our goal was to create and analyze a grading system for UNE electrodiagnostic severity.

METHODS

We retrospectively analyzed EMG reports with UNE. We then classified 112 limbs as having mild, moderate, or severe grade UNE based on electrodiagnostic findings. The association between presenting symptoms and signs, EMG findings, treatment type, and electrodiagnostic grade was statistically analyzed.

RESULTS

Seventeen limbs (15.2%) had mild, 80 (71.4%) had moderate, and 15 (13.4%) had severe UNE. Symptoms (P = .016), exam findings (P < .001), and treatment type (P = .043) were significantly associated with electrodiagnostic grade.

DISCUSSION

Our UNE grading system was significantly related to symptoms, physical exam, and treatment selection and may be useful to measure electrodiagnostic severity.

Cubital Tunnel Syndrome: Current Concepts

PURPOSE OF REVIEW

Compressive neuropathy of the ulnar nerve across the elbow is a common diagnosis encountered frequently within a hand and upper extremity clinical practice. Appropriate and timely evaluation, diagnosis, objective testing, and evidence-based decisions regarding treatment options are paramount in the optimal care of the patient with this pathology. An understanding of current literature is critical in determining and understanding best practices.

RECENT FINDINGS

A thorough review of the recent literature regarding physical examination, diagnostic testing, and nonoperative versus operative results was performed. Regarding physical examination, the glenohumeral internal rotation test and scratch collapse test are more effective and sensitive than traditional maneuvers such as Tinel's testing and the elbow flexion test. Electrodiagnostic testing, magnetic resonance imaging, and ultrasound evaluation have all been shown to be effective in diagnosing cubital tunnel syndrome. However, no single test has proven itself to be superior. Nonoperative treatment can be successful for mild cases of cubital tunnel syndrome. Surgical release techniques comparing open with endoscopic release are equivocal, and in situ release versus transposition techniques show that transposition should not be performed routinely. The diagnosis and treatment of cubital tunnel syndrome do not have a well-defined algorithm based on current literature. The treating physician must therefore utilize the available information to determine a diagnostic and treatment plan individualized to the patient. More rigorous scientific studies are needed to determine the most effective surgical approaches for cubital tunnel syndrome.

Electrodiagnostic Findings in 441 Patients with Ulnar Neuropathy - a Retrospective Study

Purpose

Ulnar neuropathy (UN) is the second most common focal neuropathy in the upper extremities. Electrodiagnostic studies (EDx), including nerve conduction study (NCS) and electromyography (EMG), are reliable tools for the diagnosis of ulnar neuropathy. We aimed to retrospectively analyze the medical records of patients diagnosed with ulnar neuropathy in a seven-year period and report our findings.

Patients and methods

In this retrospective study, documents of the patients whose ulnar nerve injury was confirmed through electrodiagnostic study in two departments of Physical Medicine and Rehabilitation were collected and demographic data, subjective complaints of the patient, the cause, and electrodiagnostic findings were extracted from each patient’s file. The following points were specifically evaluated in the electrodiagnostic records; type of injury, location, accompanying injuries, sensory nerve action potentials (SNAP) of the fifth finger, SNAP of dorsal ulnar cutaneous nerve (DUCN), compound muscle action potential (CMAP) of abductor digiti minimi (ADM) muscle, nerve conduction velocity (NCV) across elbow, patterns of muscle involvement, and the severity of insult.

Results

Out of 441 records, 305 (69.2%) were male and 68.1% were non-traumatic. Based on our clinical criteria, the intensity of the injury was mild in most cases. The elbow and forearm were the most involved regions in non-traumatic and traumatic cases respectively. Across elbow nerve conduction velocity showed decreased velocity in 71% of records. In non-traumatic cases, the most affected muscle was ADM (97%) and then FDI (85%).

Conclusion

In focal entrapments such as ulnar neuropathy, electrodiagnostic findings are very helpful in assessing location, severity, and type of injury. If a consensus is achieved for the diagnosis of UN, even retrospective studies can become valuable sources for studying UN.

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.

Compound Muscle Action Potential Amplitude Predicts the Severity of Cubital Tunnel Syndrome

BACKGROUND

Cubital tunnel syndrome has a spectrum of presentations ranging from mild paresthesias to debilitating numbness and intrinsic atrophy. Commonly, the classification of severity relies on clinical symptoms and slowing of conduction velocity across the elbow. However, changes in compound muscle action potential (CMAP) amplitude more accurately reflect axonal loss. We hypothesized that CMAP amplitude would better predict functional impairment than conduction velocity alone.

METHODS

A retrospective cohort of patients who underwent a surgical procedure for cubital tunnel syndrome over a 5-year period were included in the study. All patients had electrodiagnostic testing performed at our institution. Clinical and electrodiagnostic variables were recorded. The primary outcome was preoperative functional impairment, defined by grip and key pinch strength ratios. Multivariable regression identified which clinical and electrodiagnostic variables predicted preoperative functional impairment.

RESULTS

Eighty-three patients with a mean age of 57 years (75% male) were included in the study. The majority of patients (88%) had abnormal electrodiagnostic studies. Fifty-four percent had reduced CMAP amplitude, and 79% had slowing of conduction velocity across the elbow (recorded from the first dorsal interosseous). On bivariate analysis, older age and longer symptom duration were significantly associated (p < 0.05) with reduced CMAP amplitude and slowing of conduction velocity across the elbow, whereas body mass index (BMI), laterality, a primary surgical procedure compared with revision surgical procedure, Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire scores, and visual analog scale (VAS) scores for pain were not. Multivariable regression analysis demonstrated that reduced first dorsal interosseous CMAP amplitude independently predicted the loss of preoperative grip and key pinch strength and that slowed conduction velocity across the elbow did not.

CONCLUSIONS

Reduced first dorsal interosseous amplitude predicted preoperative weakness in grip and key pinch strength, and isolated slowing of conduction velocity across the elbow did not. CMAP amplitude is a sensitive indicator of axonal loss and an important marker of the severity of cubital tunnel syndrome. It should be considered when counseling patients with regard to their prognosis and determining the necessity and timing of operative intervention.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Ulnar Neuropathy at the Elbow Associated With Focal Demyelination in the Proximal Forearm and Intraoperative Imaging Correlation

Ulnar nerve focal demyelination (FD) in the forearm [defined as conduction block (CB) and or temporal dispersion (TD)] has been described with immune-mediated neuropathy and with compression affecting the forearm segment of the nerve. The association of FD in the forearm with entrapment ulnar neuropathy at the elbow, as well as the intraoperative imaging of the abnormal ulnar nerve at the flexor carpi ulnaris muscle level (FCU), has not been reported before. We report a 33-years-old woman presented with only sensory symptoms of the right hand suggestive of right ulnar neuropathy for the last 10 years. On clinical examination, she had reduced pinprick sensation on the little and ring fingers with no motor deficit. Nerve-conduction study showed slowing of conduction velocity across the elbow on the right when recording at the abductor digiti minimi (ADM) and first dorsal interossei (FDI). There was 63% amplitude drop when stimulating below the elbow compared to distal stimulation at the wrist. Increment inching study localized the block at 5 cm distal to the medial epicondyle. During surgical transposition, the ulnar nerve was swollen, and edematous in the segment where the nerve enters the FCU muscle, which provides a physiological explanation for the electrophysiological findings. After the surgery, the patient reported complete resolution of the symptoms. This case demonstrate that ulnar nerve motor potential FD at the proximal forearm could be recorded and it is still compatible with ulnar-nerve entrapment at the elbow.

Ulnar neuropathy at wrist: entrapment at a very "congested" site

Ulnar tunnel syndrome indicates ulnar neuropathy at different sites within the wrist. Several classifications of ulnar tunnel syndrome are present in literature, based upon typical nerve anatomy. However, anatomical variations are not uncommon and can complicate assessment. The etiology is also complex, due to the numerous potential causes of entrapment. Clinical examination, neurophysiological testing, and imaging are all used to support the diagnosis. At present, many therapeutic approaches are available, ranging from observation to surgical management. Although ulnar neuropathy at the wrist has undergone extensive prior study, unresolved questions on diagnosis and treatment remain. In the current paper, we review relevant literature and present the current knowledge on ulnar tunnel syndrome.

Normative Ulnar Nerve Conduction Study: Comparison of Two Measurement Methods

Background:

Given the high prevalence rate of ulnar neuropathy and importance of its proper management, to have a baseline information about the normative value of motor nerve conduction of first dorsal interosseous (FDI) muscle and abductor digiti minimi muscle (ADM) and their differences as well as their relation with different demographic characteristics of our population, we aimed to determine and compare the mean value of motor conduction velocity of FDI and ADM at forearm and across the elbow among the normal population.

Materials and Methods:

In this cross-sectional study, healthy participants were enrolled in the study. Ulnar nerve motor nerve conduction velocity (MNCV) was recorded from the ADM and the FDI at forearm and across the elbow. Mean MNCV of the ulnar nerve recorded from ADM and FDI was compared. In addition, MNCV of the ulnar nerve measured at the forearm and across the elbow was compared also.

Results:

During this study, 165 healthy volunteers selected and participated in the study. Mean of ulnar nerve MNCV for ADM was significantly lower than FDI, both at forearm and across the elbow (P < 0.001). Mean of ulnar nerve MNCV was significantly lower at forearm comparing than elbow level for both ADM and FDI (P < 0.001).

Conclusion:

The findings of the current study provide us a baseline data regarding the normative mean value of ulnar nerve MNCV in different locations, which could be used for providing an appropriate diagnostic protocol for ulnar nerve neuropathy. However, further studies among patients suspected with ulnar nerve neuropathy are needed.

Vibration upshot of operating mechanical sewing machine: an insight into common peroneal nerve conduction study

Background

Most of the people associated with tailoring occupation in Nepal are still using mechanical sewing machine as an alternative of new technology for tailoring. Common peroneal nerves of both right and left legs are exposed to strenuous and chronic stress exerted by vibration and paddling of mechanical sewing machine.

Methods

The study included 30 healthy male tailors and 30 healthy male individuals. Anthropometric variables as well as cardio respiratory variables were determined for each subject. Standard Nerve Conduction Techniques using constant measured distances were applied to evaluate common peroneal nerve (motor) in both legs of each individual. Data were analyzed and compared between study and control groups using Man Whitney U test setting the significance level p ≤ 0.05.

Results

Anthropometric and cardio respiratory variables were not significantly altered between the study and control groups. The Compound muscle action potential (CMAP) latency of common peroneal nerves of both right [(11.29 ± 1.25 vs. 10.03 ± 1.37), P < 0.001] and left [(11.28 ± 1.38 vs. 10.05 ± 1.37), P < 0.01] legs was found to be significantly prolonged in study group as compared to control group. The Amp-CMAP of common peroneal nerves of both right [(4.57 ± 1.21 vs. 6.22 ± 1.72), P < 0.001] and left [(4.31 ± 1.55 vs. 6.25 ± 1.70), P < 0.001] legs was found significantly reduced in study group as compared to control group. Similarly, the motor nerve conduction velocity (MNCV) of common peroneal nerves of both right [(43.72 ± 3.25 vs. 47.49 ± 4.17), P < 0.001] and left [(42.51 ± 3.82 vs. 46.76 ± 4.51), P < 0.001] legs was also found to be significantly reduced in study group in comparison to control group.

Conclusion

Operating mechanical sewing machine by paddling chronically and arduously could have attributed to abnormal nerve conduction study parameters due to vibration effect of the machine on right and left common peroneal nerves. The results of present study follow the trend towards presymptomatic or asymptomatic neuropathy similar to subclinical neuropathy.

Electrophysiologic features of ulnar neuropathy in childhood and adolescence

OBJECTIVE

To analyze patterns of nerve injury in pediatric ulnar neuropathy (PUN).

METHODS

Retrospective analysis of 49 children with PUN.

RESULTS

Sensory loss in digit V was the prevailing complaint (89%). Predominant localization was at the elbow (55%). Diminished ulnar SNAP was the most common abnormality (71%) with median axon loss estimate (MAXE) of 62%. Dorsal ulnar cutaneous (DUC) sensory nerve action potential (SNAP) was reduced in 55% with MAXE of 43%. Abductor digiti minimi (ADM) and first dorsal interosseous (FDI) compound muscle action potential (CMAP) were reduced half of the time, with MAXE of 30% and 28% respectively. There was high correlation between ulnar sensory MAXE and ADM MAXE (r=0.76, p<0.0001), FDI MAXE (r=0.81, p<0.0001) and DUC MAXE (r=0.60, p=0.0048). Neurogenic changes were seen in the ADM, FDI, flexor carpi ulnaris (FCU) and flexor digitorum profundus IV (FDP IV) in 79%, 77%, 25% and 35% respectively. Pathophysiology was demyelinating in 27%, axonal in 59% and mixed in 14%.

CONCLUSIONS

In proximal axonal lesions, sensory fibers to digit V and motor fibers to distal muscles are predominantly affected, whereas in demyelinating lesions, slowing occurs twice as frequently as conduction block.

SIGNIFICANCE

There is frequent axonal and fascicular injury in PUN.

Results of endoscopically-assisted cubital tunnel release without using any specific instrument

Background

We aimed to report the clinical and electrophysiological results of patients who were treated with an endoscopically assisted in situ release technique for cubital tunnel syndrome and to show safety and efficacy of this procedure.

Materials and methods

Twenty nine patients were included into the study. 13 patients (44.8%) were female, 16 patients (55.2%) were male. The mean age was 44.4 years (range; 22–66 years). Mean follow up period was 16.0 months (range; 7–42 months). We used Dellon classification for preoperative staging, and modified Bishop rating system for the evaluation of postoperative clinical results. Dynamometric and electromyographic measurements were obtained preoperatively and at final control.

Results

Preoperative Dellon's classification revealed 3 patients grade 1, 14 grade 2, and 12 grade 3. Modified Bishop score was very good for 21 patients (72.4%), good for 4 patients (13.8%), fair for 3 patient (10.3%), and poor for 1 patient (3.4%). At final control; the mean proportion of grip power and pinch strength of the affected hand to the contralateral normal hand was improved, and also nerve conduction velocity were improved in all patients. As complication, hematoma formation developed in two cases.

Conclusion

Our study showed that endoscopically assisted decompression technique without using any special instruments can be performed successfully with a low complication rate. It is a safe and effective method in the treatment of cubital tunnel syndrome.

Level of evidence

Level IV, Therapeutic study

Prolonged phone-call posture causes changes of ulnar motor nerve conduction across elbow

OBJECTIVE

Postures and work-hobby activities may play a role in the origin and progression of ulnar neuropathy at the elbow (UNE), whose occurrence appears to be increasing. The time spent on mobile-phone has increased in the last decades leading to an increased time spent with flexed elbow (prolonged-phone-posture, PPP). We aimed to assess the effect of PPP both in patients with symptoms of UNE and in symptom-free subjects.

METHODS

Patients with pure sensory symptoms of UNE and negative neurophysiological tests (MIN-UNE) and symptom-free subjects were enrolled. We evaluated ulnar motor nerve conduction velocity across elbow at baseline and after 6, 9, 12, 15, and 18min of PPP in both groups. Fifty-six symptom-free subjects and fifty-eight patients were enrolled. Globally 186 ulnar nerves from 114 subjects were studied.

RESULTS

Conduction velocity of ulnar nerve across the elbow significantly changed over PPP time in patients with MIN-UNE, showing a different evolution between the two groups.

CONCLUSIONS

PPP causes a modification of ulnar nerve functionality in patients with MIN-UNE.

SIGNIFICANCE

PPP may cause transient stress of ulnar nerve at elbow.

IS RDW A PREDICTIVE PARAMETER FOR CUBITAL TUNNEL SYNDROME PATIENTS REQUIRING SURGERY?

OBJECTIVE

The aim of this study was to investigate whether haemogram parameters are predictive factors for both the severity of the disease and a decision in favor of surgical treatment in patients with an established diagnosis of cubital tunnel syndrome (CuTS) .

METHODS

The medical files of patients with a diagnosis of CuTS who were followed-up conservatively (n=92) or surgically treated (n=92) were retrospectively screened and the haemogram parameters were recorded .

RESULTS

The receiver operating characteristic (ROC) curve analysis revealed an area of 0.665 under the curve, with 76.3% sensitivity and 84.8% specificity at the cut-off of a red cell distribution width (RDW) level grater than 15.45%. RDW levels higher than 15.5%, electromyography (EMG) severity, and a clinical score higher than three were found to be independently associated with surgery .

CONCLUSION

An elevated RDW value was related to the severity of the electromyogram. RDW may, therefore, be a useful independent predictor for the decision to surgical treatment of CuTS. Level of Evidence III, Retrospective Study.

Preliminary study on the lesion location and prognosis of cubital tunnel syndrome by motor nerve conduction studies

Background:

To study lesions’ location and prognosis of cubital tunnel syndrome (CubTS) by routine motor nerve conduction studies (MNCSs) and short-segment nerve conduction studies (SSNCSs, inching test).

Methods:

Thirty healthy subjects were included and 60 ulnar nerves were studied by inching studies for normal values. Sixty-six patients who diagnosed CubTS clinically were performed bilaterally by routine MNCSs and SSNCSs. Follow-up for 1-year, the information of brief complaints, clinical symptoms, and physical examination were collected.

Results:

Sixty-six patients were included, 88 of nerves was abnormal by MNCS, while 105 was abnormal by the inching studies. Medial epicondyle to 2 cm above medial epicondyle is the most common segment to be detected abnormally (59.09%), P < 0.01. Twenty-two patients were followed-up, 17 patients’ symptoms were improved. Most of the patients were treated with drugs and modification of bad habits.

Conclusions:

(1) SSNCSs can detect lesions of compressive neuropathy in CubTS more precisely than the routine motor conduction studies. (2) SSNCSs can diagnose CubTS more sensitively than routine motor conduction studies. (3) In this study, we found that medial epicondyle to 2 cm above the medial epicondyle is the most vulnerable place that the ulnar nerve compressed. (4) The patients had a better prognosis who were abnormal in motor nerve conduction time only, but not amplitude in compressed lesions than those who were abnormal both in velocity and amplitude. Our study suggests that SSNCSs is a practical method in detecting ulnar nerve compressed neuropathy, and sensitive in diagnosing CubTS. The compound muscle action potentials by SSNCSs may predict prognosis of CubTS.

Arthroscopic joint debridement and capsular release in primary and post-traumatic elbow osteoarthritis: a retrospective blinded cohort study with minimum 24-month follow-up

BACKGROUND

Elbow osteoarthritis (OA) is a degenerative condition which in the advanced stage can severely impair joint mobility. Conservative treatment remains the first choice; surgery should be considered in case of failure in patients prepared to adhere to a demanding rehabilitation protocol. We assess the effectiveness of arthroscopic joint debridement and capsular release in a series of patients with primary and post-traumatic elbow arthritis.

MATERIALS AND METHODS

Forty-eight subjects (40 males, eight females; mean age 48 years) with a preoperative diagnosis of primary (19, 40 %) or post-traumatic OA (29, 60 %) were evaluated at a mean follow-up of 44 months. Outcome measures were active range of motion (ROM), pain score, Oxford elbow score (OES), and Mayo elbow performance score (MEPS). OA severity was graded into three classes (I-III) based on X-ray findings. Statistical significance was set at 5 %.

RESULTS

At the final follow-up evaluation, active flexion/extension increased significantly (p < 0.01); pronation and supination improved, but the difference was not significant (p > 0.05). The pain score improved from 7.2 to 4.3 (p < 0.01). Both OES and MEPS improved significantly (p < 0.001). Patients with post-traumatic OA had better ROM (p = 0.0391) and clinical scores (OES, p = 0.011; MEPS, p = 0.010). ROM and clinical scores were lower but not significantly so in class II than in class I patients. A smooth coronoid and olecranon fossa was found in 38 (79 %) patients and a preserved ulnotrochlear joint space in 40 (80 %).

CONCLUSIONS

Elbow OA has become more common as a result of earlier diagnosis and an increased number of acute injuries involving the joint. Arthroscopy is an effective technique to treat OA which provides the best results with the correct indications. Prospective studies are needed to help develop guidelines enabling selection of the best treatment option.

What causes ulnar neuropathy at the elbow?

OBJECTIVE

To determine what causes ulnar neuropathy at the elbow (UNE) by analyzing patients' clinical, electrodiagnostic (EDx) and ultrasonographic (US) findings.

METHODS

In prospectively recruited patients with definite UNE, four blinded examiners took a history and performed neurologic, EDx and US examinations. A multivariate logistic regression model was used to investigate the association between UNE location and patient variables.

RESULTS

We included 117 patients; 73% with lesions in the retroepicondylar (RTC) groove and 27% under the humeroulnar aponeurotic arcade (HUA). In our multivariate model, hard manual labor (OR=152; 95% CI 12-1847; p<0.001), dominant arm involvement (OR=4.12; 95% CI 1.01-16.72; p=0.048), and age (OR=1.10; 95% CI 1.03-1.18; p=0.004) were predictive of ulnar neuropathy at HUA.

CONCLUSION

Our data suggest that UNE at HUA is related to years of hard labor affecting mainly dominant hands, and is caused by work-related changes in the HUA. By contrast, UNE in the RTC groove affects mainly the non-dominant arms of younger administrative workers and is caused by external compression of the ulnar nerve.

SIGNIFICANCE

We believe that our findings will help to improve the diagnosis and treatment of UNE patients, hopefully leading to improved clinical outcomes.

Clinical implications of real-time visualized ultrasound-guided injection for the treatment of ulnar neuropathy at the elbow: a pilot study

OBJECTIVE

To investigate the feasibility of ultrasound (US)-guided steroid injection by in-plane approach for cubital tunnel syndrome (CuTS), based on symptomatic, morphologic and electrophysiological outcomes.

METHODS

A total of 10 patients, who were clinically diagnosed as CuTS and confirmed by an electrodiagnostic study, participated in this study. US-guided injection into the cubital tunnel was performed with 40 mg triamcinolone and 2 mL of 1% lidocaine. Outcomes of the injections were evaluated at pre-injection, 1st week and 4th week after injection. Visual analog scale, self-administered questionnaire of the ulnar neuropathy at the elbow (SQUNE), and McGowan classification were used for clinical evaluation. Cross-sectional area of the ulnar nerve by US and the electrophysiological severity scale through a nerve conduction study were utilized in the evaluation of morphologic and electrophysiological changes. The cross-sectional area of the ulnar nerve was measured at 3 points of condylar, proximal, and distal level of the cubital tunnel.

RESULTS

No side effects were reported during the study period. The visual analog scale and cross-sectional area showed a significant decrease at 1st week and 4th week, as compared to baseline (p<0.05). The electrophysiological severity scale was significantly decreased at the 4th week, as compared with baseline and 1st week (p<0.05). Among the quantitative components of the scale, there were statistically significant improvements with respect to the conduction velocity and block.

CONCLUSION

The new approach of US-guided injection may be a safe tool for the treatment of CuTS. Symptomatic and morphologic recoveries preceded the electrophysiological improvement.

Granular cell tumor of the ulnar nerve: MR neurography characterization

The authors report an unusual case of ulnar neuropathy caused by granular cell tumor. The report describes the anatomic 3 Tesla MR Neurography and functional diffusion tensor findings of the case, which was subsequently confirmed on surgical excision and histopathology.

Deep renal ectopia causing sciatic mononeuropathy

INTRODUCTION

Sciatic mononeuropathy resulting from compression by an adjacent pelvic ectopic kidney has not been reported in the literature. Here, the authors present a case of a patient presenting with unilateral lower extremity paresthesia correlating to the sciatic nerve distribution.

RESULTS

MRI examination demonstrated lumbosacral plexus compression by a very unusual deeply situated renal ectopia. Physicians should consider other rare causes of mechanical lumbosacral plexus compression in patients with sciatic symptomatology.

Elbow injuries in the throwing athlete

High valgus and extension loads imparted to the athlete's elbow during repetitive overhead throwing can lead to acute and chronic pathology. Over time, normal soft tissue and bony stabilizing structures of the elbow undergo progressive structural changes and can succumb to injury. Modern diagnostic modalities, including plain radiographs, computed tomography, and magnetic resonance imaging, in addition to arthroscopy, can aid in diagnosis. Although nonoperative management is often successful, surgical intervention may be necessary before allowing return to play.

Subclinical ulnar neuropathy at the elbow in diabetic patients

Objective

To demonstrate the prevalence and characteristics of subclinical ulnar neuropathy at the elbow in diabetic patients.

Methods

One hundred and five patients with diabetes mellitus were recruited for the study of ulnar nerve conduction analysis. Clinical and demographic characteristics were assessed. Electrodiagnosis of ulnar neuropathy at the elbow was based on the criteria of the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM1 and AANEM2). The inching test of the ulnar motor nerve was additionally performed to localize the lesion.

Results

The duration of diabetes, the existence of diabetic polyneuropathy (DPN) symptoms, the duration of symptoms, and HbA1C showed significantly larger values in the DPN group (p<0.05). Ulnar neuropathy at the elbow was more common in the DPN group. There was a statistically significant difference in the number of cases that met the three diagnostic criteria between the no DPN group and the DPN group. The most common location for ulnar mononeuropathy at the elbow was the retrocondylar groove.

Conclusion

Ulnar neuropathy at the elbow is more common in patients with DPN. If the conduction velocities of both the elbow and forearm segments are decreased to less than 50 m/s, it may be useful to apply the AANEM2 criteria and inching test to diagnose ulnar neuropathy.

[The use of intraoperative electrophysiological monitoring in patients with decompression of the ulnar nerve near the elbow joint]

At the elbow, the ulnar nerve may be compressed either in the retrocondylar groove, in the cubital tunnel, or compressed by Osborne's band. Optimal surgical therapy should be directed at the specific site of involvement. It is more difficult to identify the level of ulnar nerve compression. Anatomical variations may make it difficult to identify the causes of ulnar neuropathy at the elbow. The data obtained by inspection, probing, or electroneurography do not allow one to reliably identify the compression level. Intraoperative electroneuromyography performed in conjunction with 14 ulnar nerve explorations helped localize the precise site of compression in 12 cases. Intraoperative studies helped identify compression by Osborne band in 8 patients. We conclude that intraoperative electroneuromyography identifies compression levels of ulnar neuropathy more accurately than the conventional examination methods do.